Add openai codex support

internal/auth/gemini/gemini_token.go

@@ -0,0 +1,64 @@
+// Package gemini provides authentication and token management functionality
+// for Google's Gemini AI services. It handles OAuth2 token storage, serialization,
+// and retrieval for maintaining authenticated sessions with the Gemini API.
+package gemini
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path"
+)
+
+// GeminiTokenStorage defines the structure for storing OAuth2 token information,
+// along with associated user and project details. This data is typically
+// serialized to a JSON file for persistence.
+type GeminiTokenStorage struct {
+	// Token holds the raw OAuth2 token data, including access and refresh tokens.
+	Token any `json:"token"`
+
+	// ProjectID is the Google Cloud Project ID associated with this token.
+	ProjectID string `json:"project_id"`
+
+	// Email is the email address of the authenticated user.
+	Email string `json:"email"`
+
+	// Auto indicates if the project ID was automatically selected.
+	Auto bool `json:"auto"`
+
+	// Checked indicates if the associated Cloud AI API has been verified as enabled.
+	Checked bool `json:"checked"`
+
+	// Type indicates the type (gemini, chatgpt, claude) of token storage.
+	Type string `json:"type"`
+}
+
+// SaveTokenToFile serializes the token storage to a JSON file.
+// This method creates the necessary directory structure and writes the token
+// data in JSON format to the specified file path. It ensures the file is
+// properly closed after writing.
+//
+// Parameters:
+//   - authFilePath: The full path where the token file should be saved
+//
+// Returns:
+//   - error: An error if the operation fails, nil otherwise
+func (ts *GeminiTokenStorage) SaveTokenToFile(authFilePath string) error {
+	ts.Type = "gemini"
+	if err := os.MkdirAll(path.Dir(authFilePath), 0700); err != nil {
+		return fmt.Errorf("failed to create directory: %v", err)
+	}
+
+	f, err := os.Create(authFilePath)
+	if err != nil {
+		return fmt.Errorf("failed to create token file: %w", err)
+	}
+	defer func() {
+		_ = f.Close()
+	}()
+
+	if err = json.NewEncoder(f).Encode(ts); err != nil {
+		return fmt.Errorf("failed to write token to file: %w", err)
+	}
+	return nil
+}