"use client";

import { useState, useCallback, useEffect, useRef } from 'react';
import { useLocalStorage } from '@/hooks/use-local-storage';
import { useToast } from '@/hooks/use-toast';
import { usePresence } from '@/hooks/use-presence';
import type { User, DataMode, FontStyle, Language, PrivacySettings } from '@/lib/types';
import { formatDistanceToNow as formatDistanceToNowFn } from 'date-fns';
import { ar as arLocale, enUS as enLocale } from 'date-fns/locale';
import enTranslations from '@/lib/locales/en.json';
import arTranslations from '@/lib/locales/ar.json';
import { useFirebase } from '@/contexts/firebase-context';
import { getMessaging, getToken } from "firebase/messaging";
import { doc, updateDoc } from 'firebase/firestore';


const SYNC_INTERVAL = 30;
const defaultPrivacySettings: PrivacySettings = {
    showOnline: true,
    showTyping: true,
    readReceipts: true,
    whoCanAdd: 'everyone',
    whoCanViewProfile: 'everyone',
};
const translations = { en: enTranslations, ar: arTranslations };
const locales = { ar: arLocale, en: enLocale };

interface UseSettingsProps {
    currentUser: User | null;
}

export const useSettingsCore = ({ currentUser }: UseSettingsProps) => {
    const { app, db, rtdb } = useFirebase();
    const { toast } = useToast();
    const soundsRef = useRef<Record<string, HTMLAudioElement> | null>(null);
    const [fontStyle, setFontStyle] = useLocalStorage<FontStyle>('fontStyle', 'default');
    const [language, setLanguage] = useLocalStorage<Language>('appLanguage', 'en');
    const [isLanguageLoading, setIsLanguageLoading] = useState(true);
    const [isSoundEnabled, setIsSoundEnabled] = useLocalStorage<boolean>('soundEnabled', false);
    const [dataMode, setDataMode] = useLocalStorage<DataMode>('dataMode', 'normal');
    const [privacySettings, setPrivacySettings] = useLocalStorage<PrivacySettings>('privacySettings', defaultPrivacySettings);
    const [accentColor, setAccentColor] = useLocalStorage<string>('accentColor', '221.2 83.2% 53.3%');
    const [syncCountdown, setSyncCountdown] = useState(SYNC_INTERVAL);
    const [notificationPermission, setNotificationPermission] = useState<NotificationPermission>('default');
    const [fcmToken, setFcmToken] = useState<string | null>(null);
    
    usePresence({ currentUser, rtdb, privacySettings });

    const addToast = useCallback((message: string, options?: { variant?: 'default' | 'destructive' }) => {
        toast({ title: message, variant: options?.variant });
    }, [toast]);
    
    const playSound = useCallback((sound: 'send' | 'receive' | 'touch' | 'typing') => {
        if (!isSoundEnabled || !soundsRef.current) return;
        const s = soundsRef.current[sound];
        if (s) {
            s.currentTime = 0;
            s.play().catch(e => console.error("Sound play failed:", e));
        }
    }, [isSoundEnabled]);

    const stopSound = useCallback((sound: 'typing') => {
        if (!soundsRef.current) return;
        const s = soundsRef.current[sound];
        if (s) {
            s.pause();
            s.currentTime = 0;
        }
    }, []);

    const toggleSound = () => setIsSoundEnabled(prev => !prev);
    
     useEffect(() => {
        if (typeof window !== 'undefined' && 'Notification' in window) {
            setNotificationPermission(Notification.permission);
        }

        soundsRef.current = {
            send: new Audio('/sounds/send.mp3'),
            receive: new Audio('/sounds/receive.mp3'),
            touch: new Audio('/sounds/touch.mp3'),
            typing: new Audio('/sounds/typing.mp3'),
        };
        Object.values(soundsRef.current).forEach(sound => {
            if(sound) {
                sound.preload = 'auto';
                sound.volume = 0.7;
            }
        });
        if(soundsRef.current.typing) {
            soundsRef.current.typing.loop = true;
            soundsRef.current.typing.volume = 0.3;
        }

        const storedLang = localStorage.getItem('appLanguage');
        const lang = storedLang && (storedLang === 'en' || storedLang === 'ar') ? storedLang : (typeof navigator !== 'undefined' && navigator.language.split('-')[0] === 'ar' ? 'ar' : 'en');
        setLanguage(lang);
        setIsLanguageLoading(false);

    }, [setLanguage]);

    const requestNotificationPermission = useCallback(async () => {
        if (typeof window === 'undefined' || !('Notification' in window) || !currentUser) {
            addToast("This browser does not support desktop notification or user is not logged in.", { variant: 'destructive' });
            return;
        }

        try {
            const permission = await Notification.requestPermission();
            setNotificationPermission(permission);

            if (permission === 'granted') {
                const messaging = getMessaging(app);
                // Get registration token. Initially this makes a network call, once retrieved
                // subsequent calls to getToken will return from cache.
                const currentToken = await getToken(messaging, { vapidKey: "BD6ckIt46u2iNjS-1MZ09WoWg2HP5WkZelZr8EK4cTtoU4i_JbEAJq4EsprfpaMs8JBRtCZiph3lFGSW7TsmjVM" });

                if (currentToken) {
                    setFcmToken(currentToken);
                    await updateDoc(doc(db, 'users', currentUser.uid), { fcmToken: currentToken });
                    addToast("Notifications enabled and token registered!", { variant: 'default' });
                } else {
                    addToast("Could not get notification token.", { variant: 'destructive' });
                }
            } else if (permission === 'denied') {
                addToast("Notifications blocked. You can enable them from browser settings.", { variant: 'destructive' });
            }
        } catch (error) {
            console.error("Error during notification permission request:", error);
            addToast("Failed to request notification permission.", { variant: 'destructive' });
        }
    }, [addToast, app, currentUser, db]);


    const t = useCallback((key: string, options?: Record<string, string | number>) => {
        const translationsTyped = translations as Record<Language, Record<string, string>>;
        let text = translationsTyped[language]?.[key] || translations['en']?.[key] || key;
        if (options) {
            Object.keys(options).forEach(k => {
                text = text.replace(new RegExp(`{{${k}}}`, 'g'), String(options[k]));
            });
        }
        return text;
    }, [language]);

    const formatDistanceToNow = useCallback((date: number | Date, options?: { addSuffix?: boolean }) => {
        return formatDistanceToNowFn(date, { ...options, locale: locales[language] });
    }, [language]);

    const updatePrivacySettings = useCallback(async (newSettings: Partial<PrivacySettings>) => {
        setPrivacySettings(prev => ({ ...prev, ...newSettings }));
    }, [setPrivacySettings]);


    useEffect(() => {
        if (!isLanguageLoading) {
            document.documentElement.lang = language;
            document.documentElement.dir = language === 'ar' ? 'rtl' : 'ltr';
            document.documentElement.style.setProperty('--primary', accentColor);
            document.documentElement.style.setProperty('--ring', accentColor);

            // Safer body class manipulation
            document.body.classList.remove('font-body', 'font-casual-body');
            document.body.classList.add(fontStyle === 'casual' ? 'font-casual-body' : 'font-body');
        }
    }, [language, fontStyle, isLanguageLoading, accentColor]);

    useEffect(() => {
        if (dataMode !== 'ultra') return;
        const timer = setInterval(() => {
            setSyncCountdown(prev => (prev <= 1 ? SYNC_INTERVAL : prev - 1));
        }, 1000);
        return () => clearInterval(timer);
    }, [dataMode]);

    return {
        dataMode, setDataMode, 
        isSoundEnabled, toggleSound,
        privacySettings, updatePrivacySettings,
        fontStyle, setFontStyle,
        language, setLanguage,
        accentColor, setAccentColor,
        isLanguageLoading, syncCountdown,
        notificationPermission, requestNotificationPermission,
        fcmToken, setFcmToken,
        playSound, stopSound,
        t, formatDistanceToNow, addToast
    };
}