use axum::{
    Json, Router,
    body::Body,
    extract::{Multipart, Path, State},
    response::IntoResponse,
    routing::get,
};
use sqlx::types::uuid;
use tracing::info;

use crate::{
    ctx::Ctx, error::LoftError, model::{FileRecord, FileRepository}
};

pub fn routes_file(file_repository: FileRepository) -> Router {
    Router::new()
        .route("/files", get(list_files).post(upload_file))
        .route("/files/{id}", get(get_file).delete(delete_file))
        .route("/files/{id}/download", get(download_file))
        .with_state(file_repository)
}

async fn upload_file(
    State(file_repository): State<FileRepository>,
    ctx: Ctx,
    mut multipart: Multipart,
) -> Result<Json<FileRecord>, LoftError> {
    info!("handler: upload_file");

    let mut file_name = None;
    let mut file_storage_key = None;
    let mut file_size = None;

    while let Some(field) = multipart.next_field().await.unwrap() {
        if field.name().unwrap() == "file" {
            let name = field.file_name().map(|s| s.to_string()).unwrap_or_default();
            let key = format!("{}-{}", name, uuid::Uuid::new_v4());
            let size = file_repository.upload_file(field, &key).await?;
            file_name = Some(name);
            file_storage_key = Some(key);
            file_size = Some(size);
        }
    }

    if let (Some(name), Some(key), Some(size)) = (file_name, file_storage_key, file_size) {
        let file_record = file_repository
            .create_file_record(ctx.user_id(), &name, size, &key)
            .await?;
        return Ok(Json(file_record));
    }

    Err(LoftError::UndefinedErrorType)
}

#[axum::debug_handler]
async fn get_file(
    State(file_repository): State<FileRepository>,
    Path(file_id): Path<u64>,
) -> Result<Json<FileRecord>, LoftError> {
    let record = file_repository.get_file(file_id as i64).await?;
    Ok(Json(record))
}

#[axum::debug_handler]
async fn download_file(
    State(file_repository): State<FileRepository>,
    Path(file_id): Path<u64>,
) -> Result<impl IntoResponse, LoftError> {
    let stream = file_repository.download_file(file_id as i64).await?;
    Ok(Body::from_stream(stream))
}

async fn delete_file(
    State(file_repository): State<FileRepository>,
    Path(file_id): Path<u64>,
) -> Result<Json<FileRecord>, LoftError> {
    info!("handler: delete_file");

    let file = file_repository.delete_file(file_id as i64).await?;
    Ok(Json(file))
}

async fn list_files(
    State(file_repository): State<FileRepository>,
    ctx: Ctx
) -> Result<Json<Vec<FileRecord>>, LoftError> {
    info!("handler: list_files");

    let files = file_repository.list_files(ctx.user_id()).await?;
    Ok(Json(files))
}

#[cfg(test)]
mod tests {
    use axum::{Router, middleware};
    use axum_test::{
        TestServer,
        multipart::{MultipartForm, Part},
    };
    use rand::RngExt;
    use serde_json::json;
    use sqlx::PgPool;
    use tower_cookies::CookieManagerLayer;

    use crate::{
        model::{FileRepository, UserRepository},
        web::{
            mw_auth::{mw_ctx_resolver, mw_require_auth},
            routes_file::routes_file,
        },
    };

    const BAD_AUTH_COOKIE: &str = "auth-token=user-0123456789";

    async fn file_repository() -> FileRepository {
        dotenvy::dotenv().ok();
        let database_url = std::env::var("DATABASE_URL").expect("DATABASE_URL must be set");
        let pool = PgPool::connect(&database_url).await.unwrap();
        let file_repository = FileRepository::new(pool).unwrap();
        file_repository
    }

    async fn user_repository() -> UserRepository {
        dotenvy::dotenv().ok();
        let database_url = std::env::var("DATABASE_URL").expect("DATABASE_URL must be set");
        let pool = PgPool::connect(&database_url).await.unwrap();
        let user_repository = UserRepository::new(pool).unwrap();
        user_repository
    }

    async fn test_server() -> TestServer {
        let user_repository = user_repository().await;
        let file_repository = file_repository().await;
        let routes_file =
            routes_file(file_repository.clone()).route_layer(middleware::from_fn(mw_require_auth));
        let app = Router::new()
            .nest("/api", routes_file)
            .layer(middleware::from_fn_with_state(
                user_repository,
                mw_ctx_resolver,
            ))
            .layer(CookieManagerLayer::new());

        TestServer::new(app)
    }

    async fn create_test_session(user_repository: &UserRepository) -> String {
        let user = user_repository
            .create_user("testuser".to_string(), "hash".to_string())
            .await
            .unwrap();
        let token: String = rand::rng()
            .sample_iter(&rand::distr::Alphanumeric)
            .take(64)
            .map(char::from)
            .collect();
        let expires_at = chrono::Utc::now() + chrono::Duration::days(1);
        user_repository
            .create_session(user.id, token.clone(), expires_at)
            .await
            .unwrap();
        token
    }

    async fn truncate(pool: &PgPool) {
        sqlx::query!("TRUNCATE TABLE file_records")
            .execute(pool)
            .await
            .unwrap();
    }

    #[tokio::test]
    async fn test_requires_auth() {
        let server = test_server().await;
        server.get("/api/files").await.assert_status_unauthorized();
    }

    #[tokio::test]
    async fn test_requires_auth_invalid_cookie() {
        let server = test_server().await;
        server
            .get("/api/files")
            .add_header(axum::http::header::COOKIE, BAD_AUTH_COOKIE)
            .await
            .assert_status_unauthorized();
    }

    #[tokio::test]
    #[serial_test::serial]
    async fn test_requires_auth_post() {
        let file_repository = file_repository().await;
        truncate(&file_repository.pool).await;

        let server = test_server().await;
        server
            .post("/api/files")
            .multipart(MultipartForm::new().add_part(
                "file",
                Part::bytes(b"fake_bytes".to_vec()).file_name("a.jpg"),
            ))
            .await
            .assert_status_unauthorized();
        truncate(&file_repository.pool).await;
    }

    #[tokio::test]
    #[serial_test::serial]
    async fn test_list_files_empty() {
        let user_repository = user_repository().await;
        let token = create_test_session(&user_repository).await;
        let file_repository = file_repository().await;
        truncate(&file_repository.pool).await;

        let server = test_server().await;
        server
            .get("/api/files")
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .await
            .assert_status_ok()
            .assert_json(&json!([]));
    }

    #[tokio::test]
    #[serial_test::serial]
    async fn test_upload_and_list_files() {
        let user_repository = user_repository().await;
        let token = create_test_session(&user_repository).await;
        let file_repository = file_repository().await;
        truncate(&file_repository.pool).await;

        let server = test_server().await;
        let res = server
            .post("/api/files")
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .multipart(MultipartForm::new().add_part(
                "file",
                Part::bytes(b"fake_bytes".to_vec()).file_name("a.jpg"),
            ))
            .await;

        res.assert_status_ok();
        let file = res.json::<serde_json::Value>();
        assert_eq!(file["name"], "a.jpg");

        let list = server
            .get("/api/files")
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .await
            .json::<serde_json::Value>();

        assert_eq!(list.as_array().unwrap().len(), 1);
        truncate(&file_repository.pool).await;
    }

    #[tokio::test]
    #[serial_test::serial]
    async fn test_download_file() {
        let user_repository = user_repository().await;
        let token = create_test_session(&user_repository).await;
        let file_repository = file_repository().await;
        truncate(&file_repository.pool).await;

        let server = test_server().await;
        let post_res = server
            .post("/api/files")
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .multipart(MultipartForm::new().add_part(
                "file",
                Part::bytes(b"fake_bytes".to_vec()).file_name("a.jpg"),
            ))
            .await;
        let id = post_res.json::<serde_json::Value>()["id"].as_i64().unwrap();
        let res = server
            .get(&format!("/api/files/{id}/download"))
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .await;

        res.assert_status_ok();
        assert_eq!(res.as_bytes(), b"fake_bytes".as_ref());
        truncate(&file_repository.pool).await;
    }

    #[tokio::test]
    #[serial_test::serial]
    async fn test_download_file_not_found() {
        let user_repository = user_repository().await;
        let token = create_test_session(&user_repository).await;
        let server = test_server().await;
        server
            .get("/api/files/99/download")
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .await
            .assert_status_not_found();
    }

    #[tokio::test]
    #[serial_test::serial]
    async fn test_delete_file() {
        let user_repository = user_repository().await;
        let token = create_test_session(&user_repository).await;
        let file_repository = file_repository().await;
        truncate(&file_repository.pool).await;

        let server = test_server().await;
        let post_res = server
            .post("/api/files")
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .multipart(MultipartForm::new().add_part(
                "file",
                Part::bytes(b"fake_bytes".to_vec()).file_name("a.jpg"),
            ))
            .await;
        let id = post_res.json::<serde_json::Value>()["id"].as_i64().unwrap();

        server
            .delete(&format!("/api/files/{id}"))
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .await
            .assert_status_ok();

        server
            .get(&format!("/api/files/{id}"))
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .await
            .assert_status_not_found();

        truncate(&file_repository.pool).await;
    }

    #[tokio::test]
    #[serial_test::serial]
    async fn test_delete_file_not_found() {
        let user_repository = user_repository().await;
        let token = create_test_session(&user_repository).await;
        let server = test_server().await;
        server
            .delete("/api/files/99")
            .add_header(axum::http::header::COOKIE, format!("auth-token={token}"))
            .await
            .assert_status_not_found();
    }
}