import 'package:sysfarma_mobile/src/core/network/api_client.dart';
import 'package:sysfarma_mobile/src/core/network/inventory_options_cache.dart';
import 'package:sysfarma_mobile/src/core/theme/app_tokens.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

class StocktakeListScreen extends ConsumerStatefulWidget {
  const StocktakeListScreen({super.key});

  @override
  ConsumerState<StocktakeListScreen> createState() =>
      _StocktakeListScreenState();
}

class _StocktakeListScreenState extends ConsumerState<StocktakeListScreen> {
  late Future<List<Map<String, dynamic>>> _countsFuture;

  @override
  void initState() {
    super.initState();
    _countsFuture = _loadCounts();
  }

  Future<List<Map<String, dynamic>>> _loadCounts() async {
    final response =
        await ref.read(apiClientProvider).physicalCounts(status: 'all');
    return response.data ?? const <Map<String, dynamic>>[];
  }

  void _refresh() {
    setState(() => _countsFuture = _loadCounts());
    // also refresh cached options in background
    ref.read(inventoryOptionsCacheProvider.notifier).refresh();
  }

  Future<void> _createCount() async {
    final optionsState = ref.read(inventoryOptionsCacheProvider);
    final warehouses =
        ref.read(inventoryOptionsCacheProvider.notifier).warehouses;

    if (optionsState is AsyncLoading) {
      _showMessage('Cargando almacenes…', isError: false);
      return;
    }
    if (warehouses.isEmpty) {
      _showMessage('No hay almacenes disponibles.', isError: true);
      return;
    }

    final selected = warehouses.length == 1
        ? warehouses.first
        : await showModalBottomSheet<Map<String, dynamic>>(
            context: context,
            builder: (context) => _WarehousePicker(warehouses: warehouses),
          );

    if (selected == null || !mounted) return;
    final warehouseId = int.tryParse('${selected['id']}');
    if (warehouseId == null) return;

    final response = await ref
        .read(apiClientProvider)
        .createPhysicalCount(warehouseId: warehouseId);
    if (!mounted) return;
    if (!response.success) {
      _showMessage(response.message ?? 'No se pudo crear el conteo.',
          isError: true);
      return;
    }

    final id = int.tryParse('${response.data?['id']}');
    if (id != null) {
      context.push('/stocktake/$id');
    } else {
      _refresh();
    }
  }

  void _showMessage(String message, {bool isError = false}) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(message),
        backgroundColor: isError ? AppTokens.danger : AppTokens.success,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Conteos fisicos'),
        actions: [
          IconButton(
            onPressed: _refresh,
            icon: const Icon(Icons.refresh_rounded),
            tooltip: 'Actualizar',
          ),
        ],
      ),
      floatingActionButton: Padding(
        padding: const EdgeInsets.only(bottom: 84),
        child: FloatingActionButton.extended(
          onPressed: _createCount,
          icon: const Icon(Icons.add_rounded),
          label: const Text('Nuevo conteo'),
        ),
      ),
      body: RefreshIndicator(
        onRefresh: () async => _refresh(),
        child: FutureBuilder<List<Map<String, dynamic>>>(
          future: _countsFuture,
          builder: (context, snapshot) {
            if (snapshot.connectionState == ConnectionState.waiting) {
              return const Center(child: CircularProgressIndicator());
            }
            final counts = snapshot.data ?? const [];
            if (counts.isEmpty) {
              return ListView(
                padding: AppTokens.pagePadding,
                children: const [
                  _EmptyState(
                    icon: Icons.fact_check_outlined,
                    title: 'Sin conteos',
                    subtitle:
                        'Crea un conteo para empezar a escanear productos.',
                  ),
                  SizedBox(height: 96),
                ],
              );
            }

            // Group by status for visual separation
            final pending = counts
                .where((r) =>
                    r['status'] == 'draft' || r['status'] == 'submitted')
                .toList();
            final closed = counts
                .where((r) =>
                    r['status'] == 'approved' ||
                    r['status'] == 'rejected' ||
                    r['status'] == 'cancelled')
                .toList();

            return ListView(
              padding: AppTokens.pagePadding,
              children: [
                if (pending.isNotEmpty) ...[
                  _SectionHeader(
                    label: 'En progreso',
                    count: pending.length,
                    color: AppTokens.warning,
                  ),
                  const SizedBox(height: 6),
                  ...pending.map((row) => _CountCard(row: row)),
                  const SizedBox(height: 16),
                ],
                if (closed.isNotEmpty) ...[
                  _SectionHeader(
                    label: 'Cerrados',
                    count: closed.length,
                    color: AppTokens.secondary,
                  ),
                  const SizedBox(height: 6),
                  ...closed.map((row) => _CountCard(row: row)),
                ],
                const SizedBox(height: 96),
              ],
            );
          },
        ),
      ),
    );
  }
}

// ── Warehouse picker bottom sheet ─────────────────────────────────────────────

class _WarehousePicker extends StatelessWidget {
  const _WarehousePicker({required this.warehouses});
  final List<Map<String, dynamic>> warehouses;

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Padding(
            padding: const EdgeInsets.fromLTRB(20, 16, 20, 8),
            child: Text('Selecciona almacen',
                style: Theme.of(context).textTheme.titleMedium),
          ),
          const Divider(height: 1),
          ...warehouses.map((row) => ListTile(
                leading: const Icon(Icons.warehouse_outlined),
                title: Text(row['description']?.toString() ?? 'Almacen'),
                onTap: () => Navigator.of(context).pop(row),
              )),
          const SizedBox(height: 8),
        ],
      ),
    );
  }
}

// ── Section header ─────────────────────────────────────────────────────────────

class _SectionHeader extends StatelessWidget {
  const _SectionHeader({
    required this.label,
    required this.count,
    required this.color,
  });
  final String label;
  final int count;
  final Color color;

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        Container(
          width: 3,
          height: 14,
          decoration: BoxDecoration(
            color: color,
            borderRadius: BorderRadius.circular(2),
          ),
        ),
        const SizedBox(width: 8),
        Text(label,
            style: Theme.of(context)
                .textTheme
                .labelLarge
                ?.copyWith(color: color, fontWeight: FontWeight.w700)),
        const SizedBox(width: 6),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 7, vertical: 1),
          decoration: BoxDecoration(
            color: color.withValues(alpha: 0.12),
            borderRadius: BorderRadius.circular(10),
          ),
          child: Text('$count',
              style: TextStyle(
                  fontSize: 11, fontWeight: FontWeight.w700, color: color)),
        ),
      ],
    );
  }
}

// ── Count card ─────────────────────────────────────────────────────────────────

class _CountCard extends StatelessWidget {
  const _CountCard({required this.row});
  final Map<String, dynamic> row;

  @override
  Widget build(BuildContext context) {
    final id = int.tryParse('${row['id']}') ?? 0;
    final status = row['status']?.toString() ?? '';
    final isFinal = status == 'submitted' || status == 'approved' ||
        status == 'rejected' || status == 'cancelled';

    final statusColor = _statusColor(status);
    final statusLabel = _statusLabel(status);
    final statusIcon = _statusIcon(status);

    return Card(
      margin: const EdgeInsets.only(bottom: 10),
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
        side: BorderSide(color: Colors.grey.shade200),
      ),
      child: InkWell(
        borderRadius: BorderRadius.circular(12),
        onTap: () => context.push(isFinal ? '/stocktake/$id/report' : '/stocktake/$id'),
        child: Padding(
          padding: const EdgeInsets.all(14),
          child: Row(
            children: [
              Container(
                width: 42,
                height: 42,
                decoration: BoxDecoration(
                  color: statusColor.withValues(alpha: 0.10),
                  borderRadius: BorderRadius.circular(10),
                ),
                child: Icon(statusIcon, color: statusColor, size: 22),
              ),
              const SizedBox(width: 12),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        Text('Conteo #$id',
                            style: const TextStyle(
                                fontWeight: FontWeight.w700, fontSize: 14)),
                        const Spacer(),
                        _StatusChip(
                            label: statusLabel, color: statusColor),
                      ],
                    ),
                    const SizedBox(height: 3),
                    Text(
                      row['warehouse_name']?.toString() ?? '-',
                      style: TextStyle(
                          fontSize: 12, color: Colors.grey.shade600),
                    ),
                    const SizedBox(height: 2),
                    Row(
                      children: [
                        Icon(Icons.inventory_2_outlined,
                            size: 12, color: Colors.grey.shade400),
                        const SizedBox(width: 3),
                        Text('${row['lines_count'] ?? 0} items',
                            style: TextStyle(
                                fontSize: 11, color: Colors.grey.shade500)),
                        const SizedBox(width: 10),
                        Icon(Icons.schedule_outlined,
                            size: 12, color: Colors.grey.shade400),
                        const SizedBox(width: 3),
                        Expanded(
                          child: Text(
                            row['created_at']?.toString() ?? '',
                            style: TextStyle(
                                fontSize: 11, color: Colors.grey.shade500),
                            overflow: TextOverflow.ellipsis,
                          ),
                        ),
                      ],
                    ),
                  ],
                ),
              ),
              const SizedBox(width: 6),
              Icon(Icons.chevron_right_rounded,
                  color: Colors.grey.shade400, size: 20),
            ],
          ),
        ),
      ),
    );
  }

  static String _statusLabel(String status) {
    return {
          'draft': 'Borrador',
          'submitted': 'En revision',
          'approved': 'Aprobado',
          'rejected': 'Rechazado',
          'cancelled': 'Cancelado',
        }[status] ??
        status;
  }

  static Color _statusColor(String status) {
    return {
          'draft': AppTokens.secondary,
          'submitted': AppTokens.warning,
          'approved': AppTokens.success,
          'rejected': AppTokens.danger,
          'cancelled': AppTokens.secondary,
        }[status] ??
        AppTokens.secondary;
  }

  static IconData _statusIcon(String status) {
    return {
          'draft': Icons.edit_note_rounded,
          'submitted': Icons.hourglass_top_rounded,
          'approved': Icons.check_circle_rounded,
          'rejected': Icons.cancel_rounded,
          'cancelled': Icons.block_rounded,
        }[status] ??
        Icons.fact_check_rounded;
  }
}

// ── Status chip ────────────────────────────────────────────────────────────────

class _StatusChip extends StatelessWidget {
  const _StatusChip({required this.label, required this.color});
  final String label;
  final Color color;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
      decoration: BoxDecoration(
        color: color.withValues(alpha: 0.10),
        borderRadius: BorderRadius.circular(20),
        border: Border.all(color: color.withValues(alpha: 0.3)),
      ),
      child: Text(label,
          style: TextStyle(
              fontSize: 10, fontWeight: FontWeight.w700, color: color)),
    );
  }
}

// ── Empty state ────────────────────────────────────────────────────────────────

class _EmptyState extends StatelessWidget {
  const _EmptyState({
    required this.icon,
    required this.title,
    required this.subtitle,
  });
  final IconData icon;
  final String title;
  final String subtitle;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 48),
      child: Column(
        children: [
          Icon(icon, size: 52, color: Colors.grey.shade300),
          const SizedBox(height: 14),
          Text(title,
              style: Theme.of(context)
                  .textTheme
                  .titleMedium
                  ?.copyWith(color: Colors.grey.shade600)),
          const SizedBox(height: 6),
          Text(subtitle,
              textAlign: TextAlign.center,
              style:
                  TextStyle(fontSize: 13, color: Colors.grey.shade500)),
        ],
      ),
    );
  }
}