/*
Copyright 2025 linux.do

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package payment

import (
	"encoding/base64"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"github.com/linux-do/credit/internal/common"
	"github.com/linux-do/credit/internal/db"
	"github.com/linux-do/credit/internal/model"
	"github.com/linux-do/credit/internal/util"
	"github.com/shopspring/decimal"
)

// CreateOrderRequest 商户创建订单统一请求
type CreateOrderRequest struct {
	OrderName       string          `json:"order_name" binding:"required,max=64"`
	MerchantOrderNo *string         `json:"merchant_order_no" binding:"omitempty,min=1,max=64"`
	Amount          decimal.Decimal `json:"amount" binding:"required"`
	Remark          string          `json:"remark" binding:"max=100"`
	PaymentType     string          `json:"payment_type"`
	NotifyURL       string          `json:"notify_url" binding:"omitempty,max=100,url"`
	ReturnURL       string          `json:"return_url" binding:"omitempty,max=100,url"`
}

// EPayRequest 易支付请求
type EPayRequest struct {
	ClientID        string          `form:"pid" binding:"required"`
	OrderName       string          `form:"name" binding:"required,max=64"`
	MerchantOrderNo *string         `form:"out_trade_no" binding:"required,min=1,max=64"`
	Amount          decimal.Decimal `form:"money" binding:"required"`
	NotifyURL       string          `form:"notify_url" binding:"omitempty,max=100,url"`
	ReturnURL       string          `form:"return_url" binding:"omitempty,max=100,url"`
	Device          string          `form:"device"`
	Sign            string          `form:"sign" binding:"required"`
	PayType         string          `form:"type" binding:"required"`
	SignType        string          `form:"sign_type"`
}

// LDCPayRequest LDC支付请求
type LDCPayRequest struct {
	ClientID        string          `form:"client_id" binding:"required"`
	OrderName       string          `form:"order_name" binding:"required,max=64"`
	MerchantOrderNo *string         `form:"out_trade_no" binding:"required,min=1,max=64"`
	Amount          decimal.Decimal `form:"money" binding:"required"`
	NotifyURL       string          `form:"notify_url" binding:"omitempty,max=100,url"`
	ReturnURL       string          `form:"return_url" binding:"omitempty,max=100,url"`
	PayType         string          `form:"type" binding:"required"`
	Sign            string          `form:"sign" binding:"required"`
}

// NewCreateOrderRequest 从支付请求创建通用订单请求
func NewCreateOrderRequest(orderName string, merchantOrderNo *string, amount decimal.Decimal, payType string, notifyURL string, returnURL string) *CreateOrderRequest {
	return &CreateOrderRequest{
		OrderName:       orderName,
		MerchantOrderNo: merchantOrderNo,
		Amount:          amount,
		PaymentType:     payType,
		NotifyURL:       notifyURL,
		ReturnURL:       returnURL,
	}
}

// RequireMerchantAuth 验证商户 ClientID/ClientSecret（Basic Auth）
func RequireMerchantAuth() gin.HandlerFunc {
	return func(c *gin.Context) {
		// Authorization: Basic base64(ClientID:ClientSecret)
		authHeader := c.GetHeader("Authorization")
		if authHeader == "" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, util.Err("缺少认证信息"))
			return
		}

		// 解析 Basic Auth
		parts := strings.SplitN(authHeader, " ", 2)
		if len(parts) != 2 || parts[0] != "Basic" {
			c.AbortWithStatusJSON(http.StatusUnauthorized, util.Err("认证格式错误"))
			return
		}

		// 解码 base64
		decoded, err := base64.StdEncoding.DecodeString(parts[1])
		if err != nil {
			c.AbortWithStatusJSON(http.StatusUnauthorized, util.Err("认证信息解码失败"))
			return
		}

		// 解析 ClientID:ClientSecret
		credentials := strings.SplitN(string(decoded), ":", 2)
		if len(credentials) != 2 {
			c.AbortWithStatusJSON(http.StatusUnauthorized, util.Err("认证信息格式错误"))
			return
		}

		clientID := credentials[0]
		clientSecret := credentials[1]

		var apiKey model.MerchantAPIKey
		if err := db.DB(c.Request.Context()).
			Where("client_secret = ? AND client_id = ?", clientSecret, clientID).
			First(&apiKey).Error; err != nil {
			c.AbortWithStatusJSON(http.StatusUnauthorized, util.Err("认证失败"))
			return
		}

		util.SetToContext(c, APIKeyObjKey, &apiKey)

		c.Next()
	}
}

// RequireSignatureAuth 验证签名
func RequireSignatureAuth() gin.HandlerFunc {
	return func(c *gin.Context) {
		PayType := c.Request.FormValue("type")

		var apiKey model.MerchantAPIKey
		var createOrderReq *CreateOrderRequest
		var err error

		switch PayType {
		case common.PayTypeLDCPay:
			createOrderReq, err = VerifySignatureEd25519(c, &apiKey)
			if err != nil {
				c.AbortWithStatusJSON(http.StatusUnauthorized, util.Err(err.Error()))
				return
			}
		case common.PayTypeEPay:
			createOrderReq, err = VerifySignatureMD5(c, &apiKey)
			if err != nil {
				c.AbortWithStatusJSON(http.StatusUnauthorized, util.Err(err.Error()))
				return
			}
		default:
			c.AbortWithStatusJSON(http.StatusBadRequest, util.Err("不支持的请求类型"))
			return
		}

		util.SetToContext(c, CreateOrderRequestKey, createOrderReq)
		util.SetToContext(c, APIKeyObjKey, &apiKey)

		c.Next()
	}
}