buffer_codegen.rs

   1use crate::{context::LoadedContext, inline_prompt_editor::CodegenStatus};
   2use agent_settings::AgentSettings;
   3use anyhow::{Context as _, Result};
   4use uuid::Uuid;
   5
   6use cloud_llm_client::CompletionIntent;
   7use collections::HashSet;
   8use editor::{Anchor, AnchorRangeExt, MultiBuffer, MultiBufferSnapshot, ToOffset as _, ToPoint};
   9use feature_flags::{FeatureFlagAppExt as _, InlineAssistantUseToolFeatureFlag};
  10use futures::{
  11    SinkExt, Stream, StreamExt, TryStreamExt as _,
  12    channel::mpsc,
  13    future::{LocalBoxFuture, Shared},
  14    join,
  15    stream::BoxStream,
  16};
  17use gpui::{App, AppContext as _, AsyncApp, Context, Entity, EventEmitter, Subscription, Task};
  18use language::{Buffer, IndentKind, LanguageName, Point, TransactionId, line_diff};
  19use language_model::{
  20    LanguageModel, LanguageModelCompletionError, LanguageModelCompletionEvent,
  21    LanguageModelRegistry, LanguageModelRequest, LanguageModelRequestMessage,
  22    LanguageModelRequestTool, LanguageModelTextStream, LanguageModelToolChoice,
  23    LanguageModelToolUse, Role, TokenUsage,
  24};
  25use multi_buffer::MultiBufferRow;
  26use parking_lot::Mutex;
  27use prompt_store::PromptBuilder;
  28use rope::Rope;
  29use schemars::JsonSchema;
  30use serde::{Deserialize, Serialize};
  31use settings::Settings as _;
  32use smol::future::FutureExt;
  33use std::{
  34    cmp,
  35    future::Future,
  36    iter,
  37    ops::{Range, RangeInclusive},
  38    pin::Pin,
  39    sync::Arc,
  40    task::{self, Poll},
  41    time::Instant,
  42};
  43use streaming_diff::{CharOperation, LineDiff, LineOperation, StreamingDiff};
  44
  45/// Use this tool when you cannot or should not make a rewrite. This includes:
  46/// - The user's request is unclear, ambiguous, or nonsensical
  47/// - The requested change cannot be made by only editing the <rewrite_this> section
  48#[derive(Debug, Serialize, Deserialize, JsonSchema)]
  49pub struct FailureMessageInput {
  50    /// A brief message to the user explaining why you're unable to fulfill the request or to ask a question about the request.
  51    #[serde(default)]
  52    pub message: String,
  53}
  54
  55/// Replaces text in <rewrite_this></rewrite_this> tags with your replacement_text.
  56/// Only use this tool when you are confident you understand the user's request and can fulfill it
  57/// by editing the marked section.
  58#[derive(Debug, Serialize, Deserialize, JsonSchema)]
  59pub struct RewriteSectionInput {
  60    /// The text to replace the section with.
  61    #[serde(default)]
  62    pub replacement_text: String,
  63}
  64
  65pub struct BufferCodegen {
  66    alternatives: Vec<Entity<CodegenAlternative>>,
  67    pub active_alternative: usize,
  68    seen_alternatives: HashSet<usize>,
  69    subscriptions: Vec<Subscription>,
  70    buffer: Entity<MultiBuffer>,
  71    range: Range<Anchor>,
  72    initial_transaction_id: Option<TransactionId>,
  73    builder: Arc<PromptBuilder>,
  74    pub is_insertion: bool,
  75    session_id: Uuid,
  76}
  77
  78impl BufferCodegen {
  79    pub fn new(
  80        buffer: Entity<MultiBuffer>,
  81        range: Range<Anchor>,
  82        initial_transaction_id: Option<TransactionId>,
  83        session_id: Uuid,
  84        builder: Arc<PromptBuilder>,
  85        cx: &mut Context<Self>,
  86    ) -> Self {
  87        let codegen = cx.new(|cx| {
  88            CodegenAlternative::new(
  89                buffer.clone(),
  90                range.clone(),
  91                false,
  92                builder.clone(),
  93                session_id,
  94                cx,
  95            )
  96        });
  97        let mut this = Self {
  98            is_insertion: range.to_offset(&buffer.read(cx).snapshot(cx)).is_empty(),
  99            alternatives: vec![codegen],
 100            active_alternative: 0,
 101            seen_alternatives: HashSet::default(),
 102            subscriptions: Vec::new(),
 103            buffer,
 104            range,
 105            initial_transaction_id,
 106            builder,
 107            session_id,
 108        };
 109        this.activate(0, cx);
 110        this
 111    }
 112
 113    fn subscribe_to_alternative(&mut self, cx: &mut Context<Self>) {
 114        let codegen = self.active_alternative().clone();
 115        self.subscriptions.clear();
 116        self.subscriptions
 117            .push(cx.observe(&codegen, |_, _, cx| cx.notify()));
 118        self.subscriptions
 119            .push(cx.subscribe(&codegen, |_, _, event, cx| cx.emit(*event)));
 120    }
 121
 122    pub fn active_completion(&self, cx: &App) -> Option<String> {
 123        self.active_alternative().read(cx).current_completion()
 124    }
 125
 126    pub fn active_alternative(&self) -> &Entity<CodegenAlternative> {
 127        &self.alternatives[self.active_alternative]
 128    }
 129
 130    pub fn language_name(&self, cx: &App) -> Option<LanguageName> {
 131        self.active_alternative().read(cx).language_name(cx)
 132    }
 133
 134    pub fn status<'a>(&self, cx: &'a App) -> &'a CodegenStatus {
 135        &self.active_alternative().read(cx).status
 136    }
 137
 138    pub fn alternative_count(&self, cx: &App) -> usize {
 139        LanguageModelRegistry::read_global(cx)
 140            .inline_alternative_models()
 141            .len()
 142            + 1
 143    }
 144
 145    pub fn cycle_prev(&mut self, cx: &mut Context<Self>) {
 146        let next_active_ix = if self.active_alternative == 0 {
 147            self.alternatives.len() - 1
 148        } else {
 149            self.active_alternative - 1
 150        };
 151        self.activate(next_active_ix, cx);
 152    }
 153
 154    pub fn cycle_next(&mut self, cx: &mut Context<Self>) {
 155        let next_active_ix = (self.active_alternative + 1) % self.alternatives.len();
 156        self.activate(next_active_ix, cx);
 157    }
 158
 159    fn activate(&mut self, index: usize, cx: &mut Context<Self>) {
 160        self.active_alternative()
 161            .update(cx, |codegen, cx| codegen.set_active(false, cx));
 162        self.seen_alternatives.insert(index);
 163        self.active_alternative = index;
 164        self.active_alternative()
 165            .update(cx, |codegen, cx| codegen.set_active(true, cx));
 166        self.subscribe_to_alternative(cx);
 167        cx.notify();
 168    }
 169
 170    pub fn start(
 171        &mut self,
 172        primary_model: Arc<dyn LanguageModel>,
 173        user_prompt: String,
 174        context_task: Shared<Task<Option<LoadedContext>>>,
 175        cx: &mut Context<Self>,
 176    ) -> Result<()> {
 177        let alternative_models = LanguageModelRegistry::read_global(cx)
 178            .inline_alternative_models()
 179            .to_vec();
 180
 181        self.active_alternative()
 182            .update(cx, |alternative, cx| alternative.undo(cx));
 183        self.activate(0, cx);
 184        self.alternatives.truncate(1);
 185
 186        for _ in 0..alternative_models.len() {
 187            self.alternatives.push(cx.new(|cx| {
 188                CodegenAlternative::new(
 189                    self.buffer.clone(),
 190                    self.range.clone(),
 191                    false,
 192                    self.builder.clone(),
 193                    self.session_id,
 194                    cx,
 195                )
 196            }));
 197        }
 198
 199        for (model, alternative) in iter::once(primary_model)
 200            .chain(alternative_models)
 201            .zip(&self.alternatives)
 202        {
 203            alternative.update(cx, |alternative, cx| {
 204                alternative.start(user_prompt.clone(), context_task.clone(), model.clone(), cx)
 205            })?;
 206        }
 207
 208        Ok(())
 209    }
 210
 211    pub fn stop(&mut self, cx: &mut Context<Self>) {
 212        for codegen in &self.alternatives {
 213            codegen.update(cx, |codegen, cx| codegen.stop(cx));
 214        }
 215    }
 216
 217    pub fn undo(&mut self, cx: &mut Context<Self>) {
 218        self.active_alternative()
 219            .update(cx, |codegen, cx| codegen.undo(cx));
 220
 221        self.buffer.update(cx, |buffer, cx| {
 222            if let Some(transaction_id) = self.initial_transaction_id.take() {
 223                buffer.undo_transaction(transaction_id, cx);
 224                buffer.refresh_preview(cx);
 225            }
 226        });
 227    }
 228
 229    pub fn buffer(&self, cx: &App) -> Entity<MultiBuffer> {
 230        self.active_alternative().read(cx).buffer.clone()
 231    }
 232
 233    pub fn old_buffer(&self, cx: &App) -> Entity<Buffer> {
 234        self.active_alternative().read(cx).old_buffer.clone()
 235    }
 236
 237    pub fn snapshot(&self, cx: &App) -> MultiBufferSnapshot {
 238        self.active_alternative().read(cx).snapshot.clone()
 239    }
 240
 241    pub fn edit_position(&self, cx: &App) -> Option<Anchor> {
 242        self.active_alternative().read(cx).edit_position
 243    }
 244
 245    pub fn diff<'a>(&self, cx: &'a App) -> &'a Diff {
 246        &self.active_alternative().read(cx).diff
 247    }
 248
 249    pub fn last_equal_ranges<'a>(&self, cx: &'a App) -> &'a [Range<Anchor>] {
 250        self.active_alternative().read(cx).last_equal_ranges()
 251    }
 252
 253    pub fn selected_text<'a>(&self, cx: &'a App) -> Option<&'a str> {
 254        self.active_alternative().read(cx).selected_text()
 255    }
 256
 257    pub fn session_id(&self) -> Uuid {
 258        self.session_id
 259    }
 260}
 261
 262impl EventEmitter<CodegenEvent> for BufferCodegen {}
 263
 264pub struct CodegenAlternative {
 265    buffer: Entity<MultiBuffer>,
 266    old_buffer: Entity<Buffer>,
 267    snapshot: MultiBufferSnapshot,
 268    edit_position: Option<Anchor>,
 269    range: Range<Anchor>,
 270    last_equal_ranges: Vec<Range<Anchor>>,
 271    transformation_transaction_id: Option<TransactionId>,
 272    status: CodegenStatus,
 273    generation: Task<()>,
 274    diff: Diff,
 275    _subscription: gpui::Subscription,
 276    builder: Arc<PromptBuilder>,
 277    active: bool,
 278    edits: Vec<(Range<Anchor>, String)>,
 279    line_operations: Vec<LineOperation>,
 280    elapsed_time: Option<f64>,
 281    completion: Option<String>,
 282    selected_text: Option<String>,
 283    pub message_id: Option<String>,
 284    session_id: Uuid,
 285    pub description: Option<String>,
 286    pub failure: Option<String>,
 287}
 288
 289impl EventEmitter<CodegenEvent> for CodegenAlternative {}
 290
 291impl CodegenAlternative {
 292    pub fn new(
 293        buffer: Entity<MultiBuffer>,
 294        range: Range<Anchor>,
 295        active: bool,
 296        builder: Arc<PromptBuilder>,
 297        session_id: Uuid,
 298        cx: &mut Context<Self>,
 299    ) -> Self {
 300        let snapshot = buffer.read(cx).snapshot(cx);
 301
 302        let (old_buffer, _, _) = snapshot
 303            .range_to_buffer_ranges(range.clone())
 304            .pop()
 305            .unwrap();
 306        let old_buffer = cx.new(|cx| {
 307            let text = old_buffer.as_rope().clone();
 308            let line_ending = old_buffer.line_ending();
 309            let language = old_buffer.language().cloned();
 310            let language_registry = buffer
 311                .read(cx)
 312                .buffer(old_buffer.remote_id())
 313                .unwrap()
 314                .read(cx)
 315                .language_registry();
 316
 317            let mut buffer = Buffer::local_normalized(text, line_ending, cx);
 318            buffer.set_language(language, cx);
 319            if let Some(language_registry) = language_registry {
 320                buffer.set_language_registry(language_registry);
 321            }
 322            buffer
 323        });
 324
 325        Self {
 326            buffer: buffer.clone(),
 327            old_buffer,
 328            edit_position: None,
 329            message_id: None,
 330            snapshot,
 331            last_equal_ranges: Default::default(),
 332            transformation_transaction_id: None,
 333            status: CodegenStatus::Idle,
 334            generation: Task::ready(()),
 335            diff: Diff::default(),
 336            builder,
 337            active: active,
 338            edits: Vec::new(),
 339            line_operations: Vec::new(),
 340            range,
 341            elapsed_time: None,
 342            completion: None,
 343            selected_text: None,
 344            session_id,
 345            description: None,
 346            failure: None,
 347            _subscription: cx.subscribe(&buffer, Self::handle_buffer_event),
 348        }
 349    }
 350
 351    pub fn language_name(&self, cx: &App) -> Option<LanguageName> {
 352        self.old_buffer
 353            .read(cx)
 354            .language()
 355            .map(|language| language.name())
 356    }
 357
 358    pub fn set_active(&mut self, active: bool, cx: &mut Context<Self>) {
 359        if active != self.active {
 360            self.active = active;
 361
 362            if self.active {
 363                let edits = self.edits.clone();
 364                self.apply_edits(edits, cx);
 365                if matches!(self.status, CodegenStatus::Pending) {
 366                    let line_operations = self.line_operations.clone();
 367                    self.reapply_line_based_diff(line_operations, cx);
 368                } else {
 369                    self.reapply_batch_diff(cx).detach();
 370                }
 371            } else if let Some(transaction_id) = self.transformation_transaction_id.take() {
 372                self.buffer.update(cx, |buffer, cx| {
 373                    buffer.undo_transaction(transaction_id, cx);
 374                    buffer.forget_transaction(transaction_id, cx);
 375                });
 376            }
 377        }
 378    }
 379
 380    fn handle_buffer_event(
 381        &mut self,
 382        _buffer: Entity<MultiBuffer>,
 383        event: &multi_buffer::Event,
 384        cx: &mut Context<Self>,
 385    ) {
 386        if let multi_buffer::Event::TransactionUndone { transaction_id } = event
 387            && self.transformation_transaction_id == Some(*transaction_id)
 388        {
 389            self.transformation_transaction_id = None;
 390            self.generation = Task::ready(());
 391            cx.emit(CodegenEvent::Undone);
 392        }
 393    }
 394
 395    pub fn last_equal_ranges(&self) -> &[Range<Anchor>] {
 396        &self.last_equal_ranges
 397    }
 398
 399    pub fn use_streaming_tools(model: &dyn LanguageModel, cx: &App) -> bool {
 400        model.supports_streaming_tools()
 401            && cx.has_flag::<InlineAssistantUseToolFeatureFlag>()
 402            && AgentSettings::get_global(cx).inline_assistant_use_streaming_tools
 403    }
 404
 405    pub fn start(
 406        &mut self,
 407        user_prompt: String,
 408        context_task: Shared<Task<Option<LoadedContext>>>,
 409        model: Arc<dyn LanguageModel>,
 410        cx: &mut Context<Self>,
 411    ) -> Result<()> {
 412        if let Some(transformation_transaction_id) = self.transformation_transaction_id.take() {
 413            self.buffer.update(cx, |buffer, cx| {
 414                buffer.undo_transaction(transformation_transaction_id, cx);
 415            });
 416        }
 417
 418        self.edit_position = Some(self.range.start.bias_right(&self.snapshot));
 419
 420        if Self::use_streaming_tools(model.as_ref(), cx) {
 421            let request = self.build_request(&model, user_prompt, context_task, cx)?;
 422            let completion_events = cx.spawn({
 423                let model = model.clone();
 424                async move |_, cx| model.stream_completion(request.await, cx).await
 425            });
 426            self.generation = self.handle_completion(model, completion_events, cx);
 427        } else {
 428            let stream: LocalBoxFuture<Result<LanguageModelTextStream>> =
 429                if user_prompt.trim().to_lowercase() == "delete" {
 430                    async { Ok(LanguageModelTextStream::default()) }.boxed_local()
 431                } else {
 432                    let request = self.build_request(&model, user_prompt, context_task, cx)?;
 433                    cx.spawn({
 434                        let model = model.clone();
 435                        async move |_, cx| {
 436                            Ok(model.stream_completion_text(request.await, cx).await?)
 437                        }
 438                    })
 439                    .boxed_local()
 440                };
 441            self.generation = self.handle_stream(model, stream, cx);
 442        }
 443
 444        Ok(())
 445    }
 446
 447    fn build_request_tools(
 448        &self,
 449        model: &Arc<dyn LanguageModel>,
 450        user_prompt: String,
 451        context_task: Shared<Task<Option<LoadedContext>>>,
 452        cx: &mut App,
 453    ) -> Result<Task<LanguageModelRequest>> {
 454        let buffer = self.buffer.read(cx).snapshot(cx);
 455        let language = buffer.language_at(self.range.start);
 456        let language_name = if let Some(language) = language.as_ref() {
 457            if Arc::ptr_eq(language, &language::PLAIN_TEXT) {
 458                None
 459            } else {
 460                Some(language.name())
 461            }
 462        } else {
 463            None
 464        };
 465
 466        let language_name = language_name.as_ref();
 467        let start = buffer.point_to_buffer_offset(self.range.start);
 468        let end = buffer.point_to_buffer_offset(self.range.end);
 469        let (buffer, range) = if let Some((start, end)) = start.zip(end) {
 470            let (start_buffer, start_buffer_offset) = start;
 471            let (end_buffer, end_buffer_offset) = end;
 472            if start_buffer.remote_id() == end_buffer.remote_id() {
 473                (start_buffer.clone(), start_buffer_offset..end_buffer_offset)
 474            } else {
 475                anyhow::bail!("invalid transformation range");
 476            }
 477        } else {
 478            anyhow::bail!("invalid transformation range");
 479        };
 480
 481        let system_prompt = self
 482            .builder
 483            .generate_inline_transformation_prompt_tools(
 484                language_name,
 485                buffer,
 486                range.start.0..range.end.0,
 487            )
 488            .context("generating content prompt")?;
 489
 490        let temperature = AgentSettings::temperature_for_model(model, cx);
 491
 492        let tool_input_format = model.tool_input_format();
 493        let tool_choice = model
 494            .supports_tool_choice(LanguageModelToolChoice::Any)
 495            .then_some(LanguageModelToolChoice::Any);
 496
 497        Ok(cx.spawn(async move |_cx| {
 498            let mut messages = vec![LanguageModelRequestMessage {
 499                role: Role::System,
 500                content: vec![system_prompt.into()],
 501                cache: false,
 502                reasoning_details: None,
 503            }];
 504
 505            let mut user_message = LanguageModelRequestMessage {
 506                role: Role::User,
 507                content: Vec::new(),
 508                cache: false,
 509                reasoning_details: None,
 510            };
 511
 512            if let Some(context) = context_task.await {
 513                context.add_to_request_message(&mut user_message);
 514            }
 515
 516            user_message.content.push(user_prompt.into());
 517            messages.push(user_message);
 518
 519            let tools = vec![
 520                LanguageModelRequestTool {
 521                    name: "rewrite_section".to_string(),
 522                    description: "Replaces text in <rewrite_this></rewrite_this> tags with your replacement_text.".to_string(),
 523                    input_schema: language_model::tool_schema::root_schema_for::<RewriteSectionInput>(tool_input_format).to_value(),
 524                },
 525                LanguageModelRequestTool {
 526                    name: "failure_message".to_string(),
 527                    description: "Use this tool to provide a message to the user when you're unable to complete a task.".to_string(),
 528                    input_schema: language_model::tool_schema::root_schema_for::<FailureMessageInput>(tool_input_format).to_value(),
 529                },
 530            ];
 531
 532            LanguageModelRequest {
 533                thread_id: None,
 534                prompt_id: None,
 535                intent: Some(CompletionIntent::InlineAssist),
 536                mode: None,
 537                tools,
 538                tool_choice,
 539                stop: Vec::new(),
 540                temperature,
 541                messages,
 542                thinking_allowed: false,
 543            }
 544        }))
 545    }
 546
 547    fn build_request(
 548        &self,
 549        model: &Arc<dyn LanguageModel>,
 550        user_prompt: String,
 551        context_task: Shared<Task<Option<LoadedContext>>>,
 552        cx: &mut App,
 553    ) -> Result<Task<LanguageModelRequest>> {
 554        if Self::use_streaming_tools(model.as_ref(), cx) {
 555            return self.build_request_tools(model, user_prompt, context_task, cx);
 556        }
 557
 558        let buffer = self.buffer.read(cx).snapshot(cx);
 559        let language = buffer.language_at(self.range.start);
 560        let language_name = if let Some(language) = language.as_ref() {
 561            if Arc::ptr_eq(language, &language::PLAIN_TEXT) {
 562                None
 563            } else {
 564                Some(language.name())
 565            }
 566        } else {
 567            None
 568        };
 569
 570        let language_name = language_name.as_ref();
 571        let start = buffer.point_to_buffer_offset(self.range.start);
 572        let end = buffer.point_to_buffer_offset(self.range.end);
 573        let (buffer, range) = if let Some((start, end)) = start.zip(end) {
 574            let (start_buffer, start_buffer_offset) = start;
 575            let (end_buffer, end_buffer_offset) = end;
 576            if start_buffer.remote_id() == end_buffer.remote_id() {
 577                (start_buffer.clone(), start_buffer_offset..end_buffer_offset)
 578            } else {
 579                anyhow::bail!("invalid transformation range");
 580            }
 581        } else {
 582            anyhow::bail!("invalid transformation range");
 583        };
 584
 585        let prompt = self
 586            .builder
 587            .generate_inline_transformation_prompt(
 588                user_prompt,
 589                language_name,
 590                buffer,
 591                range.start.0..range.end.0,
 592            )
 593            .context("generating content prompt")?;
 594
 595        let temperature = AgentSettings::temperature_for_model(model, cx);
 596
 597        Ok(cx.spawn(async move |_cx| {
 598            let mut request_message = LanguageModelRequestMessage {
 599                role: Role::User,
 600                content: Vec::new(),
 601                cache: false,
 602                reasoning_details: None,
 603            };
 604
 605            if let Some(context) = context_task.await {
 606                context.add_to_request_message(&mut request_message);
 607            }
 608
 609            request_message.content.push(prompt.into());
 610
 611            LanguageModelRequest {
 612                thread_id: None,
 613                prompt_id: None,
 614                intent: Some(CompletionIntent::InlineAssist),
 615                mode: None,
 616                tools: Vec::new(),
 617                tool_choice: None,
 618                stop: Vec::new(),
 619                temperature,
 620                messages: vec![request_message],
 621                thinking_allowed: false,
 622            }
 623        }))
 624    }
 625
 626    pub fn handle_stream(
 627        &mut self,
 628        model: Arc<dyn LanguageModel>,
 629        stream: impl 'static + Future<Output = Result<LanguageModelTextStream>>,
 630        cx: &mut Context<Self>,
 631    ) -> Task<()> {
 632        let anthropic_reporter = language_model::AnthropicEventReporter::new(&model, cx);
 633        let session_id = self.session_id;
 634        let model_telemetry_id = model.telemetry_id();
 635        let model_provider_id = model.provider_id().to_string();
 636        let start_time = Instant::now();
 637
 638        // Make a new snapshot and re-resolve anchor in case the document was modified.
 639        // This can happen often if the editor loses focus and is saved + reformatted,
 640        // as in https://github.com/zed-industries/zed/issues/39088
 641        self.snapshot = self.buffer.read(cx).snapshot(cx);
 642        self.range = self.snapshot.anchor_after(self.range.start)
 643            ..self.snapshot.anchor_after(self.range.end);
 644
 645        let snapshot = self.snapshot.clone();
 646        let selected_text = snapshot
 647            .text_for_range(self.range.start..self.range.end)
 648            .collect::<Rope>();
 649
 650        self.selected_text = Some(selected_text.to_string());
 651
 652        let selection_start = self.range.start.to_point(&snapshot);
 653
 654        // Start with the indentation of the first line in the selection
 655        let mut suggested_line_indent = snapshot
 656            .suggested_indents(selection_start.row..=selection_start.row, cx)
 657            .into_values()
 658            .next()
 659            .unwrap_or_else(|| snapshot.indent_size_for_line(MultiBufferRow(selection_start.row)));
 660
 661        // If the first line in the selection does not have indentation, check the following lines
 662        if suggested_line_indent.len == 0 && suggested_line_indent.kind == IndentKind::Space {
 663            for row in selection_start.row..=self.range.end.to_point(&snapshot).row {
 664                let line_indent = snapshot.indent_size_for_line(MultiBufferRow(row));
 665                // Prefer tabs if a line in the selection uses tabs as indentation
 666                if line_indent.kind == IndentKind::Tab {
 667                    suggested_line_indent.kind = IndentKind::Tab;
 668                    break;
 669                }
 670            }
 671        }
 672
 673        let language_name = {
 674            let multibuffer = self.buffer.read(cx);
 675            let snapshot = multibuffer.snapshot(cx);
 676            let ranges = snapshot.range_to_buffer_ranges(self.range.clone());
 677            ranges
 678                .first()
 679                .and_then(|(buffer, _, _)| buffer.language())
 680                .map(|language| language.name())
 681        };
 682
 683        self.diff = Diff::default();
 684        self.status = CodegenStatus::Pending;
 685        let mut edit_start = self.range.start.to_offset(&snapshot);
 686        let completion = Arc::new(Mutex::new(String::new()));
 687        let completion_clone = completion.clone();
 688
 689        cx.notify();
 690        cx.spawn(async move |codegen, cx| {
 691            let stream = stream.await;
 692
 693            let token_usage = stream
 694                .as_ref()
 695                .ok()
 696                .map(|stream| stream.last_token_usage.clone());
 697            let message_id = stream
 698                .as_ref()
 699                .ok()
 700                .and_then(|stream| stream.message_id.clone());
 701            let generate = async {
 702                let model_telemetry_id = model_telemetry_id.clone();
 703                let model_provider_id = model_provider_id.clone();
 704                let (mut diff_tx, mut diff_rx) = mpsc::channel(1);
 705                let message_id = message_id.clone();
 706                let line_based_stream_diff: Task<anyhow::Result<()>> = cx.background_spawn({
 707                    let anthropic_reporter = anthropic_reporter.clone();
 708                    let language_name = language_name.clone();
 709                    async move {
 710                        let mut response_latency = None;
 711                        let request_start = Instant::now();
 712                        let diff = async {
 713                            let chunks = StripInvalidSpans::new(
 714                                stream?.stream.map_err(|error| error.into()),
 715                            );
 716                            futures::pin_mut!(chunks);
 717
 718                            let mut diff = StreamingDiff::new(selected_text.to_string());
 719                            let mut line_diff = LineDiff::default();
 720
 721                            let mut new_text = String::new();
 722                            let mut base_indent = None;
 723                            let mut line_indent = None;
 724                            let mut first_line = true;
 725
 726                            while let Some(chunk) = chunks.next().await {
 727                                if response_latency.is_none() {
 728                                    response_latency = Some(request_start.elapsed());
 729                                }
 730                                let chunk = chunk?;
 731                                completion_clone.lock().push_str(&chunk);
 732
 733                                let mut lines = chunk.split('\n').peekable();
 734                                while let Some(line) = lines.next() {
 735                                    new_text.push_str(line);
 736                                    if line_indent.is_none()
 737                                        && let Some(non_whitespace_ch_ix) =
 738                                            new_text.find(|ch: char| !ch.is_whitespace())
 739                                    {
 740                                        line_indent = Some(non_whitespace_ch_ix);
 741                                        base_indent = base_indent.or(line_indent);
 742
 743                                        let line_indent = line_indent.unwrap();
 744                                        let base_indent = base_indent.unwrap();
 745                                        let indent_delta = line_indent as i32 - base_indent as i32;
 746                                        let mut corrected_indent_len = cmp::max(
 747                                            0,
 748                                            suggested_line_indent.len as i32 + indent_delta,
 749                                        )
 750                                            as usize;
 751                                        if first_line {
 752                                            corrected_indent_len = corrected_indent_len
 753                                                .saturating_sub(selection_start.column as usize);
 754                                        }
 755
 756                                        let indent_char = suggested_line_indent.char();
 757                                        let mut indent_buffer = [0; 4];
 758                                        let indent_str =
 759                                            indent_char.encode_utf8(&mut indent_buffer);
 760                                        new_text.replace_range(
 761                                            ..line_indent,
 762                                            &indent_str.repeat(corrected_indent_len),
 763                                        );
 764                                    }
 765
 766                                    if line_indent.is_some() {
 767                                        let char_ops = diff.push_new(&new_text);
 768                                        line_diff.push_char_operations(&char_ops, &selected_text);
 769                                        diff_tx
 770                                            .send((char_ops, line_diff.line_operations()))
 771                                            .await?;
 772                                        new_text.clear();
 773                                    }
 774
 775                                    if lines.peek().is_some() {
 776                                        let char_ops = diff.push_new("\n");
 777                                        line_diff.push_char_operations(&char_ops, &selected_text);
 778                                        diff_tx
 779                                            .send((char_ops, line_diff.line_operations()))
 780                                            .await?;
 781                                        if line_indent.is_none() {
 782                                            // Don't write out the leading indentation in empty lines on the next line
 783                                            // This is the case where the above if statement didn't clear the buffer
 784                                            new_text.clear();
 785                                        }
 786                                        line_indent = None;
 787                                        first_line = false;
 788                                    }
 789                                }
 790                            }
 791
 792                            let mut char_ops = diff.push_new(&new_text);
 793                            char_ops.extend(diff.finish());
 794                            line_diff.push_char_operations(&char_ops, &selected_text);
 795                            line_diff.finish(&selected_text);
 796                            diff_tx
 797                                .send((char_ops, line_diff.line_operations()))
 798                                .await?;
 799
 800                            anyhow::Ok(())
 801                        };
 802
 803                        let result = diff.await;
 804
 805                        let error_message = result.as_ref().err().map(|error| error.to_string());
 806                        telemetry::event!(
 807                            "Assistant Responded",
 808                            kind = "inline",
 809                            phase = "response",
 810                            session_id = session_id.to_string(),
 811                            model = model_telemetry_id,
 812                            model_provider = model_provider_id,
 813                            language_name = language_name.as_ref().map(|n| n.to_string()),
 814                            message_id = message_id.as_deref(),
 815                            response_latency = response_latency,
 816                            error_message = error_message.as_deref(),
 817                        );
 818
 819                        anthropic_reporter.report(language_model::AnthropicEventData {
 820                            completion_type: language_model::AnthropicCompletionType::Editor,
 821                            event: language_model::AnthropicEventType::Response,
 822                            language_name: language_name.map(|n| n.to_string()),
 823                            message_id,
 824                        });
 825
 826                        result?;
 827                        Ok(())
 828                    }
 829                });
 830
 831                while let Some((char_ops, line_ops)) = diff_rx.next().await {
 832                    codegen.update(cx, |codegen, cx| {
 833                        codegen.last_equal_ranges.clear();
 834
 835                        let edits = char_ops
 836                            .into_iter()
 837                            .filter_map(|operation| match operation {
 838                                CharOperation::Insert { text } => {
 839                                    let edit_start = snapshot.anchor_after(edit_start);
 840                                    Some((edit_start..edit_start, text))
 841                                }
 842                                CharOperation::Delete { bytes } => {
 843                                    let edit_end = edit_start + bytes;
 844                                    let edit_range = snapshot.anchor_after(edit_start)
 845                                        ..snapshot.anchor_before(edit_end);
 846                                    edit_start = edit_end;
 847                                    Some((edit_range, String::new()))
 848                                }
 849                                CharOperation::Keep { bytes } => {
 850                                    let edit_end = edit_start + bytes;
 851                                    let edit_range = snapshot.anchor_after(edit_start)
 852                                        ..snapshot.anchor_before(edit_end);
 853                                    edit_start = edit_end;
 854                                    codegen.last_equal_ranges.push(edit_range);
 855                                    None
 856                                }
 857                            })
 858                            .collect::<Vec<_>>();
 859
 860                        if codegen.active {
 861                            codegen.apply_edits(edits.iter().cloned(), cx);
 862                            codegen.reapply_line_based_diff(line_ops.iter().cloned(), cx);
 863                        }
 864                        codegen.edits.extend(edits);
 865                        codegen.line_operations = line_ops;
 866                        codegen.edit_position = Some(snapshot.anchor_after(edit_start));
 867
 868                        cx.notify();
 869                    })?;
 870                }
 871
 872                // Streaming stopped and we have the new text in the buffer, and a line-based diff applied for the whole new buffer.
 873                // That diff is not what a regular diff is and might look unexpected, ergo apply a regular diff.
 874                // It's fine to apply even if the rest of the line diffing fails, as no more hunks are coming through `diff_rx`.
 875                let batch_diff_task =
 876                    codegen.update(cx, |codegen, cx| codegen.reapply_batch_diff(cx))?;
 877                let (line_based_stream_diff, ()) = join!(line_based_stream_diff, batch_diff_task);
 878                line_based_stream_diff?;
 879
 880                anyhow::Ok(())
 881            };
 882
 883            let result = generate.await;
 884            let elapsed_time = start_time.elapsed().as_secs_f64();
 885
 886            codegen
 887                .update(cx, |this, cx| {
 888                    this.message_id = message_id;
 889                    this.last_equal_ranges.clear();
 890                    if let Err(error) = result {
 891                        this.status = CodegenStatus::Error(error);
 892                    } else {
 893                        this.status = CodegenStatus::Done;
 894                    }
 895                    this.elapsed_time = Some(elapsed_time);
 896                    this.completion = Some(completion.lock().clone());
 897                    if let Some(usage) = token_usage {
 898                        let usage = usage.lock();
 899                        telemetry::event!(
 900                            "Inline Assistant Completion",
 901                            model = model_telemetry_id,
 902                            model_provider = model_provider_id,
 903                            input_tokens = usage.input_tokens,
 904                            output_tokens = usage.output_tokens,
 905                        )
 906                    }
 907
 908                    cx.emit(CodegenEvent::Finished);
 909                    cx.notify();
 910                })
 911                .ok();
 912        })
 913    }
 914
 915    pub fn current_completion(&self) -> Option<String> {
 916        self.completion.clone()
 917    }
 918
 919    #[cfg(any(test, feature = "test-support"))]
 920    pub fn current_description(&self) -> Option<String> {
 921        self.description.clone()
 922    }
 923
 924    #[cfg(any(test, feature = "test-support"))]
 925    pub fn current_failure(&self) -> Option<String> {
 926        self.failure.clone()
 927    }
 928
 929    pub fn selected_text(&self) -> Option<&str> {
 930        self.selected_text.as_deref()
 931    }
 932
 933    pub fn stop(&mut self, cx: &mut Context<Self>) {
 934        self.last_equal_ranges.clear();
 935        if self.diff.is_empty() {
 936            self.status = CodegenStatus::Idle;
 937        } else {
 938            self.status = CodegenStatus::Done;
 939        }
 940        self.generation = Task::ready(());
 941        cx.emit(CodegenEvent::Finished);
 942        cx.notify();
 943    }
 944
 945    pub fn undo(&mut self, cx: &mut Context<Self>) {
 946        self.buffer.update(cx, |buffer, cx| {
 947            if let Some(transaction_id) = self.transformation_transaction_id.take() {
 948                buffer.undo_transaction(transaction_id, cx);
 949                buffer.refresh_preview(cx);
 950            }
 951        });
 952    }
 953
 954    fn apply_edits(
 955        &mut self,
 956        edits: impl IntoIterator<Item = (Range<Anchor>, String)>,
 957        cx: &mut Context<CodegenAlternative>,
 958    ) {
 959        let transaction = self.buffer.update(cx, |buffer, cx| {
 960            // Avoid grouping agent edits with user edits.
 961            buffer.finalize_last_transaction(cx);
 962            buffer.start_transaction(cx);
 963            buffer.edit(edits, None, cx);
 964            buffer.end_transaction(cx)
 965        });
 966
 967        if let Some(transaction) = transaction {
 968            if let Some(first_transaction) = self.transformation_transaction_id {
 969                // Group all agent edits into the first transaction.
 970                self.buffer.update(cx, |buffer, cx| {
 971                    buffer.merge_transactions(transaction, first_transaction, cx)
 972                });
 973            } else {
 974                self.transformation_transaction_id = Some(transaction);
 975                self.buffer
 976                    .update(cx, |buffer, cx| buffer.finalize_last_transaction(cx));
 977            }
 978        }
 979    }
 980
 981    fn reapply_line_based_diff(
 982        &mut self,
 983        line_operations: impl IntoIterator<Item = LineOperation>,
 984        cx: &mut Context<Self>,
 985    ) {
 986        let old_snapshot = self.snapshot.clone();
 987        let old_range = self.range.to_point(&old_snapshot);
 988        let new_snapshot = self.buffer.read(cx).snapshot(cx);
 989        let new_range = self.range.to_point(&new_snapshot);
 990
 991        let mut old_row = old_range.start.row;
 992        let mut new_row = new_range.start.row;
 993
 994        self.diff.deleted_row_ranges.clear();
 995        self.diff.inserted_row_ranges.clear();
 996        for operation in line_operations {
 997            match operation {
 998                LineOperation::Keep { lines } => {
 999                    old_row += lines;
1000                    new_row += lines;
1001                }
1002                LineOperation::Delete { lines } => {
1003                    let old_end_row = old_row + lines - 1;
1004                    let new_row = new_snapshot.anchor_before(Point::new(new_row, 0));
1005
1006                    if let Some((_, last_deleted_row_range)) =
1007                        self.diff.deleted_row_ranges.last_mut()
1008                    {
1009                        if *last_deleted_row_range.end() + 1 == old_row {
1010                            *last_deleted_row_range = *last_deleted_row_range.start()..=old_end_row;
1011                        } else {
1012                            self.diff
1013                                .deleted_row_ranges
1014                                .push((new_row, old_row..=old_end_row));
1015                        }
1016                    } else {
1017                        self.diff
1018                            .deleted_row_ranges
1019                            .push((new_row, old_row..=old_end_row));
1020                    }
1021
1022                    old_row += lines;
1023                }
1024                LineOperation::Insert { lines } => {
1025                    let new_end_row = new_row + lines - 1;
1026                    let start = new_snapshot.anchor_before(Point::new(new_row, 0));
1027                    let end = new_snapshot.anchor_before(Point::new(
1028                        new_end_row,
1029                        new_snapshot.line_len(MultiBufferRow(new_end_row)),
1030                    ));
1031                    self.diff.inserted_row_ranges.push(start..end);
1032                    new_row += lines;
1033                }
1034            }
1035
1036            cx.notify();
1037        }
1038    }
1039
1040    fn reapply_batch_diff(&mut self, cx: &mut Context<Self>) -> Task<()> {
1041        let old_snapshot = self.snapshot.clone();
1042        let old_range = self.range.to_point(&old_snapshot);
1043        let new_snapshot = self.buffer.read(cx).snapshot(cx);
1044        let new_range = self.range.to_point(&new_snapshot);
1045
1046        cx.spawn(async move |codegen, cx| {
1047            let (deleted_row_ranges, inserted_row_ranges) = cx
1048                .background_spawn(async move {
1049                    let old_text = old_snapshot
1050                        .text_for_range(
1051                            Point::new(old_range.start.row, 0)
1052                                ..Point::new(
1053                                    old_range.end.row,
1054                                    old_snapshot.line_len(MultiBufferRow(old_range.end.row)),
1055                                ),
1056                        )
1057                        .collect::<String>();
1058                    let new_text = new_snapshot
1059                        .text_for_range(
1060                            Point::new(new_range.start.row, 0)
1061                                ..Point::new(
1062                                    new_range.end.row,
1063                                    new_snapshot.line_len(MultiBufferRow(new_range.end.row)),
1064                                ),
1065                        )
1066                        .collect::<String>();
1067
1068                    let old_start_row = old_range.start.row;
1069                    let new_start_row = new_range.start.row;
1070                    let mut deleted_row_ranges: Vec<(Anchor, RangeInclusive<u32>)> = Vec::new();
1071                    let mut inserted_row_ranges = Vec::new();
1072                    for (old_rows, new_rows) in line_diff(&old_text, &new_text) {
1073                        let old_rows = old_start_row + old_rows.start..old_start_row + old_rows.end;
1074                        let new_rows = new_start_row + new_rows.start..new_start_row + new_rows.end;
1075                        if !old_rows.is_empty() {
1076                            deleted_row_ranges.push((
1077                                new_snapshot.anchor_before(Point::new(new_rows.start, 0)),
1078                                old_rows.start..=old_rows.end - 1,
1079                            ));
1080                        }
1081                        if !new_rows.is_empty() {
1082                            let start = new_snapshot.anchor_before(Point::new(new_rows.start, 0));
1083                            let new_end_row = new_rows.end - 1;
1084                            let end = new_snapshot.anchor_before(Point::new(
1085                                new_end_row,
1086                                new_snapshot.line_len(MultiBufferRow(new_end_row)),
1087                            ));
1088                            inserted_row_ranges.push(start..end);
1089                        }
1090                    }
1091                    (deleted_row_ranges, inserted_row_ranges)
1092                })
1093                .await;
1094
1095            codegen
1096                .update(cx, |codegen, cx| {
1097                    codegen.diff.deleted_row_ranges = deleted_row_ranges;
1098                    codegen.diff.inserted_row_ranges = inserted_row_ranges;
1099                    cx.notify();
1100                })
1101                .ok();
1102        })
1103    }
1104
1105    fn handle_completion(
1106        &mut self,
1107        model: Arc<dyn LanguageModel>,
1108        completion_stream: Task<
1109            Result<
1110                BoxStream<
1111                    'static,
1112                    Result<LanguageModelCompletionEvent, LanguageModelCompletionError>,
1113                >,
1114                LanguageModelCompletionError,
1115            >,
1116        >,
1117        cx: &mut Context<Self>,
1118    ) -> Task<()> {
1119        self.diff = Diff::default();
1120        self.status = CodegenStatus::Pending;
1121
1122        cx.notify();
1123        // Leaving this in generation so that STOP equivalent events are respected even
1124        // while we're still pre-processing the completion event
1125        cx.spawn(async move |codegen, cx| {
1126            let finish_with_status = |status: CodegenStatus, cx: &mut AsyncApp| {
1127                let _ = codegen.update(cx, |this, cx| {
1128                    this.status = status;
1129                    cx.emit(CodegenEvent::Finished);
1130                    cx.notify();
1131                });
1132            };
1133
1134            let mut completion_events = match completion_stream.await {
1135                Ok(events) => events,
1136                Err(err) => {
1137                    finish_with_status(CodegenStatus::Error(err.into()), cx);
1138                    return;
1139                }
1140            };
1141
1142            enum ToolUseOutput {
1143                Rewrite {
1144                    text: String,
1145                    description: Option<String>,
1146                },
1147                Failure(String),
1148            }
1149
1150            enum ModelUpdate {
1151                Description(String),
1152                Failure(String),
1153            }
1154
1155            let chars_read_so_far = Arc::new(Mutex::new(0usize));
1156            let process_tool_use = move |tool_use: LanguageModelToolUse| -> Option<ToolUseOutput> {
1157                let mut chars_read_so_far = chars_read_so_far.lock();
1158                match tool_use.name.as_ref() {
1159                    "rewrite_section" => {
1160                        let Ok(input) =
1161                            serde_json::from_value::<RewriteSectionInput>(tool_use.input)
1162                        else {
1163                            return None;
1164                        };
1165                        let text = input.replacement_text[*chars_read_so_far..].to_string();
1166                        *chars_read_so_far = input.replacement_text.len();
1167                        Some(ToolUseOutput::Rewrite {
1168                            text,
1169                            description: None,
1170                        })
1171                    }
1172                    "failure_message" => {
1173                        let Ok(mut input) =
1174                            serde_json::from_value::<FailureMessageInput>(tool_use.input)
1175                        else {
1176                            return None;
1177                        };
1178                        Some(ToolUseOutput::Failure(std::mem::take(&mut input.message)))
1179                    }
1180                    _ => None,
1181                }
1182            };
1183
1184            let (message_tx, mut message_rx) = futures::channel::mpsc::unbounded::<ModelUpdate>();
1185
1186            cx.spawn({
1187                let codegen = codegen.clone();
1188                async move |cx| {
1189                    while let Some(update) = message_rx.next().await {
1190                        let _ = codegen.update(cx, |this, _cx| match update {
1191                            ModelUpdate::Description(d) => this.description = Some(d),
1192                            ModelUpdate::Failure(f) => this.failure = Some(f),
1193                        });
1194                    }
1195                }
1196            })
1197            .detach();
1198
1199            let mut message_id = None;
1200            let mut first_text = None;
1201            let last_token_usage = Arc::new(Mutex::new(TokenUsage::default()));
1202            let total_text = Arc::new(Mutex::new(String::new()));
1203
1204            loop {
1205                if let Some(first_event) = completion_events.next().await {
1206                    match first_event {
1207                        Ok(LanguageModelCompletionEvent::StartMessage { message_id: id }) => {
1208                            message_id = Some(id);
1209                        }
1210                        Ok(LanguageModelCompletionEvent::ToolUse(tool_use)) => {
1211                            if let Some(output) = process_tool_use(tool_use) {
1212                                let (text, update) = match output {
1213                                    ToolUseOutput::Rewrite { text, description } => {
1214                                        (Some(text), description.map(ModelUpdate::Description))
1215                                    }
1216                                    ToolUseOutput::Failure(message) => {
1217                                        (None, Some(ModelUpdate::Failure(message)))
1218                                    }
1219                                };
1220                                if let Some(update) = update {
1221                                    let _ = message_tx.unbounded_send(update);
1222                                }
1223                                first_text = text;
1224                                if first_text.is_some() {
1225                                    break;
1226                                }
1227                            }
1228                        }
1229                        Ok(LanguageModelCompletionEvent::UsageUpdate(token_usage)) => {
1230                            *last_token_usage.lock() = token_usage;
1231                        }
1232                        Ok(LanguageModelCompletionEvent::Text(text)) => {
1233                            let mut lock = total_text.lock();
1234                            lock.push_str(&text);
1235                        }
1236                        Ok(e) => {
1237                            log::warn!("Unexpected event: {:?}", e);
1238                            break;
1239                        }
1240                        Err(e) => {
1241                            finish_with_status(CodegenStatus::Error(e.into()), cx);
1242                            break;
1243                        }
1244                    }
1245                }
1246            }
1247
1248            let Some(first_text) = first_text else {
1249                finish_with_status(CodegenStatus::Done, cx);
1250                return;
1251            };
1252
1253            let move_last_token_usage = last_token_usage.clone();
1254
1255            let text_stream = Box::pin(futures::stream::once(async { Ok(first_text) }).chain(
1256                completion_events.filter_map(move |e| {
1257                    let process_tool_use = process_tool_use.clone();
1258                    let last_token_usage = move_last_token_usage.clone();
1259                    let total_text = total_text.clone();
1260                    let mut message_tx = message_tx.clone();
1261                    async move {
1262                        match e {
1263                            Ok(LanguageModelCompletionEvent::ToolUse(tool_use)) => {
1264                                let Some(output) = process_tool_use(tool_use) else {
1265                                    return None;
1266                                };
1267                                let (text, update) = match output {
1268                                    ToolUseOutput::Rewrite { text, description } => {
1269                                        (Some(text), description.map(ModelUpdate::Description))
1270                                    }
1271                                    ToolUseOutput::Failure(message) => {
1272                                        (None, Some(ModelUpdate::Failure(message)))
1273                                    }
1274                                };
1275                                if let Some(update) = update {
1276                                    let _ = message_tx.send(update).await;
1277                                }
1278                                text.map(Ok)
1279                            }
1280                            Ok(LanguageModelCompletionEvent::UsageUpdate(token_usage)) => {
1281                                *last_token_usage.lock() = token_usage;
1282                                None
1283                            }
1284                            Ok(LanguageModelCompletionEvent::Text(text)) => {
1285                                let mut lock = total_text.lock();
1286                                lock.push_str(&text);
1287                                None
1288                            }
1289                            Ok(LanguageModelCompletionEvent::Stop(_reason)) => None,
1290                            e => {
1291                                log::error!("UNEXPECTED EVENT {:?}", e);
1292                                None
1293                            }
1294                        }
1295                    }
1296                }),
1297            ));
1298
1299            let language_model_text_stream = LanguageModelTextStream {
1300                message_id: message_id,
1301                stream: text_stream,
1302                last_token_usage,
1303            };
1304
1305            let Some(task) = codegen
1306                .update(cx, move |codegen, cx| {
1307                    codegen.handle_stream(model, async { Ok(language_model_text_stream) }, cx)
1308                })
1309                .ok()
1310            else {
1311                return;
1312            };
1313
1314            task.await;
1315        })
1316    }
1317}
1318
1319#[derive(Copy, Clone, Debug)]
1320pub enum CodegenEvent {
1321    Finished,
1322    Undone,
1323}
1324
1325struct StripInvalidSpans<T> {
1326    stream: T,
1327    stream_done: bool,
1328    buffer: String,
1329    first_line: bool,
1330    line_end: bool,
1331    starts_with_code_block: bool,
1332}
1333
1334impl<T> StripInvalidSpans<T>
1335where
1336    T: Stream<Item = Result<String>>,
1337{
1338    fn new(stream: T) -> Self {
1339        Self {
1340            stream,
1341            stream_done: false,
1342            buffer: String::new(),
1343            first_line: true,
1344            line_end: false,
1345            starts_with_code_block: false,
1346        }
1347    }
1348}
1349
1350impl<T> Stream for StripInvalidSpans<T>
1351where
1352    T: Stream<Item = Result<String>>,
1353{
1354    type Item = Result<String>;
1355
1356    fn poll_next(self: Pin<&mut Self>, cx: &mut task::Context) -> Poll<Option<Self::Item>> {
1357        const CODE_BLOCK_DELIMITER: &str = "```";
1358        const CURSOR_SPAN: &str = "<|CURSOR|>";
1359
1360        let this = unsafe { self.get_unchecked_mut() };
1361        loop {
1362            if !this.stream_done {
1363                let mut stream = unsafe { Pin::new_unchecked(&mut this.stream) };
1364                match stream.as_mut().poll_next(cx) {
1365                    Poll::Ready(Some(Ok(chunk))) => {
1366                        this.buffer.push_str(&chunk);
1367                    }
1368                    Poll::Ready(Some(Err(error))) => return Poll::Ready(Some(Err(error))),
1369                    Poll::Ready(None) => {
1370                        this.stream_done = true;
1371                    }
1372                    Poll::Pending => return Poll::Pending,
1373                }
1374            }
1375
1376            let mut chunk = String::new();
1377            let mut consumed = 0;
1378            if !this.buffer.is_empty() {
1379                let mut lines = this.buffer.split('\n').enumerate().peekable();
1380                while let Some((line_ix, line)) = lines.next() {
1381                    if line_ix > 0 {
1382                        this.first_line = false;
1383                    }
1384
1385                    if this.first_line {
1386                        let trimmed_line = line.trim();
1387                        if lines.peek().is_some() {
1388                            if trimmed_line.starts_with(CODE_BLOCK_DELIMITER) {
1389                                consumed += line.len() + 1;
1390                                this.starts_with_code_block = true;
1391                                continue;
1392                            }
1393                        } else if trimmed_line.is_empty()
1394                            || prefixes(CODE_BLOCK_DELIMITER)
1395                                .any(|prefix| trimmed_line.starts_with(prefix))
1396                        {
1397                            break;
1398                        }
1399                    }
1400
1401                    let line_without_cursor = line.replace(CURSOR_SPAN, "");
1402                    if lines.peek().is_some() {
1403                        if this.line_end {
1404                            chunk.push('\n');
1405                        }
1406
1407                        chunk.push_str(&line_without_cursor);
1408                        this.line_end = true;
1409                        consumed += line.len() + 1;
1410                    } else if this.stream_done {
1411                        if !this.starts_with_code_block
1412                            || !line_without_cursor.trim().ends_with(CODE_BLOCK_DELIMITER)
1413                        {
1414                            if this.line_end {
1415                                chunk.push('\n');
1416                            }
1417
1418                            chunk.push_str(line);
1419                        }
1420
1421                        consumed += line.len();
1422                    } else {
1423                        let trimmed_line = line.trim();
1424                        if trimmed_line.is_empty()
1425                            || prefixes(CURSOR_SPAN).any(|prefix| trimmed_line.ends_with(prefix))
1426                            || prefixes(CODE_BLOCK_DELIMITER)
1427                                .any(|prefix| trimmed_line.ends_with(prefix))
1428                        {
1429                            break;
1430                        } else {
1431                            if this.line_end {
1432                                chunk.push('\n');
1433                                this.line_end = false;
1434                            }
1435
1436                            chunk.push_str(&line_without_cursor);
1437                            consumed += line.len();
1438                        }
1439                    }
1440                }
1441            }
1442
1443            this.buffer = this.buffer.split_off(consumed);
1444            if !chunk.is_empty() {
1445                return Poll::Ready(Some(Ok(chunk)));
1446            } else if this.stream_done {
1447                return Poll::Ready(None);
1448            }
1449        }
1450    }
1451}
1452
1453fn prefixes(text: &str) -> impl Iterator<Item = &str> {
1454    (0..text.len() - 1).map(|ix| &text[..ix + 1])
1455}
1456
1457#[derive(Default)]
1458pub struct Diff {
1459    pub deleted_row_ranges: Vec<(Anchor, RangeInclusive<u32>)>,
1460    pub inserted_row_ranges: Vec<Range<Anchor>>,
1461}
1462
1463impl Diff {
1464    fn is_empty(&self) -> bool {
1465        self.deleted_row_ranges.is_empty() && self.inserted_row_ranges.is_empty()
1466    }
1467}
1468
1469#[cfg(test)]
1470mod tests {
1471    use super::*;
1472    use futures::{
1473        Stream,
1474        stream::{self},
1475    };
1476    use gpui::TestAppContext;
1477    use indoc::indoc;
1478    use language::{Buffer, Point};
1479    use language_model::fake_provider::FakeLanguageModel;
1480    use language_model::{LanguageModelRegistry, TokenUsage};
1481    use languages::rust_lang;
1482    use rand::prelude::*;
1483    use settings::SettingsStore;
1484    use std::{future, sync::Arc};
1485
1486    #[gpui::test(iterations = 10)]
1487    async fn test_transform_autoindent(cx: &mut TestAppContext, mut rng: StdRng) {
1488        init_test(cx);
1489
1490        let text = indoc! {"
1491            fn main() {
1492                let x = 0;
1493                for _ in 0..10 {
1494                    x += 1;
1495                }
1496            }
1497        "};
1498        let buffer = cx.new(|cx| Buffer::local(text, cx).with_language(rust_lang(), cx));
1499        let buffer = cx.new(|cx| MultiBuffer::singleton(buffer, cx));
1500        let range = buffer.read_with(cx, |buffer, cx| {
1501            let snapshot = buffer.snapshot(cx);
1502            snapshot.anchor_before(Point::new(1, 0))..snapshot.anchor_after(Point::new(4, 5))
1503        });
1504        let prompt_builder = Arc::new(PromptBuilder::new(None).unwrap());
1505        let codegen = cx.new(|cx| {
1506            CodegenAlternative::new(
1507                buffer.clone(),
1508                range.clone(),
1509                true,
1510                prompt_builder,
1511                Uuid::new_v4(),
1512                cx,
1513            )
1514        });
1515
1516        let chunks_tx = simulate_response_stream(&codegen, cx);
1517
1518        let mut new_text = concat!(
1519            "       let mut x = 0;\n",
1520            "       while x < 10 {\n",
1521            "           x += 1;\n",
1522            "       }",
1523        );
1524        while !new_text.is_empty() {
1525            let max_len = cmp::min(new_text.len(), 10);
1526            let len = rng.random_range(1..=max_len);
1527            let (chunk, suffix) = new_text.split_at(len);
1528            chunks_tx.unbounded_send(chunk.to_string()).unwrap();
1529            new_text = suffix;
1530            cx.background_executor.run_until_parked();
1531        }
1532        drop(chunks_tx);
1533        cx.background_executor.run_until_parked();
1534
1535        assert_eq!(
1536            buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx).text()),
1537            indoc! {"
1538                fn main() {
1539                    let mut x = 0;
1540                    while x < 10 {
1541                        x += 1;
1542                    }
1543                }
1544            "}
1545        );
1546    }
1547
1548    #[gpui::test(iterations = 10)]
1549    async fn test_autoindent_when_generating_past_indentation(
1550        cx: &mut TestAppContext,
1551        mut rng: StdRng,
1552    ) {
1553        init_test(cx);
1554
1555        let text = indoc! {"
1556            fn main() {
1557                le
1558            }
1559        "};
1560        let buffer = cx.new(|cx| Buffer::local(text, cx).with_language(rust_lang(), cx));
1561        let buffer = cx.new(|cx| MultiBuffer::singleton(buffer, cx));
1562        let range = buffer.read_with(cx, |buffer, cx| {
1563            let snapshot = buffer.snapshot(cx);
1564            snapshot.anchor_before(Point::new(1, 6))..snapshot.anchor_after(Point::new(1, 6))
1565        });
1566        let prompt_builder = Arc::new(PromptBuilder::new(None).unwrap());
1567        let codegen = cx.new(|cx| {
1568            CodegenAlternative::new(
1569                buffer.clone(),
1570                range.clone(),
1571                true,
1572                prompt_builder,
1573                Uuid::new_v4(),
1574                cx,
1575            )
1576        });
1577
1578        let chunks_tx = simulate_response_stream(&codegen, cx);
1579
1580        cx.background_executor.run_until_parked();
1581
1582        let mut new_text = concat!(
1583            "t mut x = 0;\n",
1584            "while x < 10 {\n",
1585            "    x += 1;\n",
1586            "}", //
1587        );
1588        while !new_text.is_empty() {
1589            let max_len = cmp::min(new_text.len(), 10);
1590            let len = rng.random_range(1..=max_len);
1591            let (chunk, suffix) = new_text.split_at(len);
1592            chunks_tx.unbounded_send(chunk.to_string()).unwrap();
1593            new_text = suffix;
1594            cx.background_executor.run_until_parked();
1595        }
1596        drop(chunks_tx);
1597        cx.background_executor.run_until_parked();
1598
1599        assert_eq!(
1600            buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx).text()),
1601            indoc! {"
1602                fn main() {
1603                    let mut x = 0;
1604                    while x < 10 {
1605                        x += 1;
1606                    }
1607                }
1608            "}
1609        );
1610    }
1611
1612    #[gpui::test(iterations = 10)]
1613    async fn test_autoindent_when_generating_before_indentation(
1614        cx: &mut TestAppContext,
1615        mut rng: StdRng,
1616    ) {
1617        init_test(cx);
1618
1619        let text = concat!(
1620            "fn main() {\n",
1621            "  \n",
1622            "}\n" //
1623        );
1624        let buffer = cx.new(|cx| Buffer::local(text, cx).with_language(rust_lang(), cx));
1625        let buffer = cx.new(|cx| MultiBuffer::singleton(buffer, cx));
1626        let range = buffer.read_with(cx, |buffer, cx| {
1627            let snapshot = buffer.snapshot(cx);
1628            snapshot.anchor_before(Point::new(1, 2))..snapshot.anchor_after(Point::new(1, 2))
1629        });
1630        let prompt_builder = Arc::new(PromptBuilder::new(None).unwrap());
1631        let codegen = cx.new(|cx| {
1632            CodegenAlternative::new(
1633                buffer.clone(),
1634                range.clone(),
1635                true,
1636                prompt_builder,
1637                Uuid::new_v4(),
1638                cx,
1639            )
1640        });
1641
1642        let chunks_tx = simulate_response_stream(&codegen, cx);
1643
1644        cx.background_executor.run_until_parked();
1645
1646        let mut new_text = concat!(
1647            "let mut x = 0;\n",
1648            "while x < 10 {\n",
1649            "    x += 1;\n",
1650            "}", //
1651        );
1652        while !new_text.is_empty() {
1653            let max_len = cmp::min(new_text.len(), 10);
1654            let len = rng.random_range(1..=max_len);
1655            let (chunk, suffix) = new_text.split_at(len);
1656            chunks_tx.unbounded_send(chunk.to_string()).unwrap();
1657            new_text = suffix;
1658            cx.background_executor.run_until_parked();
1659        }
1660        drop(chunks_tx);
1661        cx.background_executor.run_until_parked();
1662
1663        assert_eq!(
1664            buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx).text()),
1665            indoc! {"
1666                fn main() {
1667                    let mut x = 0;
1668                    while x < 10 {
1669                        x += 1;
1670                    }
1671                }
1672            "}
1673        );
1674    }
1675
1676    #[gpui::test(iterations = 10)]
1677    async fn test_autoindent_respects_tabs_in_selection(cx: &mut TestAppContext) {
1678        init_test(cx);
1679
1680        let text = indoc! {"
1681            func main() {
1682            \tx := 0
1683            \tfor i := 0; i < 10; i++ {
1684            \t\tx++
1685            \t}
1686            }
1687        "};
1688        let buffer = cx.new(|cx| Buffer::local(text, cx));
1689        let buffer = cx.new(|cx| MultiBuffer::singleton(buffer, cx));
1690        let range = buffer.read_with(cx, |buffer, cx| {
1691            let snapshot = buffer.snapshot(cx);
1692            snapshot.anchor_before(Point::new(0, 0))..snapshot.anchor_after(Point::new(4, 2))
1693        });
1694        let prompt_builder = Arc::new(PromptBuilder::new(None).unwrap());
1695        let codegen = cx.new(|cx| {
1696            CodegenAlternative::new(
1697                buffer.clone(),
1698                range.clone(),
1699                true,
1700                prompt_builder,
1701                Uuid::new_v4(),
1702                cx,
1703            )
1704        });
1705
1706        let chunks_tx = simulate_response_stream(&codegen, cx);
1707        let new_text = concat!(
1708            "func main() {\n",
1709            "\tx := 0\n",
1710            "\tfor x < 10 {\n",
1711            "\t\tx++\n",
1712            "\t}", //
1713        );
1714        chunks_tx.unbounded_send(new_text.to_string()).unwrap();
1715        drop(chunks_tx);
1716        cx.background_executor.run_until_parked();
1717
1718        assert_eq!(
1719            buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx).text()),
1720            indoc! {"
1721                func main() {
1722                \tx := 0
1723                \tfor x < 10 {
1724                \t\tx++
1725                \t}
1726                }
1727            "}
1728        );
1729    }
1730
1731    #[gpui::test]
1732    async fn test_inactive_codegen_alternative(cx: &mut TestAppContext) {
1733        init_test(cx);
1734
1735        let text = indoc! {"
1736            fn main() {
1737                let x = 0;
1738            }
1739        "};
1740        let buffer = cx.new(|cx| Buffer::local(text, cx).with_language(rust_lang(), cx));
1741        let buffer = cx.new(|cx| MultiBuffer::singleton(buffer, cx));
1742        let range = buffer.read_with(cx, |buffer, cx| {
1743            let snapshot = buffer.snapshot(cx);
1744            snapshot.anchor_before(Point::new(1, 0))..snapshot.anchor_after(Point::new(1, 14))
1745        });
1746        let prompt_builder = Arc::new(PromptBuilder::new(None).unwrap());
1747        let codegen = cx.new(|cx| {
1748            CodegenAlternative::new(
1749                buffer.clone(),
1750                range.clone(),
1751                false,
1752                prompt_builder,
1753                Uuid::new_v4(),
1754                cx,
1755            )
1756        });
1757
1758        let chunks_tx = simulate_response_stream(&codegen, cx);
1759        chunks_tx
1760            .unbounded_send("let mut x = 0;\nx += 1;".to_string())
1761            .unwrap();
1762        drop(chunks_tx);
1763        cx.run_until_parked();
1764
1765        // The codegen is inactive, so the buffer doesn't get modified.
1766        assert_eq!(
1767            buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx).text()),
1768            text
1769        );
1770
1771        // Activating the codegen applies the changes.
1772        codegen.update(cx, |codegen, cx| codegen.set_active(true, cx));
1773        assert_eq!(
1774            buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx).text()),
1775            indoc! {"
1776                fn main() {
1777                    let mut x = 0;
1778                    x += 1;
1779                }
1780            "}
1781        );
1782
1783        // Deactivating the codegen undoes the changes.
1784        codegen.update(cx, |codegen, cx| codegen.set_active(false, cx));
1785        cx.run_until_parked();
1786        assert_eq!(
1787            buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx).text()),
1788            text
1789        );
1790    }
1791
1792    #[gpui::test]
1793    async fn test_strip_invalid_spans_from_codeblock() {
1794        assert_chunks("Lorem ipsum dolor", "Lorem ipsum dolor").await;
1795        assert_chunks("```\nLorem ipsum dolor", "Lorem ipsum dolor").await;
1796        assert_chunks("```\nLorem ipsum dolor\n```", "Lorem ipsum dolor").await;
1797        assert_chunks(
1798            "```html\n```js\nLorem ipsum dolor\n```\n```",
1799            "```js\nLorem ipsum dolor\n```",
1800        )
1801        .await;
1802        assert_chunks("``\nLorem ipsum dolor\n```", "``\nLorem ipsum dolor\n```").await;
1803        assert_chunks("Lorem<|CURSOR|> ipsum", "Lorem ipsum").await;
1804        assert_chunks("Lorem ipsum", "Lorem ipsum").await;
1805        assert_chunks("```\n<|CURSOR|>Lorem ipsum\n```", "Lorem ipsum").await;
1806
1807        async fn assert_chunks(text: &str, expected_text: &str) {
1808            for chunk_size in 1..=text.len() {
1809                let actual_text = StripInvalidSpans::new(chunks(text, chunk_size))
1810                    .map(|chunk| chunk.unwrap())
1811                    .collect::<String>()
1812                    .await;
1813                assert_eq!(
1814                    actual_text, expected_text,
1815                    "failed to strip invalid spans, chunk size: {}",
1816                    chunk_size
1817                );
1818            }
1819        }
1820
1821        fn chunks(text: &str, size: usize) -> impl Stream<Item = Result<String>> {
1822            stream::iter(
1823                text.chars()
1824                    .collect::<Vec<_>>()
1825                    .chunks(size)
1826                    .map(|chunk| Ok(chunk.iter().collect::<String>()))
1827                    .collect::<Vec<_>>(),
1828            )
1829        }
1830    }
1831
1832    fn init_test(cx: &mut TestAppContext) {
1833        cx.update(LanguageModelRegistry::test);
1834        cx.set_global(cx.update(SettingsStore::test));
1835    }
1836
1837    fn simulate_response_stream(
1838        codegen: &Entity<CodegenAlternative>,
1839        cx: &mut TestAppContext,
1840    ) -> mpsc::UnboundedSender<String> {
1841        let (chunks_tx, chunks_rx) = mpsc::unbounded();
1842        let model = Arc::new(FakeLanguageModel::default());
1843        codegen.update(cx, |codegen, cx| {
1844            codegen.generation = codegen.handle_stream(
1845                model,
1846                future::ready(Ok(LanguageModelTextStream {
1847                    message_id: None,
1848                    stream: chunks_rx.map(Ok).boxed(),
1849                    last_token_usage: Arc::new(Mutex::new(TokenUsage::default())),
1850                })),
1851                cx,
1852            );
1853        });
1854        chunks_tx
1855    }
1856}