package gifts

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
)

type Repository struct {
	db *sql.DB
}

func NewRepository(db *sql.DB) *Repository {
	return &Repository{db: db}
}

func (r *Repository) GetPublicBySlug(ctx context.Context, slug string) (PublicGift, error) {
	var gift PublicGift
	err := r.db.QueryRowContext(ctx, `
		SELECT id, slug, recipient_name, sender_name, title, intro_message, reveal_message
		FROM gifts
		WHERE slug = $1 AND status = 'published'
	`, slug).Scan(
		&gift.ID,
		&gift.Slug,
		&gift.RecipientName,
		&gift.SenderName,
		&gift.Title,
		&gift.IntroMessage,
		&gift.RevealMessage,
	)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return PublicGift{}, ErrNotFound
		}
		return PublicGift{}, fmt.Errorf("find gift: %w", err)
	}

	rows, err := r.db.QueryContext(ctx, `
		SELECT id, type, title, text, media_url, sort_order, metadata
		FROM gift_items
		WHERE gift_id = $1
		ORDER BY sort_order ASC, id ASC
	`, gift.ID)
	if err != nil {
		return PublicGift{}, fmt.Errorf("find gift items: %w", err)
	}
	defer rows.Close()

	gift.Items = make([]PublicGiftItem, 0)
	for rows.Next() {
		var (
			item     PublicGiftItem
			title    sql.NullString
			text     sql.NullString
			mediaURL sql.NullString
			metadata []byte
		)

		if err := rows.Scan(
			&item.ID,
			&item.Type,
			&title,
			&text,
			&mediaURL,
			&item.SortOrder,
			&metadata,
		); err != nil {
			return PublicGift{}, fmt.Errorf("scan gift item: %w", err)
		}

		item.Title = title.String
		item.Text = text.String
		item.MediaURL = mediaURL.String
		if len(metadata) == 0 {
			item.Metadata = []byte(`{}`)
		} else {
			item.Metadata = metadata
		}
		gift.Items = append(gift.Items, item)
	}

	if err := rows.Err(); err != nil {
		return PublicGift{}, fmt.Errorf("iterate gift items: %w", err)
	}

	return gift, nil
}

// Store is the read contract used by the service. Keeping it small makes the
// HTTP layer straightforward to test without a running database.
type Store interface {
	GetPublicBySlug(context.Context, string) (PublicGift, error)
}

var _ Store = (*Repository)(nil)