package handler

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"strconv"
	"time"

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

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

// AdminWithdrawalsList GET /api/admin/withdrawals（支持分页 page、pageSize，筛选 status）
func AdminWithdrawalsList(c *gin.Context) {
	statusFilter := c.Query("status")
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("pageSize", "10"))
	if page < 1 {
		page = 1
	}
	if pageSize < 1 || pageSize > 100 {
		pageSize = 10
	}

	db := database.DB()
	q := db.Model(&model.Withdrawal{})
	if statusFilter != "" && statusFilter != "all" {
		q = q.Where("status = ?", statusFilter)
	}
	var total int64
	q.Count(&total)

	var list []model.Withdrawal
	query := db.Order("created_at DESC")
	if statusFilter != "" && statusFilter != "all" {
		query = query.Where("status = ?", statusFilter)
	}
	if err := query.Offset((page - 1) * pageSize).Limit(pageSize).Find(&list).Error; err != nil {
		c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error(), "withdrawals": []interface{}{}, "stats": gin.H{"total": 0}})
		return
	}
	userIds := make([]string, 0, len(list))
	seen := make(map[string]bool)
	for _, w := range list {
		if !seen[w.UserID] {
			seen[w.UserID] = true
			userIds = append(userIds, w.UserID)
		}
	}
	var users []model.User
	if len(userIds) > 0 {
		database.DB().Where("id IN ?", userIds).Find(&users)
	}
	userMap := make(map[string]*model.User)
	for i := range users {
		userMap[users[i].ID] = &users[i]
	}
	withdrawals := make([]gin.H, 0, len(list))
	for _, w := range list {
		u := userMap[w.UserID]
		userName := "未知用户"
		var userAvatar *string
		account := "未绑定微信号"
		if w.WechatID != nil && *w.WechatID != "" {
			account = *w.WechatID
		}
		if u != nil {
			if u.Nickname != nil {
				userName = *u.Nickname
			}
			userAvatar = u.Avatar
			if u.WechatID != nil && *u.WechatID != "" {
				account = *u.WechatID
			}
		}
		st := "pending"
		if w.Status != nil {
			st = *w.Status
			if st == "success" {
				st = "completed"
			} else if st == "failed" {
				st = "rejected"
			} else if st == "pending_confirm" {
				st = "pending_confirm"
			}
		}
		userConfirmedAt := interface{}(nil)
		if w.UserConfirmedAt != nil && !w.UserConfirmedAt.IsZero() {
			userConfirmedAt = w.UserConfirmedAt.Format("2006-01-02 15:04:05")
		}
		withdrawals = append(withdrawals, gin.H{
			"id": w.ID, "userId": w.UserID, "userName": userName, "userAvatar": userAvatar,
			"amount": w.Amount, "status": st, "createdAt": w.CreatedAt,
			"method": "wechat", "account": account,
			"userConfirmedAt": userConfirmedAt,
		})
	}

	totalPages := int(total) / pageSize
	if int(total)%pageSize > 0 {
		totalPages++
	}
	var pendingCount, successCount, failedCount int64
	var pendingAmount, successAmount float64
	db.Model(&model.Withdrawal{}).Where("status IN ?", []string{"pending", "pending_confirm", "processing"}).Count(&pendingCount)
	db.Model(&model.Withdrawal{}).Where("status IN ?", []string{"pending", "pending_confirm", "processing"}).Select("COALESCE(SUM(amount), 0)").Scan(&pendingAmount)
	db.Model(&model.Withdrawal{}).Where("status IN ?", []string{"success", "completed"}).Count(&successCount)
	db.Model(&model.Withdrawal{}).Where("status IN ?", []string{"success", "completed"}).Select("COALESCE(SUM(amount), 0)").Scan(&successAmount)
	db.Model(&model.Withdrawal{}).Where("status IN ?", []string{"failed", "rejected"}).Count(&failedCount)

	c.JSON(http.StatusOK, gin.H{
		"success": true, "withdrawals": withdrawals,
		"total": total, "page": page, "pageSize": pageSize, "totalPages": totalPages,
		"stats": gin.H{
			"total": total, "pendingCount": pendingCount, "pendingAmount": pendingAmount,
			"successCount": successCount, "successAmount": successAmount, "failedCount": failedCount,
		},
	})
}

// AdminWithdrawalsAction PUT /api/admin/withdrawals 审核/打款
// approve：先调微信转账接口打款，成功则标为 processing，失败则标为 failed 并返回错误。
// 若未初始化微信转账客户端，则仅将状态标为 success（线下打款后批准）。
// reject：直接标为 failed。
func AdminWithdrawalsAction(c *gin.Context) {
	var body struct {
		ID           string `json:"id"`
		Action       string `json:"action"`
		ErrorMessage string `json:"errorMessage"`
		Reason       string `json:"reason"`
	}
	if err := c.ShouldBindJSON(&body); err != nil || body.ID == "" {
		c.JSON(http.StatusOK, gin.H{"success": false, "error": "缺少 id 或请求体无效"})
		return
	}
	reason := body.ErrorMessage
	if reason == "" {
		reason = body.Reason
	}
	if reason == "" && body.Action == "reject" {
		reason = "管理员拒绝"
	}

	db := database.DB()
	now := time.Now()

	switch body.Action {
	case "reject":
		err := db.Model(&model.Withdrawal{}).Where("id = ?", body.ID).Updates(map[string]interface{}{
			"status":         "failed",
			"error_message":  reason,
			"fail_reason":    reason,
			"processed_at":   now,
		}).Error
		if err != nil {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
			return
		}
		c.JSON(http.StatusOK, gin.H{"success": true, "message": "已拒绝"})
		return

	case "approve":
		var w model.Withdrawal
		if err := db.Where("id = ?", body.ID).First(&w).Error; err != nil {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "提现记录不存在"})
			return
		}
		st := ""
		if w.Status != nil {
			st = *w.Status
		}
		if st != "pending" && st != "processing" && st != "pending_confirm" {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "当前状态不允许批准"})
			return
		}

		openID := ""
		if w.WechatOpenid != nil && *w.WechatOpenid != "" {
			openID = *w.WechatOpenid
		}
		if openID == "" {
			var u model.User
			if err := db.Where("id = ?", w.UserID).First(&u).Error; err == nil && u.OpenID != nil {
				openID = *u.OpenID
			}
		}
		if openID == "" {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "用户未绑定微信 openid，无法打款"})
			return
		}

		// 批准前二次校验可提现金额，与申请时口径一致，防止退款/冲正后超额打款
		available, _, _, _, _ := computeAvailableWithdraw(db, w.UserID)
		if w.Amount > available {
			c.JSON(http.StatusOK, gin.H{
				"success": false,
				"error":   "用户当前可提现不足，无法批准",
				"message": fmt.Sprintf("用户当前可提现 ¥%.2f，本笔申请 ¥%.2f，可能因退款/冲正导致。请核对后再批或联系用户。", available, w.Amount),
			})
			return
		}

		// 调用微信转账接口：按提现手续费扣除后打款，例如申请100元、手续费5%则实际打款95元
		remark := "提现"
		if w.Remark != nil && *w.Remark != "" {
			remark = *w.Remark
		}
		withdrawFee := 0.0
		var refCfg model.SystemConfig
		if err := db.Where("config_key = ?", "referral_config").First(&refCfg).Error; err == nil {
			var refVal map[string]interface{}
			if err := json.Unmarshal(refCfg.ConfigValue, &refVal); err == nil {
				if v, ok := refVal["withdrawFee"].(float64); ok {
					withdrawFee = v / 100
				}
			}
		}
		actualAmount := w.Amount * (1 - withdrawFee)
		if actualAmount < 0.01 {
			actualAmount = 0.01
		}
		amountFen := int(actualAmount * 100)
		if amountFen < 1 {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "提现金额异常"})
			return
		}
		outBillNo := w.ID // 商户单号，回调时 out_bill_no 即此值，用于更新该条提现
		params := wechat.FundAppTransferParams{
			OutBillNo:       outBillNo,
			OpenID:          openID,
			Amount:          amountFen,
			Remark:          remark,
			NotifyURL:       "", // 由 wechat 包从配置读取 WechatTransferURL
			TransferSceneId: "1005",
		}

		result, err := wechat.InitiateTransferByFundApp(params)
		if err != nil {
			errMsg := err.Error()
			fmt.Printf("[AdminWithdrawals] 发起转账失败 id=%s: %s\n", body.ID, errMsg)
			// 未初始化或未配置转账：仅标记为已打款并提示线下处理
			if errMsg == "支付/转账未初始化，请先调用 wechat.Init" || errMsg == "转账客户端未初始化" {
				_ = db.Model(&w).Updates(map[string]interface{}{
					"status":       "success",
					"processed_at": now,
				}).Error
				c.JSON(http.StatusOK, gin.H{
					"success": true,
					"message": "已标记为已打款。当前未接入微信转账，请线下打款。",
				})
				return
			}
			// 微信接口报错或其它失败：把微信/具体原因返回给管理端展示，不返回「微信处理中」
			failMsg := errMsg
			_ = db.Model(&w).Updates(map[string]interface{}{
				"status":        "failed",
				"fail_reason":   failMsg,
				"error_message": failMsg,
				"processed_at":  now,
			}).Error
			c.JSON(http.StatusOK, gin.H{
				"success": false,
				"error":   "发起打款失败",
				"message": failMsg, // 管理端直接展示微信报错信息（如 IP 白名单、参数错误等）
			})
			return
		}

		// 防护：微信未返回商户单号时也按失败返回，避免管理端显示「已发起打款」却无单号
		if result.OutBillNo == "" {
			failMsg := "微信未返回商户单号，请检查商户平台（如 IP 白名单）或查看服务端日志"
			_ = db.Model(&w).Updates(map[string]interface{}{
				"status":        "failed",
				"fail_reason":   failMsg,
				"error_message": failMsg,
				"processed_at":  now,
			}).Error
			c.JSON(http.StatusOK, gin.H{
				"success": false,
				"error":   "发起打款失败",
				"message": failMsg,
			})
			return
		}

		// 打款已受理（微信同步返回），立即落库：商户单号、微信单号、package_info、按 state 设 status（不依赖回调）
		fmt.Printf("[AdminWithdrawals] 微信已受理 id=%s out_bill_no=%s transfer_bill_no=%s state=%s\n", body.ID, result.OutBillNo, result.TransferBillNo, result.State)
		rowStatus := "processing"
		if result.State == "WAIT_USER_CONFIRM" {
			rowStatus = "pending_confirm" // 待用户在小程序点击确认收款，回调在用户确认后才触发
		}
		upd := map[string]interface{}{
			"status":       rowStatus,
			"detail_no":    result.OutBillNo,
			"batch_no":     result.OutBillNo,
			"batch_id":     result.TransferBillNo,
			"processed_at": now,
		}
		if result.PackageInfo != "" {
			upd["package_info"] = result.PackageInfo
		}
		if err := db.Model(&w).Updates(upd).Error; err != nil {
			fmt.Printf("[AdminWithdrawals] 更新提现状态失败 id=%s: %v\n", body.ID, err)
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "更新状态失败: " + err.Error()})
			return
		}
		// 发起转账成功后发订阅消息（异步，失败不影响接口返回）
		if openID != "" {
			go func() {
				ctx := context.Background()
				if err := wechat.SendWithdrawSubscribeMessage(ctx, openID, w.Amount, true); err != nil {
					fmt.Printf("[AdminWithdrawals] 订阅消息发送失败 id=%s: %v\n", body.ID, err)
				}
			}()
		}
		c.JSON(http.StatusOK, gin.H{
			"success": true,
			"message": "已发起打款，微信处理中",
			"data": gin.H{
				"out_bill_no":      result.OutBillNo,
				"transfer_bill_no": result.TransferBillNo,
			},
		})
		return

	default:
		c.JSON(http.StatusOK, gin.H{"success": false, "error": "action 须为 approve 或 reject"})
	}
}

// AdminWithdrawalsSync POST /api/admin/withdrawals/sync 主动向微信查询转账结果并更新状态（无回调时的备选）
// body: { "id": "提现记录id" } 同步单条；不传 id 或 id 为空则同步所有 processing/pending_confirm
func AdminWithdrawalsSync(c *gin.Context) {
	var body struct {
		ID string `json:"id"`
	}
	_ = c.ShouldBindJSON(&body)

	db := database.DB()
	var list []model.Withdrawal
	if body.ID != "" {
		var w model.Withdrawal
		if err := db.Where("id = ?", body.ID).First(&w).Error; err != nil {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "提现记录不存在"})
			return
		}
		list = []model.Withdrawal{w}
	} else {
		if err := db.Where("status IN ?", []string{"processing", "pending_confirm"}).
			Find(&list).Error; err != nil || len(list) == 0 {
			c.JSON(http.StatusOK, gin.H{"success": true, "message": "暂无待同步记录", "synced": 0})
			return
		}
	}

	now := time.Now()
	synced := 0
	for _, w := range list {
		batchNo := ""
		detailNo := ""
		if w.BatchNo != nil {
			batchNo = *w.BatchNo
		}
		if w.DetailNo != nil {
			detailNo = *w.DetailNo
		}
		if detailNo == "" {
			continue
		}
		var status, failReason string
		// FundApp 单笔：batch_no == detail_no 时用商户单号查询
		if batchNo == detailNo {
			state, _, fail, err := wechat.QueryTransferByOutBill(detailNo)
			if err != nil {
				continue
			}
			status = state
			failReason = fail
		} else {
			res, err := wechat.QueryTransfer(batchNo, detailNo)
			if err != nil {
				continue
			}
			if s, ok := res["detail_status"].(string); ok {
				status = s
			}
			if s, ok := res["fail_reason"].(string); ok {
				failReason = s
			}
		}
		up := map[string]interface{}{"processed_at": now}
		switch status {
		case "SUCCESS":
			up["status"] = "success"
		case "FAIL":
			up["status"] = "failed"
			if failReason != "" {
				up["fail_reason"] = failReason
			}
		default:
			continue
		}
		if err := db.Model(&model.Withdrawal{}).Where("id = ?", w.ID).Updates(up).Error; err != nil {
			continue
		}
		synced++
		fmt.Printf("[AdminWithdrawals] 同步状态 id=%s -> %s\n", w.ID, up["status"])
	}

	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "已向微信查询并更新",
		"synced":  synced,
		"total":   len(list),
	})
}