import * as Device from "expo-device";
import * as Notifications from "expo-notifications";
import { useEffect, useState } from "react";
import { Platform } from "react-native";

type RegisterTokenParams = {
	apiKey?: string | null;
	backendUrl: string;
	appVersion?: string;
	locale?: string;
	topics?: string[];
};

export function usePushNotifications({
	apiKey,
	backendUrl,
	appVersion = "1.0.0",
	locale,
	topics
}: RegisterTokenParams & { apiKey?: string | null }) {
	const [expoPushToken, setExpoPushToken] = useState<string | null>(null);

	useEffect(() => {
		if (!apiKey) return;
		(async () => {
			const token = await registerForPushNotificationsAsync();
			if (token) {
				setExpoPushToken(token);
				await registerTokenWithBackend(token);
			}
		})();
	}, [apiKey]);

	const registerTokenWithBackend = async (token: string) => {
		try {
			await fetch(`${backendUrl}/register_token`, {
				method: "POST",
				headers: {
					"Content-Type": "application/json",
					"X-API-Key": apiKey ?? "",
				},
				body: JSON.stringify({
					token,
					platform: Platform.OS,
					app_ver: appVersion,
					locale,
					topics
				})
			});
			console.log("Push token registered with backend ✅");
		} catch (error) {
			console.error("Failed to register token with backend:", error);
		}
	};

	return expoPushToken;
}

async function registerForPushNotificationsAsync() {
	if (!Device.isDevice) {
		console.log("Must use physical device for Push Notifications");
		return null;
	}

	const { status: existingStatus } = await Notifications.getPermissionsAsync();
	let finalStatus = existingStatus;

	if (existingStatus !== "granted") {
		const { status } = await Notifications.requestPermissionsAsync();
		finalStatus = status;
	}

	if (finalStatus !== "granted") {
		console.log("Permission not granted for push notifications.");
		return null;
	}

	const tokenData = await Notifications.getExpoPushTokenAsync();
	const token = tokenData.data;
	console.log("Expo Push Token:", token);

	// Android-specific setup
	if (Platform.OS === "android") {
		await Notifications.setNotificationChannelAsync("default", {
			name: "default",
			importance: Notifications.AndroidImportance.MAX,
			vibrationPattern: [0, 250, 250, 250],
			lightColor: "#FF231F7C"
		});
	}

	return token;
}