//! Library routes — DB-backed.
//!
//! GET  /library/collections     — collections derived from synced items
//! GET  /library/series          — series names
//! GET  /library/genres          — genres
//! GET  /library/items           — search / browse
//! GET  /library/items/:id       — single item
//! GET  /library/sync/status     — latest sync log per provider
//! POST /library/sync            — trigger an ad-hoc sync (auth)
//!
//! Admin (nested under /admin/library):
//! GET  /admin/library/settings  — app_settings key/value
//! PUT  /admin/library/settings  — update app_settings

use std::collections::HashMap;
use std::sync::Arc;

use axum::{
    Json, Router,
    extract::{Path, Query, RawQuery, State},
    http::StatusCode,
    response::IntoResponse,
    routing::{get, post, put},
};
use domain::{ContentType, ILibraryRepository, LibrarySearchFilter, LibrarySyncAdapter, SeasonSummary, ShowSummary};
use serde::{Deserialize, Serialize};

use crate::{error::ApiError, extractors::{AdminUser, CurrentUser}, state::AppState};

// ============================================================================
// Routers
// ============================================================================

pub fn router() -> Router<AppState> {
    Router::new()
        .route("/collections", get(list_collections))
        .route("/series", get(list_series))
        .route("/genres", get(list_genres))
        .route("/items", get(search_items))
        .route("/items/:id", get(get_item))
        .route("/shows", get(list_shows))
        .route("/shows/:name/seasons", get(list_seasons))
        .route("/sync/status", get(sync_status))
        .route("/sync", post(trigger_sync))
}

pub fn admin_router() -> Router<AppState> {
    Router::new()
        .route("/settings", get(get_settings).put(update_settings))
}

// ============================================================================
// Response DTOs
// ============================================================================

#[derive(Debug, Serialize)]
struct CollectionResponse {
    id: String,
    name: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    collection_type: Option<String>,
}

#[derive(Debug, Serialize)]
struct LibraryItemResponse {
    id: String,
    title: String,
    content_type: String,
    duration_secs: u32,
    #[serde(skip_serializing_if = "Option::is_none")]
    series_name: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    season_number: Option<u32>,
    #[serde(skip_serializing_if = "Option::is_none")]
    episode_number: Option<u32>,
    #[serde(skip_serializing_if = "Option::is_none")]
    year: Option<u16>,
    genres: Vec<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    thumbnail_url: Option<String>,
}

#[derive(Debug, Serialize)]
struct PagedResponse<T: Serialize> {
    items: Vec<T>,
    total: u32,
}

#[derive(Debug, Serialize)]
struct ShowSummaryResponse {
    series_name: String,
    episode_count: u32,
    season_count: u32,
    #[serde(skip_serializing_if = "Option::is_none")]
    thumbnail_url: Option<String>,
    genres: Vec<String>,
}

#[derive(Debug, Serialize)]
struct SeasonSummaryResponse {
    season_number: u32,
    episode_count: u32,
    #[serde(skip_serializing_if = "Option::is_none")]
    thumbnail_url: Option<String>,
}

#[derive(Debug, Serialize)]
struct SyncLogResponse {
    id: i64,
    provider_id: String,
    started_at: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    finished_at: Option<String>,
    items_found: u32,
    status: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    error_msg: Option<String>,
}

// ============================================================================
// Query params
// ============================================================================

#[derive(Debug, Deserialize)]
struct CollectionsQuery {
    provider: Option<String>,
}

#[derive(Debug, Deserialize)]
struct SeriesQuery {
    provider: Option<String>,
}

#[derive(Debug, Deserialize)]
struct GenresQuery {
    #[serde(rename = "type")]
    content_type: Option<String>,
    provider: Option<String>,
}

#[derive(Debug, Default, Deserialize)]
struct ItemsQuery {
    q: Option<String>,
    #[serde(rename = "type")]
    content_type: Option<String>,
    #[serde(default)]
    series: Vec<String>,
    #[serde(default)]
    genres: Vec<String>,
    collection: Option<String>,
    limit: Option<u32>,
    offset: Option<u32>,
    provider: Option<String>,
    season: Option<u32>,
}

#[derive(Debug, Default, Deserialize)]
struct ShowsQuery {
    q: Option<String>,
    provider: Option<String>,
    #[serde(default)]
    genres: Vec<String>,
}

#[derive(Debug, Deserialize)]
struct SeasonsQuery {
    provider: Option<String>,
}

// ============================================================================
// Handlers
// ============================================================================

async fn list_collections(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
    Query(params): Query<CollectionsQuery>,
) -> Result<Json<Vec<CollectionResponse>>, ApiError> {
    let cols = state
        .library_repo
        .list_collections(params.provider.as_deref())
        .await?;
    let resp = cols
        .into_iter()
        .map(|c| CollectionResponse {
            id: c.id,
            name: c.name,
            collection_type: c.collection_type,
        })
        .collect();
    Ok(Json(resp))
}

async fn list_series(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
    Query(params): Query<SeriesQuery>,
) -> Result<Json<Vec<String>>, ApiError> {
    let series = state
        .library_repo
        .list_series(params.provider.as_deref())
        .await?;
    Ok(Json(series))
}

async fn list_genres(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
    Query(params): Query<GenresQuery>,
) -> Result<Json<Vec<String>>, ApiError> {
    let ct = parse_content_type(params.content_type.as_deref())?;
    let genres = state
        .library_repo
        .list_genres(ct.as_ref(), params.provider.as_deref())
        .await?;
    Ok(Json(genres))
}

async fn search_items(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
    RawQuery(raw_query): RawQuery,
) -> Result<Json<PagedResponse<LibraryItemResponse>>, ApiError> {
    let qs_config = serde_qs::Config::new(2, false);
    let params: ItemsQuery = raw_query
        .as_deref()
        .map(|q| qs_config.deserialize_str::<ItemsQuery>(q))
        .transpose()
        .map_err(|e| ApiError::validation(e.to_string()))?
        .unwrap_or_default();

    let limit = params.limit.unwrap_or(50).min(200);
    let offset = params.offset.unwrap_or(0);

    let filter = LibrarySearchFilter {
        provider_id: params.provider,
        content_type: parse_content_type(params.content_type.as_deref())?,
        series_names: params.series,
        collection_id: params.collection,
        genres: params.genres,
        search_term: params.q,
        season_number: params.season,
        offset,
        limit,
        ..Default::default()
    };

    let (items, total) = state.library_repo.search(&filter).await?;
    let resp = items.into_iter().map(library_item_to_response).collect();
    Ok(Json(PagedResponse { items: resp, total }))
}

async fn get_item(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
    Path(id): Path<String>,
) -> Result<Json<LibraryItemResponse>, ApiError> {
    let item = state
        .library_repo
        .get_by_id(&id)
        .await?
        .ok_or_else(|| ApiError::NotFound(format!("Library item '{}' not found", id)))?;
    Ok(Json(library_item_to_response(item)))
}

async fn sync_status(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
) -> Result<Json<Vec<SyncLogResponse>>, ApiError> {
    let entries = state.library_repo.latest_sync_status().await?;
    let resp = entries
        .into_iter()
        .map(|e| SyncLogResponse {
            id: e.id,
            provider_id: e.provider_id,
            started_at: e.started_at,
            finished_at: e.finished_at,
            items_found: e.items_found,
            status: e.status,
            error_msg: e.error_msg,
        })
        .collect();
    Ok(Json(resp))
}

async fn trigger_sync(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
) -> Result<impl IntoResponse, ApiError> {
    use domain::IProviderRegistry as _;
    let provider_ids: Vec<String> = {
        let reg = state.provider_registry.read().await;
        reg.provider_ids()
    };

    // 409 if any provider is already syncing
    for pid in &provider_ids {
        let running = state.library_repo.is_sync_running(pid).await?;
        if running {
            return Ok((
                StatusCode::CONFLICT,
                Json(serde_json::json!({
                    "error": format!("Sync already running for provider '{}'", pid)
                })),
            )
                .into_response());
        }
    }

    // Spawn background sync
    let sync_adapter: Arc<dyn LibrarySyncAdapter> = Arc::clone(&state.library_sync_adapter);
    let registry = Arc::clone(&state.provider_registry);
    tokio::spawn(async move {
        let providers: Vec<(String, Arc<dyn domain::IMediaProvider>)> = {
            let reg = registry.read().await;
            provider_ids
                .iter()
                .filter_map(|id| reg.get_provider(id).map(|p| (id.clone(), p)))
                .collect()
        };

        for (pid, provider) in providers {
            let result = sync_adapter.sync_provider(provider.as_ref(), &pid).await;
            if let Some(ref err) = result.error {
                tracing::warn!("manual sync: provider '{}' failed: {}", pid, err);
            } else {
                tracing::info!(
                    "manual sync: provider '{}' done — {} items in {}ms",
                    pid, result.items_found, result.duration_ms
                );
            }
        }
    });

    Ok((
        StatusCode::ACCEPTED,
        Json(serde_json::json!({ "message": "Sync started" })),
    )
        .into_response())
}

async fn list_shows(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
    Query(params): Query<ShowsQuery>,
) -> Result<Json<Vec<ShowSummaryResponse>>, ApiError> {
    let shows = state
        .library_repo
        .list_shows(
            params.provider.as_deref(),
            params.q.as_deref(),
            &params.genres,
        )
        .await?;
    let resp = shows
        .into_iter()
        .map(|s| ShowSummaryResponse {
            series_name: s.series_name,
            episode_count: s.episode_count,
            season_count: s.season_count,
            thumbnail_url: s.thumbnail_url,
            genres: s.genres,
        })
        .collect();
    Ok(Json(resp))
}

async fn list_seasons(
    State(state): State<AppState>,
    CurrentUser(_user): CurrentUser,
    Path(name): Path<String>,
    Query(params): Query<SeasonsQuery>,
) -> Result<Json<Vec<SeasonSummaryResponse>>, ApiError> {
    let seasons = state
        .library_repo
        .list_seasons(&name, params.provider.as_deref())
        .await?;
    let resp = seasons
        .into_iter()
        .map(|s| SeasonSummaryResponse {
            season_number: s.season_number,
            episode_count: s.episode_count,
            thumbnail_url: s.thumbnail_url,
        })
        .collect();
    Ok(Json(resp))
}

async fn get_settings(
    State(state): State<AppState>,
    AdminUser(_user): AdminUser,
) -> Result<Json<HashMap<String, serde_json::Value>>, ApiError> {
    let pairs = state.app_settings_repo.get_all().await?;
    let map: HashMap<String, serde_json::Value> = pairs
        .into_iter()
        .map(|(k, v)| {
            // Try to parse as number first, then bool, then keep as string
            let val = if let Ok(n) = v.parse::<i64>() {
                serde_json::Value::Number(n.into())
            } else if let Ok(b) = v.parse::<bool>() {
                serde_json::Value::Bool(b)
            } else {
                serde_json::Value::String(v)
            };
            (k, val)
        })
        .collect();
    Ok(Json(map))
}

async fn update_settings(
    State(state): State<AppState>,
    AdminUser(_user): AdminUser,
    Json(body): Json<HashMap<String, serde_json::Value>>,
) -> Result<Json<HashMap<String, serde_json::Value>>, ApiError> {
    for (key, val) in &body {
        let val_str = match val {
            serde_json::Value::String(s) => s.clone(),
            serde_json::Value::Number(n) => n.to_string(),
            serde_json::Value::Bool(b) => b.to_string(),
            other => other.to_string(),
        };
        state.app_settings_repo.set(key, &val_str).await?;
    }
    // Return the updated state
    let pairs = state.app_settings_repo.get_all().await?;
    let map: HashMap<String, serde_json::Value> = pairs
        .into_iter()
        .map(|(k, v)| {
            let val = if let Ok(n) = v.parse::<i64>() {
                serde_json::Value::Number(n.into())
            } else if let Ok(b) = v.parse::<bool>() {
                serde_json::Value::Bool(b)
            } else {
                serde_json::Value::String(v)
            };
            (k, val)
        })
        .collect();
    Ok(Json(map))
}

// ============================================================================
// Helpers
// ============================================================================

fn parse_content_type(s: Option<&str>) -> Result<Option<ContentType>, ApiError> {
    match s {
        None | Some("") => Ok(None),
        Some("movie") => Ok(Some(ContentType::Movie)),
        Some("episode") => Ok(Some(ContentType::Episode)),
        Some("short") => Ok(Some(ContentType::Short)),
        Some(other) => Err(ApiError::validation(format!(
            "Unknown content type '{}'. Use movie, episode, or short.",
            other
        ))),
    }
}

fn library_item_to_response(item: domain::LibraryItem) -> LibraryItemResponse {
    LibraryItemResponse {
        id: item.id,
        title: item.title,
        content_type: match item.content_type {
            ContentType::Movie => "movie".into(),
            ContentType::Episode => "episode".into(),
            ContentType::Short => "short".into(),
        },
        duration_secs: item.duration_secs,
        series_name: item.series_name,
        season_number: item.season_number,
        episode_number: item.episode_number,
        year: item.year,
        genres: item.genres,
        thumbnail_url: item.thumbnail_url,
    }
}