//! Internal HTTP API for worker-to-orchestrator communication.
//!
//! This runs on a separate port (default 50051) from the web gateway.
//! All endpoints are authenticated via per-job bearer tokens.

use std::collections::{HashMap, VecDeque};
use std::sync::Arc;

use axum::extract::{Path, State};
use axum::http::StatusCode;
use axum::routing::{get, post};
use axum::{Json, Router};
use serde::{Deserialize, Serialize};
use tokio::sync::{Mutex, broadcast};
use uuid::Uuid;

use crate::channels::web::types::SseEvent;
use crate::db::Database;
use crate::llm::{CompletionRequest, LlmProvider, ToolCompletionRequest};
use crate::orchestrator::auth::{TokenStore, worker_auth_middleware};
use crate::orchestrator::job_manager::ContainerJobManager;
use crate::worker::api::JobEventPayload;
use crate::worker::api::{
    CompletionReport, JobDescription, ProxyCompletionRequest, ProxyCompletionResponse,
    ProxyToolCompletionRequest, ProxyToolCompletionResponse, StatusUpdate,
};

/// A follow-up prompt queued for a Claude Code bridge.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PendingPrompt {
    pub content: String,
    pub done: bool,
}

/// Shared state for the orchestrator API.
#[derive(Clone)]
pub struct OrchestratorState {
    pub llm: Arc<dyn LlmProvider>,
    pub job_manager: Arc<ContainerJobManager>,
    pub token_store: TokenStore,
    /// Broadcast channel for job events (consumed by the web gateway SSE).
    pub job_event_tx: Option<broadcast::Sender<(Uuid, SseEvent)>>,
    /// Buffered follow-up prompts for sandbox jobs, keyed by job_id.
    pub prompt_queue: Arc<Mutex<HashMap<Uuid, VecDeque<PendingPrompt>>>>,
    /// Database handle for persisting job events.
    pub store: Option<Arc<dyn Database>>,
}

/// The orchestrator's internal API server.
pub struct OrchestratorApi;

impl OrchestratorApi {
    /// Build the axum router for the internal API.
    pub fn router(state: OrchestratorState) -> Router {
        Router::new()
            // Worker routes: authenticated via route_layer middleware.
            .route("/worker/{job_id}/job", get(get_job))
            .route("/worker/{job_id}/llm/complete", post(llm_complete))
            .route(
                "/worker/{job_id}/llm/complete_with_tools",
                post(llm_complete_with_tools),
            )
            .route("/worker/{job_id}/status", post(report_status))
            .route("/worker/{job_id}/complete", post(report_complete))
            .route("/worker/{job_id}/event", post(job_event_handler))
            .route("/worker/{job_id}/prompt", get(get_prompt_handler))
            .route_layer(axum::middleware::from_fn_with_state(
                state.token_store.clone(),
                worker_auth_middleware,
            ))
            // Unauthenticated routes (added after the layer).
            .route("/health", get(health_check))
            .with_state(state)
    }

    /// Start the internal API server on the given port.
    ///
    /// On macOS/Windows (Docker Desktop), binds to loopback only because
    /// Docker Desktop routes `host.docker.internal` through its VM to the
    /// host's `127.0.0.1`.
    ///
    /// On Linux, containers reach the host via the docker bridge gateway
    /// (`172.17.0.1`), which is NOT loopback. Binding to `127.0.0.1`
    /// would reject container traffic. We bind to all interfaces instead
    /// and rely on `worker_auth_middleware` (applied as a route_layer on
    /// every `/worker/` endpoint) to reject unauthenticated requests.
    pub async fn start(
        state: OrchestratorState,
        port: u16,
    ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
        let router = Self::router(state);
        let addr = if cfg!(target_os = "linux") {
            std::net::SocketAddr::from(([0, 0, 0, 0], port))
        } else {
            std::net::SocketAddr::from(([127, 0, 0, 1], port))
        };

        tracing::info!("Orchestrator internal API listening on {}", addr);

        let listener = tokio::net::TcpListener::bind(addr).await?;
        axum::serve(listener, router).await?;

        Ok(())
    }
}

// -- Handlers --
//
// All /worker/ handlers below are behind the worker_auth_middleware route_layer,
// so they don't need to validate tokens themselves.

async fn health_check() -> &'static str {
    "ok"
}

async fn get_job(
    State(state): State<OrchestratorState>,
    Path(job_id): Path<Uuid>,
) -> Result<Json<JobDescription>, StatusCode> {
    let handle = state
        .job_manager
        .get_handle(job_id)
        .await
        .ok_or(StatusCode::NOT_FOUND)?;

    Ok(Json(JobDescription {
        title: format!("Job {}", job_id),
        description: handle.task_description,
        project_dir: handle.project_dir.map(|p| p.display().to_string()),
    }))
}

async fn llm_complete(
    State(state): State<OrchestratorState>,
    Path(job_id): Path<Uuid>,
    Json(req): Json<ProxyCompletionRequest>,
) -> Result<Json<ProxyCompletionResponse>, StatusCode> {
    let completion_req = CompletionRequest {
        messages: req.messages,
        max_tokens: req.max_tokens,
        temperature: req.temperature,
        stop_sequences: req.stop_sequences,
        metadata: std::collections::HashMap::new(),
    };

    let resp = state.llm.complete(completion_req).await.map_err(|e| {
        tracing::error!("LLM completion failed for job {}: {}", job_id, e);
        StatusCode::BAD_GATEWAY
    })?;

    Ok(Json(ProxyCompletionResponse {
        content: resp.content,
        input_tokens: resp.input_tokens,
        output_tokens: resp.output_tokens,
        finish_reason: format_finish_reason(resp.finish_reason),
    }))
}

async fn llm_complete_with_tools(
    State(state): State<OrchestratorState>,
    Path(job_id): Path<Uuid>,
    Json(req): Json<ProxyToolCompletionRequest>,
) -> Result<Json<ProxyToolCompletionResponse>, StatusCode> {
    let tool_req = ToolCompletionRequest {
        messages: req.messages,
        tools: req.tools,
        max_tokens: req.max_tokens,
        temperature: req.temperature,
        tool_choice: req.tool_choice,
        metadata: std::collections::HashMap::new(),
    };

    let resp = state.llm.complete_with_tools(tool_req).await.map_err(|e| {
        tracing::error!("LLM tool completion failed for job {}: {}", job_id, e);
        StatusCode::BAD_GATEWAY
    })?;

    Ok(Json(ProxyToolCompletionResponse {
        content: resp.content,
        tool_calls: resp.tool_calls,
        input_tokens: resp.input_tokens,
        output_tokens: resp.output_tokens,
        finish_reason: format_finish_reason(resp.finish_reason),
    }))
}

async fn report_status(
    Path(job_id): Path<Uuid>,
    Json(update): Json<StatusUpdate>,
) -> Result<StatusCode, StatusCode> {
    tracing::debug!(
        job_id = %job_id,
        state = %update.state,
        iteration = update.iteration,
        "Worker status update"
    );

    Ok(StatusCode::OK)
}

async fn report_complete(
    State(state): State<OrchestratorState>,
    Path(job_id): Path<Uuid>,
    Json(report): Json<CompletionReport>,
) -> Result<Json<serde_json::Value>, StatusCode> {
    if report.success {
        tracing::info!(
            job_id = %job_id,
            "Worker reported job complete"
        );
    } else {
        tracing::warn!(
            job_id = %job_id,
            message = ?report.message,
            "Worker reported job failure"
        );
    }

    // Store the result and clean up the container
    let result = crate::orchestrator::job_manager::CompletionResult {
        success: report.success,
        message: report.message.clone(),
    };
    let _ = state.job_manager.complete_job(job_id, result).await;

    Ok(Json(serde_json::json!({"status": "ok"})))
}

// -- Sandbox job event handlers --

/// Receive a job event from a worker or Claude Code bridge and broadcast + persist it.
async fn job_event_handler(
    State(state): State<OrchestratorState>,
    Path(job_id): Path<Uuid>,
    Json(payload): Json<JobEventPayload>,
) -> Result<StatusCode, StatusCode> {
    tracing::debug!(
        job_id = %job_id,
        event_type = %payload.event_type,
        "Job event received"
    );

    // Persist to DB (fire-and-forget)
    if let Some(ref store) = state.store {
        let store = Arc::clone(store);
        let event_type = payload.event_type.clone();
        let data = payload.data.clone();
        tokio::spawn(async move {
            if let Err(e) = store.save_job_event(job_id, &event_type, &data).await {
                tracing::warn!(job_id = %job_id, "Failed to persist job event: {}", e);
            }
        });
    }

    // Convert to SSE event and broadcast
    let job_id_str = job_id.to_string();
    let sse_event = match payload.event_type.as_str() {
        "message" => SseEvent::JobMessage {
            job_id: job_id_str,
            role: payload
                .data
                .get("role")
                .and_then(|v| v.as_str())
                .unwrap_or("assistant")
                .to_string(),
            content: payload
                .data
                .get("content")
                .and_then(|v| v.as_str())
                .unwrap_or("")
                .to_string(),
        },
        "tool_use" => SseEvent::JobToolUse {
            job_id: job_id_str,
            tool_name: payload
                .data
                .get("tool_name")
                .and_then(|v| v.as_str())
                .unwrap_or("unknown")
                .to_string(),
            input: payload
                .data
                .get("input")
                .cloned()
                .unwrap_or(serde_json::Value::Null),
        },
        "tool_result" => SseEvent::JobToolResult {
            job_id: job_id_str,
            tool_name: payload
                .data
                .get("tool_name")
                .and_then(|v| v.as_str())
                .unwrap_or("unknown")
                .to_string(),
            output: payload
                .data
                .get("output")
                .and_then(|v| v.as_str())
                .unwrap_or("")
                .to_string(),
        },
        "result" => SseEvent::JobResult {
            job_id: job_id_str,
            status: payload
                .data
                .get("status")
                .and_then(|v| v.as_str())
                .unwrap_or("unknown")
                .to_string(),
            session_id: payload
                .data
                .get("session_id")
                .and_then(|v| v.as_str())
                .map(|s| s.to_string()),
        },
        _ => SseEvent::JobStatus {
            job_id: job_id_str,
            message: payload
                .data
                .get("message")
                .and_then(|v| v.as_str())
                .unwrap_or("")
                .to_string(),
        },
    };

    // Broadcast via the channel (if configured)
    if let Some(ref tx) = state.job_event_tx {
        let _ = tx.send((job_id, sse_event));
    }

    Ok(StatusCode::OK)
}

/// Return the next queued follow-up prompt for a Claude Code bridge.
/// Returns 204 No Content if no prompt is available.
async fn get_prompt_handler(
    State(state): State<OrchestratorState>,
    Path(job_id): Path<Uuid>,
) -> Result<(StatusCode, Json<serde_json::Value>), StatusCode> {
    let mut queue = state.prompt_queue.lock().await;
    if let Some(prompts) = queue.get_mut(&job_id)
        && let Some(prompt) = prompts.pop_front()
    {
        return Ok((
            StatusCode::OK,
            Json(serde_json::json!({
                "content": prompt.content,
                "done": prompt.done,
            })),
        ));
    }

    // Return 204 with an empty body. The Json wrapper requires some value
    // but the status code signals "nothing here".
    Ok((StatusCode::NO_CONTENT, Json(serde_json::Value::Null)))
}

fn format_finish_reason(reason: crate::llm::FinishReason) -> String {
    match reason {
        crate::llm::FinishReason::Stop => "stop".to_string(),
        crate::llm::FinishReason::Length => "length".to_string(),
        crate::llm::FinishReason::ToolUse => "tool_use".to_string(),
        crate::llm::FinishReason::ContentFilter => "content_filter".to_string(),
        crate::llm::FinishReason::Unknown => "unknown".to_string(),
    }
}

#[cfg(test)]
mod tests {
    use std::collections::HashMap;

    use axum::body::Body;
    use axum::http::Request;
    use tower::ServiceExt;
    use uuid::Uuid;

    use crate::error::LlmError;
    use crate::llm::{
        CompletionRequest, CompletionResponse, ToolCompletionRequest, ToolCompletionResponse,
    };
    use crate::orchestrator::auth::TokenStore;
    use crate::orchestrator::job_manager::{ContainerJobConfig, ContainerJobManager};

    use super::*;

    /// Stub LLM provider that panics if called (tests only exercise routing/auth).
    struct StubLlm;

    #[async_trait::async_trait]
    impl crate::llm::LlmProvider for StubLlm {
        fn model_name(&self) -> &str {
            "stub"
        }
        fn cost_per_token(&self) -> (rust_decimal::Decimal, rust_decimal::Decimal) {
            (rust_decimal::Decimal::ZERO, rust_decimal::Decimal::ZERO)
        }
        async fn complete(&self, _req: CompletionRequest) -> Result<CompletionResponse, LlmError> {
            Err(LlmError::RequestFailed {
                provider: "stub".into(),
                reason: "not implemented".into(),
            })
        }
        async fn complete_with_tools(
            &self,
            _req: ToolCompletionRequest,
        ) -> Result<ToolCompletionResponse, LlmError> {
            Err(LlmError::RequestFailed {
                provider: "stub".into(),
                reason: "not implemented".into(),
            })
        }
    }

    fn test_state() -> OrchestratorState {
        let token_store = TokenStore::new();
        let jm = ContainerJobManager::new(ContainerJobConfig::default(), token_store.clone());
        OrchestratorState {
            llm: Arc::new(StubLlm),
            job_manager: Arc::new(jm),
            token_store,
            job_event_tx: None,
            prompt_queue: Arc::new(Mutex::new(HashMap::new())),
            store: None,
        }
    }

    #[tokio::test]
    async fn health_requires_no_auth() {
        let state = test_state();
        let router = OrchestratorApi::router(state);

        let req = Request::builder()
            .uri("/health")
            .body(Body::empty())
            .unwrap();

        let resp = router.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
    }

    #[tokio::test]
    async fn worker_route_rejects_missing_token() {
        let state = test_state();
        let router = OrchestratorApi::router(state);

        let job_id = Uuid::new_v4();
        let req = Request::builder()
            .uri(format!("/worker/{}/job", job_id))
            .body(Body::empty())
            .unwrap();

        let resp = router.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
    }

    #[tokio::test]
    async fn worker_route_rejects_wrong_token() {
        let state = test_state();
        let router = OrchestratorApi::router(state);

        let job_id = Uuid::new_v4();
        let req = Request::builder()
            .uri(format!("/worker/{}/job", job_id))
            .header("Authorization", "Bearer totally-bogus")
            .body(Body::empty())
            .unwrap();

        let resp = router.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
    }

    #[tokio::test]
    async fn worker_route_accepts_valid_token() {
        let state = test_state();
        let job_id = Uuid::new_v4();
        let token = state.token_store.create_token(job_id).await;

        let router = OrchestratorApi::router(state);

        let req = Request::builder()
            .uri(format!("/worker/{}/job", job_id))
            .header("Authorization", format!("Bearer {}", token))
            .body(Body::empty())
            .unwrap();

        let resp = router.oneshot(req).await.unwrap();
        // 404 because no container exists for this job_id, but NOT 401.
        assert_eq!(resp.status(), StatusCode::NOT_FOUND);
    }

    #[tokio::test]
    async fn token_for_job_a_rejected_on_job_b() {
        let state = test_state();
        let job_a = Uuid::new_v4();
        let job_b = Uuid::new_v4();
        let token_a = state.token_store.create_token(job_a).await;

        let router = OrchestratorApi::router(state);

        // Use job_a's token to hit job_b's endpoint
        let req = Request::builder()
            .uri(format!("/worker/{}/job", job_b))
            .header("Authorization", format!("Bearer {}", token_a))
            .body(Body::empty())
            .unwrap();

        let resp = router.oneshot(req).await.unwrap();
        assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
    }
}