package handler

import (
	"encoding/json"
	"fmt"
	"math"
	"net/http"
	"time"

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

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

const defaultBindingDays = 30

// ReferralBind POST /api/referral/bind 推荐码绑定（新绑定/续期/切换）
func ReferralBind(c *gin.Context) {
	var req struct {
		UserID       string `json:"userId"`
		ReferralCode string `json:"referralCode" binding:"required"`
		OpenID       string `json:"openId"`
		Source       string `json:"source"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "用户ID和推荐码不能为空"})
		return
	}
	effectiveUserID := req.UserID
	if effectiveUserID == "" && req.OpenID != "" {
		effectiveUserID = "user_" + req.OpenID[len(req.OpenID)-8:]
	}
	if effectiveUserID == "" || req.ReferralCode == "" {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "用户ID和推荐码不能为空"})
		return
	}

	db := database.DB()
	bindingDays := defaultBindingDays
	var cfg model.SystemConfig
	if err := db.Where("config_key = ?", "referral_config").First(&cfg).Error; err == nil {
		var config map[string]interface{}
		if _ = json.Unmarshal(cfg.ConfigValue, &config); config["bindingDays"] != nil {
			if v, ok := config["bindingDays"].(float64); ok {
				bindingDays = int(v)
			}
		}
	}

	var referrer model.User
	if err := db.Where("referral_code = ?", req.ReferralCode).First(&referrer).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "推荐码无效"})
		return
	}
	if referrer.ID == effectiveUserID {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "不能使用自己的推荐码"})
		return
	}

	var user model.User
	if err := db.Where("id = ?", effectiveUserID).First(&user).Error; err != nil {
		if req.OpenID != "" {
			if err := db.Where("open_id = ?", req.OpenID).First(&user).Error; err != nil {
				c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "用户不存在"})
				return
			}
		} else {
			c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "用户不存在"})
			return
		}
	}

	expiryDate := time.Now().AddDate(0, 0, bindingDays)
	var existing model.ReferralBinding
	err := db.Where("referee_id = ? AND status = ?", user.ID, "active").Order("binding_date DESC").First(&existing).Error
	action := "new"
	var oldReferrerID interface{}

	if err == nil {
		if existing.ReferrerID == referrer.ID {
			action = "renew"
			db.Model(&existing).Updates(map[string]interface{}{
				"expiry_date":  expiryDate,
				"binding_date": time.Now(),
			})
		} else {
			action = "switch"
			oldReferrerID = existing.ReferrerID
			db.Model(&existing).Update("status", "cancelled")
			bindID := fmt.Sprintf("bind_%d_%s", time.Now().UnixNano(), randomStr(6))
			db.Create(&model.ReferralBinding{
				ID:          bindID,
				ReferrerID:  referrer.ID,
				RefereeID:   user.ID,
				ReferralCode: req.ReferralCode,
				Status:      refString("active"),
				ExpiryDate:  expiryDate,
				BindingDate: time.Now(),
			})
		}
	} else {
		bindID := fmt.Sprintf("bind_%d_%s", time.Now().UnixNano(), randomStr(6))
		db.Create(&model.ReferralBinding{
			ID:          bindID,
			ReferrerID:  referrer.ID,
			RefereeID:   user.ID,
			ReferralCode: req.ReferralCode,
			Status:      refString("active"),
			ExpiryDate:  expiryDate,
			BindingDate: time.Now(),
		})
		db.Model(&model.User{}).Where("id = ?", referrer.ID).UpdateColumn("referral_count", gorm.Expr("COALESCE(referral_count, 0) + 1"))
	}

	msg := "绑定成功"
	if action == "renew" {
		msg = "绑定已续期"
	} else if action == "switch" {
		msg = "推荐人已切换"
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": msg,
		"data": gin.H{
			"action":       action,
			"referrer":     gin.H{"id": referrer.ID, "nickname": getStringValue(referrer.Nickname)},
			"expiryDate":   expiryDate,
			"bindingDays": bindingDays,
			"oldReferrerId": oldReferrerID,
		},
	})
}

func refString(s string) *string { return &s }
func randomStr(n int) string {
	const letters = "abcdefghijklmnopqrstuvwxyz0123456789"
	b := make([]byte, n)
	for i := range b {
		b[i] = letters[time.Now().UnixNano()%int64(len(letters))]
	}
	return string(b)
}

// ReferralData GET /api/referral/data 获取分销数据统计
func ReferralData(c *gin.Context) {
	userId := c.Query("userId")
	if userId == "" {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "用户ID不能为空"})
		return
	}

	db := database.DB()
	
	// 获取分销配置（与 soul-admin 推广设置一致）
	distributorShare := 0.9
	minWithdrawAmount := 10.0
	bindingDays := defaultBindingDays
	userDiscount := 5
	withdrawFee := 5.0

	var cfg model.SystemConfig
	if err := db.Where("config_key = ?", "referral_config").First(&cfg).Error; err == nil {
		var config map[string]interface{}
		if err := json.Unmarshal(cfg.ConfigValue, &config); err == nil {
			if share, ok := config["distributorShare"].(float64); ok {
				distributorShare = share / 100
			}
			if minAmount, ok := config["minWithdrawAmount"].(float64); ok {
				minWithdrawAmount = minAmount
			}
			if days, ok := config["bindingDays"].(float64); ok && days > 0 {
				bindingDays = int(days)
			}
			if discount, ok := config["userDiscount"].(float64); ok {
				userDiscount = int(discount)
			}
			if fee, ok := config["withdrawFee"].(float64); ok {
				withdrawFee = fee
			}
		}
	}

	// 1. 查询用户基本信息
	var user model.User
	if err := db.Where("id = ?", userId).First(&user).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"success": false, "error": "用户不存在"})
		return
	}

	// 2. 绑定统计
	var totalBindings int64
	db.Model(&model.ReferralBinding{}).Where("referrer_id = ?", userId).Count(&totalBindings)

	var activeBindings int64
	db.Model(&model.ReferralBinding{}).Where(
		"referrer_id = ? AND status = 'active' AND expiry_date > ?",
		userId, time.Now(),
	).Count(&activeBindings)

	var convertedBindings int64
	db.Model(&model.ReferralBinding{}).Where(
		"referrer_id = ? AND status = 'active' AND purchase_count > 0",
		userId,
	).Count(&convertedBindings)

	var expiredBindings int64
	db.Model(&model.ReferralBinding{}).Where(
		"referrer_id = ? AND (status IN ('expired', 'cancelled') OR (status = 'active' AND expiry_date <= ?))",
		userId, time.Now(),
	).Count(&expiredBindings)

	// 3. 付款统计
	var paidOrders []model.Order
	db.Where("referrer_id = ? AND status = ?", userId, "paid").Find(&paidOrders)

	totalAmount := 0.0
	totalCommission := 0.0
	uniqueUsers := make(map[string]bool)
	for i := range paidOrders {
		totalAmount += paidOrders[i].Amount
		totalCommission += computeOrderCommission(db, &paidOrders[i], nil)
		uniqueUsers[paidOrders[i].UserID] = true
	}
	uniquePaidCount := len(uniqueUsers)

	// 4. 访问统计
	totalVisits := int(totalBindings)
	var visitCount int64
	if err := db.Model(&model.ReferralVisit{}).
		Select("COUNT(DISTINCT visitor_id) as count").
		Where("referrer_id = ?", userId).
		Count(&visitCount).Error; err == nil {
		totalVisits = int(visitCount)
	}

	// 5. 提现统计（与小程序可提现逻辑一致：可提现 = 累计佣金 - 已提现 - 待审核）
	// 待审核 = pending + processing + pending_confirm，与 /api/withdraw/pending-confirm 口径一致
	var pendingWithdraw struct{ Total float64 }
	db.Model(&model.Withdrawal{}).
		Select("COALESCE(SUM(amount), 0) as total").
		Where("user_id = ? AND status IN ?", userId, []string{"pending", "processing", "pending_confirm"}).
		Scan(&pendingWithdraw)

	var successWithdraw struct{ Total float64 }
	db.Model(&model.Withdrawal{}).
		Select("COALESCE(SUM(amount), 0) as total").
		Where("user_id = ? AND status = ?", userId, "success").
		Scan(&successWithdraw)

	pendingWithdrawAmount := pendingWithdraw.Total
	withdrawnFromTable := successWithdraw.Total

	// 6. 获取活跃绑定用户列表
	var activeBindingsList []model.ReferralBinding
	db.Where("referrer_id = ? AND status = 'active' AND expiry_date > ?", userId, time.Now()).
		Order("binding_date DESC").
		Limit(20).
		Find(&activeBindingsList)

	activeUsers := []gin.H{}
	for _, b := range activeBindingsList {
		var referee model.User
		db.Where("id = ?", b.RefereeID).First(&referee)
		
		daysRemaining := int(time.Until(b.ExpiryDate).Hours() / 24)
		if daysRemaining < 0 {
			daysRemaining = 0
		}

		activeUsers = append(activeUsers, gin.H{
			"id":           b.RefereeID,
			"nickname":     getStringValue(referee.Nickname),
			"avatar":       getStringValue(referee.Avatar),
			"daysRemaining": daysRemaining,
			"hasFullBook":  getBoolValue(referee.HasFullBook),
			"bindingDate":  b.BindingDate,
			"status":       "active",
		})
	}

	// 7. 获取已转化用户列表
	var convertedBindingsList []model.ReferralBinding
	db.Where("referrer_id = ? AND status = 'active' AND purchase_count > 0", userId).
		Order("last_purchase_date DESC").
		Limit(20).
		Find(&convertedBindingsList)

	convertedUsers := []gin.H{}
	for _, b := range convertedBindingsList {
		var referee model.User
		db.Where("id = ?", b.RefereeID).First(&referee)

		commission := 0.0
		if b.TotalCommission != nil {
			commission = *b.TotalCommission
		}
		orderAmount := commission / distributorShare

		convertedUsers = append(convertedUsers, gin.H{
			"id":             b.RefereeID,
			"nickname":       getStringValue(referee.Nickname),
			"avatar":         getStringValue(referee.Avatar),
			"commission":     commission,
			"orderAmount":    orderAmount,
			"purchaseCount":  getIntValue(b.PurchaseCount),
			"conversionDate": b.LastPurchaseDate,
			"status":         "converted",
		})
	}

	// 8. 获取已过期用户列表
	var expiredBindingsList []model.ReferralBinding
	db.Where(
		"referrer_id = ? AND (status = 'expired' OR (status = 'active' AND expiry_date <= ?))",
		userId, time.Now(),
	).Order("expiry_date DESC").Limit(20).Find(&expiredBindingsList)

	expiredUsers := []gin.H{}
	for _, b := range expiredBindingsList {
		var referee model.User
		db.Where("id = ?", b.RefereeID).First(&referee)

		expiredUsers = append(expiredUsers, gin.H{
			"id":          b.RefereeID,
			"nickname":    getStringValue(referee.Nickname),
			"avatar":      getStringValue(referee.Avatar),
			"bindingDate": b.BindingDate,
			"expiryDate":  b.ExpiryDate,
			"status":      "expired",
		})
	}

	// 9. 获取收益明细
	var earningsDetailsList []model.Order
	db.Where("referrer_id = ? AND status = 'paid'", userId).
		Order("pay_time DESC").
		Limit(20).
		Find(&earningsDetailsList)

	earningsDetails := []gin.H{}
	for i := range earningsDetailsList {
		e := &earningsDetailsList[i]
		var buyer model.User
		db.Where("id = ?", e.UserID).First(&buyer)

		commission := computeOrderCommission(db, e, nil)
		earningsDetails = append(earningsDetails, gin.H{
			"id":            e.ID,
			"orderSn":       e.OrderSN,
			"amount":        e.Amount,
			"commission":    commission,
			"productType":   e.ProductType,
			"productId":     getStringValue(e.ProductID),
			"description":   getStringValue(e.Description),
			"buyerNickname": getStringValue(buyer.Nickname),
			"buyerAvatar":   getStringValue(buyer.Avatar),
			"payTime":       e.PayTime,
		})
	}

	// 计算收益（totalCommission 已按订单逐条计算）
	estimatedEarnings := totalCommission
	availableEarnings := totalCommission - withdrawnFromTable - pendingWithdrawAmount
	if availableEarnings < 0 {
		availableEarnings = 0
	}

	// 计算即将过期用户数（7天内）
	sevenDaysLater := time.Now().Add(7 * 24 * time.Hour)
	expiringCount := 0
	for _, b := range activeBindingsList {
		if b.ExpiryDate.After(time.Now()) && b.ExpiryDate.Before(sevenDaysLater) {
			expiringCount++
		}
	}

	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"data": gin.H{
			// 核心可见数据
			"bindingCount":  activeBindings,
			"visitCount":    totalVisits,
			"paidCount":     uniquePaidCount,
			"expiredCount":  expiredBindings,

			// 收益数据
			"totalCommission":       round(totalCommission, 2),
			"availableEarnings":     round(availableEarnings, 2),
			"pendingWithdrawAmount": round(pendingWithdrawAmount, 2),
			"withdrawnEarnings":     withdrawnFromTable,
			"earnings":              getFloatValue(user.Earnings),
			"pendingEarnings":       getFloatValue(user.PendingEarnings),
			"estimatedEarnings":     round(estimatedEarnings, 2),
			"shareRate":             int(distributorShare * 100),
			"minWithdrawAmount":     minWithdrawAmount,
			"bindingDays":           bindingDays,
			"userDiscount":          userDiscount,
			"withdrawFee":           withdrawFee,

			// 推荐码
			"referralCode":  getStringValue(user.ReferralCode),
			"referralCount": getIntValue(user.ReferralCount),

			// 详细统计
			"stats": gin.H{
				"totalBindings":      totalBindings,
				"activeBindings":     activeBindings,
				"convertedBindings":  convertedBindings,
				"expiredBindings":    expiredBindings,
				"expiringCount":      expiringCount,
				"totalPaymentAmount": totalAmount,
			},

			// 用户列表
			"activeUsers":    activeUsers,
			"convertedUsers": convertedUsers,
			"expiredUsers":   expiredUsers,

			// 收益明细
			"earningsDetails": earningsDetails,
		},
	})
}

// round 四舍五入保留小数
func round(val float64, precision int) float64 {
	ratio := math.Pow(10, float64(precision))
	return math.Round(val*ratio) / ratio
}

// MyEarnings GET /api/miniprogram/earnings 仅返回「我的收益」卡片所需数据（累计、可提现、推荐人数），用于我的页展示与刷新
func MyEarnings(c *gin.Context) {
	userId := c.Query("userId")
	if userId == "" {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "用户ID不能为空"})
		return
	}
	db := database.DB()
	var user model.User
	if err := db.Where("id = ?", userId).First(&user).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"success": false, "error": "用户不存在"})
		return
	}
	var paidOrders []model.Order
	db.Where("referrer_id = ? AND status = ?", userId, "paid").Find(&paidOrders)
	totalCommission := 0.0
	for i := range paidOrders {
		totalCommission += computeOrderCommission(db, &paidOrders[i], nil)
	}
	var pendingWithdraw struct{ Total float64 }
	db.Model(&model.Withdrawal{}).
		Select("COALESCE(SUM(amount), 0) as total").
		Where("user_id = ? AND status IN ?", userId, []string{"pending", "processing", "pending_confirm"}).
		Scan(&pendingWithdraw)
	var successWithdraw struct{ Total float64 }
	db.Model(&model.Withdrawal{}).
		Select("COALESCE(SUM(amount), 0) as total").
		Where("user_id = ? AND status = ?", userId, "success").
		Scan(&successWithdraw)
	pendingWithdrawAmount := pendingWithdraw.Total
	withdrawnFromTable := successWithdraw.Total
	availableEarnings := totalCommission - withdrawnFromTable - pendingWithdrawAmount
	if availableEarnings < 0 {
		availableEarnings = 0
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"data": gin.H{
			"totalCommission":   round(totalCommission, 2),
			"availableEarnings": round(availableEarnings, 2),
			"referralCount":     getIntValue(user.ReferralCount),
		},
	})
}

// ReferralVisit POST /api/referral/visit 记录推荐访问（不需登录）
func ReferralVisit(c *gin.Context) {
	var req struct {
		ReferralCode string `json:"referralCode" binding:"required"`
		VisitorOpenID string `json:"visitorOpenId"`
		VisitorID    string `json:"visitorId"`
		Source       string `json:"source"`
		Page         string `json:"page"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "推荐码不能为空"})
		return
	}
	db := database.DB()
	var referrer model.User
	if err := db.Where("referral_code = ?", req.ReferralCode).First(&referrer).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "推荐码无效"})
		return
	}
	source := req.Source
	if source == "" {
		source = "miniprogram"
	}
	visitorID := req.VisitorID
	if visitorID == "" {
		visitorID = ""
	}
	vOpenID := req.VisitorOpenID
	vPage := req.Page
	err := db.Create(&model.ReferralVisit{
		ReferrerID:   referrer.ID,
		VisitorID:    strPtrOrNil(visitorID),
		VisitorOpenID: strPtrOrNil(vOpenID),
		Source:       strPtrOrNil(source),
		Page:         strPtrOrNil(vPage),
	}).Error
	if err != nil {
		c.JSON(http.StatusOK, gin.H{"success": true, "message": "已处理"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "message": "访问已记录"})
}
func strPtrOrNil(s string) *string {
	if s == "" {
		return nil
	}
	return &s
}