package adtracking

import (
	"context"
	"strings"
	"time"

	"gorm.io/gorm"
)

type Repository struct {
	db *gorm.DB
}

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

func (r *Repository) CreateLink(ctx context.Context, link *AdTrackingLink) error {
	return r.db.WithContext(ctx).Create(link).Error
}

func (r *Repository) UpdateLink(ctx context.Context, id uint64, updates map[string]interface{}) error {
	return r.db.WithContext(ctx).Model(&AdTrackingLink{}).Where("id = ?", id).Updates(updates).Error
}

func (r *Repository) FindLinkByID(ctx context.Context, id uint64) (*AdTrackingLink, error) {
	var link AdTrackingLink
	if err := r.db.WithContext(ctx).Where("id = ?", id).First(&link).Error; err != nil {
		return nil, err
	}
	return &link, nil
}

func (r *Repository) FindLinkByCode(ctx context.Context, code string) (*AdTrackingLink, error) {
	var link AdTrackingLink
	if err := r.db.WithContext(ctx).Where("code = ?", code).First(&link).Error; err != nil {
		return nil, err
	}
	return &link, nil
}

func (r *Repository) RecordClick(ctx context.Context, click *AdTrackingClick) error {
	return r.db.WithContext(ctx).Create(click).Error
}

func (r *Repository) ListLinks(ctx context.Context, query ListTrackingLinksQuery, baseURL string) ([]TrackingLinkItem, int64, error) {
	tx := r.db.WithContext(ctx).Model(&AdTrackingLink{})

	if kw := strings.TrimSpace(query.Keyword); kw != "" {
		like := "%" + kw + "%"
		tx = tx.Where("name LIKE ? OR code LIKE ? OR notes LIKE ?", like, like, like)
	}
	if ct := strings.TrimSpace(query.ChannelType); ct != "" && ct != "all" {
		tx = tx.Where("channel_type = ?", ct)
	}
	if st := strings.TrimSpace(query.Status); st != "" && st != "all" {
		tx = tx.Where("status = ?", st)
	}

	var total int64
	if err := tx.Count(&total).Error; err != nil {
		return nil, 0, err
	}

	page := query.Page
	if page < 1 {
		page = 1
	}
	pageSize := query.PageSize
	if pageSize < 1 || pageSize > 100 {
		pageSize = 20
	}
	offset := (page - 1) * pageSize

	var links []AdTrackingLink
	if err := tx.Order("id DESC").Offset(offset).Limit(pageSize).Find(&links).Error; err != nil {
		return nil, 0, err
	}

	if len(links) == 0 {
		return []TrackingLinkItem{}, total, nil
	}

	linkIDs := make([]uint64, 0, len(links))
	codes := make([]string, 0, len(links))
	for _, l := range links {
		linkIDs = append(linkIDs, l.ID)
		codes = append(codes, l.Code)
	}

	// 1. 批量聚合点击数据 (PV, UV, IP)
	type clickStat struct {
		LinkID uint64 `gorm:"column:link_id"`
		PV     int64  `gorm:"column:pv"`
		UV     int64  `gorm:"column:uv"`
		IP     int64  `gorm:"column:ips"`
	}
	var clickStats []clickStat
	_ = r.db.WithContext(ctx).
		Table("ad_tracking_clicks").
		Select("link_id, COUNT(*) as pv, COUNT(DISTINCT visitor_id) as uv, COUNT(DISTINCT ip) as ips").
		Where("link_id IN (?)", linkIDs).
		Group("link_id").
		Scan(&clickStats).Error

	clickStatMap := make(map[uint64]clickStat, len(clickStats))
	for _, cs := range clickStats {
		clickStatMap[cs.LinkID] = cs
	}

	// 2. 批量聚合注册人数
	type userStat struct {
		TrackCode string `gorm:"column:register_track_code"`
		Count     int64  `gorm:"column:reg_count"`
	}
	var userStats []userStat
	_ = r.db.WithContext(ctx).
		Table("users").
		Select("register_track_code, COUNT(*) as reg_count").
		Where("register_track_code IN (?)", codes).
		Group("register_track_code").
		Scan(&userStats).Error

	userStatMap := make(map[string]int64, len(userStats))
	for _, us := range userStats {
		userStatMap[us.TrackCode] = us.Count
	}

	// 3. 批量聚合订单数据 (总订单数, 成交订单数, 成交GMV)
	type orderStat struct {
		TrackCode   string `gorm:"column:source_track_code"`
		OrderCount  int64  `gorm:"column:order_count"`
		PaidCount   int64  `gorm:"column:paid_order_count"`
		PaidGMVCent int64  `gorm:"column:paid_gmv_cent"`
	}
	var orderStats []orderStat
	_ = r.db.WithContext(ctx).
		Table("rental_orders").
		Select("source_track_code, COUNT(*) as order_count, SUM(CASE WHEN status NOT IN ('pending_payment', 'cancelled', 'closed') THEN 1 ELSE 0 END) as paid_order_count, COALESCE(SUM(CASE WHEN status NOT IN ('pending_payment', 'cancelled', 'closed') THEN rent_amount_cent ELSE 0 END), 0) as paid_gmv_cent").
		Where("source_track_code IN (?)", codes).
		Group("source_track_code").
		Scan(&orderStats).Error

	orderStatMap := make(map[string]orderStat, len(orderStats))
	for _, os := range orderStats {
		orderStatMap[os.TrackCode] = os
	}

	// 组装最终结果
	items := make([]TrackingLinkItem, 0, len(links))
	cleanBaseURL := strings.TrimRight(baseURL, "/")
	for _, l := range links {
		cs := clickStatMap[l.ID]
		regCount := userStatMap[l.Code]
		os := orderStatMap[l.Code]

		var convRate float64
		if cs.UV > 0 {
			convRate = float64(os.OrderCount) / float64(cs.UV) * 100.0
		}

		shortURL := cleanBaseURL + "/r/" + l.Code

		items = append(items, TrackingLinkItem{
			ID:             l.ID,
			Name:           l.Name,
			Code:           l.Code,
			ChannelType:    l.ChannelType,
			TargetURL:      l.TargetURL,
			ShortURL:       shortURL,
			Status:         l.Status,
			CostCent:       l.CostCent,
			Notes:          l.Notes,
			CreatedBy:      l.CreatedBy,
			CreatedAt:      l.CreatedAt,
			UpdatedAt:      l.UpdatedAt,
			ClickPV:        cs.PV,
			ClickUV:        cs.UV,
			ClickIP:        cs.IP,
			RegisterCount:  regCount,
			OrderCount:     os.OrderCount,
			PaidOrderCount: os.PaidCount,
			PaidGMVCent:    os.PaidGMVCent,
			ConversionRate: convRate,
		})
	}

	return items, total, nil
}

func (r *Repository) GetOverviewStats(ctx context.Context) (*TrackingOverviewStats, error) {
	stats := &TrackingOverviewStats{}

	// 链接总数与启用数
	_ = r.db.WithContext(ctx).Model(&AdTrackingLink{}).Count(&stats.TotalLinks).Error
	_ = r.db.WithContext(ctx).Model(&AdTrackingLink{}).Where("status = 'active'").Count(&stats.ActiveLinks).Error

	// 累计点击
	type clickTotal struct {
		PV  int64 `gorm:"column:pv"`
		UV  int64 `gorm:"column:uv"`
		IPs int64 `gorm:"column:ips"`
	}
	var ct clickTotal
	_ = r.db.WithContext(ctx).
		Table("ad_tracking_clicks").
		Select("COUNT(*) as pv, COUNT(DISTINCT visitor_id) as uv, COUNT(DISTINCT ip) as ips").
		Scan(&ct).Error
	stats.TotalPV = ct.PV
	stats.TotalUV = ct.UV
	stats.TotalIP = ct.IPs

	// 累计注册
	_ = r.db.WithContext(ctx).
		Table("users").
		Where("register_track_code IS NOT NULL AND register_track_code != ''").
		Count(&stats.TotalRegisters).Error

	// 累计订单与GMV
	type orderTotal struct {
		TotalOrders     int64 `gorm:"column:total_orders"`
		TotalPaidOrders int64 `gorm:"column:total_paid_orders"`
		TotalPaidGMV    int64 `gorm:"column:total_paid_gmv"`
	}
	var ot orderTotal
	_ = r.db.WithContext(ctx).
		Table("rental_orders").
		Select("COUNT(*) as total_orders, SUM(CASE WHEN status NOT IN ('pending_payment', 'cancelled', 'closed') THEN 1 ELSE 0 END) as total_paid_orders, COALESCE(SUM(CASE WHEN status NOT IN ('pending_payment', 'cancelled', 'closed') THEN rent_amount_cent ELSE 0 END), 0) as total_paid_gmv").
		Where("source_track_code IS NOT NULL AND source_track_code != ''").
		Scan(&ot).Error
	stats.TotalOrders = ot.TotalOrders
	stats.TotalPaidOrders = ot.TotalPaidOrders
	stats.TotalPaidGMVCent = ot.TotalPaidGMV

	// 今日数据计算（按本地时区获取今日 00:00:00，避免 UTC 截断产生 8 小时偏差）
	now := time.Now()
	todayStart := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())

	// 今日点击
	var todayCt clickTotal
	_ = r.db.WithContext(ctx).
		Table("ad_tracking_clicks").
		Select("COUNT(*) as pv, COUNT(DISTINCT visitor_id) as uv").
		Where("created_at >= ?", todayStart).
		Scan(&todayCt).Error
	stats.TodayPV = todayCt.PV
	stats.TodayUV = todayCt.UV

	// 今日注册
	_ = r.db.WithContext(ctx).
		Table("users").
		Where("register_track_code IS NOT NULL AND register_track_code != '' AND created_at >= ?", todayStart).
		Count(&stats.TodayRegisters).Error

	// 今日订单
	var todayOt orderTotal
	_ = r.db.WithContext(ctx).
		Table("rental_orders").
		Select("COUNT(*) as total_orders, COALESCE(SUM(CASE WHEN status NOT IN ('pending_payment', 'cancelled', 'closed') THEN rent_amount_cent ELSE 0 END), 0) as total_paid_gmv").
		Where("source_track_code IS NOT NULL AND source_track_code != '' AND created_at >= ?", todayStart).
		Scan(&todayOt).Error
	stats.TodayOrders = todayOt.TotalOrders
	stats.TodayPaidGMVCent = todayOt.TotalPaidGMV

	return stats, nil
}