package v1

import (
	"io"
	"net/http"

	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/internal/dto"
	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/internal/middleware"
	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/internal/service"
	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/pkg/app"
	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/pkg/errcode"
	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/pkg/wechat"
	"github.com/gin-gonic/gin"
)

// OrderHandler 订单与退款相关接口。
type OrderHandler struct {
	svc *service.OrderService
}

// NewOrderHandler 创建订单 handler。
func NewOrderHandler() *OrderHandler {
	return &OrderHandler{svc: service.NewOrderService()}
}

// Create 创建订单并发起微信下单。
func (h *OrderHandler) Create(c *gin.Context) {
	response := app.NewResponse(c)
	userID, ok := middleware.GetUserID(c.Request.Context())
	if !ok {
		response.ToErrorResponse(errcode.Unauthorized)
		return
	}
	var request dto.OrderCreateRequest
	if err := c.ShouldBindJSON(&request); err != nil {
		response.ToErrorResponse(errcode.InvalidParams.WithDetails(err.Error()))
		return
	}
	out, e := h.svc.Create(c.Request.Context(), userID, &request)
	if e != nil {
		response.ToErrorResponse(e)
		return
	}
	response.ToResponse(out)
}

// VirtualCreate 创建虚拟支付订单（小程序虚拟支付，覆盖 iOS/Android 全终端）。
func (h *OrderHandler) VirtualCreate(c *gin.Context) {
	response := app.NewResponse(c)
	userID, ok := middleware.GetUserID(c.Request.Context())
	if !ok {
		response.ToErrorResponse(errcode.Unauthorized)
		return
	}
	var request dto.VirtualOrderCreateRequest
	if err := c.ShouldBindJSON(&request); err != nil {
		response.ToErrorResponse(errcode.InvalidParams.WithDetails(err.Error()))
		return
	}
	out, e := h.svc.VirtualOrderCreate(c.Request.Context(), userID, &request)
	if e != nil {
		response.ToErrorResponse(e)
		return
	}
	response.ToResponse(out)
}

// List 分页查询我的订单。
func (h *OrderHandler) List(c *gin.Context) {
	response := app.NewResponse(c)
	userID, ok := middleware.GetUserID(c.Request.Context())
	if !ok {
		response.ToErrorResponse(errcode.Unauthorized)
		return
	}
	var request dto.OrderListRequest
	if err := c.ShouldBindQuery(&request); err != nil {
		response.ToErrorResponse(errcode.InvalidParams.WithDetails(err.Error()))
		return
	}
	out, e := h.svc.List(c.Request.Context(), userID, &request)
	if e != nil {
		response.ToErrorResponse(e)
		return
	}
	response.ToResponse(out)
}

// Cancel 取消订单（orderNo 来自路径参数）。
func (h *OrderHandler) Cancel(c *gin.Context) {
	response := app.NewResponse(c)
	userID, ok := middleware.GetUserID(c.Request.Context())
	if !ok {
		response.ToErrorResponse(errcode.Unauthorized)
		return
	}
	request := dto.OrderCancelRequest{OrderNo: c.Param("orderNo")}
	if request.OrderNo == "" {
		response.ToErrorResponse(errcode.InvalidParams)
		return
	}
	out, e := h.svc.Cancel(c.Request.Context(), userID, &request)
	if e != nil {
		response.ToErrorResponse(e)
		return
	}
	response.ToResponse(out)
}

// RefundApply 申请退款。
func (h *OrderHandler) RefundApply(c *gin.Context) {
	response := app.NewResponse(c)
	userID, ok := middleware.GetUserID(c.Request.Context())
	if !ok {
		response.ToErrorResponse(errcode.Unauthorized)
		return
	}
	var request dto.RefundApplyRequest
	if err := c.ShouldBindJSON(&request); err != nil {
		response.ToErrorResponse(errcode.InvalidParams.WithDetails(err.Error()))
		return
	}
	out, e := h.svc.RefundApply(c.Request.Context(), userID, &request)
	if e != nil {
		response.ToErrorResponse(e)
		return
	}
	response.ToResponse(out)
}

// PayNotify 微信支付结果回调（公开，按微信规范返回受理结果）。
func (h *OrderHandler) PayNotify(c *gin.Context) {
	if e := h.svc.PayNotify(c.Request.Context(), c.Request); e != nil {
		wechatCallbackFail(c, e.Msg())
		return
	}
	wechatCallbackSuccess(c)
}

// RefundNotify 微信退款结果回调（公开，按微信规范返回受理结果）。
func (h *OrderHandler) RefundNotify(c *gin.Context) {
	if e := h.svc.RefundNotify(c.Request.Context(), c.Request); e != nil {
		wechatCallbackFail(c, e.Msg())
		return
	}
	wechatCallbackSuccess(c)
}

// XPayVerify 虚拟支付消息推送 URL 配置验证（GET）：校验签名并原样回显 echostr。
// 兼容两种模式：安全模式带 msg_signature 且 echostr 为密文（需解密后回显明文）；
// 明文模式带 signature，直接回显 echostr。
func (h *OrderHandler) XPayVerify(c *gin.Context) {
	timestamp := c.Query("timestamp")
	nonce := c.Query("nonce")
	echostr := c.Query("echostr")

	if msgSignature := c.Query("msg_signature"); msgSignature != "" {
		plain, err := wechat.DecodeEchoStr(echostr, timestamp, nonce, msgSignature)
		if err != nil {
			// 兼容模式：echostr 可能仍是明文（msg_signature 对明文计算），原样回显。
			c.String(http.StatusOK, echostr)
			return
		}
		c.String(http.StatusOK, plain)
		return
	}

	if wechat.VerifyNotifyURL(timestamp, nonce, c.Query("signature")) {
		c.String(http.StatusOK, echostr)
		return
	}
	c.String(http.StatusUnauthorized, "invalid signature")
}

// XPayNotify 虚拟支付消息推送回调（POST，公开，按虚拟支付规范返回 ErrCode 应答）。
// 安全模式下包体为密文信封：先验签解密再交给业务层，回包同样加密；明文模式直接透传。
func (h *OrderHandler) XPayNotify(c *gin.Context) {
	raw, err := io.ReadAll(c.Request.Body)
	if err != nil {
		writeXPayNotifyReply(c, false, false)
		return
	}

	encrypted := wechat.IsEncryptedNotify(c.Query("msg_signature"))
	body := raw
	if encrypted {
		plain, derr := wechat.DecodeEncryptedNotify(raw, c.Query("timestamp"), c.Query("nonce"), c.Query("msg_signature"))
		if derr != nil {
			// 验签/解密失败：回失败应答触发微信重试（fail-closed）。
			writeXPayNotifyReply(c, true, false)
			return
		}
		body = plain
	}

	resp := h.svc.XPayNotify(c.Request.Context(), body)
	c.Data(http.StatusOK, "application/json; charset=utf-8", encryptIfNeeded(c, resp, encrypted))
}

// writeXPayNotifyReply 按模式构造应答：加密模式下加密，否则回明文。
func writeXPayNotifyReply(c *gin.Context, encrypted, success bool) {
	resp := wechat.BuildNotifyResponse(success)
	c.Data(http.StatusOK, "application/json; charset=utf-8", encryptIfNeeded(c, resp, encrypted))
}

// encryptIfNeeded 安全模式下把明文应答加密为信封；加密不可用时退回明文（仍返回 200）。
func encryptIfNeeded(c *gin.Context, plain []byte, encrypted bool) []byte {
	if !encrypted {
		return plain
	}
	out, err := wechat.EncodeEncryptedNotify(plain, c.Query("nonce"))
	if err != nil {
		return plain
	}
	return out
}

// wechatCallbackSuccess 按微信规范返回受理成功，避免微信重复回调。
func wechatCallbackSuccess(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{"code": "SUCCESS", "message": "成功"})
}

// wechatCallbackFail 按微信规范返回受理失败，微信将按策略重试。
func wechatCallbackFail(c *gin.Context, message string) {
	c.JSON(http.StatusInternalServerError, gin.H{"code": "FAIL", "message": message})
}