package payment

import (
	"errors"
	"io"
	"log"
	"net/http"
	"strconv"

	"hfb_sys/backend/internal/integrations/payment/leshua"
	"hfb_sys/backend/internal/middleware"
	"hfb_sys/backend/internal/modules/order"
	"hfb_sys/backend/pkg/response"

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

type Handler struct {
	service *Service
}

func NewHandler(service *Service) *Handler {
	return &Handler{service: service}
}

func (h *Handler) Start(c *gin.Context) {
	userID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	orderID, ok := parseID(c)
	if !ok {
		return
	}
	var req StartPaymentRequest
	_ = c.ShouldBindJSON(&req)
	item, err := h.service.Start(userID, orderID, req, c.ClientIP())
	if err != nil {
		writePaymentError(c, err)
		return
	}
	response.OK(c, item)
}

func (h *Handler) Query(c *gin.Context) {
	userID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	orderID, ok := parseID(c)
	if !ok {
		return
	}
	item, err := h.service.Query(userID, orderID)
	if err != nil {
		writePaymentError(c, err)
		return
	}
	response.OK(c, item)
}

func (h *Handler) WalletRecharge(c *gin.Context) {
	userID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	var req WalletRechargePaymentRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "充值金额不正确")
		return
	}
	item, err := h.service.StartWalletRecharge(userID, req, c.ClientIP())
	if err != nil {
		writePaymentError(c, err)
		return
	}
	response.OK(c, item)
}

func (h *Handler) WalletRechargeQuery(c *gin.Context) {
	userID, ok := currentUserID(c)
	if !ok {
		response.Unauthorized(c, "缺少用户上下文")
		return
	}
	paymentID, ok := parseID(c)
	if !ok {
		return
	}
	item, err := h.service.QueryWalletRecharge(userID, paymentID)
	if err != nil {
		writePaymentError(c, err)
		return
	}
	response.OK(c, item)
}

func (h *Handler) LeshuaNotify(c *gin.Context) {
	body, err := io.ReadAll(io.LimitReader(c.Request.Body, 1<<20))
	if err != nil {
		c.String(http.StatusBadRequest, "FAIL")
		return
	}
	params, err := leshua.ParsePayload(body)
	if err != nil {
		c.String(http.StatusBadRequest, "FAIL")
		return
	}
	rawPayload := string(body)
	contentType := c.GetHeader("Content-Type")
	log.Printf(
		"[payment] leshua notify received third_order_id=%s leshua_order_id=%s status=%s amount=%s content_type=%s raw_payload=%s",
		params["third_order_id"],
		params["leshua_order_id"],
		params["status"],
		params["amount"],
		contentType,
		rawPayload,
	)
	result, err := h.service.HandleLeshuaNotify(params, rawPayload, contentType)
	if err != nil || result == nil || !result.OK {
		log.Printf("[payment] leshua notify failed third_order_id=%s err=%v", params["third_order_id"], err)
		c.String(http.StatusOK, "FAIL")
		return
	}
	log.Printf("[payment] leshua notify processed third_order_id=%s status=%s", params["third_order_id"], params["status"])
	c.String(http.StatusOK, result.Message)
}

func currentUserID(c *gin.Context) (uint64, bool) {
	value, ok := c.Get(middleware.ContextUserID)
	if !ok {
		return 0, false
	}
	userID, ok := value.(uint64)
	return userID, ok
}

func parseID(c *gin.Context) (uint64, bool) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil || id == 0 {
		response.BadRequest(c, "ID 不正确")
		return 0, false
	}
	return id, true
}

func writePaymentError(c *gin.Context, err error) {
	switch {
	case errors.Is(err, ErrDependencyUnavailable):
		response.ServiceUnavailable(c, "数据库未连接")
	case errors.Is(err, ErrPaymentUnavailable):
		response.Error(c, http.StatusBadGateway, "payment_unavailable", "支付渠道暂不可用")
	case errors.Is(err, ErrPaymentCannotStart), errors.Is(err, order.ErrOrderCannotPay):
		response.Error(c, http.StatusConflict, "payment_cannot_start", "当前订单不能支付")
	case errors.Is(err, ErrPaymentVerifyFailed):
		response.Error(c, http.StatusForbidden, "payment_verify_failed", "支付通知验签失败")
	case errors.Is(err, ErrPaymentNotFound), errors.Is(err, gorm.ErrRecordNotFound), order.IsNotFound(err):
		response.Error(c, http.StatusNotFound, "payment_not_found", "支付单不存在")
	case errors.Is(err, order.ErrListingUnavailable):
		response.Error(c, http.StatusConflict, "listing_unavailable", "该账号暂不可租")
	default:
		response.Error(c, http.StatusInternalServerError, "payment_error", "支付处理失败")
	}
}