refactor(core): 任务与模型协议治理 - 拆分服务职责并禁止已发起任务取消

backend/internal/handler/response.go

@@ -0,0 +1,98 @@
+package handler
+
+import (
+	"errors"
+	"log"
+	"net/http"
+	"strings"
+
+	"infinite-canvas/backend/internal/service"
+
+	"github.com/gin-gonic/gin"
+)
+
+const internalErrorMessage = "系统处理失败，请稍后重试"
+
+func ok(c *gin.Context, data any) {
+	c.JSON(http.StatusOK, gin.H{"code": 0, "data": data, "msg": "ok"})
+}
+
+// fail 只接受调用方已经确认可公开的错误；service 返回值统一交给 failService 投影。
+func fail(c *gin.Context, status int, err error) {
+	message := http.StatusText(status)
+	if err != nil && strings.TrimSpace(err.Error()) != "" {
+		message = err.Error()
+	}
+	writeFailure(c, status, status, message)
+}
+
+func failService(c *gin.Context, err error) {
+	var appErr *service.AppError
+	if errors.As(err, &appErr) && validErrorStatus(appErr.Status) {
+		code := appErr.Code
+		if code == 0 {
+			code = appErr.Status
+		}
+		message := strings.TrimSpace(appErr.Message)
+		if message == "" {
+			message = safeInternalErrorMessage(appErr.Status)
+		}
+		if appErr.Status >= http.StatusInternalServerError {
+			diagnosticErr := appErr.Cause
+			if diagnosticErr == nil {
+				diagnosticErr = appErr
+			}
+			logHandlerError(c, appErr.Status, diagnosticErr)
+		}
+		writeFailure(c, appErr.Status, code, message)
+		return
+	}
+	failInternal(c, http.StatusInternalServerError, err)
+}
+
+// failInternal 保留真实 HTTP 状态，但绝不把未分类错误原文写入响应。
+func failInternal(c *gin.Context, status int, err error) {
+	if !validErrorStatus(status) {
+		status = http.StatusInternalServerError
+	}
+	logHandlerError(c, status, err)
+	writeFailure(c, status, status, safeInternalErrorMessage(status))
+}
+
+func writeFailure(c *gin.Context, status int, code int, message string) {
+	c.JSON(status, gin.H{"code": code, "data": nil, "msg": message})
+}
+
+func validErrorStatus(status int) bool {
+	return status >= http.StatusBadRequest && status <= 599
+}
+
+func safeInternalErrorMessage(status int) string {
+	switch status {
+	case http.StatusBadGateway:
+		return "上游服务暂时不可用，请稍后重试"
+	case http.StatusServiceUnavailable:
+		return "服务暂时不可用，请稍后重试"
+	case http.StatusGatewayTimeout:
+		return "上游服务响应超时，请稍后重试"
+	default:
+		return internalErrorMessage
+	}
+}
+
+func logHandlerError(c *gin.Context, status int, err error) {
+	if err == nil {
+		return
+	}
+	method := ""
+	route := ""
+	if c != nil && c.Request != nil {
+		method = c.Request.Method
+		route = c.FullPath()
+		if route == "" {
+			route = "<unmatched>"
+		}
+	}
+	// 普通访问日志会输出 Gin error；这里只记录错误类型，避免密钥或上游响应体进入日志。
+	log.Printf("handler request failed: method=%s route=%s status=%d error_type=%T", method, route, status, err)
+}