package albums

import (
	"context"
	"errors"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"

	"galo/internal/httpx"
	"galo/internal/models"
)

var ErrNotFound = errors.New("album not found")

type Store struct {
	pool *pgxpool.Pool
}

func NewStore(pool *pgxpool.Pool) *Store { return &Store{pool: pool} }

func (s *Store) Create(ctx context.Context, a *models.Album) error {
	return s.pool.QueryRow(ctx,
		`INSERT INTO albums (id, owner_id, title, description, cover_photo_id)
		 VALUES ($1, $2, $3, $4, $5)
		 RETURNING created_at, updated_at`,
		a.ID, a.OwnerID, a.Title, a.Description, a.CoverPhotoID,
	).Scan(&a.CreatedAt, &a.UpdatedAt)
}

func (s *Store) OwnerID(ctx context.Context, id string) (string, error) {
	var ownerID string
	err := s.pool.QueryRow(ctx, `SELECT owner_id FROM albums WHERE id = $1`, id).Scan(&ownerID)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return "", httpx.NotFound("album_not_found", "album not found")
		}
		return "", err
	}
	return ownerID, nil
}

func (s *Store) GetByID(ctx context.Context, id string) (*models.Album, error) {
	var a models.Album
	err := s.pool.QueryRow(ctx,
		`SELECT a.id, a.owner_id, a.title, a.description, a.cover_photo_id, a.created_at, a.updated_at,
		        COALESCE(ce.storage_key, co.storage_key, ''), COALESCE(cem.storage_key, com.storage_key, ''),
		        (SELECT count(*) FROM photos WHERE album_id = a.id AND deleted_at IS NULL),
		        (SELECT count(*) FROM album_members WHERE album_id = a.id)
		 FROM albums a
		 LEFT JOIN photo_objects cpo ON cpo.photo_id = a.cover_photo_id AND cpo.role = 'thumb'
		 LEFT JOIN objects co ON co.id = cpo.object_id
		 LEFT JOIN photo_objects cpm ON cpm.photo_id = a.cover_photo_id AND cpm.role = 'medium'
		 LEFT JOIN objects com ON com.id = cpm.object_id
		 LEFT JOIN photo_objects cpe ON cpe.photo_id = a.cover_photo_id AND cpe.role = 'edit_thumb'
		 LEFT JOIN objects ce ON ce.id = cpe.object_id
		 LEFT JOIN photo_objects cpem ON cpem.photo_id = a.cover_photo_id AND cpem.role = 'edit_medium'
		 LEFT JOIN objects cem ON cem.id = cpem.object_id
		 WHERE a.id = $1`, id).
		Scan(&a.ID, &a.OwnerID, &a.Title, &a.Description, &a.CoverPhotoID, &a.CreatedAt, &a.UpdatedAt, &a.CoverThumbKey, &a.CoverMediumKey, &a.PhotosCount, &a.MembersCount)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	return &a, nil
}

func (s *Store) ListForUser(ctx context.Context, userID string) ([]models.Album, error) {
	rows, err := s.pool.Query(ctx,
		`SELECT a.id, a.owner_id, a.title, a.description, a.cover_photo_id, a.created_at, a.updated_at,
		        COALESCE(ce.storage_key, co.storage_key, ''), COALESCE(cem.storage_key, com.storage_key, ''),
		        (SELECT count(*) FROM photos WHERE album_id = a.id AND deleted_at IS NULL),
		        (SELECT count(*) FROM album_members WHERE album_id = a.id)
		 FROM albums a
		 LEFT JOIN album_members m ON m.album_id = a.id AND m.user_id = $1
		 LEFT JOIN photo_objects cpo ON cpo.photo_id = a.cover_photo_id AND cpo.role = 'thumb'
		 LEFT JOIN objects co ON co.id = cpo.object_id
		 LEFT JOIN photo_objects cpm ON cpm.photo_id = a.cover_photo_id AND cpm.role = 'medium'
		 LEFT JOIN objects com ON com.id = cpm.object_id
		 LEFT JOIN photo_objects cpe ON cpe.photo_id = a.cover_photo_id AND cpe.role = 'edit_thumb'
		 LEFT JOIN objects ce ON ce.id = cpe.object_id
		 LEFT JOIN photo_objects cpem ON cpem.photo_id = a.cover_photo_id AND cpem.role = 'edit_medium'
		 LEFT JOIN objects cem ON cem.id = cpem.object_id
		 WHERE a.owner_id = $1 OR m.user_id IS NOT NULL
		 ORDER BY a.created_at DESC`, userID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	out := []models.Album{}
	for rows.Next() {
		var a models.Album
		if err := rows.Scan(&a.ID, &a.OwnerID, &a.Title, &a.Description, &a.CoverPhotoID, &a.CreatedAt, &a.UpdatedAt, &a.CoverThumbKey, &a.CoverMediumKey, &a.PhotosCount, &a.MembersCount); err != nil {
			return nil, err
		}
		out = append(out, a)
	}
	return out, rows.Err()
}

func (s *Store) Update(ctx context.Context, a *models.Album) error {
	return s.pool.QueryRow(ctx,
		`UPDATE albums
		 SET title = $2, description = $3, cover_photo_id = $4, updated_at = now()
		 WHERE id = $1
		 RETURNING updated_at`,
		a.ID, a.Title, a.Description, a.CoverPhotoID,
	).Scan(&a.UpdatedAt)
}

func (s *Store) Delete(ctx context.Context, id string) error {
	tag, err := s.pool.Exec(ctx, `DELETE FROM albums WHERE id = $1`, id)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

// TrashPhotosByAlbum soft-deletes all photos of an album so they can be restored
// or permanently removed from the trash after the album is gone.
func (s *Store) TrashPhotosByAlbum(ctx context.Context, albumID string) error {
	_, err := s.pool.Exec(ctx,
		`UPDATE photos SET deleted_at = now() WHERE album_id = $1 AND deleted_at IS NULL`, albumID)
	return err
}