//! Endpoints API REST pour Radio France
//!
//! Ce module définit les handlers HTTP pour accéder aux stations Radio France,
//! leurs métadonnées live et les flux de streaming.

use crate::models::LiveResponse;
use crate::playlist::StationGroups;
use crate::pmoserver_ext::RadioFranceState;
use axum::{
    body::Body,
    extract::{Path, State},
    http::{HeaderMap, StatusCode},
    response::{IntoResponse, Response},
    routing::get,
    Json, Router,
};
use futures::StreamExt;
use serde_json;
use std::sync::Arc;

// ============ Gestion des erreurs ============

struct AppError(String);

impl IntoResponse for AppError {
    fn into_response(self) -> Response {
        let (status, message) = match self.0.as_str() {
            "not_found" => (StatusCode::NOT_FOUND, self.0),
            "internal_error" => (StatusCode::INTERNAL_SERVER_ERROR, self.0),
            "bad_gateway" => (StatusCode::BAD_GATEWAY, self.0),
            _ => (StatusCode::INTERNAL_SERVER_ERROR, self.0),
        };

        let body = Json(serde_json::json!({
            "error": message
        }));

        (status, body).into_response()
    }
}

impl From<String> for AppError {
    fn from(err: String) -> Self {
        Self(err)
    }
}

/// Crée le router pour l'API Radio France
pub fn create_router(state: RadioFranceState) -> Router {
    Router::new()
        .route("/stations", get(get_stations))
        .route("/{slug}/metadata", get(get_metadata))
        .route("/{slug}/stream", get(proxy_stream))
        .route("/default-logo", get(get_default_logo))
        .with_state(state)
}

// ============================================================================
// Route Handlers
// ============================================================================

/// GET /api/radiofrance/stations
/// Returns the grouped list of stations
#[axum::debug_handler]
async fn get_stations(
    State(state): State<RadioFranceState>,
) -> Result<Json<StationGroups>, AppError> {
    let stations = state
        .client
        .get_stations()
        .await
        .map_err(|e| AppError(e.to_string()))?;

    let groups = StationGroups::from_stations(stations);
    Ok(Json(groups))
}

/// GET /api/radiofrance/{slug}/metadata
/// Returns live metadata for a station (with caching)
async fn get_metadata(
    State(state): State<RadioFranceState>,
    Path(slug): Path<String>,
) -> Result<Json<LiveResponse>, AppError> {
    let metadata = state
        .client
        .get_live_metadata(&slug)
        .await
        .map_err(|e| AppError(e.to_string()))?;

    Ok(Json(metadata))
}

/// GET /api/radiofrance/{slug}/stream
/// Proxies the AAC stream from Radio France (passthrough, no transcoding)
async fn proxy_stream(
    State(state): State<RadioFranceState>,
    Path(slug): Path<String>,
) -> Result<Response, AppError> {
    // Start metadata refresh when stream is accessed
    #[cfg(feature = "logging")]
    tracing::info!("Stream proxy accessed for station: {}", slug);

    if let Some(ref source) = state.source {
        // Spawn refresh task (non-blocking)
        let source_clone = Arc::clone(source);
        let slug_clone = slug.clone();
        tokio::spawn(async move {
            if let Err(e) = source_clone.start_metadata_refresh(&slug_clone).await {
                #[cfg(feature = "logging")]
                tracing::error!("Failed to start metadata refresh for {}: {}", slug_clone, e);
            }
        });
    } else {
        #[cfg(feature = "logging")]
        tracing::warn!("No source available to start metadata refresh");
    }

    // Get the stream URL
    let stream_url = state
        .client
        .get_stream_url(&slug)
        .await
        .map_err(|e| AppError(format!("Stream not found: {}", e)))?;

    // Connect to the Radio France stream
    let response = reqwest::get(&stream_url)
        .await
        .map_err(|e| AppError(format!("Failed to connect: {}", e)))?;

    if !response.status().is_success() {
        return Err(AppError(format!("Upstream returned {}", response.status())));
    }

    // Build response headers
    let mut headers = HeaderMap::new();
    headers.insert("content-type", "audio/aac".parse().unwrap());
    headers.insert("cache-control", "no-cache".parse().unwrap());

    // Create streaming body with cleanup on disconnect
    let stream = response
        .bytes_stream()
        .map(|chunk| chunk.map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e)));

    // Wrap the stream to detect when client disconnects
    let source_for_cleanup = state.source.clone();
    let slug_for_cleanup = slug.clone();
    let monitored_stream =
        futures::stream::unfold((stream, false), move |(mut stream, mut done)| {
            let source = source_for_cleanup.clone();
            let slug = slug_for_cleanup.clone();
            async move {
                if done {
                    return None;
                }

                match stream.next().await {
                    Some(Ok(chunk)) => Some((Ok(chunk), (stream, false))),
                    Some(Err(e)) => {
                        // Error occurred, stop refresh
                        #[cfg(feature = "logging")]
                        tracing::info!("Stream error for {}, stopping refresh", slug);
                        if let Some(src) = source {
                            src.stop_metadata_refresh(&slug).await;
                        }
                        Some((Err(e), (stream, true)))
                    }
                    None => {
                        // Stream ended normally, stop refresh
                        #[cfg(feature = "logging")]
                        tracing::info!("Stream ended for {}, stopping refresh", slug);
                        if let Some(src) = source {
                            src.stop_metadata_refresh(&slug).await;
                        }
                        None
                    }
                }
            }
        });

    let body = Body::from_stream(monitored_stream);

    Ok((headers, body).into_response())
}

/// GET /api/radiofrance/default-logo
/// Returns the default Radio France logo (embedded in binary)
async fn get_default_logo() -> impl IntoResponse {
    use crate::source::RADIOFRANCE_DEFAULT_IMAGE;

    let mut headers = HeaderMap::new();
    headers.insert("Content-Type", "image/webp".parse().unwrap());
    headers.insert("Cache-Control", "public, max-age=86400".parse().unwrap());

    (headers, RADIOFRANCE_DEFAULT_IMAGE).into_response()
}