package database

import (
	"context"
	"encoding/json"
	"regexp"
	"strings"
	"time"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5/pgxpool"
)

type DB struct {
	pool *pgxpool.Pool
}

func New(ctx context.Context, databaseURL string) (*DB, error) {
	pool, err := pgxpool.New(ctx, databaseURL)
	if err != nil {
		return nil, err
	}

	if err := pool.Ping(ctx); err != nil {
		return nil, err
	}

	return &DB{pool: pool}, nil
}

func (db *DB) Close() {
	db.pool.Close()
}

type Artist struct {
	ID          string
	Name        string
	SortName    string
	ArtistType  string
	Description string
	Genres      []Genre
	ExternalIDs []ExternalID
}

type Album struct {
	ID          string
	Title       string
	AlbumType   string
	ReleaseDate string
	Genres      []Genre
}

type Genre struct {
	ID   string `json:"id"`
	Name string `json:"name"`
}

type ExternalID struct {
	Source   string `json:"source"`
	SourceID string `json:"source_id"`
	URL      string `json:"url"`
}

type ArtistMetadataRow struct {
	ID              uuid.UUID       `json:"id"`
	ForeignArtistID *string         `json:"foreign_artist_id"`
	Name            string          `json:"name"`
	SortName        *string         `json:"sort_name"`
	ArtistType      *string         `json:"artist_type"`
	Genres          json.RawMessage `json:"genres"`
	CreatedAt       time.Time       `json:"created_at"`
	UpdatedAt       time.Time       `json:"updated_at"`
}

type AlbumRow struct {
	ID               uuid.UUID  `json:"id"`
	ArtistMetadataID uuid.UUID  `json:"artist_metadata_id"`
	ForeignAlbumID   *string    `json:"foreign_album_id"`
	Title            string     `json:"title"`
	AlbumType        *string    `json:"album_type"`
	ReleaseDate      *time.Time `json:"release_date"`
	Monitored        bool       `json:"monitored"`
	AddedAt          time.Time  `json:"added_at"`
}

type AlbumWithArtistRow struct {
	ID             uuid.UUID  `json:"id"`
	ForeignAlbumID *string    `json:"foreign_album_id"`
	Title          string     `json:"title"`
	AlbumType      *string    `json:"album_type"`
	ReleaseDate    *time.Time `json:"release_date"`
	Monitored      bool       `json:"monitored"`
	AddedAt        time.Time  `json:"added_at"`
	ArtistID       uuid.UUID  `json:"artist_id"`
	ArtistName     string     `json:"artist_name"`
}

func (db *DB) UpsertArtistMetadata(ctx context.Context, artist *Artist) (uuid.UUID, error) {
	id, err := uuid.Parse(artist.ID)
	if err != nil {
		id = uuid.New()
	}

	genres, _ := json.Marshal(artist.Genres)
	links, _ := json.Marshal(artist.ExternalIDs)

	var resultID uuid.UUID
	err = db.pool.QueryRow(ctx, `
		INSERT INTO artist_metadata (
			id, foreign_artist_id, name, sort_name, disambiguation,
			artist_type, status, overview, genres, links, updated_at
		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, NOW())
		ON CONFLICT (foreign_artist_id) DO UPDATE SET
			name = EXCLUDED.name,
			sort_name = EXCLUDED.sort_name,
			artist_type = EXCLUDED.artist_type,
			overview = EXCLUDED.overview,
			genres = EXCLUDED.genres,
			links = EXCLUDED.links,
			updated_at = NOW()
		RETURNING id
	`, id, artist.ID, artist.Name, artist.SortName, artist.Description,
		artist.ArtistType, "active", artist.Description, genres, links).Scan(&resultID)

	return resultID, err
}

var cleanTitleRegex = regexp.MustCompile(`[^a-z0-9]`)

func (db *DB) UpsertAlbum(ctx context.Context, album *Album, artistMetadataID uuid.UUID) (uuid.UUID, error) {
	id, err := uuid.Parse(album.ID)
	if err != nil {
		id = uuid.New()
	}

	genres, _ := json.Marshal(album.Genres)
	images, _ := json.Marshal([]any{})

	var releaseDate *time.Time
	if album.ReleaseDate != "" {
		if t, err := time.Parse("2006-01-02", album.ReleaseDate); err == nil {
			releaseDate = &t
		}
	}

	cleanTitle := cleanTitleRegex.ReplaceAllString(strings.ToLower(album.Title), "")

	var resultID uuid.UUID
	err = db.pool.QueryRow(ctx, `
		INSERT INTO albums (
			id, artist_metadata_id, foreign_album_id, title, clean_title,
			overview, album_type, release_date, images, genres
		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
		ON CONFLICT (foreign_album_id) DO UPDATE SET
			title = EXCLUDED.title,
			album_type = EXCLUDED.album_type,
			release_date = EXCLUDED.release_date,
			genres = EXCLUDED.genres
		RETURNING id
	`, id, artistMetadataID, album.ID, album.Title, cleanTitle,
		"", album.AlbumType, releaseDate, images, genres).Scan(&resultID)

	return resultID, err
}

func (db *DB) ListArtists(ctx context.Context) ([]ArtistMetadataRow, error) {
	rows, err := db.pool.Query(ctx, `
		SELECT id, foreign_artist_id, name, sort_name, artist_type, genres, created_at, updated_at
		FROM artist_metadata
		ORDER BY name
	`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var artists []ArtistMetadataRow
	for rows.Next() {
		var a ArtistMetadataRow
		err := rows.Scan(&a.ID, &a.ForeignArtistID, &a.Name, &a.SortName, &a.ArtistType, &a.Genres, &a.CreatedAt, &a.UpdatedAt)
		if err != nil {
			return nil, err
		}
		artists = append(artists, a)
	}

	return artists, nil
}

func (db *DB) ListAlbumsByArtist(ctx context.Context, artistMetadataID uuid.UUID) ([]AlbumRow, error) {
	rows, err := db.pool.Query(ctx, `
		SELECT id, artist_metadata_id, foreign_album_id, title, album_type, release_date, monitored, added_at
		FROM albums
		WHERE artist_metadata_id = $1
		ORDER BY release_date DESC NULLS LAST
	`, artistMetadataID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var albums []AlbumRow
	for rows.Next() {
		var a AlbumRow
		err := rows.Scan(&a.ID, &a.ArtistMetadataID, &a.ForeignAlbumID, &a.Title, &a.AlbumType, &a.ReleaseDate, &a.Monitored, &a.AddedAt)
		if err != nil {
			return nil, err
		}
		albums = append(albums, a)
	}

	return albums, nil
}

func (db *DB) ListAllAlbums(ctx context.Context) ([]AlbumWithArtistRow, error) {
	rows, err := db.pool.Query(ctx, `
		SELECT 
			a.id, a.foreign_album_id, a.title, a.album_type, a.release_date, a.monitored, a.added_at,
			am.id as artist_id, am.name as artist_name
		FROM albums a
		JOIN artist_metadata am ON a.artist_metadata_id = am.id
		ORDER BY a.added_at DESC
	`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var albums []AlbumWithArtistRow
	for rows.Next() {
		var a AlbumWithArtistRow
		err := rows.Scan(&a.ID, &a.ForeignAlbumID, &a.Title, &a.AlbumType, &a.ReleaseDate, &a.Monitored, &a.AddedAt, &a.ArtistID, &a.ArtistName)
		if err != nil {
			return nil, err
		}
		albums = append(albums, a)
	}

	return albums, nil
}

func (db *DB) CountArtists(ctx context.Context) (int64, error) {
	var count int64
	err := db.pool.QueryRow(ctx, "SELECT COUNT(*) FROM artist_metadata").Scan(&count)
	return count, err
}

func (db *DB) CountAlbums(ctx context.Context) (int64, error) {
	var count int64
	err := db.pool.QueryRow(ctx, "SELECT COUNT(*) FROM albums").Scan(&count)
	return count, err
}