chore(init): 初始化解忧商行项目并完成 Phase 0 基座

backend/pkg/response/response.go

@@ -0,0 +1,92 @@
+package response
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+const contextResponseCode = "response_code"
+
+type Body struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+	Data    any    `json:"data,omitempty"`
+}
+
+func OK(c *gin.Context, data any) {
+	c.JSON(http.StatusOK, Body{
+		Code:    "ok",
+		Message: "ok",
+		Data:    data,
+	})
+}
+
+func Created(c *gin.Context, data any) {
+	c.JSON(http.StatusCreated, Body{
+		Code:    "ok",
+		Message: "created",
+		Data:    data,
+	})
+}
+
+func Error(c *gin.Context, status int, code, message string) {
+	if status >= http.StatusInternalServerError && len(c.Errors) == 0 {
+		RecordError(c, fmt.Errorf("未记录原始错误: %s", code))
+	}
+	c.Set(contextResponseCode, code)
+	c.JSON(status, Body{
+		Code:    code,
+		Message: message,
+	})
+}
+
+// RecordError 保存原始错误，供统一请求日志记录服务端故障原因。
+func RecordError(c *gin.Context, err error) {
+	if c == nil || err == nil || errors.Is(err, context.Canceled) {
+		return
+	}
+	for _, item := range c.Errors {
+		if errors.Is(item.Err, err) {
+			return
+		}
+	}
+	_ = c.Error(err)
+}
+
+// CodeFromContext 返回已经写入响应的稳定业务错误码。
+func CodeFromContext(c *gin.Context) string {
+	value, ok := c.Get(contextResponseCode)
+	if !ok {
+		return ""
+	}
+	code, _ := value.(string)
+	return code
+}
+
+func BadRequest(c *gin.Context, message string) {
+	Error(c, http.StatusBadRequest, "bad_request", message)
+}
+
+func Forbidden(c *gin.Context, message string) {
+	Error(c, http.StatusForbidden, "forbidden", message)
+}
+
+func Unauthorized(c *gin.Context, message string) {
+	Error(c, http.StatusUnauthorized, "unauthorized", message)
+}
+
+func ServiceUnavailable(c *gin.Context, message string) {
+	Error(c, http.StatusServiceUnavailable, "service_unavailable", message)
+}
+
+func NotFound(c *gin.Context, message string) {
+	Error(c, http.StatusNotFound, "not_found", message)
+}
+
+func InternalServerError(c *gin.Context, message string) {
+	Error(c, http.StatusInternalServerError, "internal_server_error", message)
+}