// NOTE: This file is stable and usually should not be modified.
// It is important that all functionality in this file is preserved, and should only be modified if explicitly requested.

import React, { useState, useEffect } from 'react';
import { Shield, UserPlus, Sparkles, Cloud, Smartphone, Check, Loader2, KeyRound } from 'lucide-react';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Dialog, DialogContent, DialogHeader, DialogDescription } from "@/components/ui/dialog";
import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
import { useLoginActions } from '@/hooks/useLoginActions';
import { useToast } from '@/hooks/useToast';
import { cn } from '@/lib/utils';


interface LoginDialogProps {
  isOpen: boolean;
  onClose: () => void;
  onLogin: () => void;
  onSignup?: () => void;
}

export const LoginDialog: React.FC<LoginDialogProps> = ({ isOpen, onClose, onLogin, onSignup }) => {
  const [isLoading, setIsLoading] = useState(false);
  const [bunkerUri, setBunkerUri] = useState('');
  const [bunkerError, setBunkerError] = useState('');
  const [nsecInput, setNsecInput] = useState('');
  const [nsecError, setNsecError] = useState('');

  // Amber NIP-55 state
  const [amberStep, setAmberStep] = useState<'idle' | 'waiting' | 'paste' | 'done'>('idle');
  const [pubkeyInput, setPubkeyInput] = useState('');
  const [pubkeyError, setPubkeyError] = useState('');

  const login = useLoginActions();
  const { toast } = useToast();

  const isAndroid = /Android/i.test(navigator.userAgent);

  // Step 1: open Amber asking it to copy pubkey to clipboard (no callback URL)
  const handleAmberLogin = () => {
    // nostrsigner: with no callbackUrl → Amber copies pubkey to clipboard
    // This works on ALL Android browsers including GrapheneOS Vanadium
    window.location.href = 'intent:#Intent;scheme=nostrsigner;S.compressionType=none;S.returnType=signature;S.type=get_public_key;end';
    setAmberStep('waiting');
  };

  // Step 2: user comes back — try clipboard automatically, else show paste input
  useEffect(() => {
    if (amberStep !== 'waiting') return;
    const handleVisible = async () => {
      if (document.visibilityState !== 'visible') return;
      // Try reading clipboard automatically
      try {
        const text = await navigator.clipboard.readText();
        const clean = text.trim().toLowerCase();
        if (/^[0-9a-f]{64}$/.test(clean)) {
          completeLogin(clean);
          return;
        }
      } catch { /* clipboard permission denied — fall through to paste UI */ }
      // Show paste input
      setAmberStep('paste');
    };
    document.addEventListener('visibilitychange', handleVisible);
    return () => document.removeEventListener('visibilitychange', handleVisible);
  }, [amberStep]);

  const completeLogin = (pubkey: string) => {
    try {
      login.amber(pubkey);
      setAmberStep('done');
      toast({ title: '🛹 Logged in!', description: 'Connected via Amber!' });
      setTimeout(() => { onLogin(); onClose(); }, 800);
    } catch (e) {
      console.error('[Amber] login.amber() failed:', e);
      setAmberStep('idle');
      toast({ title: 'Login failed', description: 'Could not log in with Amber. Try again.', variant: 'destructive' });
    }
  };

  const handlePubkeySubmit = () => {
    const clean = pubkeyInput.trim().toLowerCase();
    if (!/^[0-9a-f]{64}$/.test(clean)) {
      setPubkeyError('Must be a 64-character hex pubkey');
      return;
    }
    completeLogin(clean);
  };

  // Reset when dialog closes
  useEffect(() => {
    if (!isOpen) {
      setAmberStep('idle');
      setPubkeyInput('');
      setPubkeyError('');
      setBunkerUri('');
      setBunkerError('');
      setNsecInput('');
      setNsecError('');
      setIsLoading(false);
    }
  }, [isOpen]);

  const handleBunkerLogin = async () => {
    const uri = bunkerUri.trim();
    if (!uri.startsWith('bunker://')) { setBunkerError('Must start with bunker://'); return; }
    setIsLoading(true);
    setBunkerError('');
    try {
      await login.bunker(uri);
      toast({ title: '🛹 Logged in!', description: 'Connected via bunker!' });
      onLogin(); onClose();
    } catch (e: unknown) {
      setBunkerError(`Failed: ${(e as Error)?.message ?? 'Check your bunker URI'}`);
    } finally { setIsLoading(false); }
  };

  const handleNsecLogin = () => {
    const val = nsecInput.trim();
    if (!val.startsWith('nsec1')) { setNsecError('Must start with nsec1'); return; }
    try {
      login.nsec(val);
      toast({ title: '🛹 Logged in!' });
      onLogin(); onClose();
    } catch (e: unknown) {
      setNsecError(`Invalid nsec: ${(e as Error)?.message ?? 'Check your key'}`);
    }
  };

  const handleExtensionLogin = async () => {
    try { await login.extension(); onLogin(); onClose(); }
    catch { toast({ title: 'No extension found', description: 'Install Alby or another NIP-07 extension.', variant: 'destructive' }); }
  };

  return (
    <Dialog open={isOpen} onOpenChange={onClose}>
      <DialogContent className={cn("w-[calc(100%-1rem)] sm:max-w-md max-h-[90vh] max-h-[90dvh] p-0 overflow-hidden rounded-2xl bg-black border-2 border-[#ff0040]/50")}>
        <DialogHeader className={cn('px-4 sm:px-6 pt-4 sm:pt-6 pb-1')}>
          <DialogDescription className="text-center text-sm text-gray-400">
            Sign up or log in to continue
          </DialogDescription>
        </DialogHeader>

        <div className='px-4 sm:px-6 pt-2 pb-6 space-y-4 overflow-y-auto'>
          {/* Sign Up */}
          <div className='relative p-5 rounded-2xl bg-black border-2 border-[#ccff00]/50 overflow-hidden'>
            <div className="absolute inset-0 bg-[#ccff00]/5 blur-xl" />
            <div className='relative z-10 text-center space-y-3'>
              <div className='flex justify-center items-center gap-2'>
                <Sparkles className='w-5 h-5 text-[#ccff00]' />
                <span className='font-bold text-[#ccff00] uppercase tracking-wide'>New here?</span>
              </div>
              <p className='text-xs text-gray-300'>Create a free account. No email required.</p>
              <Button onClick={() => { onClose(); onSignup?.(); }} className='w-full rounded-full py-3 font-bold bg-[#ccff00] text-black hover:bg-[#ccff00]/90 uppercase'>
                <UserPlus className='w-4 h-4 mr-2' />Create Account
              </Button>
            </div>
          </div>

          <div className='relative flex items-center'>
            <div className='flex-1 border-t border-gray-800' />
            <span className='px-3 text-xs text-gray-500'>Or log in</span>
            <div className='flex-1 border-t border-gray-800' />
          </div>

          <Tabs defaultValue={isAndroid ? 'amber' : 'bunker'} className="w-full">
            <TabsList className="grid w-full grid-cols-4 bg-black/50 border border-[#ff0040]/30 rounded-lg mb-4 h-auto p-1">
              <TabsTrigger value="amber" className="flex items-center gap-1 text-xs py-2 px-1">
                <Smartphone className="w-3 h-3" /><span>Amber</span>
              </TabsTrigger>
              <TabsTrigger value="bunker" className="flex items-center gap-1 text-xs py-2 px-1">
                <Cloud className="w-3 h-3" /><span>Bunker</span>
              </TabsTrigger>
              <TabsTrigger value="nsec" className="flex items-center gap-1 text-xs py-2 px-1">
                <KeyRound className="w-3 h-3" /><span>nsec</span>
              </TabsTrigger>
              <TabsTrigger value="extension" className="flex items-center gap-1 text-xs py-2 px-1">
                <Shield className="w-3 h-3" /><span>Ext</span>
              </TabsTrigger>
            </TabsList>

            {/* ── AMBER TAB ── */}
            <TabsContent value='amber' className='space-y-3'>

              {/* Done */}
              {amberStep === 'done' && (
                <div className='text-center p-5 rounded-xl bg-black/50 border-2 border-green-500/30 space-y-3'>
                  <Check className='w-10 h-10 mx-auto text-green-500' />
                  <p className='text-sm text-green-400 font-bold'>Logged in!</p>
                  <Loader2 className="w-4 h-4 mx-auto animate-spin text-green-500" />
                </div>
              )}

              {/* Step 1 idle — show login button */}
              {amberStep === 'idle' && (
                <div className='text-center p-5 rounded-xl bg-black/50 border-2 border-[#ccff00]/30 space-y-4'>
                  <div className="w-14 h-14 rounded-full bg-[#ccff00]/10 border-2 border-[#ccff00]/40 flex items-center justify-center mx-auto">
                    <Smartphone className='w-7 h-7 text-[#ccff00]' />
                  </div>
                  <div>
                    <p className='text-sm text-white font-bold'>Login with Amber</p>
                    <p className='text-xs text-gray-400 mt-1'>Opens Amber → approve → come back here.</p>
                  </div>
                  <Button
                    className='w-full rounded-full py-3 bg-[#ccff00] text-black hover:bg-[#ccff00]/90 font-bold uppercase'
                    onClick={handleAmberLogin}
                  >
                    <Smartphone className="w-4 h-4 mr-2" />Open Amber
                  </Button>
                </div>
              )}

              {/* Step 2 waiting — app just navigated to Amber */}
              {amberStep === 'waiting' && (
                <div className='text-center p-5 rounded-xl bg-black/50 border-2 border-[#ccff00]/40 space-y-4'>
                  <Loader2 className='w-8 h-8 text-[#ccff00] animate-spin mx-auto' />
                  <div>
                    <p className='text-sm text-white font-bold'>Approve in Amber</p>
                    <p className='text-xs text-gray-400 mt-1'>Tap "Get public key" in Amber, then come back here.</p>
                  </div>
                  <Button variant="ghost" className='text-xs text-gray-500 h-auto py-2'
                    onClick={() => setAmberStep('paste')}>
                    Already approved? Paste pubkey manually
                  </Button>
                  <Button variant="ghost" className='text-xs text-gray-600 h-auto py-1'
                    onClick={() => setAmberStep('idle')}>Cancel</Button>
                </div>
              )}

              {/* Step 3 paste — clipboard read failed or user chose manual */}
              {amberStep === 'paste' && (
                <div className='p-5 rounded-xl bg-black/50 border-2 border-[#ccff00]/30 space-y-4'>
                  <div className='text-center'>
                    <Smartphone className='w-8 h-8 mx-auto mb-2 text-[#ccff00]' />
                    <p className='text-sm text-white font-bold'>Paste your pubkey</p>
                    <p className='text-xs text-gray-400 mt-1'>
                      In Amber: tap your profile → copy public key (hex). Paste it below.
                    </p>
                  </div>
                  <div className='space-y-2'>
                    <Input
                      placeholder='hex pubkey (64 characters)...'
                      value={pubkeyInput}
                      onChange={e => { setPubkeyInput(e.target.value); setPubkeyError(''); }}
                      className='bg-black/60 border-[#ccff00]/30 text-white placeholder:text-gray-600 text-xs font-mono'
                      autoComplete='off'
                      autoCorrect='off'
                      spellCheck={false}
                    />
                    {pubkeyError && <p className="text-xs text-red-400">{pubkeyError}</p>}
                  </div>
                  <Button
                    className='w-full rounded-full py-3 bg-[#ccff00] text-black hover:bg-[#ccff00]/90 font-bold uppercase'
                    disabled={!pubkeyInput.trim()}
                    onClick={handlePubkeySubmit}
                  >
                    <Check className='w-4 h-4 mr-2' />Connect
                  </Button>
                  <Button variant="ghost" className='w-full text-xs text-gray-600 h-auto py-1'
                    onClick={() => setAmberStep('idle')}>Back</Button>
                </div>
              )}

            </TabsContent>

            {/* ── BUNKER TAB ── */}
            <TabsContent value='bunker' className='space-y-3'>
              <div className='p-5 rounded-xl bg-black/50 border-2 border-blue-500/30 space-y-4'>
                <div className='text-center'>
                  <Cloud className='w-10 h-10 mx-auto mb-2 text-blue-400' />
                  <p className='text-sm text-white font-bold'>Bunker (NIP-46)</p>
                  <p className='text-xs text-gray-400 mt-1'>Paste your <code className='text-blue-300'>bunker://</code> URI.</p>
                </div>
                <div className='text-xs text-gray-300 bg-black/40 rounded-lg p-3 space-y-1 border border-gray-800'>
                  <p><strong className='text-blue-300'>Amber:</strong> Settings → NIP-46 Bunker → Create → Copy</p>
                  <p><strong className='text-blue-300'>nsec.app:</strong> Connect app → Copy bunker URI</p>
                </div>
                <div className='space-y-2'>
                  <Input placeholder='bunker://...' value={bunkerUri} onChange={e => { setBunkerUri(e.target.value); setBunkerError(''); }} className='bg-black/60 border-blue-500/30 text-white placeholder:text-gray-600 text-xs font-mono' autoComplete='off' autoCorrect='off' spellCheck={false} />
                  {bunkerError && <p className="text-xs text-red-400">{bunkerError}</p>}
                </div>
                <Button className='w-full rounded-full py-3 bg-blue-500 hover:bg-blue-600 text-white font-bold uppercase' disabled={isLoading || !bunkerUri.trim()} onClick={handleBunkerLogin}>
                  {isLoading ? <Loader2 className='w-4 h-4 animate-spin mr-2' /> : <Cloud className='w-4 h-4 mr-2' />}Connect
                </Button>
                <div className='flex gap-2 justify-center'>
                  <a href="https://nsec.app" target="_blank" rel="noopener noreferrer" className="text-xs px-3 py-1 bg-blue-500/20 text-blue-400 rounded-full hover:bg-blue-500/30">nsec.app →</a>
                  <a href="https://nostrum.social" target="_blank" rel="noopener noreferrer" className="text-xs px-3 py-1 bg-blue-500/20 text-blue-400 rounded-full hover:bg-blue-500/30">Nostrum →</a>
                </div>
              </div>
            </TabsContent>

            {/* ── NSEC TAB ── */}
            <TabsContent value='nsec' className='space-y-3'>
              <div className='p-5 rounded-xl bg-black/50 border-2 border-yellow-500/30 space-y-4'>
                <div className='text-center'>
                  <KeyRound className='w-10 h-10 mx-auto mb-2 text-yellow-400' />
                  <p className='text-sm text-white font-bold'>Secret Key (nsec)</p>
                  <p className='text-xs text-gray-400 mt-1'>Paste your Nostr secret key directly.</p>
                </div>
                <div className='p-3 rounded-lg bg-yellow-500/10 border border-yellow-500/30'>
                  <p className='text-xs text-yellow-300'>⚠️ Only use this on a trusted device. Never share your nsec.</p>
                </div>
                <div className='space-y-2'>
                  <Input type="password" placeholder='nsec1...' value={nsecInput} onChange={e => { setNsecInput(e.target.value); setNsecError(''); }} className='bg-black/60 border-yellow-500/30 text-white placeholder:text-gray-600 text-xs font-mono' autoComplete='off' autoCorrect='off' spellCheck={false} />
                  {nsecError && <p className="text-xs text-red-400">{nsecError}</p>}
                </div>
                <Button className='w-full rounded-full py-3 bg-yellow-500 hover:bg-yellow-600 text-black font-bold uppercase' disabled={!nsecInput.trim()} onClick={handleNsecLogin}>
                  <KeyRound className='w-4 h-4 mr-2' />Login
                </Button>
              </div>
            </TabsContent>

            {/* ── EXTENSION TAB ── */}
            <TabsContent value='extension' className='space-y-3'>
              <div className='text-center p-5 rounded-xl bg-black/50 border-2 border-[#ff0040]/30 space-y-4'>
                <Shield className='w-10 h-10 mx-auto text-[#ff0040]' />
                <div>
                  <p className='text-sm text-white font-bold'>Browser Extension (NIP-07)</p>
                  <p className='text-xs text-gray-400 mt-1'>Best for desktop. Works with Alby, nos2x, Flamingo.</p>
                </div>
                <Button className='w-full rounded-full py-3 bg-[#ff0040] hover:bg-[#ff0040]/90 text-white font-bold uppercase' onClick={handleExtensionLogin}>
                  Login with Extension
                </Button>
              </div>
            </TabsContent>
          </Tabs>
        </div>
      </DialogContent>
    </Dialog>
  );
};

export default LoginDialog;