Implemented sync functionality with sheets and email sending

src/lib/google/auth/client.ts

@@ -98,6 +98,122 @@ export async function getUserInfo(accessToken: string): Promise<{ email: string;
 	}
 }
 
+/**
+ * Authenticate with Google using OAuth popup flow
+ * @returns Authentication result with success status and tokens
+ */
+export async function authenticateWithGoogle(): Promise<{
+	success: boolean;
+	refreshToken?: string;
+	userEmail?: string;
+	error?: string;
+}> {
+	if (!browser) {
+		return { success: false, error: 'Not in browser environment' };
+	}
+
+	return new Promise((resolve) => {
+		try {
+			// Open popup window for OAuth
+			const popup = window.open(
+				'/auth/google',
+				'google-auth',
+				'width=500,height=600,scrollbars=yes,resizable=yes,left=' + 
+				Math.round(window.screen.width / 2 - 250) + ',top=' + 
+				Math.round(window.screen.height / 2 - 300)
+			);
+
+			if (!popup) {
+				resolve({ success: false, error: 'Failed to open popup window. Please allow popups for this site.' });
+				return;
+			}
+
+			let authCompleted = false;
+			let popupTimer: number | null = null;
+			
+			// Store current timestamp to detect changes in localStorage
+			const startTimestamp = localStorage.getItem('google_auth_timestamp') ?? '0';
+			
+			// Poll localStorage for auth completion
+			const pollInterval = setInterval(() => {
+				try {
+					const currentTimestamp = localStorage.getItem('google_auth_timestamp');
+					
+					// If timestamp has changed, auth is complete
+					if (currentTimestamp && currentTimestamp !== startTimestamp) {
+						handleAuthSuccess();
+					}
+				} catch (e) {
+					console.error('Error checking auth timestamp:', e);
+				}
+			}, 500); // Poll every 500ms
+			
+			// Common handler for authentication success
+			function handleAuthSuccess() {
+				if (authCompleted) return; // Prevent duplicate handling
+				
+				authCompleted = true;
+				
+				// Clean up timers
+				clearInterval(pollInterval);
+				if (popupTimer) clearTimeout(popupTimer);
+				
+				// Get tokens from localStorage
+				const refreshToken = localStorage.getItem('google_refresh_token');
+				const userEmail = localStorage.getItem('google_user_email');
+				
+				if (refreshToken) {
+					resolve({
+						success: true,
+						refreshToken,
+						userEmail: userEmail ?? undefined
+					});
+				} else {
+					resolve({ success: false, error: 'No refresh token found after authentication' });
+				}
+			}
+			
+			// Clean up function to handle all cleanup in one place
+			const cleanUp = () => {
+				clearInterval(pollInterval);
+				if (popupTimer) clearTimeout(popupTimer);
+			};
+
+			// Set a timeout for initial auth check
+			popupTimer = setTimeout(() => {
+				if (!authCompleted) {
+					cleanUp();
+					// Check if tokens were stored by the popup before it was closed
+					const refreshToken = localStorage.getItem('google_refresh_token');
+					const userEmail = localStorage.getItem('google_user_email');
+					
+					if (refreshToken) {
+						resolve({
+							success: true,
+							refreshToken,
+							userEmail: userEmail ?? undefined
+						});
+					} else {
+						resolve({ success: false, error: 'Authentication timeout or cancelled' });
+					}
+				}
+			}, 30 * 1000) as unknown as number;
+
+			// Final cleanup timeout
+			setTimeout(() => {
+				if (!authCompleted) {
+					cleanUp();
+					resolve({ success: false, error: 'Authentication timeout' });
+				}
+			}, 60 * 1000);
+
+		} catch (error) {
+			console.error('Error connecting to Google:', error);
+			resolve({ success: false, error: error instanceof Error ? error.message : 'Unknown error' });
+		}
+	});
+}
+
 /**
  * Revoke a Google access token
  * @param accessToken - Google access token to revoke