import 'package:flutter/material.dart';
import 'package:mobile_scanner/mobile_scanner.dart';
import 'package:provider/provider.dart';
import 'package:farolero/l10n/generated/app_localizations.dart';
import '../servicios/servicio_nearby.dart';
import '../tema/tema_app.dart';

/// Pantalla para unirse a una partida multidispositivo
class PantallaUnirse extends StatefulWidget {
  const PantallaUnirse({super.key});

  @override
  State<PantallaUnirse> createState() => _PantallaUnirseState();
}

class _PantallaUnirseState extends State<PantallaUnirse> {
  final _nombreController = TextEditingController();
  final _formKey = GlobalKey<FormState>();
  bool _escaneando = false;
  bool _conectando = false;
  String? _error;
  String? _salaEncontrada;

  @override
  void dispose() {
    _nombreController.dispose();
    super.dispose();
  }

  Future<void> _iniciarEscaneo() async {
    if (!_formKey.currentState!.validate()) return;
    setState(() {
      _escaneando = true;
      _error = null;
    });
  }

  Future<void> _onQRDetectado(BarcodeCapture capture) async {
    if (_conectando) return;

    for (final barcode in capture.barcodes) {
      final valor = barcode.rawValue;
      if (valor == null) continue;

      final datos = ServicioNearby.parsearQR(valor);
      if (datos != null) {
        setState(() {
          _escaneando = false;
          _conectando = true;
          _salaEncontrada = datos['sala'] as String? ?? 'Sala';
        });

        // Iniciar búsqueda de hosts via Nearby
        final nearby = context.read<ServicioNearby>();
        final ok = await nearby.buscarHosts(_nombreController.text.trim());

        if (!ok && mounted) {
          setState(() {
            _conectando = false;
            _error = 'No se pudo iniciar la búsqueda. Verifica Bluetooth y ubicación.';
          });
        }
        return;
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final nearby = context.watch<ServicioNearby>();

    // Si estamos conectados, mostrar pantalla de espera
    if (nearby.conectado && !nearby.esHost) {
      return _buildPantallaEspera(context, l10n, nearby);
    }

    return Scaffold(
      appBar: AppBar(
        title: Text(l10n.joinGameTitle),
        leading: IconButton(
          icon: const Icon(Icons.close),
          onPressed: () async {
            await nearby.desconectar();
            if (context.mounted) Navigator.pop(context);
          },
        ),
      ),
      body: _escaneando
          ? _buildEscaner(context, l10n)
          : _buildFormulario(context, l10n),
    );
  }

  Widget _buildFormulario(BuildContext context, AppLocalizations l10n) {
    return Padding(
      padding: const EdgeInsets.all(32),
      child: Form(
        key: _formKey,
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text('📱', style: TextStyle(fontSize: 64)),
            const SizedBox(height: 24),
            Text(
              l10n.joinGameTitle,
              style: Theme.of(context).textTheme.headlineMedium,
            ),
            const SizedBox(height: 8),
            Text(
              l10n.enterNameAndScan,
              style: Theme.of(context).textTheme.bodyLarge,
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 32),

            // Campo nombre
            TextFormField(
              controller: _nombreController,
              decoration: InputDecoration(
                labelText: l10n.yourName,
                prefixIcon: const Icon(Icons.person),
              ),
              validator: (v) {
                if (v == null || v.trim().isEmpty) {
                  return l10n.nameRequired;
                }
                return null;
              },
              textCapitalization: TextCapitalization.words,
            ),
            const SizedBox(height: 24),

            if (_conectando) ...[
              const CircularProgressIndicator(color: TemaApp.colorAcento),
              const SizedBox(height: 12),
              Text(
                '${l10n.connectingTo} ${_salaEncontrada ?? ""}...',
                style: Theme.of(context).textTheme.bodyMedium,
              ),
            ] else ...[
              // Botón escanear QR
              SizedBox(
                width: double.infinity,
                child: ElevatedButton.icon(
                  onPressed: _iniciarEscaneo,
                  icon: const Icon(Icons.qr_code_scanner),
                  label: Text(l10n.scanQR),
                ),
              ),
            ],

            if (_error != null) ...[
              const SizedBox(height: 16),
              Container(
                padding: const EdgeInsets.all(12),
                decoration: BoxDecoration(
                  color: TemaApp.colorAcento.withValues(alpha: 0.1),
                  borderRadius: BorderRadius.circular(12),
                ),
                child: Text(
                  _error!,
                  style: const TextStyle(color: TemaApp.colorAcento),
                  textAlign: TextAlign.center,
                ),
              ),
            ],
          ],
        ),
      ),
    );
  }

  Widget _buildEscaner(BuildContext context, AppLocalizations l10n) {
    return Stack(
      children: [
        MobileScanner(
          onDetect: _onQRDetectado,
        ),
        // Overlay
        Positioned(
          bottom: 0,
          left: 0,
          right: 0,
          child: Container(
            padding: const EdgeInsets.all(24),
            decoration: BoxDecoration(
              gradient: LinearGradient(
                begin: Alignment.topCenter,
                end: Alignment.bottomCenter,
                colors: [
                  Colors.transparent,
                  Colors.black.withValues(alpha: 0.8),
                ],
              ),
            ),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(
                  l10n.scanHostQR,
                  style: Theme.of(context).textTheme.titleLarge?.copyWith(
                    color: Colors.white,
                  ),
                ),
                const SizedBox(height: 16),
                OutlinedButton(
                  onPressed: () => setState(() => _escaneando = false),
                  style: OutlinedButton.styleFrom(
                    foregroundColor: Colors.white,
                    side: const BorderSide(color: Colors.white),
                  ),
                  child: Text(l10n.cancel),
                ),
              ],
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildPantallaEspera(
    BuildContext context,
    AppLocalizations l10n,
    ServicioNearby nearby,
  ) {
    return Scaffold(
      appBar: AppBar(
        title: Text(_salaEncontrada ?? l10n.joinGameTitle),
        leading: IconButton(
          icon: const Icon(Icons.close),
          onPressed: () async {
            await nearby.desconectar();
            if (context.mounted) Navigator.pop(context);
          },
        ),
      ),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(32),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              const Text('✅', style: TextStyle(fontSize: 64)),
              const SizedBox(height: 24),
              Text(
                l10n.connectedWaiting,
                style: Theme.of(context).textTheme.headlineMedium,
                textAlign: TextAlign.center,
              ),
              const SizedBox(height: 12),
              Text(
                '${l10n.yourName}: ${_nombreController.text}',
                style: Theme.of(context).textTheme.bodyLarge,
              ),
              const SizedBox(height: 32),
              const CircularProgressIndicator(color: TemaApp.colorNaranja),
              const SizedBox(height: 16),
              Text(
                l10n.waitingForHost,
                style: Theme.of(context).textTheme.bodyMedium,
              ),
            ],
          ),
        ),
      ),
    );
  }
}