import 'dart:convert';
import 'dart:io';

import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:share_plus/share_plus.dart' show Share, XFile;
import 'package:path_provider/path_provider.dart';
import 'package:uuid/uuid.dart';
import '../estado/estado_radio.dart';
import '../modelos/emisora.dart';
import '../modelos/preset_ecualizador.dart';
import '../widgets/ecualizador_widget.dart';

class PantallaAjustes extends StatelessWidget {
  const PantallaAjustes({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Ajustes')),
      body: ListView(
        children: const [
          _SeccionEcualizador(),
          Divider(),
          _SeccionEmisoras(),
          Divider(),
          _SeccionBackup(),
          Divider(),
          _SeccionInfo(),
        ],
      ),
    );
  }
}

// ── Sección Ecualizador ───────────────────────────────────────────────────────

class _SeccionEcualizador extends StatelessWidget {
  const _SeccionEcualizador();

  @override
  Widget build(BuildContext context) {
    return Consumer<EstadoRadio>(
      builder: (ctx, estado, _) {
        final disponible = estado.ecualizadorDisponible;
        final emisoraActual = estado.emisoraActual;
        final mostrarModoPorEmisora =
            emisoraActual != null && estado.emisoraActualEsFavorita;
        final usandoEqPropio = estado.emisoraActualTienePresetPropio;

        return Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              Row(
                children: [
                  const Icon(Icons.equalizer),
                  const SizedBox(width: 12),
                  Text('Ecualizador', style: Theme.of(ctx).textTheme.titleMedium),
                  const Spacer(),
                  if (!disponible)
                    Chip(
                      label: const Text('Se guarda aunque no esté activo'),
                      visualDensity: VisualDensity.compact,
                    ),
                ],
              ),
              if (mostrarModoPorEmisora) ...[
                const SizedBox(height: 8),
                SwitchListTile.adaptive(
                  contentPadding: EdgeInsets.zero,
                  title: const Text('Usar EQ propio para esta favorita'),
                  subtitle: Text(
                    usandoEqPropio
                        ? 'Activo para ${emisoraActual.nombre}'
                        : 'Usando EQ principal para ${emisoraActual.nombre}',
                  ),
                  value: usandoEqPropio,
                  onChanged: (usarPropio) {
                    estado.cambiarModoEcualizadorEmisoraActual(
                      usarPropio: usarPropio,
                    );
                  },
                ),
              ],
              const SizedBox(height: 8),
              PresetsEcualizadorWidget(
                presetActual: estado.presetEcualizador,
                onSeleccionar: (p) => estado.cambiarPresetEcualizador(p),
              ),
              const SizedBox(height: 12),
              EcualizadorWidget(
                preset: estado.presetEcualizador,
                onCambio: (p) {
                  estado.cambiarPresetEcualizador(p);
                },
              ),
            ],
          ),
        );
      },
    );
  }
}

// ── Sección Emisoras personalizadas ──────────────────────────────────────────

class _SeccionEmisoras extends StatelessWidget {
  const _SeccionEmisoras();

  @override
  Widget build(BuildContext context) {
    final estado = context.watch<EstadoRadio>();
    final custom = estado.emisorasCustom;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Padding(
          padding: const EdgeInsets.fromLTRB(16, 12, 16, 4),
          child: Row(
            children: [
              const Icon(Icons.add_circle_outline),
              const SizedBox(width: 12),
              Text('Emisoras personalizadas',
                  style: Theme.of(context).textTheme.titleMedium),
              const Spacer(),
              TextButton.icon(
                icon: const Icon(Icons.add),
                label: const Text('Añadir'),
                onPressed: () => _mostrarFormularioAnadir(context),
              ),
            ],
          ),
        ),
        if (custom.isEmpty)
          const Padding(
            padding: EdgeInsets.fromLTRB(16, 4, 16, 12),
            child: Text('No hay emisoras personalizadas.',
                style: TextStyle(color: Colors.grey)),
          )
        else
          for (final emisora in custom)
            ListTile(
              leading: const Icon(Icons.radio),
              title: Text(emisora.nombre),
              subtitle: Text(emisora.url, maxLines: 1, overflow: TextOverflow.ellipsis),
              trailing: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  IconButton(
                    icon: const Icon(Icons.play_arrow),
                    tooltip: 'Reproducir',
                    onPressed: () => context.read<EstadoRadio>().reproducir(emisora),
                  ),
                  IconButton(
                    icon: const Icon(Icons.delete_outline),
                    tooltip: 'Eliminar',
                    onPressed: () => context.read<EstadoRadio>().eliminarEmitoraCustom(emisora.uuid),
                  ),
                ],
              ),
            ),
      ],
    );
  }

  Future<void> _mostrarFormularioAnadir(BuildContext context) async {
    await showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      builder: (ctx) => const _FormularioEmisora(),
    );
  }
}

class _FormularioEmisora extends StatefulWidget {
  const _FormularioEmisora();

  @override
  State<_FormularioEmisora> createState() => _FormularioEmisoraState();
}

class _FormularioEmisoraState extends State<_FormularioEmisora> {
  final _formKey = GlobalKey<FormState>();
  final _nombreCtrl = TextEditingController();
  final _urlCtrl = TextEditingController();
  final _paisCtrl = TextEditingController();
  bool _guardando = false;

  @override
  void dispose() {
    _nombreCtrl.dispose();
    _urlCtrl.dispose();
    _paisCtrl.dispose();
    super.dispose();
  }

  Future<void> _guardar() async {
    if (!_formKey.currentState!.validate()) return;
    setState(() => _guardando = true);

    final emisora = Emisora(
      uuid: const Uuid().v4(),
      nombre: _nombreCtrl.text.trim(),
      url: _urlCtrl.text.trim(),
      pais: _paisCtrl.text.trim().isEmpty ? null : _paisCtrl.text.trim(),
    );

    await context.read<EstadoRadio>().agregarEmitoraCustom(emisora);
    if (mounted) Navigator.pop(context);
  }

  @override
  Widget build(BuildContext context) {
    final bottom = MediaQuery.of(context).viewInsets.bottom;
    return Padding(
      padding: EdgeInsets.fromLTRB(16, 16, 16, 16 + bottom),
      child: Form(
        key: _formKey,
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text('Añadir emisora', style: Theme.of(context).textTheme.titleLarge),
            const SizedBox(height: 16),
            TextFormField(
              controller: _nombreCtrl,
              decoration: const InputDecoration(labelText: 'Nombre *', border: OutlineInputBorder()),
              validator: (v) => v == null || v.trim().isEmpty ? 'Campo obligatorio' : null,
            ),
            const SizedBox(height: 12),
            TextFormField(
              controller: _urlCtrl,
              decoration: const InputDecoration(
                labelText: 'URL del stream *',
                hintText: 'http://stream.ejemplo.com:8000/radio',
                border: OutlineInputBorder(),
              ),
              keyboardType: TextInputType.url,
              validator: (v) {
                if (v == null || v.trim().isEmpty) return 'Campo obligatorio';
                final uri = Uri.tryParse(v.trim());
                if (uri == null || !uri.hasScheme) return 'URL no válida';
                return null;
              },
            ),
            const SizedBox(height: 12),
            TextFormField(
              controller: _paisCtrl,
              decoration: const InputDecoration(
                labelText: 'País (opcional)',
                border: OutlineInputBorder(),
              ),
            ),
            const SizedBox(height: 20),
            FilledButton(
              onPressed: _guardando ? null : _guardar,
              child: _guardando
                  ? const SizedBox(height: 20, width: 20, child: CircularProgressIndicator(strokeWidth: 2))
                  : const Text('Guardar emisora'),
            ),
          ],
        ),
      ),
    );
  }
}

// ── Sección Backup ────────────────────────────────────────────────────────────

class _SeccionBackup extends StatelessWidget {
  const _SeccionBackup();

  Future<void> _exportar(BuildContext context) async {
    try {
      final estado = context.read<EstadoRadio>();
      final config = await estado.exportarConfig();
      final json = const JsonEncoder.withIndent('  ').convert(config);

      final dir = await getTemporaryDirectory();
      final file = File('${dir.path}/pluriwave-backup.json');
      await file.writeAsString(json);

      await Share.shareXFiles(
        [XFile(file.path)],
        subject: 'PluriWave — copia de seguridad',
        text: 'Configuración de PluriWave exportada el ${DateTime.now().toLocal()}',
      );
    } catch (e) {
      if (context.mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Error al exportar: $e')),
        );
      }
    }
  }

  Future<void> _importar(BuildContext context) async {
    try {
      final result = await FilePicker.platform.pickFiles(
        type: FileType.custom,
        allowedExtensions: ['json'],
      );
      if (result == null || result.files.single.path == null) return;

      final file = File(result.files.single.path!);
      final json = jsonDecode(await file.readAsString()) as Map<String, dynamic>;

      if (context.mounted) {
        final confirmar = await showDialog<bool>(
          context: context,
          builder: (ctx) => AlertDialog(
            title: const Text('Importar configuración'),
            content: const Text(
                'Esto añadirá los favoritos, emisoras y presets del fichero. '
                '¿Continuar?'),
            actions: [
              TextButton(
                  onPressed: () => Navigator.pop(ctx, false),
                  child: const Text('Cancelar')),
              FilledButton(
                  onPressed: () => Navigator.pop(ctx, true),
                  child: const Text('Importar')),
            ],
          ),
        );
        if (confirmar != true) return;
        if (context.mounted) {
          await context.read<EstadoRadio>().importarConfig(json);
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('Configuración importada correctamente')),
          );
        }
      }
    } catch (e) {
      if (context.mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Error al importar: $e')),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Padding(
          padding: const EdgeInsets.fromLTRB(16, 12, 16, 4),
          child: Row(
            children: [
              const Icon(Icons.backup_outlined),
              const SizedBox(width: 12),
              Text('Copia de seguridad',
                  style: Theme.of(context).textTheme.titleMedium),
            ],
          ),
        ),
        ListTile(
          leading: const Icon(Icons.upload_outlined),
          title: const Text('Exportar configuración'),
          subtitle: const Text('Favoritos, emisoras custom y presets de EQ'),
          onTap: () => _exportar(context),
        ),
        ListTile(
          leading: const Icon(Icons.download_outlined),
          title: const Text('Importar configuración'),
          subtitle: const Text('Restaurar desde un fichero de copia de seguridad'),
          onTap: () => _importar(context),
        ),
      ],
    );
  }
}

// ── Sección Info ──────────────────────────────────────────────────────────────

class _SeccionInfo extends StatelessWidget {
  const _SeccionInfo();

  @override
  Widget build(BuildContext context) {
    return Consumer<EstadoRadio>(
      builder: (ctx, estado, _) => Column(
        children: [
          ListTile(
            leading: const Icon(Icons.info_outline),
            title: const Text('PluriWave'),
            subtitle: const Text('v0.3.0 — Radio mundial'),
          ),
          FutureBuilder<int>(
            future: estado.favoritos.obtenerTodos().then((l) => l.length),
            builder: (ctx, snap) => ListTile(
              leading: const Icon(Icons.favorite_outline),
              title: const Text('Favoritos guardados'),
              trailing: Text(snap.data?.toString() ?? '—',
                  style: Theme.of(ctx).textTheme.bodyLarge),
            ),
          ),
          ListTile(
            leading: const Icon(Icons.verified_outlined),
            title: const Text('Filtro de emisoras'),
            subtitle: const Text('Solo emisoras verificadas como activas'),
            trailing: const Icon(Icons.check_circle, color: Colors.green),
          ),
          ListTile(
            leading: const Icon(Icons.music_note_outlined),
            title: const Text('Audio en background'),
            subtitle: const Text('Continúa al apagar la pantalla'),
            trailing: const Icon(Icons.check_circle, color: Colors.green),
          ),
        ],
      ),
    );
  }
}