fix(openai-oauth): 改进错误处理和代理支持

- 使用 ApplicationError 返回详细错误信息到前端
- 添加 User-Agent: codex-cli/0.91.0
- 移除 ForceHTTP2 以兼容 HTTP 代理
- 修复代理获取失败时静默忽略的问题
- 500 错误时记录完整错误日志

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/internal/pkg/response/response.go

@@ -2,6 +2,7 @@
 package response
 
 import (
+	"log"
 	"math"
 	"net/http"
 
@@ -74,6 +75,12 @@ func ErrorFrom(c *gin.Context, err error) bool {
 	}
 
 	statusCode, status := infraerrors.ToHTTP(err)
+
+	// Log internal errors with full details for debugging
+	if statusCode >= 500 {
+		log.Printf("[ERROR] %s %s\n  Error: %s", c.Request.Method, c.Request.URL.Path, err.Error())
+	}
+
 	ErrorWithDetails(c, statusCode, status.Message, status.Reason, status.Metadata)
 	return true
 }

backend/internal/repository/openai_oauth_service.go

@@ -2,11 +2,11 @@ package repository
 
 import (
 	"context"
-	"fmt"
+	"net/http"
 	"net/url"
-	"strings"
 	"time"
 
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/openai"
 	"github.com/Wei-Shaw/sub2api/internal/service"
 	"github.com/imroc/req/v3"
@@ -22,7 +22,7 @@ type openaiOAuthService struct {
 }
 
 func (s *openaiOAuthService) ExchangeCode(ctx context.Context, code, codeVerifier, redirectURI, proxyURL string) (*openai.TokenResponse, error) {
-	client := createOpenAIReqClient(s.tokenURL, proxyURL)
+	client := createOpenAIReqClient(proxyURL)
 
 	if redirectURI == "" {
 		redirectURI = openai.DefaultRedirectURI
@@ -39,23 +39,24 @@ func (s *openaiOAuthService) ExchangeCode(ctx context.Context, code, codeVerifie
 
 	resp, err := client.R().
 		SetContext(ctx).
+		SetHeader("User-Agent", "codex-cli/0.91.0").
 		SetFormDataFromValues(formData).
 		SetSuccessResult(&tokenResp).
 		Post(s.tokenURL)
 
 	if err != nil {
-		return nil, fmt.Errorf("request failed: %w", err)
+		return nil, infraerrors.Newf(http.StatusBadGateway, "OPENAI_OAUTH_REQUEST_FAILED", "request failed: %v", err)
 	}
 
 	if !resp.IsSuccessState() {
-		return nil, fmt.Errorf("token exchange failed: status %d, body: %s", resp.StatusCode, resp.String())
+		return nil, infraerrors.Newf(http.StatusBadGateway, "OPENAI_OAUTH_TOKEN_EXCHANGE_FAILED", "token exchange failed: status %d, body: %s", resp.StatusCode, resp.String())
 	}
 
 	return &tokenResp, nil
 }
 
 func (s *openaiOAuthService) RefreshToken(ctx context.Context, refreshToken, proxyURL string) (*openai.TokenResponse, error) {
-	client := createOpenAIReqClient(s.tokenURL, proxyURL)
+	client := createOpenAIReqClient(proxyURL)
 
 	formData := url.Values{}
 	formData.Set("grant_type", "refresh_token")
@@ -67,29 +68,25 @@ func (s *openaiOAuthService) RefreshToken(ctx context.Context, refreshToken, pro
 
 	resp, err := client.R().
 		SetContext(ctx).
+		SetHeader("User-Agent", "codex-cli/0.91.0").
 		SetFormDataFromValues(formData).
 		SetSuccessResult(&tokenResp).
 		Post(s.tokenURL)
 
 	if err != nil {
-		return nil, fmt.Errorf("request failed: %w", err)
+		return nil, infraerrors.Newf(http.StatusBadGateway, "OPENAI_OAUTH_REQUEST_FAILED", "request failed: %v", err)
 	}
 
 	if !resp.IsSuccessState() {
-		return nil, fmt.Errorf("token refresh failed: status %d, body: %s", resp.StatusCode, resp.String())
+		return nil, infraerrors.Newf(http.StatusBadGateway, "OPENAI_OAUTH_TOKEN_REFRESH_FAILED", "token refresh failed: status %d, body: %s", resp.StatusCode, resp.String())
 	}
 
 	return &tokenResp, nil
 }
 
-func createOpenAIReqClient(tokenURL, proxyURL string) *req.Client {
+func createOpenAIReqClient(proxyURL string) *req.Client {
-	forceHTTP2 := false
-	if parsedURL, err := url.Parse(tokenURL); err == nil {
-		forceHTTP2 = strings.EqualFold(parsedURL.Scheme, "https")
-	}
 	return getSharedReqClient(reqClientOptions{
-		ProxyURL:   proxyURL,
+		ProxyURL: proxyURL,
-		Timeout:    120 * time.Second,
+		Timeout:  120 * time.Second,
-		ForceHTTP2: forceHTTP2,
 	})
 }

backend/internal/service/openai_oauth_service.go

@@ -2,9 +2,10 @@ package service
 
 import (
 	"context"
-	"fmt"
+	"net/http"
 	"time"
 
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/openai"
 )
 
@@ -35,12 +36,12 @@ func (s *OpenAIOAuthService) GenerateAuthURL(ctx context.Context, proxyID *int64
 	// Generate PKCE values
 	state, err := openai.GenerateState()
 	if err != nil {
-		return nil, fmt.Errorf("failed to generate state: %w", err)
+		return nil, infraerrors.Newf(http.StatusInternalServerError, "OPENAI_OAUTH_STATE_FAILED", "failed to generate state: %v", err)
 	}
 
 	codeVerifier, err := openai.GenerateCodeVerifier()
 	if err != nil {
-		return nil, fmt.Errorf("failed to generate code verifier: %w", err)
+		return nil, infraerrors.Newf(http.StatusInternalServerError, "OPENAI_OAUTH_VERIFIER_FAILED", "failed to generate code verifier: %v", err)
 	}
 
 	codeChallenge := openai.GenerateCodeChallenge(codeVerifier)
@@ -48,14 +49,17 @@ func (s *OpenAIOAuthService) GenerateAuthURL(ctx context.Context, proxyID *int64
 	// Generate session ID
 	sessionID, err := openai.GenerateSessionID()
 	if err != nil {
-		return nil, fmt.Errorf("failed to generate session ID: %w", err)
+		return nil, infraerrors.Newf(http.StatusInternalServerError, "OPENAI_OAUTH_SESSION_FAILED", "failed to generate session ID: %v", err)
 	}
 
 	// Get proxy URL if specified
 	var proxyURL string
 	if proxyID != nil {
 		proxy, err := s.proxyRepo.GetByID(ctx, *proxyID)
-		if err == nil && proxy != nil {
+		if err != nil {
+			return nil, infraerrors.Newf(http.StatusBadRequest, "OPENAI_OAUTH_PROXY_NOT_FOUND", "proxy not found: %v", err)
+		}
+		if proxy != nil {
 			proxyURL = proxy.URL()
 		}
 	}
@@ -110,14 +114,17 @@ func (s *OpenAIOAuthService) ExchangeCode(ctx context.Context, input *OpenAIExch
 	// Get session
 	session, ok := s.sessionStore.Get(input.SessionID)
 	if !ok {
-		return nil, fmt.Errorf("session not found or expired")
+		return nil, infraerrors.New(http.StatusBadRequest, "OPENAI_OAUTH_SESSION_NOT_FOUND", "session not found or expired")
 	}
 
-	// Get proxy URL
+	// Get proxy URL: prefer input.ProxyID, fallback to session.ProxyURL
 	proxyURL := session.ProxyURL
 	if input.ProxyID != nil {
 		proxy, err := s.proxyRepo.GetByID(ctx, *input.ProxyID)
-		if err == nil && proxy != nil {
+		if err != nil {
+			return nil, infraerrors.Newf(http.StatusBadRequest, "OPENAI_OAUTH_PROXY_NOT_FOUND", "proxy not found: %v", err)
+		}
+		if proxy != nil {
 			proxyURL = proxy.URL()
 		}
 	}
@@ -131,7 +138,7 @@ func (s *OpenAIOAuthService) ExchangeCode(ctx context.Context, input *OpenAIExch
 	// Exchange code for token
 	tokenResp, err := s.oauthClient.ExchangeCode(ctx, input.Code, session.CodeVerifier, redirectURI, proxyURL)
 	if err != nil {
-		return nil, fmt.Errorf("failed to exchange code: %w", err)
+		return nil, err
 	}
 
 	// Parse ID token to get user info
@@ -201,12 +208,12 @@ func (s *OpenAIOAuthService) RefreshToken(ctx context.Context, refreshToken stri
 // RefreshAccountToken refreshes token for an OpenAI account
 func (s *OpenAIOAuthService) RefreshAccountToken(ctx context.Context, account *Account) (*OpenAITokenInfo, error) {
 	if !account.IsOpenAI() {
-		return nil, fmt.Errorf("account is not an OpenAI account")
+		return nil, infraerrors.New(http.StatusBadRequest, "OPENAI_OAUTH_INVALID_ACCOUNT", "account is not an OpenAI account")
 	}
 
 	refreshToken := account.GetOpenAIRefreshToken()
 	if refreshToken == "" {
-		return nil, fmt.Errorf("no refresh token available")
+		return nil, infraerrors.New(http.StatusBadRequest, "OPENAI_OAUTH_NO_REFRESH_TOKEN", "no refresh token available")
 	}
 
 	var proxyURL string