use deadpool_sqlite::Pool;
use std::{collections::HashMap, path::PathBuf, sync::Arc, time::Instant};
use tokio::{sync::Mutex, task::JoinSet};

use tonic::{Request, Response, Status};
use walkdir::{DirEntry, WalkDir};

use crate::{
    checksum::generate_hash,
    database::tracks::{
        add_track_to_playlist, create_playlist, delete_playlist, get_playlist, get_playlists,
        get_tracks, insert_tracks, remove_track_from_playlist, swap_playlist_tracks,
    },
    music::metadata::{extract_track_data, TrackMetadata},
    proto::library::{
        library_server::Library, AddTrackToPlaylistRequest, CreatePlaylistRequest,
        CreatePlaylistResponse, DeletePlaylistRequest, ListPlaylistsResponse,
        RemoveTrackFromPlaylistRequest, SwapTracksRequest, Track, TrackList,
    },
    state::GrooveState,
};

pub struct LibraryService {
    #[allow(dead_code)]
    state: GrooveState,
    pool: Pool,
}

impl LibraryService {
    pub fn new(state: GrooveState, pool: Pool) -> Self {
        Self { state, pool }
    }
}

#[tonic::async_trait]
impl Library for LibraryService {
    async fn list_tracks(&self, _request: Request<()>) -> Result<Response<TrackList>, Status> {
        let Ok(tracks) = get_tracks(&self.pool).await else {
            return Err(Status::internal(""));
        };

        let response = TrackList {
            tracks: tracks
                .into_iter()
                .map(|t| Track {
                    hash: t.hash.clone(),
                    name: t.name.clone(),
                    artist_name: t.artist_name.clone(),
                    artist_id: t.artist_id,
                    duration: t.duration,
                })
                .collect::<Vec<Track>>(),
        };

        Ok(Response::new(response))
    }

    async fn list_playlists(
        &self,
        _request: Request<()>,
    ) -> Result<Response<ListPlaylistsResponse>, Status> {
        let Ok(playlists) = get_playlists(&self.pool).await else {
            return Err(Status::internal(""));
        };

        let response = ListPlaylistsResponse { playlists };

        Ok(Response::new(response))
    }

    async fn create_playlist(
        &self,
        request: Request<CreatePlaylistRequest>,
    ) -> Result<Response<CreatePlaylistResponse>, Status> {
        let input = request.get_ref();

        let Ok(playlist) = create_playlist(&self.pool, &input.name).await else {
            return Err(Status::internal(""));
        };

        let response = CreatePlaylistResponse {
            playlist: Some(playlist),
        };

        Ok(Response::new(response))
    }

    async fn delete_playlist(
        &self,
        request: Request<DeletePlaylistRequest>,
    ) -> Result<Response<()>, Status> {
        let input = request.get_ref();

        let Ok(success) = delete_playlist(&self.pool, input.id).await else {
            return Err(Status::internal(""));
        };

        if !success {
            return Err(Status::internal(""));
        }

        Ok(Response::new(()))
    }

    async fn add_track_to_playlist(
        &self,
        request: Request<AddTrackToPlaylistRequest>,
    ) -> Result<Response<TrackList>, Status> {
        let input = request.get_ref();

        let Ok(success) =
            add_track_to_playlist(&self.pool, input.playlist_id, &input.track_hash).await
        else {
            return Err(Status::internal(""));
        };

        if !success {
            return Err(Status::internal(""));
        }

        let Ok(playlist) = get_playlist(&self.pool, input.playlist_id).await else {
            return Err(Status::internal(""));
        };

        let response = TrackList {
            tracks: playlist.tracks,
        };

        Ok(Response::new(response))
    }

    async fn remove_track_from_playlist(
        &self,
        request: Request<RemoveTrackFromPlaylistRequest>,
    ) -> Result<Response<TrackList>, Status> {
        let input = request.get_ref();

        let Ok(success) =
            remove_track_from_playlist(&self.pool, input.playlist_id, input.track_rank).await
        else {
            return Err(Status::internal(""));
        };

        if !success {
            return Err(Status::internal(""));
        }

        let Ok(playlist) = get_playlist(&self.pool, input.playlist_id).await else {
            return Err(Status::internal(""));
        };

        let response = TrackList {
            tracks: playlist.tracks,
        };

        Ok(Response::new(response))
    }

    async fn swap_tracks(
        &self,
        request: Request<SwapTracksRequest>,
    ) -> Result<Response<TrackList>, Status> {
        let input = request.get_ref();

        let Ok(success) =
            swap_playlist_tracks(&self.pool, input.playlist_id, input.a_rank, input.b_rank).await
        else {
            return Err(Status::internal(""));
        };

        if !success {
            return Err(Status::internal(""));
        }

        let Ok(playlist) = get_playlist(&self.pool, input.playlist_id).await else {
            return Err(Status::internal(""));
        };

        let response = TrackList {
            tracks: playlist.tracks,
        };

        Ok(Response::new(response))
    }
}

pub async fn index_path(path: PathBuf, db: &Pool, path_id: u64) -> Result<(), rusqlite::Error> {
    let home = home::home_dir().unwrap();

    let correct_path = path.to_str().unwrap().replace("~", home.to_str().unwrap());
    let path_offset = correct_path.len() + 1;

    let now = Instant::now();

    let entries: Vec<DirEntry> = WalkDir::new(correct_path)
        .into_iter()
        .filter_map(Result::ok)
        .collect();

    let tracks: Arc<Mutex<HashMap<String, TrackMetadata>>> = Arc::new(Mutex::new(HashMap::new()));
    let mut set = JoinSet::new();

    for entry in entries.into_iter() {
        if entry.file_type().is_file() && entry.path().extension().is_some_and(|ext| ext == "mp3") {
            let tracks = tracks.clone();
            set.spawn(async move {
                let file_path = entry.path();
                if let Ok(content) = std::fs::read(file_path) {
                    let hash = generate_hash(&content);

                    let relative_path =
                        file_path.to_str().unwrap().to_string()[path_offset..].to_string();

                    if let Some(metadata) = extract_track_data(content, relative_path) {
                        tracks.lock().await.insert(hash, metadata);
                    }
                }
            });
        }
    }

    set.join_all().await;

    let elapsed = now.elapsed();

    println!("indexing took {:.2?}", elapsed);

    let now = Instant::now();

    insert_tracks(db, Arc::try_unwrap(tracks).unwrap().into_inner(), path_id).await?;

    let elapsed = now.elapsed();

    println!("inserting took {:.2?}", elapsed);

    Ok(())
}