package repository

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

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

	"shop/internal/models"
)

type ReservationRepository struct {
	pool *pgxpool.Pool
}

func NewReservationRepository(pool *pgxpool.Pool) *ReservationRepository {
	return &ReservationRepository{pool: pool}
}

func (r *ReservationRepository) Create(ctx context.Context, res *models.Reservation) error {
	return r.pool.QueryRow(ctx, `
		INSERT INTO product_reservations (product_id, session_key, user_id, customer_name, customer_phone, expires_at)
		VALUES ($1, $2, $3, $4, $5, $6)
		RETURNING id, created_at
	`, res.ProductID, res.SessionKey, res.UserID, res.CustomerName, res.CustomerPhone, res.ExpiresAt,
	).Scan(&res.ID, &res.CreatedAt)
}

func (r *ReservationRepository) ActiveByProduct(ctx context.Context, productID int) (*models.Reservation, error) {
	var res models.Reservation
	var userID sql.NullInt64
	err := r.pool.QueryRow(ctx, `
		SELECT id, product_id, session_key, user_id, customer_name, customer_phone, expires_at, created_at
		FROM product_reservations
		WHERE product_id = $1 AND expires_at > NOW()
		ORDER BY created_at DESC
		LIMIT 1
	`, productID).Scan(
		&res.ID, &res.ProductID, &res.SessionKey, &userID,
		&res.CustomerName, &res.CustomerPhone, &res.ExpiresAt, &res.CreatedAt,
	)
	if err != nil {
		return nil, err
	}
	if userID.Valid {
		id := int(userID.Int64)
		res.UserID = &id
	}
	return &res, nil
}

func (r *ReservationRepository) ReplaceForProduct(ctx context.Context, res *models.Reservation) error {
	tx, err := r.pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer tx.Rollback(ctx)

	_, err = tx.Exec(ctx, `DELETE FROM product_reservations WHERE product_id = $1`, res.ProductID)
	if err != nil {
		return err
	}

	err = tx.QueryRow(ctx, `
		INSERT INTO product_reservations (product_id, session_key, user_id, customer_name, customer_phone, expires_at)
		VALUES ($1, $2, $3, $4, $5, $6)
		RETURNING id, created_at
	`, res.ProductID, res.SessionKey, res.UserID, res.CustomerName, res.CustomerPhone, res.ExpiresAt,
	).Scan(&res.ID, &res.CreatedAt)
	if err != nil {
		return err
	}
	return tx.Commit(ctx)
}

func (r *ReservationRepository) ExpiresIn() time.Duration {
	return 24 * time.Hour
}