"use client";

import { useState, useCallback, useEffect } from "react";
import { useSearchParams, useRouter } from 'next/navigation';
import type { ChatRecipient, User, Group, CallType } from "@/lib/types";

import { useAuth } from "@/contexts/auth-context";
import { useSettings } from "@/contexts/settings-context";
import { useCalls } from "@/contexts/calls-context";
import { useContacts } from "@/contexts/contacts-context";
import { UserList } from "@/components/user-list";
import { ChatWindow } from "@/app/chat-window";
import { CreateGroupModal } from "@/components/create-group-modal";
import { ViewProfileModal } from "@/components/view-profile-modal";
import { AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent, AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle } from "@/components/ui/alert-dialog";
import { ImagePreviewModal } from "@/components/image-preview-modal";
import { AddGroupMembersModal } from "@/components/add-group-members-modal";
import { CallModal } from "@/components/call-modal";
import { SettingsPage } from "@/components/settings-page";
import { MobileBottomNav } from "@/components/mobile-bottom-nav";
import { Input } from "@/components/ui/input";
import { ChangeNameModal } from "@/components/change-name-modal";
import { ChangeStatusModal } from "@/components/change-status-modal";
import { ChangeBioModal } from "@/components/change-bio-modal";
import { cn } from "@/lib/utils";
import { NetworkStatusIndicator } from "@/components/network-status-indicator";
import { Capacitor } from '@capacitor/core';
import { PushNotifications } from '@capacitor/push-notifications';
import { WelcomeScreen } from "./welcome-screen";


export function ChatInterface() {
    const { currentUser, authStatus, signOutUser } = useAuth();
    const { t } = useSettings();
    const { callState, startVideoCall, answerCall, startAudioCall, endCall } = useCalls();
    const { findUserByPublicId } = useContacts();
    const searchParams = useSearchParams();
    const router = useRouter();
    
    const [recipient, setRecipient] = useState<ChatRecipient | null>(null);
    const [isCreateGroupModalOpen, setCreateGroupModalOpen] = useState(false);
    const [isSettingsOpen, setSettingsOpen] = useState(false);
    const [settingsSection, setSettingsSection] = useState<string | undefined>(undefined);
    const [viewingProfile, setViewingProfile] = useState<User | null>(null);
    const [isSignOutModalOpen, setSignOutModalOpen] = useState(false);
    const [signOutConfirmText, setSignOutConfirmText] = useState('');
    const [imageToPreview, setImageToPreview] = useState<string | null>(null);
    const [groupToAddMembers, setGroupToAddMembers] = useState<Group | null>(null);

    // State for granular modals
    const [isChangeNameModalOpen, setChangeNameModalOpen] = useState(false);
    const [isChangeStatusModalOpen, setChangeStatusModalOpen] = useState(false);
    const [isChangeBioModalOpen, setChangeBioModalOpen] = useState(false);

    
    const handleStartCall = useCallback((peer: User, type: CallType) => {
        if (type === 'video') {
            startVideoCall(peer);
        } else {
            startAudioCall(peer);
        }
    }, [startAudioCall, startVideoCall]);
    
    const handleUserSelection = useCallback((userOrGroup: User | Group) => {
        if (!currentUser) return;

        if ('members' in userOrGroup) { // It's a Group
             if (userOrGroup.members[currentUser.uid]) {
                setRecipient({ ...userOrGroup.info, uid: userOrGroup.id, isGroup: true, displayName: userOrGroup.info.name, photoURL: userOrGroup.info.photoURL, publicId: userOrGroup.id });
            }
        } else { // It's a User
             if (userOrGroup.uid !== currentUser.uid) {
                setRecipient({ ...userOrGroup, isGroup: false, uid: userOrGroup.uid, displayName: userOrGroup.displayName });
            }
        }
    }, [currentUser]);


    useEffect(() => {
        const senderId = searchParams.get('senderId');
        if (senderId && currentUser) {
            findUserByPublicId(senderId).then(user => {
                if (user) {
                    handleUserSelection(user);
                }
            });
        }
    }, [searchParams, currentUser, findUserByPublicId, handleUserSelection]);
    
    useEffect(() => {
        if (Capacitor.getPlatform() === 'web') return;
    
        // Clear any existing listeners to avoid duplicates when the component re-renders
        PushNotifications.removeAllListeners().then(() => {
            PushNotifications.addListener('pushNotificationActionPerformed', (action) => {
                const { actionId, notification } = action;
                const data = notification.data || {};
                
                console.log(`[Push Action] Received action: ${actionId}`, data);
    
                if (data && data.type === 'incoming-call') {
                    // Important: Check if this action corresponds to the current incoming call
                    if (callState.status === 'incoming' && callState.channelName === data.channelName) {
                         if (actionId === 'answer') {
                            console.log('[Push Action] Answering call...');
                            answerCall();
                        } else if (actionId === 'decline') {
                             console.log('[Push Action] Declining call...');
                            endCall();
                        }
                    } else {
                        console.warn(`[Push Action] Received action for call ${data.channelName}, but current call state is ${callState.status} for channel ${callState.channelName}. Action ignored.`);
                    }
                }
            });
        });
    
        // Cleanup on component unmount
        return () => {
             PushNotifications.removeAllListeners();
        }
    }, [callState.status, callState.channelName, answerCall, endCall]); // Dependencies ensure the listener always has the latest state handlers

    const openSettings = useCallback((section?: string) => {
        setSettingsSection(section);
        setSettingsOpen(true);
        setRecipient(null); // Close any open chat window
    }, []);

    const openChangeNameModal = useCallback(() => setChangeNameModalOpen(true), []);
    const openChangeStatusModal = useCallback(() => setChangeStatusModalOpen(true), []);
    const openChangeBioModal = useCallback(() => setChangeBioModalOpen(true), []);

    if (authStatus !== 'authenticated' || !currentUser) {
        return null;
    }

    const handleSignOut = async () => {
        await signOutUser();
        setSignOutModalOpen(false);
        setSignOutConfirmText('');
    };

    const isMobile = typeof window !== 'undefined' && window.innerWidth < 768;
    const showMobileNav = isMobile && !recipient && !isSettingsOpen;
    const isSignOutConfirmValid = signOutConfirmText.toLowerCase() === t('leaveWord') || signOutConfirmText.toLowerCase() === 'leave';
    const numericUid = parseInt(currentUser.uid.replace(/[^0-9]/g, '').substring(0, 8), 10) || Math.floor(Math.random() * 100000);

    return (
        <>
            <NetworkStatusIndicator />
            <div className="relative h-full w-full flex overflow-hidden">
                {/* Pane 1: User List (always visible on desktop, conditionally on mobile) */}
                <div className={cn(
                    "h-full flex-col md:flex md:w-80 lg:w-96 md:flex-shrink-0 md:border-r",
                    (recipient || isSettingsOpen) ? "hidden" : "flex w-full"
                )}>
                    <UserList 
                        onSelectRecipient={(r) => { setRecipient(r); setSettingsOpen(false); }}
                        onOpenCreateGroup={() => setCreateGroupModalOpen(true)}
                        onOpenSettings={openSettings}
                        onSignOut={() => setSignOutModalOpen(true)}
                        onViewProfile={setViewingProfile}
                    />
                </div>

                {/* Pane 2: Main Content (Chat, Settings, or Welcome) */}
                <div className={cn(
                    "h-full flex-1 flex-col",
                    // On mobile, this pane is only visible if a chat or settings is open
                    (!recipient && !isSettingsOpen) ? "hidden md:flex" : "flex"
                )}>
                    {isSettingsOpen ? (
                        <SettingsPage 
                            onClose={() => setSettingsOpen(false)} 
                            initialSection={settingsSection}
                        />
                    ) : recipient ? (
                        <ChatWindow
                            recipient={recipient}
                            onClose={() => setRecipient(null)}
                            onViewProfile={setViewingProfile}
                            onPreviewImage={setImageToPreview}
                            onAddMembers={(group) => setGroupToAddMembers(group)}
                            onStartCall={handleStartCall}
                            onOpenSettings={openSettings}
                            openChangeNameModal={openChangeNameModal}
                            openChangeStatusModal={openChangeStatusModal}
                            openChangeBioModal={openChangeBioModal}
                        />
                    ) : (
                        // This only shows on desktop when no chat/settings are open
                        <WelcomeScreen />
                    )}
                </div>

                {/* Mobile nav is only shown on the UserList screen */}
                {showMobileNav && <MobileBottomNav onOpenSettings={openSettings} />}
            </div>

            <CreateGroupModal isOpen={isCreateGroupModalOpen} onClose={() => setCreateGroupModalOpen(false)} />
            <ViewProfileModal 
                user={viewingProfile} 
                isOpen={!!viewingProfile} 
                onClose={() => setViewingProfile(null)} 
                onStartChat={handleUserSelection} 
            />
            
            {groupToAddMembers && (
                <AddGroupMembersModal 
                    isOpen={!!groupToAddMembers} 
                    onClose={() => setGroupToAddMembers(null)} 
                    group={groupToAddMembers}
                />
            )}
            <ImagePreviewModal imageUrl={imageToPreview} isOpen={!!imageToPreview} onClose={() => setImageToPreview(null)} />
            
            <ChangeNameModal isOpen={isChangeNameModalOpen} onClose={() => setChangeNameModalOpen(false)} />
            <ChangeStatusModal isOpen={isChangeStatusModalOpen} onClose={() => setChangeStatusModalOpen(false)} />
            <ChangeBioModal isOpen={isChangeBioModalOpen} onClose={() => setChangeBioModalOpen(false)} />

            <AlertDialog open={isSignOutModalOpen} onOpenChange={setSignOutModalOpen}>
                <AlertDialogContent>
                    <AlertDialogHeader>
                        <AlertDialogTitle>{t('signOutConfirmationTitle')}</AlertDialogTitle>
                        <AlertDialogDescription>
                            {t('signOutConfirmationDescription', { word: t('leaveWord') })}
                        </AlertDialogDescription>
                    </AlertDialogHeader>
                    <Input 
                        value={signOutConfirmText}
                        onChange={(e) => setSignOutConfirmText(e.target.value)}
                        placeholder={t('leaveWord')}
                        autoFocus
                    />
                    <AlertDialogFooter>
                        <AlertDialogCancel onClick={() => setSignOutConfirmText('')}>{t('cancel')}</AlertDialogCancel>
                        <AlertDialogAction onClick={handleSignOut} disabled={!isSignOutConfirmValid} className="bg-destructive text-destructive-foreground hover:bg-destructive/90">
                            {t('signOut')}
                        </AlertDialogAction>
                    </AlertDialogFooter>
                </AlertDialogContent>
            </AlertDialog>

            <CallModal
                callState={callState}
                onAnswerCall={answerCall}
                onEndCall={endCall}
                uid={numericUid}
                userName={currentUser.displayName}
            />
        </>
    );
}