use std::sync::Arc;

use crate::{AgentTool, ToolCallEventStream};
use agent_client_protocol as acp;
use anyhow::{Result, anyhow};
use cloud_llm_client::WebSearchResponse;
use gpui::{App, AppContext, Task};
use language_model::{
    LanguageModelProviderId, LanguageModelToolResultContent, ZED_CLOUD_PROVIDER_ID,
};
use schemars::JsonSchema;
use serde::{Deserialize, Serialize};
use ui::prelude::*;
use web_search::WebSearchRegistry;

/// Search the web for information using your query.
/// Use this when you need real-time information, facts, or data that might not be in your training.
/// Results will include snippets and links from relevant web pages.
#[derive(Debug, Serialize, Deserialize, JsonSchema)]
pub struct WebSearchToolInput {
    /// The search term or question to query on the web.
    query: String,
}

#[derive(Debug, Serialize, Deserialize)]
#[serde(transparent)]
pub struct WebSearchToolOutput(WebSearchResponse);

impl From<WebSearchToolOutput> for LanguageModelToolResultContent {
    fn from(value: WebSearchToolOutput) -> Self {
        serde_json::to_string(&value.0)
            .expect("Failed to serialize WebSearchResponse")
            .into()
    }
}

pub struct WebSearchTool;

impl AgentTool for WebSearchTool {
    type Input = WebSearchToolInput;
    type Output = WebSearchToolOutput;

    fn name() -> &'static str {
        "web_search"
    }

    fn kind() -> acp::ToolKind {
        acp::ToolKind::Fetch
    }

    fn initial_title(&self, _input: Result<Self::Input, serde_json::Value>) -> SharedString {
        "Searching the Web".into()
    }

    /// We currently only support Zed Cloud as a provider.
    fn supported_provider(&self, provider: &LanguageModelProviderId) -> bool {
        provider == &ZED_CLOUD_PROVIDER_ID
    }

    fn run(
        self: Arc<Self>,
        input: Self::Input,
        event_stream: ToolCallEventStream,
        cx: &mut App,
    ) -> Task<Result<Self::Output>> {
        let Some(provider) = WebSearchRegistry::read_global(cx).active_provider() else {
            return Task::ready(Err(anyhow!("Web search is not available.")));
        };

        let search_task = provider.search(input.query, cx);
        cx.background_spawn(async move {
            let response = match search_task.await {
                Ok(response) => response,
                Err(err) => {
                    event_stream.update_fields(acp::ToolCallUpdateFields {
                        title: Some("Web Search Failed".to_string()),
                        ..Default::default()
                    });
                    return Err(err);
                }
            };

            emit_update(&response, &event_stream);
            Ok(WebSearchToolOutput(response))
        })
    }

    fn replay(
        &self,
        _input: Self::Input,
        output: Self::Output,
        event_stream: ToolCallEventStream,
        _cx: &mut App,
    ) -> Result<()> {
        emit_update(&output.0, &event_stream);
        Ok(())
    }
}

fn emit_update(response: &WebSearchResponse, event_stream: &ToolCallEventStream) {
    let result_text = if response.results.len() == 1 {
        "1 result".to_string()
    } else {
        format!("{} results", response.results.len())
    };
    event_stream.update_fields(acp::ToolCallUpdateFields {
        title: Some(format!("Searched the web: {result_text}")),
        content: Some(
            response
                .results
                .iter()
                .map(|result| acp::ToolCallContent::Content {
                    content: acp::ContentBlock::ResourceLink(acp::ResourceLink {
                        name: result.title.clone(),
                        uri: result.url.clone(),
                        title: Some(result.title.clone()),
                        description: Some(result.text.clone()),
                        mime_type: None,
                        annotations: None,
                        size: None,
                    }),
                })
                .collect(),
        ),
        ..Default::default()
    });
}