feat: key接口完善及错误处理

internal/errors/parser.go

@@ -0,0 +1,81 @@
+package errors
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+const (
+	// maxErrorBodyLength defines the maximum length of an error message to be stored or returned.
+	maxErrorBodyLength = 2048
+)
+
+// standardErrorResponse matches formats like: {"error": {"message": "..."}}
+type standardErrorResponse struct {
+	Error struct {
+		Message string `json:"message"`
+	} `json:"error"`
+}
+
+// vendorErrorResponse matches formats like: {"error_msg": "..."}
+type vendorErrorResponse struct {
+	ErrorMsg string `json:"error_msg"`
+}
+
+// simpleErrorResponse matches formats like: {"error": "..."}
+type simpleErrorResponse struct {
+	Error string `json:"error"`
+}
+
+// rootMessageErrorResponse matches formats like: {"message": "..."}
+type rootMessageErrorResponse struct {
+	Message string `json:"message"`
+}
+
+// ParseUpstreamError attempts to parse a structured error message from an upstream response body
+// using a chain of responsibility pattern. It tries various common formats and gracefully
+// degrades to a raw string if all parsing attempts fail.
+func ParseUpstreamError(body []byte) string {
+	// 1. Attempt to parse the standard OpenAI/Gemini format.
+	var stdErr standardErrorResponse
+	if err := json.Unmarshal(body, &stdErr); err == nil {
+		if msg := strings.TrimSpace(stdErr.Error.Message); msg != "" {
+			return truncateString(msg, maxErrorBodyLength)
+		}
+	}
+
+	// 2. Attempt to parse vendor-specific format (e.g., Baidu).
+	var vendorErr vendorErrorResponse
+	if err := json.Unmarshal(body, &vendorErr); err == nil {
+		if msg := strings.TrimSpace(vendorErr.ErrorMsg); msg != "" {
+			return truncateString(msg, maxErrorBodyLength)
+		}
+	}
+
+	// 3. Attempt to parse simple error format.
+	var simpleErr simpleErrorResponse
+	if err := json.Unmarshal(body, &simpleErr); err == nil {
+		if msg := strings.TrimSpace(simpleErr.Error); msg != "" {
+			return truncateString(msg, maxErrorBodyLength)
+		}
+	}
+
+	// 4. Attempt to parse root-level message format.
+	var rootMsgErr rootMessageErrorResponse
+	if err := json.Unmarshal(body, &rootMsgErr); err == nil {
+		if msg := strings.TrimSpace(rootMsgErr.Message); msg != "" {
+			return truncateString(msg, maxErrorBodyLength)
+		}
+	}
+
+	// 5. Graceful Degradation: If all parsing fails, return the raw (but safe) body.
+	return truncateString(string(body), maxErrorBodyLength)
+}
+
+// truncateString ensures a string does not exceed a maximum length.
+func truncateString(s string, maxLength int) string {
+	if len(s) > maxLength {
+		return s[:maxLength]
+	}
+	return s
+}