feat: 新增支持codex转发

backend/internal/repository/openai_oauth_service.go

@@ -0,0 +1,92 @@
+package repository
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"time"
+
+	"sub2api/internal/pkg/openai"
+	"sub2api/internal/service/ports"
+
+	"github.com/imroc/req/v3"
+)
+
+type openaiOAuthService struct{}
+
+// NewOpenAIOAuthClient creates a new OpenAI OAuth client
+func NewOpenAIOAuthClient() ports.OpenAIOAuthClient {
+	return &openaiOAuthService{}
+}
+
+func (s *openaiOAuthService) ExchangeCode(ctx context.Context, code, codeVerifier, redirectURI, proxyURL string) (*openai.TokenResponse, error) {
+	client := createOpenAIReqClient(proxyURL)
+
+	if redirectURI == "" {
+		redirectURI = openai.DefaultRedirectURI
+	}
+
+	formData := url.Values{}
+	formData.Set("grant_type", "authorization_code")
+	formData.Set("client_id", openai.ClientID)
+	formData.Set("code", code)
+	formData.Set("redirect_uri", redirectURI)
+	formData.Set("code_verifier", codeVerifier)
+
+	var tokenResp openai.TokenResponse
+
+	resp, err := client.R().
+		SetContext(ctx).
+		SetFormDataFromValues(formData).
+		SetSuccessResult(&tokenResp).
+		Post(openai.TokenURL)
+
+	if err != nil {
+		return nil, fmt.Errorf("request failed: %w", err)
+	}
+
+	if !resp.IsSuccessState() {
+		return nil, fmt.Errorf("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(proxyURL)
+
+	formData := url.Values{}
+	formData.Set("grant_type", "refresh_token")
+	formData.Set("refresh_token", refreshToken)
+	formData.Set("client_id", openai.ClientID)
+	formData.Set("scope", openai.RefreshScopes)
+
+	var tokenResp openai.TokenResponse
+
+	resp, err := client.R().
+		SetContext(ctx).
+		SetFormDataFromValues(formData).
+		SetSuccessResult(&tokenResp).
+		Post(openai.TokenURL)
+
+	if err != nil {
+		return nil, fmt.Errorf("request failed: %w", err)
+	}
+
+	if !resp.IsSuccessState() {
+		return nil, fmt.Errorf("token refresh failed: status %d, body: %s", resp.StatusCode, resp.String())
+	}
+
+	return &tokenResp, nil
+}
+
+func createOpenAIReqClient(proxyURL string) *req.Client {
+	client := req.C().
+		SetTimeout(60 * time.Second)
+
+	if proxyURL != "" {
+		client.SetProxyURL(proxyURL)
+	}
+
+	return client
+}