refactor: 重构项目结构

internal/errors/errors.go

@@ -0,0 +1,129 @@
+// Package errors defines custom error types for the application
+package errors
+
+import (
+	"fmt"
+	"net/http"
+)
+
+// ErrorCode represents different types of errors
+type ErrorCode int
+
+const (
+	// Configuration errors
+	ErrConfigInvalid ErrorCode = iota + 1000
+	ErrConfigMissing
+	ErrConfigValidation
+
+	// Key management errors
+	ErrNoKeysAvailable ErrorCode = iota + 2000
+	ErrKeyFileNotFound
+	ErrKeyFileInvalid
+	ErrAllKeysBlacklisted
+
+	// Proxy errors
+	ErrProxyRequest ErrorCode = iota + 3000
+	ErrProxyResponse
+	ErrProxyTimeout
+	ErrProxyRetryExhausted
+
+	// Authentication errors
+	ErrAuthInvalid ErrorCode = iota + 4000
+	ErrAuthMissing
+	ErrAuthExpired
+
+	// Server errors
+	ErrServerInternal ErrorCode = iota + 5000
+	ErrServerUnavailable
+)
+
+// AppError represents a custom application error
+type AppError struct {
+	Code       ErrorCode `json:"code"`
+	Message    string    `json:"message"`
+	Details    string    `json:"details,omitempty"`
+	HTTPStatus int       `json:"-"`
+	Cause      error     `json:"-"`
+}
+
+// Error implements the error interface
+func (e *AppError) Error() string {
+	if e.Details != "" {
+		return fmt.Sprintf("[%d] %s: %s", e.Code, e.Message, e.Details)
+	}
+	return fmt.Sprintf("[%d] %s", e.Code, e.Message)
+}
+
+// Unwrap returns the underlying error
+func (e *AppError) Unwrap() error {
+	return e.Cause
+}
+
+// NewAppError creates a new application error
+func NewAppError(code ErrorCode, message string) *AppError {
+	return &AppError{
+		Code:       code,
+		Message:    message,
+		HTTPStatus: getHTTPStatusForCode(code),
+	}
+}
+
+// NewAppErrorWithDetails creates a new application error with details
+func NewAppErrorWithDetails(code ErrorCode, message, details string) *AppError {
+	return &AppError{
+		Code:       code,
+		Message:    message,
+		Details:    details,
+		HTTPStatus: getHTTPStatusForCode(code),
+	}
+}
+
+// NewAppErrorWithCause creates a new application error with underlying cause
+func NewAppErrorWithCause(code ErrorCode, message string, cause error) *AppError {
+	return &AppError{
+		Code:       code,
+		Message:    message,
+		HTTPStatus: getHTTPStatusForCode(code),
+		Cause:      cause,
+	}
+}
+
+// getHTTPStatusForCode maps error codes to HTTP status codes
+func getHTTPStatusForCode(code ErrorCode) int {
+	switch {
+	case code >= 1000 && code < 2000: // Configuration errors
+		return http.StatusInternalServerError
+	case code >= 2000 && code < 3000: // Key management errors
+		return http.StatusServiceUnavailable
+	case code >= 3000 && code < 4000: // Proxy errors
+		return http.StatusBadGateway
+	case code >= 4000 && code < 5000: // Authentication errors
+		return http.StatusUnauthorized
+	case code >= 5000 && code < 6000: // Server errors
+		return http.StatusInternalServerError
+	default:
+		return http.StatusInternalServerError
+	}
+}
+
+// IsRetryable determines if an error is retryable
+func IsRetryable(err error) bool {
+	if appErr, ok := err.(*AppError); ok {
+		switch appErr.Code {
+		case ErrProxyTimeout, ErrServerUnavailable:
+			return true
+		default:
+			return false
+		}
+	}
+	return false
+}
+
+// Common error instances
+var (
+	ErrNoAPIKeysAvailable = NewAppError(ErrNoKeysAvailable, "No API keys available")
+	ErrAllAPIKeysBlacklisted = NewAppError(ErrAllKeysBlacklisted, "All API keys are blacklisted")
+	ErrInvalidConfiguration = NewAppError(ErrConfigInvalid, "Invalid configuration")
+	ErrAuthenticationRequired = NewAppError(ErrAuthMissing, "Authentication required")
+	ErrInvalidAuthToken = NewAppError(ErrAuthInvalid, "Invalid authentication token")
+)