feat(channels): align email oauth authorization

internal/handler/api/v1/google_channel_handler.go

@@ -21,6 +21,7 @@ import (
 	"github.com/gochat/gochat/internal/repository"
 	"github.com/gochat/gochat/internal/service"
 	applogger "github.com/gochat/gochat/pkg/logger"
+	"github.com/gochat/gochat/pkg/response"
 )
 
 // GoogleChannelHandler handles Google Chat channel management.
@@ -80,6 +81,34 @@ func (h *GoogleChannelHandler) Authorization(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"authorization_url": authURL})
 }
 
+// ChatwootAuthorization creates a Google email OAuth authorization URL.
+// POST /api/v1/accounts/:account_id/google/authorization
+func (h *GoogleChannelHandler) ChatwootAuthorization(c *gin.Context) {
+	accountID, err := parseUintParam(c, "account_id")
+	if err != nil {
+		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
+		return
+	}
+
+	redirectURL, err := buildChatwootEmailOAuthAuthorizationURL(accountID, chatwootEmailOAuthAuthorizationConfig{
+		ClientIDEnv:     "GOOGLE_OAUTH_CLIENT_ID",
+		ClientSecretEnv: "GOOGLE_OAUTH_CLIENT_SECRET",
+		AuthorizeURL:    "https://accounts.google.com/o/oauth2/auth",
+		RedirectPath:    "/google/callback",
+		Scope:           "email profile https://mail.google.com/",
+		ExtraParams: map[string]string{
+			"prompt":      "consent",
+			"access_type": "offline",
+		},
+	})
+	if err != nil {
+		applogger.L().Errorf("Failed to build Google authorization URL: %v", err)
+		c.JSON(http.StatusUnprocessableEntity, gin.H{"success": false})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"success": true, "url": redirectURL})
+}
+
 // === OAuth Callback ===
 
 // GoogleOAuthCallbackRequest is the DTO for Google OAuth callback.