"use client";

import React, { useState } from 'react';
import { doc, setDoc, getDoc, writeBatch } from "firebase/firestore";
import { useAuth } from '@/contexts/auth-context';
import { useFirebase } from '@/contexts/firebase-context';
import { useSettings } from '@/contexts/settings-context';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Card, CardContent, CardDescription, CardFooter, CardHeader, CardTitle } from '@/components/ui/card';
import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
import { Logo } from './logo';
import { Sparkles, Languages, HelpCircle, ArrowRight, ArrowLeft } from 'lucide-react';
import words from 'mnemonic-words';
import { cn } from '@/lib/utils';
import type { Language } from '@/lib/types';
import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription, DialogTrigger } from '@/components/ui/dialog';
import { Separator } from './ui/separator';
import { Progress } from './ui/progress';


const InfoBubble = ({ text, emoji }: { text: string, emoji: string }) => (
    <div className="info-bubble pointer-events-none">
        <span className="mr-1">{emoji}</span>
        {text}
    </div>
);

const TOTAL_STEPS = 3;

const StepIndicator = ({ current, total, t }: { current: number, total: number, t: (key: string) => string }) => (
    <div className="w-full px-2 pb-2">
        <Progress value={(current / total) * 100} className="h-2" />
        <p className="text-xs text-muted-foreground text-center mt-2">
            {t('step')} {current} / {total}
        </p>
    </div>
);


export const Onboarding = () => {
    const { setAuthStatus, auth, handleAuthenticatedUser } = useAuth();
    const { db } = useFirebase();
    const { addToast, t, language, setLanguage, playSound } = useSettings();
    const [displayName, setDisplayName] = useState('');
    const [publicId, setPublicId] = useState('');
    const [recoveryId, setRecoveryId] = useState('');
    const [step, setStep] = useState(1);
    const [isLoading, setIsLoading] = useState(false);
    

    const handleNextStep = () => {
        playSound('touch');
        if (step === 1 && !displayName.trim()) {
            addToast(t('nameCannotBeEmpty'));
            return;
        }
        if (step === 2 && publicId.trim().length < 4) {
            addToast(t('publicIdMinLength'));
            return;
        }
        setStep(prev => prev + 1);
    }
    
    const handlePrevStep = () => {
        playSound('touch');
        setStep(prev => prev - 1);
    }

    const handleCreateProfile = async () => {
        setIsLoading(true);
        playSound('touch');
        const trimmedDisplayName = displayName.trim();
        const trimmedPublicId = publicId.trim().toLowerCase();
        const trimmedRecoveryId = recoveryId.trim();

        if (!trimmedRecoveryId || trimmedRecoveryId.length < 8) {
            addToast("Recovery ID must be at least 8 characters.");
            setIsLoading(false);
            return;
        }

        try {
            const publicIdRef = doc(db, 'publicIds', trimmedPublicId);
            const recoveryIdRef = doc(db, 'recovery', trimmedRecoveryId);

            const [publicIdSnap, recoveryIdSnap] = await Promise.all([
                getDoc(publicIdRef),
                getDoc(recoveryIdRef)
            ]);

            if (publicIdSnap.exists()) {
                addToast("This Public ID is already taken. Please choose another.");
                setStep(2); // Go back to public ID step
                setIsLoading(false);
                return;
            }
            if (recoveryIdSnap.exists()) {
                addToast("This Recovery ID is already in use. Please choose a more unique one.");
                setIsLoading(false);
                return;
            }

            const user = auth.currentUser;
            if (!user) throw new Error("User not signed in.");

            const androidId = localStorage.getItem('android_id');

            const profile = {
                uid: user.uid,
                displayName: trimmedDisplayName,
                publicId: trimmedPublicId,
                photoURL: `https://api.dicebear.com/8.x/initials/svg?seed=${trimmedDisplayName}`,
                ...(androidId && { androidId }),
            };
            
            const batch = writeBatch(db);
            batch.set(doc(db, 'users', user.uid), profile);
            batch.set(doc(db, 'publicIds', trimmedPublicId), { uid: user.uid });
            batch.set(recoveryIdRef, { uid: user.uid });

            await batch.commit();

            setStep(TOTAL_STEPS + 1); // Go to confirmation step
        } catch (error: any) {
            console.error("Profile creation error:", error);
            addToast(`Error: ${error.message}`);
        } finally {
            setIsLoading(false);
        }
    };
        
    const handleFinishOnboarding = () => {
        playSound('touch');
        if (auth.currentUser) {
            handleAuthenticatedUser(auth.currentUser);
        } else {
            setAuthStatus('loading');
        }
    }

    const generateRandomRecoveryId = () => {
        playSound('touch');
        const randomWords = [];
        for (let i = 0; i < 4; i++) {
            const randomIndex = Math.floor(Math.random() * words.length);
            randomWords.push(words[randomIndex]);
        }
        setRecoveryId(randomWords.join('-'));
    };
    
    const handleLanguageChange = (lang: Language) => {
        playSound('touch');
        setLanguage(lang);
    };

    if (step > TOTAL_STEPS) {
        return (
             <div className="min-h-svh flex items-center justify-center bg-background p-4">
                <Card className="w-full max-w-md">
                    <CardHeader>
                        <Logo />
                        <CardTitle className="text-center">{t('recoveryTitle')}</CardTitle>
                        <CardDescription className="text-center">{t('recoveryDescription')}</CardDescription>
                    </CardHeader>
                    <CardContent>
                        <Alert variant="default">
                            <AlertTitle>{t('yourRecoveryId')}</AlertTitle>
                            <AlertDescription>
                                {t('youChose')}: <strong className="font-mono">{recoveryId}</strong>. {t('keepItSafe')}!
                            </AlertDescription>
                        </Alert>
                    </CardContent>
                    <CardFooter>
                         <Button onClick={handleFinishOnboarding} className="w-full btn-gradient">{t('continueToApp')}</Button>
                    </CardFooter>
                </Card>
            </div>
        );
    }
    
    const renderStepContent = () => {
        switch (step) {
            case 1:
                return (
                    <div className="space-y-1">
                        <Label htmlFor="displayName">{t('displayNameLabel')}</Label>
                        <Input id="displayName" type="text" value={displayName} onChange={e => setDisplayName(e.target.value)} placeholder={t('displayNameLabel')} autoFocus/>
                        <p className="text-xs text-muted-foreground px-2">{t('displayNameHint')}</p>
                    </div>
                );
            case 2:
                return (
                     <div className="space-y-1">
                        <Label htmlFor="publicId">{t('publicIdLabel')}</Label>
                        <Input id="publicId" type="text" value={publicId} onChange={e => setPublicId(e.target.value.replace(/[^a-z0-9-]/gi, '').toLowerCase())} placeholder={t('publicIdLabel')} autoFocus/>
                        <p className="text-xs text-muted-foreground px-2">{t('publicIdHint')}</p>
                    </div>
                );
            case 3:
                return (
                     <div className="space-y-1">
                         <Label htmlFor="recoveryId">{t('recoveryIdPlaceholder')}</Label>
                        <div className="flex items-center gap-2">
                            <Input id="recoveryId" type="text" value={recoveryId} onChange={e => setRecoveryId(e.target.value)} placeholder={t('recoveryIdPlaceholder')} className="flex-1" autoFocus/>
                            <Button variant="ghost" size="icon" onClick={generateRandomRecoveryId} title="Generate random ID">
                                <Sparkles className="h-5 w-5" />
                            </Button>
                        </div>
                        <p className="text-xs text-muted-foreground px-2">{t('recoveryIdHint')}</p>
                    </div>
                );
            default:
                return null;
        }
    }

    return (
        <div className="min-h-svh flex justify-center bg-background p-4 sm:p-6 md:p-8" dir={language === 'ar' ? 'rtl' : 'ltr'}>
             <div className="absolute top-0 left-0 right-0 h-screen w-screen overflow-hidden pointer-events-none">
                 <InfoBubble emoji="💡" text={t('bubble1')} />
                 <InfoBubble emoji="🔒" text={t('bubble2')} />
                 <InfoBubble emoji="👤" text={t('bubble3')} />
                 <InfoBubble emoji="✨" text={t('bubble4')} />
            </div>
            <Card className="w-full max-w-sm z-10 bg-background/80 backdrop-blur-sm self-center">
                 <CardHeader>
                    <div className="relative w-full flex justify-center mb-4">
                        <Logo />
                    </div>
                    <div className="flex items-center justify-center gap-2 pt-2">
                        <CardTitle className="text-center">{t('createProfileTitle')}</CardTitle>
                        <Dialog>
                            <DialogTrigger asChild>
                                <Button variant="ghost" size="icon" className="h-6 w-6">
                                    <HelpCircle className="h-4 w-4" />
                                </Button>
                            </DialogTrigger>
                            <DialogContent>
                                <DialogHeader>
                                    <DialogTitle>{t('howLoginWorksTitle')}</DialogTitle>
                                </DialogHeader>
                                <div className="space-y-4 text-sm text-muted-foreground">
                                    <p>{t('howLoginWorksP1')}</p>
                                    <ul className="space-y-2 list-disc pl-5">
                                        <li><strong className="text-foreground">{t('howLoginWorksL1Title')}</strong> {t('howLoginWorksL1Text')}</li>
                                        <li><strong className="text-foreground">{t('howLoginWorksL2Title')}</strong> {t('howLoginWorksL2Text')}</li>
                                    </ul>
                                    <p>{t('howLoginWorksP2')}</p>
                                </div>
                            </DialogContent>
                        </Dialog>
                    </div>
                     <CardDescription className="text-center pt-2">
                        {t('onboardingDescription')}
                    </CardDescription>
                </CardHeader>
                <CardContent className="space-y-4">
                    <StepIndicator current={step} total={TOTAL_STEPS} t={t} />
                    {renderStepContent()}
                </CardContent>
                <CardFooter className="flex-col gap-4">
                    <div className="w-full flex justify-between items-center">
                        <Button variant="outline" onClick={handlePrevStep} disabled={step === 1}>
                             <ArrowLeft className="h-4 w-4" />
                        </Button>
                        {step < TOTAL_STEPS ? (
                             <Button onClick={handleNextStep}>
                                 {t('nextStep')} <ArrowRight className="h-4 w-4" />
                            </Button>
                        ) : (
                             <Button onClick={handleCreateProfile} disabled={isLoading} className="btn-gradient flex-1">
                                {isLoading ? t('creating') : t('createProfileButton')}
                            </Button>
                        )}
                    </div>
                    <Separator />
                     <div className="w-full flex justify-center items-center gap-2">
                        <Button variant={language === 'en' ? 'secondary' : 'ghost'} size="sm" onClick={() => handleLanguageChange('en')}>English</Button>
                        <Languages className="w-4 h-4 text-muted-foreground"/>
                        <Button variant={language === 'ar' ? 'secondary' : 'ghost'} size="sm" onClick={() => handleLanguageChange('ar')}>العربية</Button>
                    </div>
                     <p className="text-center text-sm text-muted-foreground">
                        {t('haveAnAccount')}{' '}
                        <Button variant="link" className="p-0" onClick={() => { playSound('touch'); setAuthStatus('recovery'); }}>
                            {t('recoverAccount')}
                        </Button>
                    </p>
                </CardFooter>
            </Card>
        </div>
    );
};