feat(auth): add GitHub Copilot authentication and API integration

Add complete GitHub Copilot support including: - Device flow OAuth authentication via GitHub's official client ID - Token management with automatic caching (25 min TTL) - OpenAI-compatible API executor for api.githubcopilot.com - 16 model definitions (GPT-5 variants, Claude variants, Gemini, Grok, Raptor) - CLI login command via -github-copilot-login flag - SDK authenticator and refresh registry integration Enables users to authenticate with their GitHub Copilot subscription and use it as a backend provider alongside existing providers.
2026-07-12 01:25:13 +00:00 · 2025-11-27 20:14:30 +01:00
parent d2e4639b2a
commit 3a9ac7ef33
12 changed files with 1563 additions and 1 deletions
@@ -0,0 +1,183 @@
+package copilot
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+)
+
+// OAuthError represents an OAuth-specific error.
+type OAuthError struct {
+	// Code is the OAuth error code.
+	Code string `json:"error"`
+	// Description is a human-readable description of the error.
+	Description string `json:"error_description,omitempty"`
+	// URI is a URI identifying a human-readable web page with information about the error.
+	URI string `json:"error_uri,omitempty"`
+	// StatusCode is the HTTP status code associated with the error.
+	StatusCode int `json:"-"`
+}
+
+// Error returns a string representation of the OAuth error.
+func (e *OAuthError) Error() string {
+	if e.Description != "" {
+		return fmt.Sprintf("OAuth error %s: %s", e.Code, e.Description)
+	}
+	return fmt.Sprintf("OAuth error: %s", e.Code)
+}
+
+// NewOAuthError creates a new OAuth error with the specified code, description, and status code.
+func NewOAuthError(code, description string, statusCode int) *OAuthError {
+	return &OAuthError{
+		Code:        code,
+		Description: description,
+		StatusCode:  statusCode,
+	}
+}
+
+// AuthenticationError represents authentication-related errors.
+type AuthenticationError struct {
+	// Type is the type of authentication error.
+	Type string `json:"type"`
+	// Message is a human-readable message describing the error.
+	Message string `json:"message"`
+	// Code is the HTTP status code associated with the error.
+	Code int `json:"code"`
+	// Cause is the underlying error that caused this authentication error.
+	Cause error `json:"-"`
+}
+
+// Error returns a string representation of the authentication error.
+func (e *AuthenticationError) Error() string {
+	if e.Cause != nil {
+		return fmt.Sprintf("%s: %s (caused by: %v)", e.Type, e.Message, e.Cause)
+	}
+	return fmt.Sprintf("%s: %s", e.Type, e.Message)
+}
+
+// Common authentication error types for GitHub Copilot device flow.
+var (
+	// ErrDeviceCodeFailed represents an error when requesting the device code fails.
+	ErrDeviceCodeFailed = &AuthenticationError{
+		Type:    "device_code_failed",
+		Message: "Failed to request device code from GitHub",
+		Code:    http.StatusBadRequest,
+	}
+
+	// ErrDeviceCodeExpired represents an error when the device code has expired.
+	ErrDeviceCodeExpired = &AuthenticationError{
+		Type:    "device_code_expired",
+		Message: "Device code has expired. Please try again.",
+		Code:    http.StatusGone,
+	}
+
+	// ErrAuthorizationPending represents a pending authorization state (not an error, used for polling).
+	ErrAuthorizationPending = &AuthenticationError{
+		Type:    "authorization_pending",
+		Message: "Authorization is pending. Waiting for user to authorize.",
+		Code:    http.StatusAccepted,
+	}
+
+	// ErrSlowDown represents a request to slow down polling.
+	ErrSlowDown = &AuthenticationError{
+		Type:    "slow_down",
+		Message: "Polling too frequently. Slowing down.",
+		Code:    http.StatusTooManyRequests,
+	}
+
+	// ErrAccessDenied represents an error when the user denies authorization.
+	ErrAccessDenied = &AuthenticationError{
+		Type:    "access_denied",
+		Message: "User denied authorization",
+		Code:    http.StatusForbidden,
+	}
+
+	// ErrTokenExchangeFailed represents an error when token exchange fails.
+	ErrTokenExchangeFailed = &AuthenticationError{
+		Type:    "token_exchange_failed",
+		Message: "Failed to exchange device code for access token",
+		Code:    http.StatusBadRequest,
+	}
+
+	// ErrPollingTimeout represents an error when polling times out.
+	ErrPollingTimeout = &AuthenticationError{
+		Type:    "polling_timeout",
+		Message: "Timeout waiting for user authorization",
+		Code:    http.StatusRequestTimeout,
+	}
+
+	// ErrUserInfoFailed represents an error when fetching user info fails.
+	ErrUserInfoFailed = &AuthenticationError{
+		Type:    "user_info_failed",
+		Message: "Failed to fetch GitHub user information",
+		Code:    http.StatusBadRequest,
+	}
+)
+
+// NewAuthenticationError creates a new authentication error with a cause based on a base error.
+func NewAuthenticationError(baseErr *AuthenticationError, cause error) *AuthenticationError {
+	return &AuthenticationError{
+		Type:    baseErr.Type,
+		Message: baseErr.Message,
+		Code:    baseErr.Code,
+		Cause:   cause,
+	}
+}
+
+// IsAuthenticationError checks if an error is an authentication error.
+func IsAuthenticationError(err error) bool {
+	var authenticationError *AuthenticationError
+	ok := errors.As(err, &authenticationError)
+	return ok
+}
+
+// IsOAuthError checks if an error is an OAuth error.
+func IsOAuthError(err error) bool {
+	var oAuthError *OAuthError
+	ok := errors.As(err, &oAuthError)
+	return ok
+}
+
+// GetUserFriendlyMessage returns a user-friendly error message based on the error type.
+func GetUserFriendlyMessage(err error) string {
+	switch {
+	case IsAuthenticationError(err):
+		var authErr *AuthenticationError
+		errors.As(err, &authErr)
+		switch authErr.Type {
+		case "device_code_failed":
+			return "Failed to start GitHub authentication. Please check your network connection and try again."
+		case "device_code_expired":
+			return "The authentication code has expired. Please try again."
+		case "authorization_pending":
+			return "Waiting for you to authorize the application on GitHub."
+		case "slow_down":
+			return "Please wait a moment before trying again."
+		case "access_denied":
+			return "Authentication was cancelled or denied."
+		case "token_exchange_failed":
+			return "Failed to complete authentication. Please try again."
+		case "polling_timeout":
+			return "Authentication timed out. Please try again."
+		case "user_info_failed":
+			return "Failed to get your GitHub account information. Please try again."
+		default:
+			return "Authentication failed. Please try again."
+		}
+	case IsOAuthError(err):
+		var oauthErr *OAuthError
+		errors.As(err, &oauthErr)
+		switch oauthErr.Code {
+		case "access_denied":
+			return "Authentication was cancelled or denied."
+		case "invalid_request":
+			return "Invalid authentication request. Please try again."
+		case "server_error":
+			return "GitHub server error. Please try again later."
+		default:
+			return fmt.Sprintf("Authentication failed: %s", oauthErr.Description)
+		}
+	default:
+		return "An unexpected error occurred. Please try again."
+	}
+}