use crate::config::ProjectConfig;
use crate::http::context::AppContext;
use crate::http::workflow::{create_story_file, load_upcoming_stories, validate_story_dirs};
use crate::io::story_metadata::{parse_front_matter, parse_unchecked_todos};
use crate::workflow::{evaluate_acceptance_with_coverage, TestCaseResult, TestStatus};
use poem::handler;
use poem::http::StatusCode;
use poem::web::Data;
use poem::{Body, Request, Response};
use serde::{Deserialize, Serialize};
use serde_json::{json, Value};
use std::fs;
use std::sync::Arc;

/// Returns true when the Accept header includes text/event-stream.
fn wants_sse(req: &Request) -> bool {
    req.header("accept")
        .unwrap_or("")
        .contains("text/event-stream")
}

// ── JSON-RPC structs ──────────────────────────────────────────────

#[derive(Deserialize)]
struct JsonRpcRequest {
    jsonrpc: String,
    id: Option<Value>,
    method: String,
    #[serde(default)]
    params: Value,
}

#[derive(Serialize)]
struct JsonRpcResponse {
    jsonrpc: &'static str,
    #[serde(skip_serializing_if = "Option::is_none")]
    id: Option<Value>,
    #[serde(skip_serializing_if = "Option::is_none")]
    result: Option<Value>,
    #[serde(skip_serializing_if = "Option::is_none")]
    error: Option<JsonRpcError>,
}

#[derive(Serialize)]
struct JsonRpcError {
    code: i64,
    message: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    data: Option<Value>,
}

impl JsonRpcResponse {
    fn success(id: Option<Value>, result: Value) -> Self {
        Self {
            jsonrpc: "2.0",
            id,
            result: Some(result),
            error: None,
        }
    }

    fn error(id: Option<Value>, code: i64, message: String) -> Self {
        Self {
            jsonrpc: "2.0",
            id,
            result: None,
            error: Some(JsonRpcError {
                code,
                message,
                data: None,
            }),
        }
    }
}

// ── Poem handlers ─────────────────────────────────────────────────

#[handler]
pub async fn mcp_get_handler() -> Response {
    Response::builder()
        .status(StatusCode::METHOD_NOT_ALLOWED)
        .body(Body::empty())
}

#[handler]
pub async fn mcp_post_handler(req: &Request, body: Body, ctx: Data<&Arc<AppContext>>) -> Response {
    // Validate Content-Type
    let content_type = req.header("content-type").unwrap_or("");
    if !content_type.is_empty() && !content_type.contains("application/json") {
        return json_rpc_error_response(
            None,
            -32700,
            "Unsupported Content-Type; expected application/json".into(),
        );
    }

    let bytes = match body.into_bytes().await {
        Ok(b) => b,
        Err(_) => return json_rpc_error_response(None, -32700, "Parse error".into()),
    };

    let rpc: JsonRpcRequest = match serde_json::from_slice(&bytes) {
        Ok(r) => r,
        Err(_) => return json_rpc_error_response(None, -32700, "Parse error".into()),
    };

    if rpc.jsonrpc != "2.0" {
        return json_rpc_error_response(rpc.id, -32600, "Invalid JSON-RPC version".into());
    }

    // Notifications (no id) — accept silently
    if rpc.id.is_none() || rpc.id.as_ref() == Some(&Value::Null) {
        if rpc.method.starts_with("notifications/") {
            return Response::builder()
                .status(StatusCode::ACCEPTED)
                .body(Body::empty());
        }
        return json_rpc_error_response(None, -32600, "Missing id".into());
    }

    let sse = wants_sse(req);

    // Streaming agent output over SSE
    if sse && rpc.method == "tools/call" {
        let tool_name = rpc
            .params
            .get("name")
            .and_then(|v| v.as_str())
            .unwrap_or("");
        if tool_name == "get_agent_output" {
            return handle_agent_output_sse(rpc.id, &rpc.params, &ctx);
        }
    }

    let resp = match rpc.method.as_str() {
        "initialize" => handle_initialize(rpc.id, &rpc.params),
        "tools/list" => handle_tools_list(rpc.id),
        "tools/call" => handle_tools_call(rpc.id, &rpc.params, &ctx).await,
        _ => JsonRpcResponse::error(rpc.id, -32601, format!("Unknown method: {}", rpc.method)),
    };

    if sse {
        to_sse_response(resp)
    } else {
        to_json_response(resp)
    }
}

fn json_rpc_error_response(id: Option<Value>, code: i64, message: String) -> Response {
    to_json_response(JsonRpcResponse::error(id, code, message))
}

fn to_json_response(resp: JsonRpcResponse) -> Response {
    let body = serde_json::to_vec(&resp).unwrap_or_default();
    Response::builder()
        .status(StatusCode::OK)
        .header("Content-Type", "application/json")
        .body(Body::from(body))
}

fn to_sse_response(resp: JsonRpcResponse) -> Response {
    let json = serde_json::to_string(&resp).unwrap_or_default();
    let sse_body = format!("data: {json}\n\n");
    Response::builder()
        .status(StatusCode::OK)
        .header("Content-Type", "text/event-stream")
        .header("Cache-Control", "no-cache")
        .body(Body::from_string(sse_body))
}

/// Stream agent events as SSE — each event is a separate JSON-RPC notification,
/// followed by a final JSON-RPC response with the matching request id.
fn handle_agent_output_sse(
    id: Option<Value>,
    params: &Value,
    ctx: &AppContext,
) -> Response {
    let args = params.get("arguments").cloned().unwrap_or(json!({}));
    let story_id = match args.get("story_id").and_then(|v| v.as_str()) {
        Some(s) => s.to_string(),
        None => return to_sse_response(JsonRpcResponse::error(
            id,
            -32602,
            "Missing required argument: story_id".into(),
        )),
    };
    let agent_name = match args.get("agent_name").and_then(|v| v.as_str()) {
        Some(s) => s.to_string(),
        None => return to_sse_response(JsonRpcResponse::error(
            id,
            -32602,
            "Missing required argument: agent_name".into(),
        )),
    };
    let timeout_ms = args
        .get("timeout_ms")
        .and_then(|v| v.as_u64())
        .unwrap_or(10000)
        .min(30000);

    let mut rx = match ctx.agents.subscribe(&story_id, &agent_name) {
        Ok(rx) => rx,
        Err(e) => return to_sse_response(JsonRpcResponse::success(
            id,
            json!({ "content": [{"type": "text", "text": e}], "isError": true }),
        )),
    };

    let final_id = id;
    let stream = async_stream::stream! {
        let deadline = tokio::time::Instant::now()
            + std::time::Duration::from_millis(timeout_ms);
        let mut done = false;

        loop {
            let remaining = deadline.saturating_duration_since(tokio::time::Instant::now());
            if remaining.is_zero() {
                break;
            }

            match tokio::time::timeout(remaining, rx.recv()).await {
                Ok(Ok(event)) => {
                    let is_terminal = matches!(
                        &event,
                        crate::agents::AgentEvent::Done { .. }
                        | crate::agents::AgentEvent::Error { .. }
                    );
                    // Send each event as a JSON-RPC notification (no id)
                    if let Ok(event_json) = serde_json::to_value(&event) {
                        let notification = json!({
                            "jsonrpc": "2.0",
                            "method": "notifications/tools/progress",
                            "params": { "event": event_json }
                        });
                        if let Ok(s) = serde_json::to_string(&notification) {
                            yield Ok::<_, std::io::Error>(format!("data: {s}\n\n"));
                        }
                    }
                    if is_terminal {
                        done = true;
                        break;
                    }
                }
                Ok(Err(tokio::sync::broadcast::error::RecvError::Lagged(n))) => {
                    let notification = json!({
                        "jsonrpc": "2.0",
                        "method": "notifications/tools/progress",
                        "params": { "event": {"type": "warning", "message": format!("Skipped {n} events")} }
                    });
                    if let Ok(s) = serde_json::to_string(&notification) {
                        yield Ok::<_, std::io::Error>(format!("data: {s}\n\n"));
                    }
                }
                Ok(Err(tokio::sync::broadcast::error::RecvError::Closed)) => {
                    done = true;
                    break;
                }
                Err(_) => break, // timeout
            }
        }

        // Final response with the request id
        let final_resp = JsonRpcResponse::success(
            final_id,
            json!({
                "content": [{
                    "type": "text",
                    "text": if done { "Agent stream ended." } else { "Stream timed out; call again to continue." }
                }]
            }),
        );
        if let Ok(s) = serde_json::to_string(&final_resp) {
            yield Ok::<_, std::io::Error>(format!("data: {s}\n\n"));
        }
    };

    Response::builder()
        .status(StatusCode::OK)
        .header("Content-Type", "text/event-stream")
        .header("Cache-Control", "no-cache")
        .body(Body::from_bytes_stream(
            futures::StreamExt::map(stream, |r| r.map(bytes::Bytes::from)),
        ))
}

// ── MCP protocol handlers ─────────────────────────────────────────

fn handle_initialize(id: Option<Value>, params: &Value) -> JsonRpcResponse {
    let _protocol_version = params
        .get("protocolVersion")
        .and_then(|v| v.as_str())
        .unwrap_or("2025-03-26");

    JsonRpcResponse::success(
        id,
        json!({
            "protocolVersion": "2025-03-26",
            "capabilities": {
                "tools": {}
            },
            "serverInfo": {
                "name": "story-kit",
                "version": "1.0.0"
            }
        }),
    )
}

fn handle_tools_list(id: Option<Value>) -> JsonRpcResponse {
    JsonRpcResponse::success(
        id,
        json!({
            "tools": [
                {
                    "name": "create_story",
                    "description": "Create a new story file with front matter in upcoming/. Returns the story_id.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {
                            "name": {
                                "type": "string",
                                "description": "Human-readable story name"
                            },
                            "user_story": {
                                "type": "string",
                                "description": "Optional user story text (As a..., I want..., so that...)"
                            },
                            "acceptance_criteria": {
                                "type": "array",
                                "items": { "type": "string" },
                                "description": "Optional list of acceptance criteria"
                            }
                        },
                        "required": ["name"]
                    }
                },
                {
                    "name": "validate_stories",
                    "description": "Validate front matter on all current and upcoming story files.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {}
                    }
                },
                {
                    "name": "list_upcoming",
                    "description": "List all upcoming stories with their names and any parsing errors.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {}
                    }
                },
                {
                    "name": "get_story_todos",
                    "description": "Get unchecked acceptance criteria (todos) for a story file in current/.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {
                            "story_id": {
                                "type": "string",
                                "description": "Story identifier (filename stem, e.g. '28_my_story')"
                            }
                        },
                        "required": ["story_id"]
                    }
                },
                {
                    "name": "record_tests",
                    "description": "Record test results for a story. Only one failing test at a time is allowed.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {
                            "story_id": {
                                "type": "string",
                                "description": "Story identifier"
                            },
                            "unit": {
                                "type": "array",
                                "items": {
                                    "type": "object",
                                    "properties": {
                                        "name": { "type": "string" },
                                        "status": { "type": "string", "enum": ["pass", "fail"] },
                                        "details": { "type": "string" }
                                    },
                                    "required": ["name", "status"]
                                },
                                "description": "Unit test results"
                            },
                            "integration": {
                                "type": "array",
                                "items": {
                                    "type": "object",
                                    "properties": {
                                        "name": { "type": "string" },
                                        "status": { "type": "string", "enum": ["pass", "fail"] },
                                        "details": { "type": "string" }
                                    },
                                    "required": ["name", "status"]
                                },
                                "description": "Integration test results"
                            }
                        },
                        "required": ["story_id", "unit", "integration"]
                    }
                },
                {
                    "name": "ensure_acceptance",
                    "description": "Check whether a story can be accepted. Returns acceptance status with reasons if blocked.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {
                            "story_id": {
                                "type": "string",
                                "description": "Story identifier"
                            }
                        },
                        "required": ["story_id"]
                    }
                },
                {
                    "name": "start_agent",
                    "description": "Start an agent for a story. Creates a worktree, runs setup, and spawns the agent process.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {
                            "story_id": {
                                "type": "string",
                                "description": "Story identifier (e.g. '28_my_story')"
                            },
                            "agent_name": {
                                "type": "string",
                                "description": "Agent name from project.toml config. If omitted, uses the first configured agent."
                            }
                        },
                        "required": ["story_id"]
                    }
                },
                {
                    "name": "stop_agent",
                    "description": "Stop a running agent. Worktree is preserved for inspection.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {
                            "story_id": {
                                "type": "string",
                                "description": "Story identifier"
                            },
                            "agent_name": {
                                "type": "string",
                                "description": "Agent name to stop"
                            }
                        },
                        "required": ["story_id", "agent_name"]
                    }
                },
                {
                    "name": "list_agents",
                    "description": "List all agents with their current status, story assignment, and worktree path.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {}
                    }
                },
                {
                    "name": "get_agent_config",
                    "description": "Get the configured agent roster from project.toml (names, roles, models, allowed tools, limits).",
                    "inputSchema": {
                        "type": "object",
                        "properties": {}
                    }
                },
                {
                    "name": "reload_agent_config",
                    "description": "Reload project.toml and return the updated agent roster.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {}
                    }
                },
                {
                    "name": "get_agent_output",
                    "description": "Poll recent output from a running agent. Subscribes to the agent's event stream and collects events for up to 2 seconds. Returns text output and status events. Call repeatedly to follow progress.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {
                            "story_id": {
                                "type": "string",
                                "description": "Story identifier"
                            },
                            "agent_name": {
                                "type": "string",
                                "description": "Agent name"
                            },
                            "timeout_ms": {
                                "type": "integer",
                                "description": "How long to wait for events in milliseconds (default: 2000, max: 10000)"
                            }
                        },
                        "required": ["story_id", "agent_name"]
                    }
                },
                {
                    "name": "wait_for_agent",
                    "description": "Block until the agent reaches a terminal state (completed, failed, stopped). Returns final status and summary including session_id, worktree_path, and any commits made. Use this instead of polling get_agent_output when you want to fire-and-forget and be notified on completion.",
                    "inputSchema": {
                        "type": "object",
                        "properties": {
                            "story_id": {
                                "type": "string",
                                "description": "Story identifier"
                            },
                            "agent_name": {
                                "type": "string",
                                "description": "Agent name to wait for"
                            },
                            "timeout_ms": {
                                "type": "integer",
                                "description": "Maximum time to wait in milliseconds (default: 300000 = 5 minutes)"
                            }
                        },
                        "required": ["story_id", "agent_name"]
                    }
                }
            ]
        }),
    )
}

// ── Tool dispatch ─────────────────────────────────────────────────

async fn handle_tools_call(
    id: Option<Value>,
    params: &Value,
    ctx: &AppContext,
) -> JsonRpcResponse {
    let tool_name = params
        .get("name")
        .and_then(|v| v.as_str())
        .unwrap_or("");
    let args = params.get("arguments").cloned().unwrap_or(json!({}));

    let result = match tool_name {
        // Workflow tools
        "create_story" => tool_create_story(&args, ctx),
        "validate_stories" => tool_validate_stories(ctx),
        "list_upcoming" => tool_list_upcoming(ctx),
        "get_story_todos" => tool_get_story_todos(&args, ctx),
        "record_tests" => tool_record_tests(&args, ctx),
        "ensure_acceptance" => tool_ensure_acceptance(&args, ctx),
        // Agent tools (async)
        "start_agent" => tool_start_agent(&args, ctx).await,
        "stop_agent" => tool_stop_agent(&args, ctx).await,
        "list_agents" => tool_list_agents(ctx),
        "get_agent_config" => tool_get_agent_config(ctx),
        "reload_agent_config" => tool_get_agent_config(ctx),
        "get_agent_output" => tool_get_agent_output_poll(&args, ctx).await,
        "wait_for_agent" => tool_wait_for_agent(&args, ctx).await,
        _ => Err(format!("Unknown tool: {tool_name}")),
    };

    match result {
        Ok(content) => JsonRpcResponse::success(
            id,
            json!({
                "content": [{ "type": "text", "text": content }]
            }),
        ),
        Err(msg) => JsonRpcResponse::success(
            id,
            json!({
                "content": [{ "type": "text", "text": msg }],
                "isError": true
            }),
        ),
    }
}

// ── Tool implementations ──────────────────────────────────────────

fn tool_create_story(args: &Value, ctx: &AppContext) -> Result<String, String> {
    let name = args
        .get("name")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: name")?;
    let user_story = args.get("user_story").and_then(|v| v.as_str());
    let acceptance_criteria: Option<Vec<String>> = args
        .get("acceptance_criteria")
        .and_then(|v| serde_json::from_value(v.clone()).ok());

    let root = ctx.state.get_project_root()?;
    let story_id = create_story_file(
        &root,
        name,
        user_story,
        acceptance_criteria.as_deref(),
    )?;

    Ok(format!("Created story: {story_id}"))
}

fn tool_validate_stories(ctx: &AppContext) -> Result<String, String> {
    let root = ctx.state.get_project_root()?;
    let results = validate_story_dirs(&root)?;
    serde_json::to_string_pretty(&json!(results
        .iter()
        .map(|r| json!({
            "story_id": r.story_id,
            "valid": r.valid,
            "error": r.error,
        }))
        .collect::<Vec<_>>()))
    .map_err(|e| format!("Serialization error: {e}"))
}

fn tool_list_upcoming(ctx: &AppContext) -> Result<String, String> {
    let stories = load_upcoming_stories(ctx)?;
    serde_json::to_string_pretty(&json!(stories
        .iter()
        .map(|s| json!({
            "story_id": s.story_id,
            "name": s.name,
            "error": s.error,
        }))
        .collect::<Vec<_>>()))
    .map_err(|e| format!("Serialization error: {e}"))
}

fn tool_get_story_todos(args: &Value, ctx: &AppContext) -> Result<String, String> {
    let story_id = args
        .get("story_id")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: story_id")?;

    let root = ctx.state.get_project_root()?;
    let current_dir = root.join(".story_kit").join("stories").join("current");
    let filepath = current_dir.join(format!("{story_id}.md"));

    if !filepath.exists() {
        return Err(format!("Story file not found: {story_id}.md"));
    }

    let contents = fs::read_to_string(&filepath)
        .map_err(|e| format!("Failed to read story file: {e}"))?;

    let story_name = parse_front_matter(&contents)
        .ok()
        .and_then(|m| m.name);
    let todos = parse_unchecked_todos(&contents);

    serde_json::to_string_pretty(&json!({
        "story_id": story_id,
        "story_name": story_name,
        "todos": todos,
    }))
    .map_err(|e| format!("Serialization error: {e}"))
}

fn tool_record_tests(args: &Value, ctx: &AppContext) -> Result<String, String> {
    let story_id = args
        .get("story_id")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: story_id")?;

    let unit = parse_test_cases(args.get("unit"))?;
    let integration = parse_test_cases(args.get("integration"))?;

    let mut workflow = ctx
        .workflow
        .lock()
        .map_err(|e| format!("Lock error: {e}"))?;

    workflow.record_test_results_validated(story_id.to_string(), unit, integration)?;

    Ok("Test results recorded.".to_string())
}

fn tool_ensure_acceptance(args: &Value, ctx: &AppContext) -> Result<String, String> {
    let story_id = args
        .get("story_id")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: story_id")?;

    let workflow = ctx
        .workflow
        .lock()
        .map_err(|e| format!("Lock error: {e}"))?;

    let empty_results = Default::default();
    let results = workflow.results.get(story_id).unwrap_or(&empty_results);
    let coverage = workflow.coverage.get(story_id);
    let decision = evaluate_acceptance_with_coverage(results, coverage);

    if decision.can_accept {
        Ok("Story can be accepted. All gates pass.".to_string())
    } else {
        let mut parts = decision.reasons;
        if let Some(w) = decision.warning {
            parts.push(w);
        }
        Err(format!("Acceptance blocked: {}", parts.join("; ")))
    }
}

// ── Agent tool implementations ────────────────────────────────────

async fn tool_start_agent(args: &Value, ctx: &AppContext) -> Result<String, String> {
    let story_id = args
        .get("story_id")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: story_id")?;
    let agent_name = args.get("agent_name").and_then(|v| v.as_str());

    let project_root = ctx.agents.get_project_root(&ctx.state)?;
    let info = ctx
        .agents
        .start_agent(&project_root, story_id, agent_name)
        .await?;

    serde_json::to_string_pretty(&json!({
        "story_id": info.story_id,
        "agent_name": info.agent_name,
        "status": info.status.to_string(),
        "session_id": info.session_id,
        "worktree_path": info.worktree_path,
    }))
    .map_err(|e| format!("Serialization error: {e}"))
}

async fn tool_stop_agent(args: &Value, ctx: &AppContext) -> Result<String, String> {
    let story_id = args
        .get("story_id")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: story_id")?;
    let agent_name = args
        .get("agent_name")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: agent_name")?;

    let project_root = ctx.agents.get_project_root(&ctx.state)?;
    ctx.agents
        .stop_agent(&project_root, story_id, agent_name)
        .await?;

    Ok(format!("Agent '{agent_name}' for story '{story_id}' stopped."))
}

fn tool_list_agents(ctx: &AppContext) -> Result<String, String> {
    let agents = ctx.agents.list_agents()?;
    serde_json::to_string_pretty(&json!(agents
        .iter()
        .map(|a| json!({
            "story_id": a.story_id,
            "agent_name": a.agent_name,
            "status": a.status.to_string(),
            "session_id": a.session_id,
            "worktree_path": a.worktree_path,
        }))
        .collect::<Vec<_>>()))
    .map_err(|e| format!("Serialization error: {e}"))
}

async fn tool_get_agent_output_poll(args: &Value, ctx: &AppContext) -> Result<String, String> {
    let story_id = args
        .get("story_id")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: story_id")?;
    let agent_name = args
        .get("agent_name")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: agent_name")?;

    // Drain all accumulated events since the last poll.
    let drained = ctx.agents.drain_events(story_id, agent_name)?;

    let done = drained.iter().any(|e| {
        matches!(
            e,
            crate::agents::AgentEvent::Done { .. } | crate::agents::AgentEvent::Error { .. }
        )
    });

    let events: Vec<serde_json::Value> = drained
        .into_iter()
        .filter_map(|e| serde_json::to_value(&e).ok())
        .collect();

    serde_json::to_string_pretty(&json!({
        "events": events,
        "done": done,
        "event_count": events.len(),
        "message": if done { "Agent stream ended." } else if events.is_empty() { "No new events. Call again to continue." } else { "Events returned. Call again to continue." }
    }))
    .map_err(|e| format!("Serialization error: {e}"))
}

fn tool_get_agent_config(ctx: &AppContext) -> Result<String, String> {
    let project_root = ctx.agents.get_project_root(&ctx.state)?;
    let config = ProjectConfig::load(&project_root)?;
    serde_json::to_string_pretty(&json!(config
        .agent
        .iter()
        .map(|a| json!({
            "name": a.name,
            "role": a.role,
            "model": a.model,
            "allowed_tools": a.allowed_tools,
            "max_turns": a.max_turns,
            "max_budget_usd": a.max_budget_usd,
        }))
        .collect::<Vec<_>>()))
    .map_err(|e| format!("Serialization error: {e}"))
}

async fn tool_wait_for_agent(args: &Value, ctx: &AppContext) -> Result<String, String> {
    let story_id = args
        .get("story_id")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: story_id")?;
    let agent_name = args
        .get("agent_name")
        .and_then(|v| v.as_str())
        .ok_or("Missing required argument: agent_name")?;
    let timeout_ms = args
        .get("timeout_ms")
        .and_then(|v| v.as_u64())
        .unwrap_or(300_000); // default: 5 minutes

    let info = ctx
        .agents
        .wait_for_agent(story_id, agent_name, timeout_ms)
        .await?;

    let commits = match (&info.worktree_path, &info.base_branch) {
        (Some(wt_path), Some(base)) => get_worktree_commits(wt_path, base).await,
        _ => None,
    };

    serde_json::to_string_pretty(&json!({
        "story_id": info.story_id,
        "agent_name": info.agent_name,
        "status": info.status.to_string(),
        "session_id": info.session_id,
        "worktree_path": info.worktree_path,
        "base_branch": info.base_branch,
        "commits": commits,
    }))
    .map_err(|e| format!("Serialization error: {e}"))
}

/// Run `git log <base>..HEAD --oneline` in the worktree and return the commit
/// summaries, or `None` if git is unavailable or there are no new commits.
async fn get_worktree_commits(worktree_path: &str, base_branch: &str) -> Option<Vec<String>> {
    let wt = worktree_path.to_string();
    let base = base_branch.to_string();
    tokio::task::spawn_blocking(move || {
        let output = std::process::Command::new("git")
            .args(["log", &format!("{base}..HEAD"), "--oneline"])
            .current_dir(&wt)
            .output()
            .ok()?;

        if output.status.success() {
            let lines: Vec<String> = String::from_utf8(output.stdout)
                .ok()?
                .lines()
                .filter(|l| !l.is_empty())
                .map(|l| l.to_string())
                .collect();
            Some(lines)
        } else {
            None
        }
    })
    .await
    .ok()
    .flatten()
}

// ── Helpers ───────────────────────────────────────────────────────

fn parse_test_cases(value: Option<&Value>) -> Result<Vec<TestCaseResult>, String> {
    let arr = match value {
        Some(Value::Array(a)) => a,
        Some(Value::Null) | None => return Ok(Vec::new()),
        _ => return Err("Expected array for test cases".to_string()),
    };

    arr.iter()
        .map(|item| {
            let name = item
                .get("name")
                .and_then(|v| v.as_str())
                .ok_or("Test case missing 'name'")?
                .to_string();
            let status_str = item
                .get("status")
                .and_then(|v| v.as_str())
                .ok_or("Test case missing 'status'")?;
            let status = match status_str {
                "pass" => TestStatus::Pass,
                "fail" => TestStatus::Fail,
                other => return Err(format!("Invalid test status '{other}'. Use 'pass' or 'fail'.")),
            };
            let details = item.get("details").and_then(|v| v.as_str()).map(String::from);
            Ok(TestCaseResult {
                name,
                status,
                details,
            })
        })
        .collect()
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::http::context::AppContext;

    // ── Unit tests ────────────────────────────────────────────────

    #[test]
    fn parse_test_cases_empty() {
        let result = parse_test_cases(None).unwrap();
        assert!(result.is_empty());
    }

    #[test]
    fn parse_test_cases_valid() {
        let input = json!([
            {"name": "test1", "status": "pass"},
            {"name": "test2", "status": "fail", "details": "assertion failed"}
        ]);
        let result = parse_test_cases(Some(&input)).unwrap();
        assert_eq!(result.len(), 2);
        assert_eq!(result[0].status, TestStatus::Pass);
        assert_eq!(result[1].status, TestStatus::Fail);
        assert_eq!(result[1].details, Some("assertion failed".to_string()));
    }

    #[test]
    fn parse_test_cases_invalid_status() {
        let input = json!([{"name": "t", "status": "maybe"}]);
        assert!(parse_test_cases(Some(&input)).is_err());
    }

    #[test]
    fn json_rpc_response_serializes_success() {
        let resp = JsonRpcResponse::success(Some(json!(1)), json!({"ok": true}));
        let s = serde_json::to_string(&resp).unwrap();
        assert!(s.contains("\"result\""));
        assert!(!s.contains("\"error\""));
    }

    #[test]
    fn json_rpc_response_serializes_error() {
        let resp = JsonRpcResponse::error(Some(json!(1)), -32600, "bad".into());
        let s = serde_json::to_string(&resp).unwrap();
        assert!(s.contains("\"error\""));
        assert!(!s.contains("\"result\""));
    }

    // ── Protocol handler integration tests ────────────────────────

    #[test]
    fn initialize_returns_capabilities() {
        let resp = handle_initialize(
            Some(json!(1)),
            &json!({"protocolVersion": "2025-03-26", "capabilities": {}, "clientInfo": {"name": "test", "version": "1.0"}}),
        );
        let result = resp.result.unwrap();
        assert_eq!(result["protocolVersion"], "2025-03-26");
        assert!(result["capabilities"]["tools"].is_object());
        assert_eq!(result["serverInfo"]["name"], "story-kit");
    }

    #[test]
    fn tools_list_returns_all_tools() {
        let resp = handle_tools_list(Some(json!(2)));
        let result = resp.result.unwrap();
        let tools = result["tools"].as_array().unwrap();
        let names: Vec<&str> = tools.iter().map(|t| t["name"].as_str().unwrap()).collect();
        assert!(names.contains(&"create_story"));
        assert!(names.contains(&"validate_stories"));
        assert!(names.contains(&"list_upcoming"));
        assert!(names.contains(&"get_story_todos"));
        assert!(names.contains(&"record_tests"));
        assert!(names.contains(&"ensure_acceptance"));
        assert!(names.contains(&"start_agent"));
        assert!(names.contains(&"stop_agent"));
        assert!(names.contains(&"list_agents"));
        assert!(names.contains(&"get_agent_config"));
        assert!(names.contains(&"reload_agent_config"));
        assert!(names.contains(&"get_agent_output"));
        assert!(names.contains(&"wait_for_agent"));
        assert_eq!(tools.len(), 13);
    }

    #[test]
    fn tools_list_schemas_have_required_fields() {
        let resp = handle_tools_list(Some(json!(1)));
        let tools = resp.result.unwrap()["tools"].as_array().unwrap().clone();
        for tool in &tools {
            assert!(tool["name"].is_string(), "tool missing name");
            assert!(tool["description"].is_string(), "tool missing description");
            assert!(tool["inputSchema"].is_object(), "tool missing inputSchema");
            assert_eq!(tool["inputSchema"]["type"], "object");
        }
    }

    fn test_ctx(dir: &std::path::Path) -> AppContext {
        AppContext::new_test(dir.to_path_buf())
    }

    #[test]
    fn tool_validate_stories_empty_project() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let result = tool_validate_stories(&ctx).unwrap();
        let parsed: Vec<Value> = serde_json::from_str(&result).unwrap();
        assert!(parsed.is_empty());
    }

    #[test]
    fn tool_create_story_and_list_upcoming() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());

        // Create a story
        let result = tool_create_story(
            &json!({"name": "Test Story", "acceptance_criteria": ["AC1", "AC2"]}),
            &ctx,
        )
        .unwrap();
        assert!(result.contains("Created story:"));

        // List should return it
        let list = tool_list_upcoming(&ctx).unwrap();
        let parsed: Vec<Value> = serde_json::from_str(&list).unwrap();
        assert_eq!(parsed.len(), 1);
        assert_eq!(parsed[0]["name"], "Test Story");
    }

    #[test]
    fn tool_create_story_rejects_empty_name() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let result = tool_create_story(&json!({"name": "!!!"}), &ctx);
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("alphanumeric"));
    }

    #[test]
    fn tool_create_story_missing_name() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let result = tool_create_story(&json!({}), &ctx);
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("Missing required argument"));
    }

    #[test]
    fn tool_get_story_todos_missing_file() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let result = tool_get_story_todos(&json!({"story_id": "99_nonexistent"}), &ctx);
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("not found"));
    }

    #[test]
    fn tool_get_story_todos_returns_unchecked() {
        let tmp = tempfile::tempdir().unwrap();
        let current_dir = tmp.path().join(".story_kit").join("stories").join("current");
        fs::create_dir_all(&current_dir).unwrap();
        fs::write(
            current_dir.join("1_test.md"),
            "---\nname: Test\ntest_plan: approved\n---\n## AC\n- [ ] First\n- [x] Done\n- [ ] Second\n",
        )
        .unwrap();

        let ctx = test_ctx(tmp.path());
        let result = tool_get_story_todos(&json!({"story_id": "1_test"}), &ctx).unwrap();
        let parsed: Value = serde_json::from_str(&result).unwrap();
        assert_eq!(parsed["todos"].as_array().unwrap().len(), 2);
        assert_eq!(parsed["story_name"], "Test");
    }

    #[test]
    fn tool_record_tests_and_ensure_acceptance() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());

        // Record passing tests
        let result = tool_record_tests(
            &json!({
                "story_id": "1_test",
                "unit": [{"name": "u1", "status": "pass"}],
                "integration": [{"name": "i1", "status": "pass"}]
            }),
            &ctx,
        )
        .unwrap();
        assert!(result.contains("recorded"));

        // Should be acceptable
        let result = tool_ensure_acceptance(&json!({"story_id": "1_test"}), &ctx).unwrap();
        assert!(result.contains("All gates pass"));
    }

    #[test]
    fn tool_ensure_acceptance_blocks_on_failures() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());

        tool_record_tests(
            &json!({
                "story_id": "1_test",
                "unit": [{"name": "u1", "status": "fail"}],
                "integration": []
            }),
            &ctx,
        )
        .unwrap();

        let result = tool_ensure_acceptance(&json!({"story_id": "1_test"}), &ctx);
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("blocked"));
    }

    #[test]
    fn tool_list_agents_empty() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let result = tool_list_agents(&ctx).unwrap();
        let parsed: Vec<Value> = serde_json::from_str(&result).unwrap();
        assert!(parsed.is_empty());
    }

    #[test]
    fn handle_tools_call_unknown_tool() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let rt = tokio::runtime::Runtime::new().unwrap();
        let resp = rt.block_on(handle_tools_call(
            Some(json!(1)),
            &json!({"name": "bogus_tool", "arguments": {}}),
            &ctx,
        ));
        let result = resp.result.unwrap();
        assert_eq!(result["isError"], true);
        assert!(result["content"][0]["text"].as_str().unwrap().contains("Unknown tool"));
    }

    #[test]
    fn to_sse_response_wraps_in_data_prefix() {
        let resp = JsonRpcResponse::success(Some(json!(1)), json!({"ok": true}));
        let http_resp = to_sse_response(resp);
        assert_eq!(
            http_resp.headers().get("content-type").unwrap(),
            "text/event-stream"
        );
    }

    #[test]
    fn wants_sse_detects_accept_header() {
        // Can't easily construct a Request in tests without TestClient,
        // so test the logic indirectly via to_sse_response format
        let resp = JsonRpcResponse::success(Some(json!(1)), json!("ok"));
        let json_resp = to_json_response(resp);
        assert_eq!(
            json_resp.headers().get("content-type").unwrap(),
            "application/json"
        );
    }

    #[test]
    fn wait_for_agent_tool_in_list() {
        let resp = handle_tools_list(Some(json!(1)));
        let tools = resp.result.unwrap()["tools"].as_array().unwrap().clone();
        let wait_tool = tools.iter().find(|t| t["name"] == "wait_for_agent");
        assert!(wait_tool.is_some(), "wait_for_agent missing from tools list");
        let t = wait_tool.unwrap();
        assert!(t["description"].as_str().unwrap().contains("block") || t["description"].as_str().unwrap().contains("Block"));
        let required = t["inputSchema"]["required"].as_array().unwrap();
        let req_names: Vec<&str> = required.iter().map(|v| v.as_str().unwrap()).collect();
        assert!(req_names.contains(&"story_id"));
        assert!(req_names.contains(&"agent_name"));
    }

    #[tokio::test]
    async fn wait_for_agent_tool_missing_story_id() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let result = tool_wait_for_agent(&json!({"agent_name": "bot"}), &ctx).await;
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("story_id"));
    }

    #[tokio::test]
    async fn wait_for_agent_tool_missing_agent_name() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let result = tool_wait_for_agent(&json!({"story_id": "1_test"}), &ctx).await;
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("agent_name"));
    }

    #[tokio::test]
    async fn wait_for_agent_tool_nonexistent_agent_returns_error() {
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        let result =
            tool_wait_for_agent(&json!({"story_id": "99_nope", "agent_name": "bot", "timeout_ms": 50}), &ctx)
                .await;
        // No agent registered — should error
        assert!(result.is_err());
    }

    #[tokio::test]
    async fn wait_for_agent_tool_returns_completed_agent() {
        use crate::agents::AgentStatus;
        let tmp = tempfile::tempdir().unwrap();
        let ctx = test_ctx(tmp.path());
        ctx.agents
            .inject_test_agent("41_story", "worker", AgentStatus::Completed);

        let result = tool_wait_for_agent(
            &json!({"story_id": "41_story", "agent_name": "worker"}),
            &ctx,
        )
        .await
        .unwrap();
        let parsed: Value = serde_json::from_str(&result).unwrap();
        assert_eq!(parsed["status"], "completed");
        assert_eq!(parsed["story_id"], "41_story");
        assert_eq!(parsed["agent_name"], "worker");
        // commits key present (may be null since no real worktree)
        assert!(parsed.get("commits").is_some());
    }
}