package handler

import (
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"

	"github.com/wangjia/pay/internal/service"
	"github.com/wangjia/pay/internal/util"
)

type OrderHandler struct {
	svc *service.OrderService
}

func NewOrderHandler(svc *service.OrderService) *OrderHandler {
	return &OrderHandler{svc: svc}
}

type createOrderRequest struct {
	ProductID uint64 `json:"product_id" binding:"required"`
}

// Create POST /api/v1/orders —— 下单，返回支付宝收银台跳转 URL。
func (h *OrderHandler) Create(c *gin.Context) {
	var req createOrderRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		util.RespondError(c, http.StatusBadRequest, "bad_request", "参数错误："+err.Error())
		return
	}
	payURL, order, err := h.svc.Create(c.Request.Context(), req.ProductID, c.ClientIP())
	if err != nil {
		if errors.Is(err, service.ErrProductNotFound) {
			util.RespondError(c, http.StatusNotFound, "product_not_found", err.Error())
			return
		}
		util.RespondError(c, http.StatusInternalServerError, "create_failed", err.Error())
		return
	}
	util.RespondSuccess(c, gin.H{
		"pay_url":      payURL,
		"out_trade_no": order.OutTradeNo,
		"amount":       order.Amount,
		"subject":      order.Subject,
	})
}

// CreateQR POST /api/v1/orders/qr —— 扫码下单，返回二维码码串（前端渲染成二维码）。
func (h *OrderHandler) CreateQR(c *gin.Context) {
	var req createOrderRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		util.RespondError(c, http.StatusBadRequest, "bad_request", "参数错误："+err.Error())
		return
	}
	qr, order, err := h.svc.CreateQR(c.Request.Context(), req.ProductID, c.ClientIP())
	if err != nil {
		if errors.Is(err, service.ErrProductNotFound) {
			util.RespondError(c, http.StatusNotFound, "product_not_found", err.Error())
			return
		}
		util.RespondError(c, http.StatusInternalServerError, "create_failed", err.Error())
		return
	}
	util.RespondSuccess(c, gin.H{
		"qr_code":      qr,
		"out_trade_no": order.OutTradeNo,
		"amount":       order.Amount,
		"subject":      order.Subject,
	})
}

// AlipayNotify POST /api/v1/notify/alipay —— 异步回调。
// 成功必须返回纯文本 "success"，否则支付宝会按策略重发。
func (h *OrderHandler) AlipayNotify(c *gin.Context) {
	if err := h.svc.HandleAlipayNotify(c.Request.Context(), c.Request); err != nil {
		c.String(http.StatusOK, "failure") // 回 failure 让支付宝重试（也可记录后人工处理）
		return
	}
	c.String(http.StatusOK, "success")
}

// GetStatus GET /api/v1/orders/:out_trade_no —— 供结果页轮询订单状态。
func (h *OrderHandler) GetStatus(c *gin.Context) {
	out := c.Param("out_trade_no")
	o, err := h.svc.GetByOutTradeNo(out)
	if err != nil {
		util.RespondError(c, http.StatusNotFound, "order_not_found", "订单不存在")
		return
	}
	util.RespondSuccess(c, gin.H{
		"out_trade_no": o.OutTradeNo,
		"subject":      o.Subject,
		"amount":       o.Amount,
		"status":       o.Status,
		"trade_no":     o.TradeNo,
		"paid_at":      o.PaidAt,
	})
}