context_server_command.rs

  1use anyhow::{Context as _, Result, anyhow};
  2use assistant_slash_command::{
  3    AfterCompletion, ArgumentCompletion, SlashCommand, SlashCommandOutput,
  4    SlashCommandOutputSection, SlashCommandResult,
  5};
  6use collections::HashMap;
  7use context_server::{ContextServerId, types::Prompt};
  8use gpui::{App, Entity, Task, WeakEntity, Window};
  9use language::{BufferSnapshot, CodeLabel, LspAdapterDelegate};
 10use project::context_server_store::ContextServerStore;
 11use std::sync::Arc;
 12use std::sync::atomic::AtomicBool;
 13use text::LineEnding;
 14use ui::{IconName, SharedString};
 15use workspace::Workspace;
 16
 17use crate::create_label_for_command;
 18
 19pub struct ContextServerSlashCommand {
 20    store: Entity<ContextServerStore>,
 21    server_id: ContextServerId,
 22    prompt: Prompt,
 23}
 24
 25impl ContextServerSlashCommand {
 26    pub fn new(store: Entity<ContextServerStore>, id: ContextServerId, prompt: Prompt) -> Self {
 27        Self {
 28            server_id: id,
 29            prompt,
 30            store,
 31        }
 32    }
 33}
 34
 35impl SlashCommand for ContextServerSlashCommand {
 36    fn name(&self) -> String {
 37        self.prompt.name.clone()
 38    }
 39
 40    fn label(&self, cx: &App) -> language::CodeLabel {
 41        let mut parts = vec![self.prompt.name.as_str()];
 42        if let Some(args) = &self.prompt.arguments {
 43            if let Some(arg) = args.first() {
 44                parts.push(arg.name.as_str());
 45            }
 46        }
 47        create_label_for_command(parts[0], &parts[1..], cx)
 48    }
 49
 50    fn description(&self) -> String {
 51        match &self.prompt.description {
 52            Some(desc) => desc.clone(),
 53            None => format!("Run '{}' from {}", self.prompt.name, self.server_id),
 54        }
 55    }
 56
 57    fn menu_text(&self) -> String {
 58        match &self.prompt.description {
 59            Some(desc) => desc.clone(),
 60            None => format!("Run '{}' from {}", self.prompt.name, self.server_id),
 61        }
 62    }
 63
 64    fn requires_argument(&self) -> bool {
 65        self.prompt.arguments.as_ref().map_or(false, |args| {
 66            args.iter().any(|arg| arg.required == Some(true))
 67        })
 68    }
 69
 70    fn complete_argument(
 71        self: Arc<Self>,
 72        arguments: &[String],
 73        _cancel: Arc<AtomicBool>,
 74        _workspace: Option<WeakEntity<Workspace>>,
 75        _window: &mut Window,
 76        cx: &mut App,
 77    ) -> Task<Result<Vec<ArgumentCompletion>>> {
 78        let Ok((arg_name, arg_value)) = completion_argument(&self.prompt, arguments) else {
 79            return Task::ready(Err(anyhow!("Failed to complete argument")));
 80        };
 81
 82        let server_id = self.server_id.clone();
 83        let prompt_name = self.prompt.name.clone();
 84
 85        if let Some(server) = self.store.read(cx).get_running_server(&server_id) {
 86            cx.foreground_executor().spawn(async move {
 87                let protocol = server.client().context("Context server not initialized")?;
 88
 89                let response = protocol
 90                    .request::<context_server::types::requests::CompletionComplete>(
 91                        context_server::types::CompletionCompleteParams {
 92                            reference: context_server::types::CompletionReference::Prompt(
 93                                context_server::types::PromptReference {
 94                                    ty: context_server::types::PromptReferenceType::Prompt,
 95                                    name: prompt_name,
 96                                },
 97                            ),
 98                            argument: context_server::types::CompletionArgument {
 99                                name: arg_name,
100                                value: arg_value,
101                            },
102                            meta: None,
103                        },
104                    )
105                    .await?;
106
107                let completions = response
108                    .completion
109                    .values
110                    .into_iter()
111                    .map(|value| ArgumentCompletion {
112                        label: CodeLabel::plain(value.clone(), None),
113                        new_text: value,
114                        after_completion: AfterCompletion::Continue,
115                        replace_previous_arguments: false,
116                    })
117                    .collect();
118                Ok(completions)
119            })
120        } else {
121            Task::ready(Err(anyhow!("Context server not found")))
122        }
123    }
124
125    fn run(
126        self: Arc<Self>,
127        arguments: &[String],
128        _context_slash_command_output_sections: &[SlashCommandOutputSection<language::Anchor>],
129        _context_buffer: BufferSnapshot,
130        _workspace: WeakEntity<Workspace>,
131        _delegate: Option<Arc<dyn LspAdapterDelegate>>,
132        _window: &mut Window,
133        cx: &mut App,
134    ) -> Task<SlashCommandResult> {
135        let server_id = self.server_id.clone();
136        let prompt_name = self.prompt.name.clone();
137
138        let prompt_args = match prompt_arguments(&self.prompt, arguments) {
139            Ok(args) => args,
140            Err(e) => return Task::ready(Err(e)),
141        };
142
143        let store = self.store.read(cx);
144        if let Some(server) = store.get_running_server(&server_id) {
145            cx.foreground_executor().spawn(async move {
146                let protocol = server.client().context("Context server not initialized")?;
147                let response = protocol
148                    .request::<context_server::types::requests::PromptsGet>(
149                        context_server::types::PromptsGetParams {
150                            name: prompt_name.clone(),
151                            arguments: Some(prompt_args),
152                            meta: None,
153                        },
154                    )
155                    .await?;
156
157                anyhow::ensure!(
158                    response
159                        .messages
160                        .iter()
161                        .all(|msg| matches!(msg.role, context_server::types::Role::User)),
162                    "Prompt contains non-user roles, which is not supported"
163                );
164
165                // Extract text from user messages into a single prompt string
166                let mut prompt = response
167                    .messages
168                    .into_iter()
169                    .filter_map(|msg| match msg.content {
170                        context_server::types::MessageContent::Text { text, .. } => Some(text),
171                        _ => None,
172                    })
173                    .collect::<Vec<String>>()
174                    .join("\n\n");
175
176                // We must normalize the line endings here, since servers might return CR characters.
177                LineEnding::normalize(&mut prompt);
178
179                Ok(SlashCommandOutput {
180                    sections: vec![SlashCommandOutputSection {
181                        range: 0..(prompt.len()),
182                        icon: IconName::ZedAssistant,
183                        label: SharedString::from(
184                            response
185                                .description
186                                .unwrap_or(format!("Result from {}", prompt_name)),
187                        ),
188                        metadata: None,
189                    }],
190                    text: prompt,
191                    run_commands_in_text: false,
192                }
193                .to_event_stream())
194            })
195        } else {
196            Task::ready(Err(anyhow!("Context server not found")))
197        }
198    }
199}
200
201fn completion_argument(prompt: &Prompt, arguments: &[String]) -> Result<(String, String)> {
202    anyhow::ensure!(!arguments.is_empty(), "No arguments given");
203
204    match &prompt.arguments {
205        Some(args) if args.len() == 1 => {
206            let arg_name = args[0].name.clone();
207            let arg_value = arguments.join(" ");
208            Ok((arg_name, arg_value))
209        }
210        Some(_) => anyhow::bail!("Prompt must have exactly one argument"),
211        None => anyhow::bail!("Prompt has no arguments"),
212    }
213}
214
215fn prompt_arguments(prompt: &Prompt, arguments: &[String]) -> Result<HashMap<String, String>> {
216    match &prompt.arguments {
217        Some(args) if args.len() > 1 => {
218            anyhow::bail!("Prompt has more than one argument, which is not supported");
219        }
220        Some(args) if args.len() == 1 => {
221            if !arguments.is_empty() {
222                let mut map = HashMap::default();
223                map.insert(args[0].name.clone(), arguments.join(" "));
224                Ok(map)
225            } else if arguments.is_empty() && args[0].required == Some(false) {
226                Ok(HashMap::default())
227            } else {
228                anyhow::bail!("Prompt expects argument but none given");
229            }
230        }
231        Some(_) | None => {
232            anyhow::ensure!(
233                arguments.is_empty(),
234                "Prompt expects no arguments but some were given"
235            );
236            Ok(HashMap::default())
237        }
238    }
239}
240
241/// MCP servers can return prompts with multiple arguments. Since we only
242/// support one argument, we ignore all others. This is the necessary predicate
243/// for this.
244pub fn acceptable_prompt(prompt: &Prompt) -> bool {
245    match &prompt.arguments {
246        None => true,
247        Some(args) if args.len() <= 1 => true,
248        _ => false,
249    }
250}