use serde::Serialize;
use sqlx::mysql::{MySqlPool, MySqlPoolOptions};
use std::env;

#[derive(Serialize)]
pub struct Song {
    name: Option<String>,
    id: Option<i32>,
    lyrics: Option<String>,
    album_name: Option<String>,
    album_id: Option<i32>,
    artist_name: Option<String>,
    artist_id: Option<i32>,
}

#[derive(Serialize)]
pub struct Album {
    name: Option<String>,
    id: Option<i32>,
    artist_name: Option<String>,
    artist_id: Option<i32>,
}

#[derive(Serialize)]
pub struct Artist {
    name: Option<String>,
    id: Option<i32>,
}

pub struct DatabaseWrapper {
    db_pool: MySqlPool,
}

impl DatabaseWrapper {
    pub async fn new() -> Result<DatabaseWrapper, sqlx::Error> {
        let pool: MySqlPool = MySqlPoolOptions::new()
            .max_connections(10)
            .connect(
                env::var("DATABASE_URL")
                    .expect("environment variables are *probably not setted up!!")
                    .as_str(),
            )
            .await
            .unwrap(); /* This will break in case of error. It's intended. */

        Ok(DatabaseWrapper { db_pool: pool })
    }

    pub async fn select_songs(&self) -> Result<Vec<Song>, sqlx::Error> {
        return sqlx::query_as!(
            Song,
            "SELECT song.name, song.lyrics, song.id,
            album.name as album_name, album.id as album_id,
            artist.name as artist_name, artist.id as artist_id
            FROM song
            INNER JOIN album ON song.album_id = album.id
            INNER JOIN artist ON album.artist_id = artist.id
            ",
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_song_by_id(&self, id: String) -> Result<Vec<Song>, sqlx::Error> {
        return sqlx::query_as!(
            Song,
            "SELECT song.name, song.lyrics, song.id,
            album.name as album_name, album.id as album_id,
            artist.name as artist_name, artist.id as artist_id
            FROM song
            INNER JOIN album ON song.album_id = album.id
            INNER JOIN artist ON album.artist_id = artist.id
            WHERE song.id = ?
            ",
            id,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_songs_by_album(&self, album_id: String) -> Result<Vec<Song>, sqlx::Error> {
        return sqlx::query_as!(
            Song,
            "SELECT song.name, song.lyrics, song.id,
            album.name as album_name, album.id as album_id,
            artist.name as artist_name, artist.id as artist_id
            FROM song
            INNER JOIN album ON song.album_id = album.id
            INNER JOIN artist ON album.artist_id = artist.id
            WHERE album.id = ?
            ",
            album_id,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_songs_by_artist(
        &self,
        artist_id: String,
    ) -> Result<Vec<Song>, sqlx::Error> {
        return sqlx::query_as!(
            Song,
            "SELECT song.name, song.lyrics, song.id,
            album.name as album_name, album.id as album_id,
            artist.name as artist_name, artist.id as artist_id
            FROM song
            INNER JOIN album ON song.album_id = album.id
            INNER JOIN artist ON album.artist_id = artist.id
            WHERE artist.id = ?
            ",
            artist_id,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_songs_by_name(&self, name_raw: String) -> Result<Vec<Song>, sqlx::Error> {
        let name: String = format!("{}{}{}", "%", name_raw, "%");
        return sqlx::query_as!(
            Song,
            "SELECT song.name, song.lyrics, song.id,
            album.name as album_name, album.id as album_id,
            artist.name as artist_name, artist.id as artist_id
            FROM song
            INNER JOIN album ON song.album_id = album.id
            INNER JOIN artist ON album.artist_id = artist.id
            WHERE LOWER(song.name) LIKE LOWER(?)",
            name,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_albums(&self) -> Result<Vec<Album>, sqlx::Error> {
        return sqlx::query_as!(
            Album,
            "SELECT album.name, album.id,
            artist.name as artist_name, artist.id as artist_id
            FROM album
            INNER JOIN artist ON album.artist_id = artist.id
            ",
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_album_by_id(&self, id: String) -> Result<Vec<Album>, sqlx::Error> {
        return sqlx::query_as!(
            Album,
            "SELECT album.name, album.id,
            artist.name as artist_name, artist.id as artist_id
            FROM album
            INNER JOIN artist ON album.artist_id = artist.id
            WHERE album.id=?",
            id,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_albums_by_name(&self, name_raw: String) -> Result<Vec<Album>, sqlx::Error> {
        let name : String = format!("{}{}{}", "%", name_raw, "%");
        return sqlx::query_as!(
            Album,
            "SELECT album.name, album.id,
            artist.name as artist_name, artist.id as artist_id
            FROM album
            INNER JOIN artist ON album.artist_id = artist.id
            WHERE LOWER(album.name) LIKE LOWER(?)
            ",
            name,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_albums_by_artist_id(&self, artist_id: String) -> Result<Vec<Album>, sqlx::Error> {
        return sqlx::query_as!(
            Album,
            "SELECT album.name, album.id,
            artist.name as artist_name, artist.id as artist_id
            FROM album
            INNER JOIN artist ON album.artist_id = artist.id
            WHERE artist.id=?",
            artist_id,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_artists(&self) -> Result<Vec<Artist>, sqlx::Error> {
        return sqlx::query_as!(
            Artist,
            "SELECT name, id
            FROM artist"
            ,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_artist_by_id(&self, id: String) -> Result<Vec<Artist>, sqlx::Error> {
        return sqlx::query_as!(
            Artist,
            "SELECT name, id
            FROM artist
            WHERE id = ?"
            ,
            id,
        )
        .fetch_all(&self.db_pool)
        .await;
    }

    pub async fn select_artists_by_name(&self, name_raw: String) -> Result<Vec<Artist>, sqlx::Error> {
        let name : String = format!("{}{}{}", "%", name_raw, "%");
        return sqlx::query_as!(
            Artist,
            "SELECT name, id
            FROM artist
            WHERE name = ?"
            ,
            name,
        )
        .fetch_all(&self.db_pool)
        .await;
    }
}