use crate::schema::users::{users, User};
use crate::schema::{DatabaseError, DbConn};
use chrono::{DateTime, Utc};
use diesel::{Connection, ExpressionMethods, QueryDsl, RunQueryDsl};
use serde::{Deserialize, Serialize};
use uuid::Uuid;

table! {
    gamenight (id) {
        id -> diesel::sql_types::Uuid,
        name -> VarChar,
        datetime -> Timestamptz,
        owner_id -> Uuid,
    }
}

table! {
    known_games (id) {
        id -> diesel::sql_types::Uuid,
        name -> VarChar,
    }
}

table! {
    gamenight_gamelist(gamenight_id, game_id) {
        gamenight_id -> diesel::sql_types::Uuid,
        game_id -> diesel::sql_types::Uuid,
    }
}

table! {
    gamenight_participants(gamenight_id, user_id) {
        gamenight_id -> diesel::sql_types::Uuid,
        user_id -> diesel::sql_types::Uuid,
    }
}

#[derive(Serialize, Deserialize, Debug, Queryable, Clone, Insertable)]
#[table_name = "known_games"]
pub struct Game {
    pub id: Uuid,
    pub name: String,
}

#[derive(Serialize, Deserialize, Debug, Queryable, Insertable, Clone)]
#[table_name = "gamenight"]
pub struct Gamenight {
    pub id: Uuid,
    pub name: String,
    pub datetime: DateTime<Utc>,
    pub owner_id: Uuid,
}

#[derive(Serialize, Deserialize, Debug, Queryable, Insertable)]
#[table_name = "gamenight_gamelist"]
pub struct GamenightGameListEntry {
    pub gamenight_id: Uuid,
    pub game_id: Uuid,
}

#[derive(Serialize, Deserialize, Debug, Queryable, Insertable, Identifiable)]
#[table_name = "gamenight_participants"]
#[primary_key(gamenight_id, user_id)]
pub struct GamenightParticipantsEntry {
    pub gamenight_id: Uuid,
    pub user_id: Uuid,
}

#[derive(Serialize, Deserialize, Debug, Queryable)]
pub struct DeleteGamenight {
    pub game_id: Uuid,
}

#[derive(Serialize, Deserialize, Debug, Queryable)]
pub struct GamenightId {
    pub gamenight_id: Uuid,
}

pub async fn get_all_gamenights(conn: &DbConn) -> Result<Vec<Gamenight>, DatabaseError> {
    Ok(conn.run(|c| gamenight::table.load::<Gamenight>(c)).await?)
}

pub async fn insert_gamenight(
    conn: &DbConn,
    new_gamenight: Gamenight,
    game_list: Vec<Game>,
) -> Result<Uuid, DatabaseError> {
    Ok(conn
        .run(move |c| {
            c.transaction::<_, DatabaseError, _>(|| {
                let id: Uuid = diesel::insert_into(gamenight::table)
                    .values(&new_gamenight)
                    .returning(gamenight::id)
                    .get_result(c)?;

                let entries: Vec<GamenightGameListEntry> = game_list
                    .iter()
                    .map(|g| GamenightGameListEntry {
                        gamenight_id: new_gamenight.id.clone(),
                        game_id: g.id.clone(),
                    })
                    .collect();

                diesel::insert_into(gamenight_gamelist::table)
                    .values(entries)
                    .execute(c)?;

                Ok(id)
            })
        })
        .await?)
}

pub async fn get_gamenight(conn: &DbConn, gamenight_id: Uuid) -> Result<Gamenight, DatabaseError> {
    Ok(conn
        .run(move |c| gamenight::table.find(gamenight_id).first(c))
        .await?)
}

pub async fn delete_gamenight(conn: &DbConn, game_id: Uuid) -> Result<usize, DatabaseError> {
    Ok(conn
        .run(move |c| diesel::delete(gamenight::table.filter(gamenight::id.eq(game_id))).execute(c))
        .await?)
}

pub async fn get_all_known_games(conn: &DbConn) -> Result<Vec<Game>, DatabaseError> {
    Ok(conn.run(|c| known_games::table.load::<Game>(c)).await?)
}

pub async fn get_games_of_gamenight(
    conn: &DbConn,
    gamenight_id: Uuid,
) -> Result<Vec<Game>, DatabaseError> {
    Ok(conn
        .run::<_, Result<Vec<Game>, _>>(move |c| {
            let linked_game_ids: Vec<GamenightGameListEntry> = gamenight_gamelist::table
                .filter(gamenight_gamelist::gamenight_id.eq(gamenight_id))
                .load::<GamenightGameListEntry>(c)?;

            linked_game_ids
                .iter()
                .map(|l| {
                    known_games::table
                        .filter(known_games::id.eq(l.game_id))
                        .first::<Game>(c)
                })
                .collect()
        })
        .await?)
}

pub async fn add_game(conn: &DbConn, game: Game) -> Result<usize, DatabaseError> {
    Ok(conn
        .run(|c| {
            diesel::insert_into(known_games::table)
                .values(game)
                .execute(c)
        })
        .await?)
}

pub async fn add_unknown_games(conn: &DbConn, games: &mut Vec<Game>) -> Result<(), DatabaseError> {
    let all_games = get_all_known_games(conn).await?;
    for game in games.iter_mut() {
        if !all_games.iter().any(|g| g.name == game.name) {
            game.id = Uuid::new_v4();
            add_game(conn, game.clone()).await?;
        }
    }
    Ok(())
}

pub async fn load_participants(
    conn: &DbConn,
    gamenight_id: Uuid,
) -> Result<Vec<User>, DatabaseError> {
    Ok(conn
        .run::<_, Result<Vec<User>, _>>(move |c| {
            let linked_participants = gamenight_participants::table
                .filter(gamenight_participants::gamenight_id.eq(gamenight_id))
                .load::<GamenightParticipantsEntry>(c)?;
            linked_participants
                .iter()
                .map(|l| {
                    users::table
                        .filter(users::id.eq(l.user_id))
                        .first::<User>(c)
                })
                .collect()
        })
        .await?)
}

pub async fn add_participant(
    conn: &DbConn,
    participant: GamenightParticipantsEntry,
) -> Result<usize, DatabaseError> {
    Ok(conn
        .run(move |c| {
            diesel::insert_into(gamenight_participants::table)
                .values(&participant)
                .on_conflict_do_nothing()
                .execute(c)
        })
        .await?)
}

pub async fn remove_participant(
    conn: &DbConn,
    participant: GamenightParticipantsEntry,
) -> Result<usize, DatabaseError> {
    Ok(conn
        .run(move |c| diesel::delete(&participant).execute(c))
        .await?)
}