package repository

import (
	"context"

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

	"shop/internal/models"
)

type PriceHistoryRepository struct {
	pool *pgxpool.Pool
}

func NewPriceHistoryRepository(pool *pgxpool.Pool) *PriceHistoryRepository {
	return &PriceHistoryRepository{pool: pool}
}

func (r *PriceHistoryRepository) Record(ctx context.Context, productID int, price, salePrice float64) error {
	_, err := r.pool.Exec(ctx, `
		INSERT INTO product_price_history (product_id, price, sale_price)
		VALUES ($1, $2, NULLIF($3, 0))
	`, productID, price, salePrice)
	return err
}

func (r *PriceHistoryRepository) ByProduct(ctx context.Context, productID int, limit int) ([]models.PriceHistoryEntry, error) {
	rows, err := r.pool.Query(ctx, `
		SELECT id, product_id, price, COALESCE(sale_price, 0), recorded_at
		FROM product_price_history
		WHERE product_id = $1
		ORDER BY recorded_at DESC
		LIMIT $2
	`, productID, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var entries []models.PriceHistoryEntry
	for rows.Next() {
		var e models.PriceHistoryEntry
		if err := rows.Scan(&e.ID, &e.ProductID, &e.Price, &e.SalePrice, &e.RecordedAt); err != nil {
			return nil, err
		}
		entries = append(entries, e)
	}
	return entries, rows.Err()
}