use axum::{
    extract::{Path, State},
    http::StatusCode,
    response::Json,
    routing::{get, post},
    Router,
};
use serde::{Deserialize, Serialize};

use crate::api::server::AppState;
use crate::core::config;
use crate::core::db::PostgresDb;
use crate::core::tmdb;

#[derive(Debug, Serialize)]
struct TmdbPrefetchResponse {
    success: bool,
    file_uuid: String,
    message: String,
    cache_path: Option<String>,
}

#[derive(Debug, Serialize)]
struct TmdbProbeResponse {
    success: bool,
    file_uuid: String,
    tmdb_id: Option<u64>,
    movie_title: Option<String>,
    cast_count: Option<usize>,
    identities_created: Option<usize>,
    message: String,
}

#[derive(Debug, Serialize)]
struct TmdbResourceResponse {
    success: bool,
    status: tmdb::status::TmdbResourceStatus,
    identities_seeded: i64,
    identities_with_embedding: i64,
    cache_files: usize,
    operations: Vec<TmdbOperation>,
}

#[derive(Debug, Serialize)]
struct TmdbOperation {
    method: String,
    path: String,
    description: String,
}

#[derive(Debug, Serialize)]
struct TmdbCheckResponse {
    success: bool,
    status: tmdb::status::TmdbResourceStatus,
}

#[derive(Debug, Deserialize)]
struct PrefetchRequest {
    file_uuid: String,
}

#[derive(Debug, Deserialize)]
struct FileUuidParam {
    file_uuid: String,
}

pub fn tmdb_routes() -> Router<AppState> {
    Router::new()
        .route("/api/v1/agents/tmdb/prefetch", post(tmdb_prefetch))
        .route("/api/v1/file/:file_uuid/tmdb-probe", post(tmdb_probe_handler))
        .route("/api/v1/resource/tmdb", get(tmdb_resource_status))
        .route("/api/v1/resource/tmdb/check", post(tmdb_resource_check))
}

async fn tmdb_prefetch(
    State(state): State<AppState>,
    Json(req): Json<PrefetchRequest>,
) -> Json<TmdbPrefetchResponse> {
    let file_uuid = req.file_uuid;

    // Verify file exists in DB
    let file_exists: bool = sqlx::query_scalar(
        &format!("SELECT COUNT(*) > 0 FROM {} WHERE file_uuid = $1", crate::core::db::schema::table_name("videos"))
    )
    .bind(&file_uuid)
    .fetch_one(state.db.pool())
    .await
    .unwrap_or(false);

    if !file_exists {
        return Json(TmdbPrefetchResponse {
            success: false,
            file_uuid: file_uuid.clone(),
            message: format!("File not found: {}", file_uuid),
            cache_path: None,
        });
    }

    // Offline-first: check if identity files already exist on disk (pre-prepared)
    let identities_dir = std::path::Path::new(&*config::OUTPUT_DIR).join("identities");
    let index_path = identities_dir.join("_index.json");
    let cache_path = format!("{}/{}.tmdb.json", *config::OUTPUT_DIR, file_uuid);
    let cache_file = std::path::Path::new(&cache_path);

    if index_path.exists() && cache_file.exists() {
        return Json(TmdbPrefetchResponse {
            success: true,
            file_uuid,
            message: format!(
                "Offline: using local identity files from {}.",
                identities_dir.display()
            ),
            cache_path: Some(cache_path),
        });
    }

    if config::tmdb::API_KEY.is_none() {
        return Json(TmdbPrefetchResponse {
            success: false,
            file_uuid: file_uuid.clone(),
            message: "TMDB_API_KEY not configured and no local cache found.".to_string(),
            cache_path: None,
        });
    }

    let scripts_dir = config::SCRIPTS_DIR.clone();
    let python_path = config::PYTHON_PATH.clone();
    let agent_script = std::path::Path::new(&scripts_dir).join("tmdb_agent.py");

    if !agent_script.exists() {
        return Json(TmdbPrefetchResponse {
            success: false,
            file_uuid,
            message: format!("tmdb_agent.py not found at {}", agent_script.display()),
            cache_path: None,
        });
    }

    let db_url = config::DATABASE_URL.clone();
    let output = tokio::process::Command::new(&*python_path)
        .arg(&agent_script)
        .arg("--file-uuid")
        .arg(&file_uuid)
        .env("DATABASE_URL", &db_url)
        .env("DATABASE_SCHEMA", &*config::DATABASE_SCHEMA)
        .output()
        .await;

    match output {
        Ok(o) => {
            if o.status.success() {
                let out = String::from_utf8_lossy(&o.stdout);
                Json(TmdbPrefetchResponse {
                    success: true,
                    file_uuid,
                    message: out.lines().last().unwrap_or("OK").to_string(),
                    cache_path: Some(cache_path),
                })
            } else {
                let stderr = String::from_utf8_lossy(&o.stderr);
                Json(TmdbPrefetchResponse {
                    success: false,
                    file_uuid,
                    message: stderr.to_string(),
                    cache_path: None,
                })
            }
        }
        Err(e) => Json(TmdbPrefetchResponse {
            success: false,
            file_uuid,
            message: format!("Failed to run tmdb_agent.py: {}", e),
            cache_path: None,
        }),
    }
}

async fn tmdb_probe_handler(
    Path(params): Path<FileUuidParam>,
    State(state): State<AppState>,
) -> Result<Json<TmdbProbeResponse>, (StatusCode, Json<serde_json::Value>)> {
    let file_uuid = params.file_uuid;

    // Verify file exists
    let file_exists: bool = sqlx::query_scalar(
        &format!("SELECT COUNT(*) > 0 FROM {} WHERE file_uuid = $1", crate::core::db::schema::table_name("videos"))
    )
    .bind(&file_uuid)
    .fetch_one(state.db.pool())
    .await
    .unwrap_or(false);

    if !file_exists {
        return Err((StatusCode::NOT_FOUND, Json(serde_json::json!({
            "error": "Video not found", "file_uuid": file_uuid
        }))));
    }

    match tmdb::probe::probe_from_cache(&state.db, &file_uuid).await {
        Ok(result) => Ok(Json(TmdbProbeResponse {
            success: true,
            file_uuid,
            tmdb_id: Some(result.tmdb_id),
            movie_title: Some(result.title),
            cast_count: Some(result.cast_count),
            identities_created: Some(result.identities_created),
            message: format!(
                "Created/updated {} identities for movie ID {}",
                result.identities_created, result.tmdb_id
            ),
        })),
        Err(e) => {
            let msg = e.to_string();
            if msg.contains("not found") {
                Ok(Json(TmdbProbeResponse {
                    success: false,
                    file_uuid,
                    tmdb_id: None,
                    movie_title: None,
                    cast_count: None,
                    identities_created: None,
                    message: "No TMDb cache found. Run tmdb-prefetch first.".to_string(),
                }))
            } else {
                Err((StatusCode::INTERNAL_SERVER_ERROR, Json(serde_json::json!({
                    "error": msg, "file_uuid": file_uuid
                }))))
            }
        }
    }
}

async fn tmdb_resource_status(
    State(state): State<AppState>,
) -> Json<TmdbResourceResponse> {
    let status = tmdb::status::quick_status();
    let identities_seeded = tmdb::status::count_tmdb_identities(state.db.pool())
        .await
        .unwrap_or(0);
    let identities_with_embedding = tmdb::status::count_tmdb_identities_with_embedding(state.db.pool())
        .await
        .unwrap_or(0);
    let cache_files = tmdb::status::count_cache_files();

    Json(TmdbResourceResponse {
        success: true,
        status,
        identities_seeded,
        identities_with_embedding,
        cache_files,
        operations: vec![
            TmdbOperation {
                method: "GET".to_string(),
                path: "/api/v1/resource/tmdb".to_string(),
                description: "TMDb resource status".to_string(),
            },
            TmdbOperation {
                method: "POST".to_string(),
                path: "/api/v1/resource/tmdb/check".to_string(),
                description: "Ping TMDb API health".to_string(),
            },
            TmdbOperation {
                method: "POST".to_string(),
                path: "/api/v1/agents/tmdb/prefetch".to_string(),
                description: "Fetch TMDb data and cache locally".to_string(),
            },
            TmdbOperation {
                method: "POST".to_string(),
                path: "/api/v1/file/:file_uuid/tmdb-probe".to_string(),
                description: "Read cache and create identities".to_string(),
            },
        ],
    })
}

async fn tmdb_resource_check() -> Json<TmdbCheckResponse> {
    let status = tmdb::status::check_tmdb_api().await;
    Json(TmdbCheckResponse {
        success: status.api_reachable.unwrap_or(false) && status.api_key_configured,
        status,
    })
}