package image

import (
	"context"
	"database/sql"
	"time"
)

type Row struct {
	ID          int64
	ItemID      int64
	OriginalURL string
	ContentType string
	Bytes       []byte
	Width       int
	Height      int
	IsThumb     bool
	CreatedAt   time.Time
}

type Ref struct {
	ID      int64
	ItemID  int64
	IsThumb bool
}

func QListByItem(ctx context.Context, db *sql.DB, itemID int64) ([]Row, error) {
	rows, err := db.QueryContext(ctx, `
		SELECT id, item_id, original_url, content_type, bytes, width, height, is_thumb, created_at
		FROM image
		WHERE item_id = $1
		ORDER BY is_thumb DESC, id ASC
	`, itemID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var items []Row
	for rows.Next() {
		var row Row
		if err := rows.Scan(&row.ID, &row.ItemID, &row.OriginalURL, &row.ContentType, &row.Bytes, &row.Width, &row.Height, &row.IsThumb, &row.CreatedAt); err != nil {
			return nil, err
		}
		items = append(items, row)
	}
	return items, rows.Err()
}

func QListPrimaryRefsByItems(ctx context.Context, db *sql.DB, itemIDs []int64) (map[int64]Ref, error) {
	if len(itemIDs) == 0 {
		return map[int64]Ref{}, nil
	}

	rows, err := db.QueryContext(ctx, `
		SELECT id, item_id, is_thumb
		FROM image
		WHERE item_id = ANY($1)
		ORDER BY item_id ASC, is_thumb DESC, id ASC
	`, itemIDs)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	results := make(map[int64]Ref)
	for rows.Next() {
		var row Ref
		if err := rows.Scan(&row.ID, &row.ItemID, &row.IsThumb); err != nil {
			return nil, err
		}
		if _, exists := results[row.ItemID]; !exists {
			results[row.ItemID] = row
		}
	}
	return results, rows.Err()
}

func QFindByID(ctx context.Context, db *sql.DB, id int64) (*Row, error) {
	var row Row
	err := db.QueryRowContext(ctx, `
		SELECT id, item_id, original_url, content_type, bytes, width, height, is_thumb, created_at
		FROM image
		WHERE id = $1
		LIMIT 1
	`, id).Scan(&row.ID, &row.ItemID, &row.OriginalURL, &row.ContentType, &row.Bytes, &row.Width, &row.Height, &row.IsThumb, &row.CreatedAt)
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	return &row, nil
}

func QCreate(ctx context.Context, db *sql.DB, itemID int64, originalURL, contentType string, bytes []byte, width, height int, isThumb bool) (Row, error) {
	var row Row
	err := db.QueryRowContext(ctx, `
		INSERT INTO image (item_id, original_url, content_type, bytes, width, height, is_thumb)
		VALUES ($1, $2, $3, $4, $5, $6, $7)
		RETURNING id, item_id, original_url, content_type, bytes, width, height, is_thumb, created_at
	`, itemID, originalURL, contentType, bytes, width, height, isThumb).Scan(
		&row.ID,
		&row.ItemID,
		&row.OriginalURL,
		&row.ContentType,
		&row.Bytes,
		&row.Width,
		&row.Height,
		&row.IsThumb,
		&row.CreatedAt,
	)
	return row, err
}

func QDeleteByItem(ctx context.Context, db *sql.DB, itemID int64) error {
	_, err := db.ExecContext(ctx, `DELETE FROM image WHERE item_id = $1`, itemID)
	return err
}