package handler

import (
	"encoding/json"
	"net/http"
	"strconv"
	"sync"
	"time"

	"soul-api/internal/database"
	"soul-api/internal/model"
	"soul-api/internal/wechat"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
)

var paidStatuses = []string{"paid", "completed", "success"}

// AdminDashboardStats GET /api/admin/dashboard/stats
// 轻量聚合：总用户、付费订单数、付费用户数、总营收、转化率（无订单/用户明细）
func AdminDashboardStats(c *gin.Context) {
	db := database.DB()
	var (
		totalUsers     int64
		paidOrderCount int64
		totalRevenue   float64
		paidUserCount  int64
	)
	var wg sync.WaitGroup
	wg.Add(4)
	go func() { defer wg.Done(); db.Model(&model.User{}).Count(&totalUsers) }()
	go func() { defer wg.Done(); db.Model(&model.Order{}).Where("status IN ?", paidStatuses).Count(&paidOrderCount) }()
	go func() {
		defer wg.Done()
		db.Model(&model.Order{}).Where("status IN ?", paidStatuses).
			Select("COALESCE(SUM(amount), 0)").Scan(&totalRevenue)
	}()
	go func() {
		defer wg.Done()
		db.Table("orders").Where("status IN ?", paidStatuses).
			Select("COUNT(DISTINCT user_id)").Scan(&paidUserCount)
	}()
	wg.Wait()
	conversionRate := 0.0
	if totalUsers > 0 && paidUserCount > 0 {
		conversionRate = float64(paidUserCount) / float64(totalUsers) * 100
	}
	c.JSON(http.StatusOK, gin.H{
		"success":        true,
		"totalUsers":     totalUsers,
		"paidOrderCount": paidOrderCount,
		"paidUserCount":  paidUserCount,
		"totalRevenue":   totalRevenue,
		"conversionRate": conversionRate,
	})
}

// AdminDashboardRecentOrders GET /api/admin/dashboard/recent-orders?limit=10
func AdminDashboardRecentOrders(c *gin.Context) {
	db := database.DB()
	limit := 5
	if l := c.Query("limit"); l != "" {
		if n, err := strconv.Atoi(l); err == nil && n >= 1 && n <= 20 {
			limit = n
		}
	}
	var recentOrders []model.Order
	db.Where("status IN ?", paidStatuses).Order("created_at DESC").Limit(limit).Find(&recentOrders)
	c.JSON(http.StatusOK, gin.H{"success": true, "recentOrders": buildRecentOrdersOut(db, recentOrders)})
}

// AdminDashboardNewUsers GET /api/admin/dashboard/new-users
func AdminDashboardNewUsers(c *gin.Context) {
	db := database.DB()
	var newUsers []model.User
	db.Model(&model.User{}).Order("created_at DESC").Limit(10).Find(&newUsers)
	c.JSON(http.StatusOK, gin.H{"success": true, "newUsers": buildNewUsersOut(newUsers)})
}

// AdminDashboardOverview GET /api/admin/dashboard/overview
// 数据概览：总用户、付费订单数、付费用户数、总营收、转化率、最近订单、新用户
// 优化：6 组查询并行执行，减少总耗时
func AdminDashboardOverview(c *gin.Context) {
	db := database.DB()

	var (
		totalUsers     int64
		paidOrderCount int64
		totalRevenue   float64
		paidUserCount  int64
		recentOrders   []model.Order
		newUsers       []model.User
	)
	var wg sync.WaitGroup
	wg.Add(6)

	go func() {
		defer wg.Done()
		db.Model(&model.User{}).Count(&totalUsers)
	}()
	go func() {
		defer wg.Done()
		db.Model(&model.Order{}).Where("status IN ?", paidStatuses).Count(&paidOrderCount)
	}()
	go func() {
		defer wg.Done()
		db.Model(&model.Order{}).Where("status IN ?", paidStatuses).
			Select("COALESCE(SUM(amount), 0)").Scan(&totalRevenue)
	}()
	go func() {
		defer wg.Done()
		db.Table("orders").Where("status IN ?", paidStatuses).
			Select("COUNT(DISTINCT user_id)").Scan(&paidUserCount)
	}()
	go func() {
		defer wg.Done()
		db.Where("status IN ?", paidStatuses).
			Order("created_at DESC").Limit(5).Find(&recentOrders)
	}()
	go func() {
		defer wg.Done()
		db.Model(&model.User{}).Order("created_at DESC").Limit(10).Find(&newUsers)
	}()
	wg.Wait()

	conversionRate := 0.0
	if totalUsers > 0 && paidUserCount > 0 {
		conversionRate = float64(paidUserCount) / float64(totalUsers) * 100
	}

	recentOut := buildRecentOrdersOut(db, recentOrders)
	newOut := buildNewUsersOut(newUsers)

	c.JSON(http.StatusOK, gin.H{
		"success":         true,
		"totalUsers":      totalUsers,
		"paidOrderCount":  paidOrderCount,
		"paidUserCount":   paidUserCount,
		"totalRevenue":    totalRevenue,
		"conversionRate":  conversionRate,
		"recentOrders":    recentOut,
		"newUsers":        newOut,
	})
}

func dashStr(s *string) string {
	if s == nil || *s == "" {
		return ""
	}
	return *s
}

func buildRecentOrdersOut(db *gorm.DB, recentOrders []model.Order) []gin.H {
	if len(recentOrders) == 0 {
		return nil
	}
	userIDs := make(map[string]bool)
	for _, o := range recentOrders {
		if o.UserID != "" {
			userIDs[o.UserID] = true
		}
	}
	ids := make([]string, 0, len(userIDs))
	for id := range userIDs {
		ids = append(ids, id)
	}
	var users []model.User
	db.Where("id IN ?", ids).Find(&users)
	userMap := make(map[string]*model.User)
	for i := range users {
		userMap[users[i].ID] = &users[i]
	}
	out := make([]gin.H, 0, len(recentOrders))
	for _, o := range recentOrders {
		b, _ := json.Marshal(o)
		var m map[string]interface{}
		_ = json.Unmarshal(b, &m)
		if u := userMap[o.UserID]; u != nil {
			m["userNickname"] = dashStr(u.Nickname)
			m["userAvatar"] = resolveAvatarURL(dashStr(u.Avatar))
		} else {
			m["userNickname"] = ""
			m["userAvatar"] = ""
		}
		out = append(out, m)
	}
	return out
}

// AdminTrackStats GET /api/admin/track/stats?period=today|week|month|all
// 埋点统计：按 extra_data->module 分组，按 action+target 聚合 count
func AdminTrackStats(c *gin.Context) {
	period := c.DefaultQuery("period", "week")
	if period != "today" && period != "week" && period != "month" && period != "all" {
		period = "week"
	}
	now := time.Now()
	var start time.Time
	switch period {
	case "today":
		start = time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
	case "week":
		weekday := int(now.Weekday())
		if weekday == 0 {
			weekday = 7
		}
		start = time.Date(now.Year(), now.Month(), now.Day()-weekday+1, 0, 0, 0, 0, now.Location())
	case "month":
		start = time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
	case "all":
		start = time.Time{}
	}
	db := database.DB()
	var tracks []model.UserTrack
	q := db.Model(&model.UserTrack{})
	if !start.IsZero() {
		q = q.Where("created_at >= ?", start)
	}
	if err := q.Find(&tracks).Error; err != nil {
		c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
		return
	}
	// byModule: module -> map[key] -> count, key = action + "|" + target
	type item struct {
		Action string `json:"action"`
		Target string `json:"target"`
		Module string `json:"module"`
		Page   string `json:"page"`
		Count  int    `json:"count"`
	}
	byModule := make(map[string]map[string]*item)
	total := 0
	for _, t := range tracks {
		total++
		module := "other"
		page := ""
		if len(t.ExtraData) > 0 {
			var extra map[string]interface{}
			if err := json.Unmarshal(t.ExtraData, &extra); err == nil {
				if m, ok := extra["module"].(string); ok && m != "" {
					module = m
				}
				if p, ok := extra["page"].(string); ok {
					page = p
				}
			}
		}
		target := ""
		if t.Target != nil {
			target = *t.Target
		}
		key := t.Action + "|" + target
		if byModule[module] == nil {
			byModule[module] = make(map[string]*item)
		}
		if byModule[module][key] == nil {
			byModule[module][key] = &item{Action: t.Action, Target: target, Module: module, Page: page, Count: 0}
		}
		byModule[module][key].Count++
	}
	// 转为前端期望格式：byModule[module] = [{action,target,module,page,count},...]
	out := make(map[string][]gin.H)
	for mod, m := range byModule {
		list := make([]gin.H, 0, len(m))
		for _, v := range m {
			list = append(list, gin.H{
				"action": v.Action, "target": v.Target, "module": v.Module, "page": v.Page, "count": v.Count,
			})
		}
		out[mod] = list
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "total": total, "byModule": out})
}

// AdminBalanceSummary GET /api/admin/balance/summary
// 汇总代付金额（product_type 为 gift_pay 或 gift_pay_batch 的已支付订单），用于 Dashboard 显示「含代付 ¥xx」
func AdminBalanceSummary(c *gin.Context) {
	db := database.DB()
	var totalGifted float64
	db.Model(&model.Order{}).Where("product_type IN ? AND status IN ?", []string{"gift_pay", "gift_pay_batch"}, paidStatuses).
		Select("COALESCE(SUM(amount), 0)").Scan(&totalGifted)
	c.JSON(http.StatusOK, gin.H{"success": true, "data": gin.H{"totalGifted": totalGifted}})
}

// AdminDashboardMerchantBalance GET /api/admin/dashboard/merchant-balance
// 查询微信商户号实时余额（可用余额、待结算余额），用于看板展示
// 注意：普通商户可能需向微信申请开通权限，未开通时返回 error
func AdminDashboardMerchantBalance(c *gin.Context) {
	bal, err := wechat.QueryMerchantBalance("BASIC")
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"error":   err.Error(),
			"message": "查询商户余额失败，可能未开通权限（请联系微信支付运营申请）",
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success":         true,
		"availableAmount": bal.AvailableAmount, // 单位：分
		"pendingAmount":   bal.PendingAmount,   // 单位：分
	})
}

func buildNewUsersOut(newUsers []model.User) []gin.H {
	out := make([]gin.H, 0, len(newUsers))
	for _, u := range newUsers {
		out = append(out, gin.H{
			"id":           u.ID,
			"nickname":     dashStr(u.Nickname),
			"phone":        dashStr(u.Phone),
			"referralCode": dashStr(u.ReferralCode),
			"createdAt":    u.CreatedAt,
		})
	}
	return out
}