package pay

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

    "bindbox-game/configs"
    "bindbox-game/internal/code"
    "bindbox-game/internal/pkg/core"
    "bindbox-game/internal/repository/mysql/model"

    "github.com/wechatpay-apiv3/wechatpay-go/core/auth/verifiers"
    "github.com/wechatpay-apiv3/wechatpay-go/core/downloader"
    "github.com/wechatpay-apiv3/wechatpay-go/core/notify"
    "github.com/wechatpay-apiv3/wechatpay-go/services/payments"
    "github.com/wechatpay-apiv3/wechatpay-go/utils"
)

type notifyAck struct {
	Code    string `json:"code"`
	Message string `json:"message"`
}

// WechatNotify 微信支付回调通知处理
// 入参：微信官方通知，验签并解密resource，推进订单状态为已支付
// 幂等：若订单已为已支付则直接ACK
func (h *handler) WechatNotify() core.HandlerFunc {
    return func(ctx core.Context) {
        c := configs.Get()
        if c.WechatPay.ApiV3Key == "" {
            ctx.AbortWithError(core.Error(http.StatusBadRequest, 150000, "wechat pay config incomplete"))
            return
        }
        var handler *notify.Handler
        if c.WechatPay.PublicKeyID != "" && c.WechatPay.PublicKeyPath != "" {
            pubKey, err := utils.LoadPublicKeyWithPath(c.WechatPay.PublicKeyPath)
            if err != nil {
                ctx.AbortWithError(core.Error(http.StatusInternalServerError, 150001, err.Error()))
                return
            }
            handler = notify.NewNotifyHandler(c.WechatPay.ApiV3Key, verifiers.NewSHA256WithRSAPubkeyVerifier(c.WechatPay.PublicKeyID, *pubKey))
        } else {
            if c.WechatPay.MchID == "" || c.WechatPay.SerialNo == "" || c.WechatPay.PrivateKeyPath == "" {
                ctx.AbortWithError(core.Error(http.StatusBadRequest, 150000, "wechat pay config incomplete"))
                return
            }
            mchPrivateKey, err := utils.LoadPrivateKeyWithPath(c.WechatPay.PrivateKeyPath)
            if err != nil {
                ctx.AbortWithError(core.Error(http.StatusInternalServerError, 150002, err.Error()))
                return
            }
            if err := downloader.MgrInstance().RegisterDownloaderWithPrivateKey(ctx.RequestContext(), mchPrivateKey, c.WechatPay.SerialNo, c.WechatPay.MchID, c.WechatPay.ApiV3Key); err != nil {
                ctx.AbortWithError(core.Error(http.StatusInternalServerError, 150003, err.Error()))
                return
            }
            certificateVisitor := downloader.MgrInstance().GetCertificateVisitor(c.WechatPay.MchID)
            handler = notify.NewNotifyHandler(c.WechatPay.ApiV3Key, verifiers.NewSHA256WithRSAVerifier(certificateVisitor))
        }

        var transaction payments.Transaction
        notification, err := handler.ParseNotifyRequest(ctx.RequestContext(), ctx.Request(), &transaction)
        if err != nil {
            ctx.AbortWithError(core.Error(http.StatusBadRequest, code.ParamBindError, err.Error()))
            return
        }
        // 事件去重处理
        var existed *model.PaymentNotifyEvents
        if notification != nil && notification.ID != "" {
            existed, _ = h.readDB.PaymentNotifyEvents.WithContext(ctx.RequestContext()).Where(h.readDB.PaymentNotifyEvents.NotifyID.Eq(notification.ID)).First()
            if existed != nil && existed.Processed {
                ctx.Payload(&notifyAck{Code: "SUCCESS", Message: "OK"})
                return
            }
        }
        if transaction.OutTradeNo == nil {
            ctx.AbortWithError(core.Error(http.StatusBadRequest, code.ParamBindError, "missing out_trade_no"))
            return
        }
        paidAt := time.Now()
		if transaction.SuccessTime != nil {
			if t, err := time.Parse(time.RFC3339, *transaction.SuccessTime); err == nil {
				paidAt = t
			}
		}
        rawStr := func() string { b, _ := json.Marshal(transaction); return string(b) }()
        order, err := h.readDB.Orders.WithContext(ctx.RequestContext()).Where(h.readDB.Orders.OrderNo.Eq(*transaction.OutTradeNo)).First()
        if err != nil || order == nil {
            ctx.AbortWithError(core.Error(http.StatusBadRequest, code.ParamBindError, "order not found for out_trade_no"))
            return
        }
        tx := &model.PaymentTransactions{
            OrderID:      order.ID,
            OrderNo:      *transaction.OutTradeNo,
            Channel:      "wechat_jsapi",
            TransactionID: func() string { if transaction.TransactionId!=nil { return *transaction.TransactionId }; return "" }(),
            AmountTotal:  func() int64 { if transaction.Amount!=nil && transaction.Amount.Total!=nil { return *transaction.Amount.Total }; return 0 }(),
            SuccessTime:  paidAt,
            Raw:          rawStr,
        }
        if err := h.writeDB.PaymentTransactions.WithContext(ctx.RequestContext()).Create(tx); err != nil {
            ctx.AbortWithError(core.Error(http.StatusInternalServerError, 150006, err.Error()))
            return
        }
        // 记录事件
        if notification != nil && notification.ID != "" {
            if existed == nil {
                _ = h.writeDB.PaymentNotifyEvents.WithContext(ctx.RequestContext()).Create(&model.PaymentNotifyEvents{
                    NotifyID:     notification.ID,
                    ResourceType: notification.ResourceType,
                    EventType:    notification.EventType,
                    Summary:      notification.Summary,
                    Raw:          rawStr,
                    Processed:    false,
                })
            }
        }
        _, err = h.writeDB.Orders.WithContext(ctx.RequestContext()).Where(h.writeDB.Orders.OrderNo.Eq(*transaction.OutTradeNo), h.writeDB.Orders.Status.Eq(1)).Updates(map[string]any{
            h.writeDB.Orders.Status.ColumnName().String(): 2,
            h.writeDB.Orders.PaidAt.ColumnName().String(): paidAt,
        })
        if err != nil {
            ctx.AbortWithError(core.Error(http.StatusInternalServerError, 150005, err.Error()))
            return
        }
        // 标记事件处理完成
        if notification != nil && notification.ID != "" {
            _, _ = h.writeDB.PaymentNotifyEvents.WithContext(ctx.RequestContext()).Where(h.readDB.PaymentNotifyEvents.NotifyID.Eq(notification.ID)).Updates(map[string]any{
                h.writeDB.PaymentNotifyEvents.Processed.ColumnName().String(): true,
            })
        }
        ctx.Payload(&notifyAck{Code: "SUCCESS", Message: "OK"})
    }
}