package repository

import (
	"database/sql"
	"errors"
	"fmt"
	"strings"

	"cmautobuy/admin/model"
	"github.com/go-sql-driver/mysql"
)

var (
	ErrShopNameExists    = errors.New("店铺名称已经存在")
	ErrShopAliasExists   = errors.New("渠道店铺名称已经关联")
	ErrShopHasReferences = errors.New("店铺仍有关联数据")
)

// ListShops 返回管理页的一店一行汇总。
func ListShops(q Execer) ([]model.Shop, error) {
	rows, err := q.Query(`SELECT s.shop_id,s.display_name,s.normalized_name,s.enabled,
		COUNT(DISTINCT sp.goods_id),s.created_by_user_id,s.created_at,s.updated_at
		FROM shops s
		LEFT JOIN shopee_products sp ON sp.shop_id=s.shop_id AND sp.deleted_at IS NULL
		GROUP BY s.shop_id ORDER BY s.enabled DESC,s.normalized_name`)
	if err != nil {
		return nil, fmt.Errorf("查询店铺列表失败: %w", err)
	}
	defer rows.Close()
	var result []model.Shop
	for rows.Next() {
		var item model.Shop
		var enabled int
		if err := rows.Scan(&item.ShopID, &item.DisplayName, &item.NormalizedName, &enabled,
			&item.ShopeeProductCount,
			&item.CreatedByUserID, &item.CreatedAt, &item.UpdatedAt); err != nil {
			return nil, err
		}
		item.Enabled = enabled == 1
		result = append(result, item)
	}
	return result, rows.Err()
}

func GetShop(q Execer, shopID string) (model.Shop, bool, error) {
	var item model.Shop
	var enabled int
	err := q.QueryRow(`SELECT shop_id,display_name,normalized_name,enabled,created_by_user_id,created_at,updated_at
		FROM shops WHERE shop_id=?`, shopID).Scan(&item.ShopID, &item.DisplayName,
		&item.NormalizedName, &enabled, &item.CreatedByUserID, &item.CreatedAt, &item.UpdatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return model.Shop{}, false, nil
	}
	if err != nil {
		return model.Shop{}, false, fmt.Errorf("查询店铺失败: %w", err)
	}
	item.Enabled = enabled == 1
	return item, true, nil
}

// ListEnabledSybShopMappings 返回“店铺精确名称 → 店铺 ID”。
func ListEnabledSybShopMappings(q Execer) (map[string]string, error) {
	rows, err := q.Query(`SELECT normalized_name,shop_id FROM shops WHERE enabled=1 ORDER BY normalized_name`)
	if err != nil {
		return nil, fmt.Errorf("查询启用的 SYB 店铺配置失败: %w", err)
	}
	defer rows.Close()
	result := map[string]string{}
	for rows.Next() {
		var name, shopID string
		if err := rows.Scan(&name, &shopID); err != nil {
			return nil, err
		}
		result[name] = shopID
	}
	return result, rows.Err()
}

func FindShopIDByName(q Execer, rawName string) (string, error) {
	name := strings.TrimSpace(rawName)
	if name == "" {
		return "", nil
	}
	var shopID string
	err := q.QueryRow(`SELECT shop_id FROM shops WHERE normalized_name=?`, name).Scan(&shopID)
	if errors.Is(err, sql.ErrNoRows) {
		return "", nil
	}
	if err != nil {
		return "", fmt.Errorf("按店铺名称查询店铺失败: %w", err)
	}
	return shopID, nil
}

func InsertShop(q Execer, item model.Shop) error {
	_, err := q.Exec(`INSERT INTO shops(shop_id,display_name,normalized_name,enabled,created_by_user_id,created_at,updated_at)
		VALUES(?,?,?,?,?,?,?)`, item.ShopID, item.DisplayName, item.NormalizedName, item.Enabled,
		item.CreatedByUserID, item.CreatedAt, item.UpdatedAt)
	if err != nil {
		var mysqlErr *mysql.MySQLError
		if errors.As(err, &mysqlErr) && mysqlErr.Number == 1062 {
			return ErrShopNameExists
		}
		return fmt.Errorf("新增店铺失败: %w", err)
	}
	return nil
}

func InsertShopAlias(q Execer, item model.ShopChannelAlias) error {
	_, err := q.Exec(`INSERT INTO shop_channel_aliases(alias_id,shop_id,channel,alias_name,normalized_alias,enabled,created_at,updated_at)
		VALUES(?,?,?,?,?,?,?,?)`, item.AliasID, item.ShopID, item.Channel, item.AliasName,
		item.NormalizedAlias, item.Enabled, item.CreatedAt, item.UpdatedAt)
	if err != nil {
		var mysqlErr *mysql.MySQLError
		if errors.As(err, &mysqlErr) && mysqlErr.Number == 1062 {
			return ErrShopAliasExists
		}
		return fmt.Errorf("新增渠道店铺名称失败: %w", err)
	}
	return nil
}

func UpdateShopName(q Execer, shopID, displayName, normalizedName, updatedAt string) (bool, error) {
	result, err := q.Exec(`UPDATE shops SET display_name=?,normalized_name=?,updated_at=? WHERE shop_id=?`,
		displayName, normalizedName, updatedAt, shopID)
	if err != nil {
		var mysqlErr *mysql.MySQLError
		if errors.As(err, &mysqlErr) && mysqlErr.Number == 1062 {
			return false, ErrShopNameExists
		}
		return false, fmt.Errorf("更新店铺名称失败: %w", err)
	}
	n, err := result.RowsAffected()
	return n == 1, err
}

func SetShopEnabled(q Execer, shopID string, enabled bool, updatedAt string) (bool, error) {
	result, err := q.Exec(`UPDATE shops SET enabled=?,updated_at=? WHERE shop_id=?`, enabled, updatedAt, shopID)
	if err != nil {
		return false, fmt.Errorf("更新店铺状态失败: %w", err)
	}
	n, err := result.RowsAffected()
	return n == 1, err
}

func SetShopCompatibilityAliasesEnabled(q Execer, shopID string, enabled bool, updatedAt string) error {
	_, err := q.Exec(`UPDATE shop_channel_aliases SET enabled=?,updated_at=? WHERE shop_id=?`, enabled, updatedAt, shopID)
	if err != nil {
		return fmt.Errorf("同步店铺兼容数据状态失败: %w", err)
	}
	return nil
}

func ReplaceShopAlias(q Execer, aliasID, shopID, channel, aliasName, updatedAt string, enabled bool) error {
	if _, err := q.Exec(`DELETE FROM shop_channel_aliases WHERE shop_id=? AND channel=?`, shopID, channel); err != nil {
		return fmt.Errorf("移除旧渠道店铺名称失败: %w", err)
	}
	if strings.TrimSpace(aliasName) == "" {
		return nil
	}
	return InsertShopAlias(q, model.ShopChannelAlias{AliasID: aliasID, ShopID: shopID, Channel: channel,
		AliasName: aliasName, NormalizedAlias: strings.TrimSpace(aliasName), Enabled: enabled,
		CreatedAt: updatedAt, UpdatedAt: updatedAt})
}

// RebuildShopAssociations 按唯一店铺名称精确重建一个店铺的派生关联。
func RebuildShopAssociations(q Execer, shopID string) error {
	if _, err := q.Exec(`UPDATE syb_orders SET shop_id=NULL WHERE shop_id=?`, shopID); err != nil {
		return err
	}
	if _, err := q.Exec(`UPDATE shopee_products SET shop_id=NULL WHERE shop_id=?`, shopID); err != nil {
		return err
	}
	if _, err := q.Exec(`UPDATE syb_orders so JOIN shops s
		ON s.shop_id=? AND s.normalized_name=TRIM(so.shop_name) COLLATE utf8mb4_bin
		SET so.shop_id=s.shop_id`, shopID); err != nil {
		return err
	}
	if _, err := q.Exec(`UPDATE shopee_products sp JOIN shops s
		ON s.shop_id=? AND s.normalized_name=TRIM(sp.shopee_shop_name) COLLATE utf8mb4_bin
		SET sp.shop_id=s.shop_id`, shopID); err != nil {
		return err
	}
	return nil
}

func DeleteDisabledShop(q Execer, shopID string) (bool, error) {
	var references int
	if err := q.QueryRow(`SELECT (SELECT COUNT(*) FROM syb_orders WHERE shop_id=?)+
		(SELECT COUNT(*) FROM shopee_products WHERE shop_id=?)`, shopID, shopID).Scan(&references); err != nil {
		return false, err
	}
	if references > 0 {
		return false, ErrShopHasReferences
	}
	result, err := q.Exec(`DELETE FROM shops WHERE shop_id=? AND enabled=0`, shopID)
	if err != nil {
		return false, fmt.Errorf("删除停用店铺失败: %w", err)
	}
	n, err := result.RowsAffected()
	return n == 1, err
}

func CountUnlinkedShopeeShops(q Execer) (int, error) {
	var count int
	err := q.QueryRow(`SELECT COUNT(*) FROM shopee_products WHERE deleted_at IS NULL AND shop_id IS NULL`).Scan(&count)
	return count, err
}