添加文件: hb/client.go

hb/client.go

@@ -0,0 +1,299 @@
+package hb
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// Client 手机支付平台客户端
+type Client struct {
+	merchantId    string   // 商户编号
+	signKey       string   // 商户密钥（MD5签名使用）
+	privateKeyPEM string   // 商户RSA私钥（RSA签名使用）
+	baseURL       string   // 接口基础URL
+	httpClient    *http.Client
+}
+
+// ClientOption 客户端配置选项
+type ClientOption func(*Client)
+
+// WithSignKey 设置MD5签名密钥
+func WithSignKey(signKey string) ClientOption {
+	return func(c *Client) {
+		c.signKey = signKey
+	}
+}
+
+// WithPrivateKey 设置RSA私钥（PEM格式）
+func WithPrivateKey(privateKeyPEM string) ClientOption {
+	return func(c *Client) {
+		c.privateKeyPEM = privateKeyPEM
+	}
+}
+
+// WithBaseURL 设置接口基础URL
+func WithBaseURL(baseURL string) ClientOption {
+	return func(c *Client) {
+		c.baseURL = baseURL
+	}
+}
+
+// WithHTTPClient 设置自定义HTTP客户端
+func WithHTTPClient(httpClient *http.Client) ClientOption {
+	return func(c *Client) {
+		c.httpClient = httpClient
+	}
+}
+
+// NewClient 创建新的手机支付平台客户端
+// merchantId: 商户编号
+// opts: 配置选项
+func NewClient(merchantId string, opts ...ClientOption) (*Client, error) {
+	if merchantId == "" {
+		return nil, ErrMerchantIdEmpty
+	}
+
+	c := &Client{
+		merchantId: merchantId,
+		baseURL:    "https://ipos.10086.cn",
+		httpClient: &http.Client{},
+	}
+
+	for _, opt := range opts {
+		opt(c)
+	}
+
+	return c, nil
+}
+
+// Refund 退款接口
+// 通过中国移动手机支付渠道，将已成功交易的款项退还给用户
+func (c *Client) Refund(ctx context.Context, req *RefundRequest) (*RefundResponse, error) {
+	if req == nil {
+		return nil, fmt.Errorf("request cannot be nil")
+	}
+
+	// 设置固定参数
+	req.MerchantId = c.merchantId
+	req.Type = InterfaceTypeOrderRefund
+	req.Version = Version
+
+	// 参数校验
+	if req.RequestId == "" {
+		return nil, ErrRequestIdEmpty
+	}
+	if req.OrderId == "" {
+		return nil, ErrOrderIdEmpty
+	}
+	if req.Amount == "" {
+		return nil, ErrAmountEmpty
+	}
+	if req.SignType == "" {
+		return nil, ErrSignTypeInvalid
+	}
+	if req.SignType != SignTypeMD5 && req.SignType != SignTypeRSA {
+		return nil, ErrSignTypeInvalid
+	}
+
+	// 生成签名
+	hmac, err := c.generateRequestSign(req)
+	if err != nil {
+		return nil, fmt.Errorf("generate sign failed: %w", err)
+	}
+	req.Hmac = hmac
+
+	// 构建请求参数
+	params := c.buildRequestParams(req)
+
+	// 发送请求
+	resp, err := c.doPost(ctx, params)
+	if err != nil {
+		return nil, err
+	}
+
+	// 验证响应签名
+	if err := c.verifyResponseSign(resp); err != nil {
+		return nil, err
+	}
+
+	return resp, nil
+}
+
+// generateRequestSign 生成请求签名
+func (c *Client) generateRequestSign(req *RefundRequest) (string, error) {
+	// 构建参数字典
+	params := map[string]string{
+		"merchantId": req.MerchantId,
+		"requestId":  req.RequestId,
+		"signType":   req.SignType,
+		"type":       req.Type,
+		"version":    req.Version,
+		"orderId":    req.OrderId,
+		"amount":     req.Amount,
+	}
+
+	// 按文档指定顺序拼接签名串
+	signStr := buildSignString(params, getRequestSignKeys())
+
+	switch req.SignType {
+	case SignTypeMD5:
+		if c.signKey == "" {
+			return "", ErrSignKeyEmpty
+		}
+		return SignMD5(signStr, c.signKey), nil
+	case SignTypeRSA:
+		if c.privateKeyPEM == "" {
+			return "", ErrPrivateKeyInvalid
+		}
+		return SignRSA(signStr, c.privateKeyPEM)
+	default:
+		return "", ErrSignTypeInvalid
+	}
+}
+
+// buildRequestParams 构建请求参数（用于HTTP请求）
+func (c *Client) buildRequestParams(req *RefundRequest) url.Values {
+	params := url.Values{}
+	params.Set("merchantId", req.MerchantId)
+	params.Set("requestId", req.RequestId)
+	params.Set("signType", req.SignType)
+	params.Set("type", req.Type)
+	params.Set("version", req.Version)
+	params.Set("orderId", req.OrderId)
+	params.Set("amount", req.Amount)
+	params.Set("hmac", req.Hmac)
+	return params
+}
+
+// doPost 发送POST请求
+func (c *Client) doPost(ctx context.Context, params url.Values) (*RefundResponse, error) {
+	apiURL := c.baseURL + "/ips/cmpayService"
+
+	bodyStr := params.Encode()
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, apiURL, strings.NewReader(bodyStr))
+	if err != nil {
+		return nil, fmt.Errorf("create request failed: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded; charset=utf-8")
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("do request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read response body failed: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("unexpected status code: %d, body: %s", resp.StatusCode, string(body))
+	}
+
+	return parseResponse(string(body))
+}
+
+// parseResponse 解析响应字符串为结构体
+func parseResponse(raw string) (*RefundResponse, error) {
+	resp := &RefundResponse{}
+
+	pairs := strings.Split(raw, "&")
+	for _, pair := range pairs {
+		eqIdx := strings.IndexByte(pair, '=')
+		if eqIdx < 0 {
+			continue
+		}
+		key := pair[:eqIdx]
+		value := pair[eqIdx+1:]
+
+		switch key {
+		case "merchantId":
+			resp.MerchantId = value
+		case "payNo":
+			resp.PayNo = value
+		case "returnCode":
+			resp.ReturnCode = value
+		case "message":
+			resp.Message = value
+		case "signType":
+			resp.SignType = value
+		case "type":
+			resp.Type = value
+		case "version":
+			resp.Version = value
+		case "amount":
+			resp.Amount = value
+		case "orderId":
+			resp.OrderId = value
+		case "status":
+			resp.Status = value
+		case "serverCert":
+			resp.ServerCert = value
+		case "hmac":
+			resp.Hmac = value
+		}
+	}
+
+	return resp, nil
+}
+
+// verifyResponseSign 验证响应签名
+func (c *Client) verifyResponseSign(resp *RefundResponse) error {
+	// 构建参数字典
+	params := map[string]string{
+		"merchantId": resp.MerchantId,
+		"payNo":      resp.PayNo,
+		"returnCode": resp.ReturnCode,
+		"message":    resp.Message,
+		"signType":   resp.SignType,
+		"type":       resp.Type,
+		"version":    resp.Version,
+		"amount":     resp.Amount,
+		"orderId":    resp.OrderId,
+		"status":     resp.Status,
+	}
+
+	// 按文档指定顺序拼接签名串
+	signStr := buildSignString(params, getResponseSignKeys())
+
+	switch resp.SignType {
+	case SignTypeMD5:
+		if c.signKey == "" {
+			return ErrSignKeyEmpty
+		}
+		if !VerifyMD5(signStr, c.signKey, resp.Hmac) {
+			return ErrSignVerifyFailed
+		}
+		return nil
+	case SignTypeRSA:
+		if resp.ServerCert == "" {
+			return fmt.Errorf("response missing serverCert for RSA verification")
+		}
+		// 从证书中提取公钥
+		pubKeyPEM, err := extractPublicKeyFromCert(resp.ServerCert)
+		if err != nil {
+			return fmt.Errorf("extract public key from cert failed: %w", err)
+		}
+		return VerifyRSA(signStr, resp.Hmac, pubKeyPEM)
+	default:
+		return ErrSignTypeInvalid
+	}
+}
+
+// IsRefundSuccess 判断退款是否成功
+// 返回码为 000000 或 MCG00000 表示退款请求成功
+// 退款最终结果以 status 字段为准
+func IsRefundRequestSuccess(returnCode string) bool {
+	return returnCode == ReturnCodeSuccess || returnCode == ReturnCodeSuccessAlt
+}
+
+// IsRefundSuccess 判断退款最终结果是否成功
+func IsRefundSuccess(status string) bool {
+	return status == RefundStatusSuccess
+}