import 'package:flutter/material.dart';
import 'package:flutter_animate/flutter_animate.dart';
import 'package:provider/provider.dart';
import 'package:shimmer/shimmer.dart' as shimmer;

import '../estado/estado_radio.dart';
import '../tema/pluriwave_theme.dart';
import '../widgets/pluri_glass_surface.dart';
import '../widgets/pluri_icon.dart';
import 'package:pluriwave/widgets/tarjeta_emisora.dart';

/// Pantalla principal: emisoras populares y por género.
class PantallaInicio extends StatefulWidget {
  const PantallaInicio({super.key});

  @override
  State<PantallaInicio> createState() => _PantallaInicioState();
}

class _PantallaInicioState extends State<PantallaInicio> {
  static const _generos = [
    'pop',
    'rock',
    'jazz',
    'classical',
    'electronic',
    'news',
    'talk',
    'hip-hop',
    'country',
    'metal',
    'reggae',
    'latin',
  ];
  String? _generoSeleccionado;

  @override
  Widget build(BuildContext context) {
    final estado = context.watch<EstadoRadio>();
    final theme = Theme.of(context);
    final t = context.pluriTokens;

    return RefreshIndicator(
      onRefresh: estado.cargarPopulares,
      child: CustomScrollView(
        slivers: [
          SliverToBoxAdapter(child: _heroHeader(context)),
          SliverToBoxAdapter(child: _seccionTendencias(estado, theme)),
          SliverToBoxAdapter(child: _chipGeneros(context, theme)),
          if (estado.error != null)
            SliverToBoxAdapter(child: _errorBanner(estado, theme)),
          SliverPadding(
            padding: EdgeInsets.symmetric(horizontal: t.spacingMd),
            sliver: _gridEmisoras(estado),
          ),
        ],
      ),
    );
  }

  Widget _heroHeader(BuildContext context) {
    final t = context.pluriTokens;
    final theme = Theme.of(context);
    return Padding(
      padding: EdgeInsets.fromLTRB(
        t.spacingMd,
        t.spacingSm,
        t.spacingMd,
        t.spacingSm,
      ),
      child: PluriGlassSurface(
        borderRadius: BorderRadius.circular(t.radiusLg),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const PluriIcon(
              glyph: PluriIconGlyph.home,
              variant: PluriIconVariant.activeGlow,
              size: 30,
            ),
            const SizedBox(height: 10),
            Text(
              'PluriWave',
              style: theme.textTheme.headlineMedium?.copyWith(
                fontWeight: FontWeight.w700,
              ),
            ),
            Text(
              'Ondas vivas globales',
              style: theme.textTheme.titleMedium?.copyWith(color: t.warmCoral),
            ),
          ],
        ),
      ),
    );
  }

  Widget _seccionTendencias(EstadoRadio estado, ThemeData theme) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(16, 8, 16, 0),
      child: PluriGlassSurface(
        padding: const EdgeInsets.all(12),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('Tendencias premium', style: theme.textTheme.titleMedium),
            const SizedBox(height: 8),
            SizedBox(
              height: 56,
              child:
                  estado.cargandoPopulares
                      ? ListView.separated(
                        scrollDirection: Axis.horizontal,
                        itemCount: 5,
                        separatorBuilder: (_, __) => const SizedBox(width: 8),
                        itemBuilder: (_, __) => _ChipShimmer(theme: theme),
                      )
                      : ListView.separated(
                        scrollDirection: Axis.horizontal,
                        itemCount: estado.tendencias.length,
                        separatorBuilder: (_, __) => const SizedBox(width: 8),
                        itemBuilder: (context, i) {
                          final e = estado.tendencias[i];
                          return ActionChip(
                            avatar: const Icon(
                              Icons.graphic_eq_rounded,
                              size: 18,
                            ),
                            label: Text(e.nombre, maxLines: 1),
                            onPressed:
                                () => context.read<EstadoRadio>().reproducir(e),
                          ).animate().fadeIn(delay: (i * 50).ms);
                        },
                      ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _chipGeneros(BuildContext context, ThemeData theme) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(16, 16, 16, 8),
      child: PluriGlassSurface(
        padding: const EdgeInsets.all(12),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('Géneros', style: theme.textTheme.titleMedium),
            const SizedBox(height: 8),
            Wrap(
              spacing: 8,
              runSpacing: 4,
              children:
                  _generos.map((g) {
                    final seleccionado = _generoSeleccionado == g;
                    return FilterChip(
                      label: Text(g),
                      selected: seleccionado,
                      onSelected: (_) {
                        setState(() {
                          _generoSeleccionado = seleccionado ? null : g;
                        });
                        if (!seleccionado) {
                          context.read<EstadoRadio>().buscar(tag: g);
                        } else {
                          context.read<EstadoRadio>().cargarPopulares();
                        }
                      },
                    );
                  }).toList(),
            ),
          ],
        ),
      ),
    );
  }

  Widget _errorBanner(EstadoRadio estado, ThemeData theme) {
    return Padding(
      padding: const EdgeInsets.all(16),
      child: PluriGlassSurface(
        padding: const EdgeInsets.all(12),
        child: Row(
          children: [
            Icon(Icons.wifi_off, color: theme.colorScheme.error),
            const SizedBox(width: 8),
            Expanded(child: Text(estado.error!)),
            TextButton(
              onPressed: estado.cargarPopulares,
              child: const Text('Reintentar'),
            ),
          ],
        ),
      ),
    );
  }

  Widget _gridEmisoras(EstadoRadio estado) {
    final emisoras =
        _generoSeleccionado != null
            ? estado.resultadosBusqueda
            : estado.emisorasInicio;
    final cargando =
        estado.cargandoPopulares ||
        (_generoSeleccionado != null && estado.cargandoBusqueda);

    if (cargando) {
      return SliverGrid(
        delegate: SliverChildBuilderDelegate(
          (_, __) => const TarjetaEmisoraShimmer(),
          childCount: 12,
        ),
        gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
          crossAxisCount: 2,
          childAspectRatio: 0.85,
          crossAxisSpacing: 8,
          mainAxisSpacing: 8,
        ),
      );
    }

    if (emisoras.isEmpty) {
      return const SliverFillRemaining(
        child: Center(child: Text('No hay emisoras disponibles')),
      );
    }

    return SliverGrid(
      delegate: SliverChildBuilderDelegate(
        (context, i) => TarjetaEmisora(
          emisora: emisoras[i],
          onTap: () => context.read<EstadoRadio>().reproducir(emisoras[i]),
        ).animate().fadeIn(delay: (i * 30).ms).slideY(begin: 0.1),
        childCount: emisoras.length,
      ),
      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 2,
        childAspectRatio: 0.85,
        crossAxisSpacing: 8,
        mainAxisSpacing: 8,
      ),
    );
  }
}

class _ChipShimmer extends StatelessWidget {
  final ThemeData theme;
  const _ChipShimmer({required this.theme});

  @override
  Widget build(BuildContext context) {
    return shimmer.Shimmer.fromColors(
      baseColor: theme.colorScheme.surfaceContainerHighest,
      highlightColor: theme.colorScheme.surface,
      child: Container(
        width: 120,
        height: 56,
        decoration: BoxDecoration(
          color: theme.colorScheme.surfaceContainerHighest,
          borderRadius: BorderRadius.circular(20),
        ),
      ),
    );
  }
}