feat: add Facebook cookie parsing and auto-loading

src/facebook.ts

@@ -254,6 +254,88 @@ async function loadFacebookCookies(cookiesSource?: string, cookiePath = './cooki
 	return [];
 }
 
+/**
+ * Parse Facebook cookie string into Cookie array format
+ */
+function parseFacebookCookieString(cookieString: string): Cookie[] {
+	if (!cookieString || !cookieString.trim()) {
+		return [];
+	}
+
+	return cookieString
+		.split(';')
+		.map(pair => pair.trim())
+		.filter(pair => pair.includes('='))
+		.map(pair => {
+			const [name, value] = pair.split('=', 2);
+			const trimmedName = name.trim();
+			const trimmedValue = value.trim();
+
+			// Skip empty names or values
+			if (!trimmedName || !trimmedValue) {
+				return null;
+			}
+
+			return {
+				name: trimmedName,
+				value: decodeURIComponent(trimmedValue),
+				domain: '.facebook.com',
+				path: '/',
+				secure: true,
+				httpOnly: false,
+				sameSite: 'lax' as const,
+				expirationDate: undefined, // Session cookies
+			};
+		})
+		.filter((cookie): cookie is Cookie => cookie !== null);
+}
+
+/**
+ * Ensure Facebook cookies are available, parsing from env var if needed
+ */
+async function ensureFacebookCookies(cookiePath = './cookies/facebook.json'): Promise<Cookie[]> {
+
+	// First try to load existing cookies
+	try {
+		const existing = await loadFacebookCookies(undefined, cookiePath);
+		if (existing.length > 0) {
+			return existing;
+		}
+	} catch (error) {
+		// File doesn't exist or is invalid, continue to check env var
+	}
+
+	// Try to parse from environment variable
+	const cookieString = process.env.FACEBOOK_COOKIE;
+	if (!cookieString || !cookieString.trim()) {
+		throw new Error(
+			'No valid Facebook cookies found. Either:\n' +
+			'  1. Set FACEBOOK_COOKIE environment variable with cookie string, or\n' +
+			'  2. Create ./cookies/facebook.json manually with cookie array'
+		);
+	}
+
+	// Parse the cookie string
+	const cookies = parseFacebookCookieString(cookieString);
+	if (cookies.length === 0) {
+		throw new Error(
+			'FACEBOOK_COOKIE environment variable contains no valid cookies. ' +
+			'Expected format: "name1=value1; name2=value2;"'
+		);
+	}
+
+	// Save to file for future use
+	try {
+		await Bun.write(cookiePath, JSON.stringify(cookies, null, 2));
+		console.log(`✅ Saved ${cookies.length} Facebook cookies to ${cookiePath}`);
+	} catch (error) {
+		console.warn(`⚠️  Could not save cookies to ${cookiePath}: ${error}`);
+		// Continue anyway, we have the cookies in memory
+	}
+
+	return cookies;
+}
+
 /**
  * Format cookies array into Cookie header string
  */