package repository

import (
	"database/sql"
)


// RecordBrandView inserts a brand view record.
func RecordBrandView(d *sql.DB, userID, brand string) error {
	_, err := d.Exec(`
		INSERT INTO user_brand_views (user_id, brand) VALUES ($1, $2)
	`, userID, brand)
	return err
}

// FrequentBrand represents a brand the user interacts with frequently.
type FrequentBrand struct {
	Brand       string `json:"brand"`
	ViewCount   int    `json:"view_count"`
	FavCount    int    `json:"fav_count"`
	LogoURL     string `json:"logo_url,omitempty"`
	StyleCount  int    `json:"style_count,omitempty"`
}

// GetFrequentBrands returns brands where user has views≥3 or favorites≥2.
func GetFrequentBrands(d *sql.DB, userID string) ([]FrequentBrand, error) {
	rows, err := d.Query(`
		SELECT brand,
			   COALESCE(v.cnt, 0) AS view_count,
			   COALESCE(f.cnt, 0) AS fav_count
		FROM (
			SELECT brand, COUNT(*) AS cnt
			FROM user_brand_views
			WHERE user_id = $1
			GROUP BY brand
			HAVING COUNT(*) >= 3
		) v
		FULL OUTER JOIN (
			SELECT brand, COUNT(*) AS cnt
			FROM favorites
			WHERE user_id = $1
			GROUP BY brand
			HAVING COUNT(*) >= 2
		) f USING (brand)
		ORDER BY COALESCE(v.cnt, 0) + COALESCE(f.cnt, 0) * 2 DESC
	`, userID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var out []FrequentBrand
	for rows.Next() {
		var fb FrequentBrand
		if err := rows.Scan(&fb.Brand, &fb.ViewCount, &fb.FavCount); err != nil {
			continue
		}
		// Load brand logo and stats
		logoMap := loadBrandLogos()
		if u, ok := logoMap[fb.Brand]; ok {
			fb.LogoURL = u
		}
		// Get style count from products
		var sc int
		d.QueryRow(`SELECT COUNT(DISTINCT style_name) FROM products WHERE brand = $1`, fb.Brand).Scan(&sc)
		fb.StyleCount = sc
		out = append(out, fb)
	}
	return out, rows.Err()
}