import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:mileograph_flutter/objects/objects.dart';

class LegCard extends StatelessWidget {
  const LegCard({
    super.key,
    required this.leg,
    this.showEditButton = true,
  });

  final Leg leg;
  final bool showEditButton;

  @override
  Widget build(BuildContext context) {
    final routeSegments = _parseRouteSegments(leg.route);
    final textTheme = Theme.of(context).textTheme;
    return Card(
      child: ExpansionTile(
        tilePadding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
        leading: const Icon(Icons.train),
        title: Text('${leg.start} → ${leg.end}'),
        subtitle: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(_formatDateTime(leg.beginTime)),
            if (leg.headcode.isNotEmpty)
              Text(
                'Headcode: ${leg.headcode}',
                style: textTheme.labelSmall,
              ),
            if (leg.network.isNotEmpty)
              Text(
                leg.network,
                style: textTheme.labelSmall,
              ),
          ],
        ),
        trailing: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Column(
              mainAxisSize: MainAxisSize.min,
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.end,
              children: [
                Text(
                  '${leg.mileage.toStringAsFixed(1)} mi',
                  style: textTheme.labelLarge?.copyWith(
                    fontWeight: FontWeight.w700,
                  ),
                ),
                if (leg.tripId != 0) ...[
                  const SizedBox(height: 2),
                  Text(
                    'Trip #${leg.tripId}',
                    style: textTheme.labelSmall,
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                  ),
                ],
              ],
            ),
            if (showEditButton) ...[
              const SizedBox(width: 8),
              IconButton(
                tooltip: 'Edit entry',
                icon: const Icon(Icons.edit),
                visualDensity: VisualDensity.compact,
                padding: EdgeInsets.zero,
                constraints: const BoxConstraints(minWidth: 32, minHeight: 32),
                onPressed: () => context.push('/legs/edit/${leg.id}'),
              ),
            ],
          ],
        ),
        children: [
          Padding(
            padding: const EdgeInsets.fromLTRB(16, 0, 16, 12),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                if (leg.notes.isNotEmpty) ...[
                  Text('Notes', style: textTheme.titleSmall),
                  const SizedBox(height: 4),
                  Text(leg.notes),
                  const SizedBox(height: 12),
                ],
                if (leg.locos.isNotEmpty) ...[
                  Text('Locos', style: textTheme.titleSmall),
                  const SizedBox(height: 6),
                  Wrap(
                    spacing: 8,
                    runSpacing: 8,
                    children: _buildLocoChips(context, leg),
                  ),
                  const SizedBox(height: 12),
                ],
                if (routeSegments.isNotEmpty) ...[
                  Text('Route', style: textTheme.titleSmall),
                  const SizedBox(height: 6),
                  _buildRouteList(routeSegments),
                ],
              ],
            ),
          ),
        ],
      ),
    );
  }

  String _formatDate(DateTime? date) {
    if (date == null) return '';
    return '${date.year.toString().padLeft(4, '0')}-${date.month.toString().padLeft(2, '0')}-${date.day.toString().padLeft(2, '0')}';
  }

  String _formatDateTime(DateTime date) {
    final dateStr = _formatDate(date);
    final timeStr =
        '${date.hour.toString().padLeft(2, '0')}:${date.minute.toString().padLeft(2, '0')}';
    return '$dateStr · $timeStr';
  }

  List<Widget> _buildLocoChips(BuildContext context, Leg leg) {
    final theme = Theme.of(context);
    return leg.locos
        .map(
          (loco) => Chip(
            label: Text('${loco.locoClass} ${loco.number}'),
            avatar: const Icon(Icons.directions_railway, size: 16),
            backgroundColor: theme.colorScheme.surfaceContainerHighest,
          ),
        )
        .toList();
  }

  Widget _buildRouteList(List<String> segments) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: segments
          .map(
            (segment) => Padding(
              padding: const EdgeInsets.symmetric(vertical: 4.0),
              child: Row(
                children: [
                  const Icon(Icons.circle, size: 10),
                  const SizedBox(width: 8),
                  Expanded(child: Text(segment)),
                ],
              ),
            ),
          )
          .toList(),
    );
  }

  List<String> _parseRouteSegments(String route) {
    final trimmed = route.trim();
    if (trimmed.isEmpty) return [];
    try {
      final decoded = jsonDecode(trimmed);
      if (decoded is List) {
        return decoded.map((e) => e.toString()).toList();
      }
    } catch (_) {}
    if (trimmed.startsWith('[') && trimmed.endsWith(']')) {
      try {
        final replaced = trimmed.replaceAll("'", '"');
        final decoded = jsonDecode(replaced);
        if (decoded is List) {
          return decoded.map((e) => e.toString()).toList();
        }
      } catch (_) {}
    }
    if (trimmed.contains('->')) {
      return trimmed
          .split('->')
          .map((e) => e.trim())
          .where((e) => e.isNotEmpty)
          .toList();
    }
    if (trimmed.contains(',')) {
      return trimmed
          .split(',')
          .map((e) => e.trim())
          .where((e) => e.isNotEmpty)
          .toList();
    }
    return [trimmed];
  }
}