import 'package:flutter/material.dart';

import '../data/hub.dart';

class ModulesPage extends StatefulWidget {
  const ModulesPage({super.key});

  @override
  State<ModulesPage> createState() => _ModulesPageState();
}

class _ModulesPageState extends State<ModulesPage> {
  late Future<List<ModuleSummary>> _future;

  @override
  void initState() {
    super.initState();
    _future = HubService.instance.listModules();
  }

  void _refresh() => setState(() {
        _future = HubService.instance.listModules();
      });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Scaffold(
      appBar: AppBar(
        title: const Text('Installed Modules'),
        centerTitle: false,
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh),
            tooltip: 'Reload',
            onPressed: _refresh,
          ),
        ],
      ),
      body: FutureBuilder<List<ModuleSummary>>(
        future: _future,
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return const Center(child: CircularProgressIndicator());
          }
          if (snapshot.hasError) {
            return _ConnectionError(
              message: 'Hub unreachable: ${snapshot.error}',
              onRetry: _refresh,
            );
          }
          final modules = snapshot.data ?? [];
          if (modules.isEmpty) {
            return Center(
              child: Padding(
                padding: const EdgeInsets.all(32),
                child: Text(
                  'No modules installed.\n'
                  'Run `fai install <capability-name>` or check ~/.fai/modules/.',
                  textAlign: TextAlign.center,
                  style: theme.textTheme.bodyMedium?.copyWith(
                    color: theme.colorScheme.onSurfaceVariant,
                  ),
                ),
              ),
            );
          }
          return ListView.separated(
            padding: const EdgeInsets.all(24),
            itemCount: modules.length,
            separatorBuilder: (_, _) => const SizedBox(height: 12),
            itemBuilder: (context, i) {
              final m = modules[i];
              return Card(
                elevation: 0,
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(12),
                  side: BorderSide(color: theme.colorScheme.outlineVariant),
                ),
                child: Padding(
                  padding: const EdgeInsets.all(16),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Row(
                        children: [
                          Text(
                            m.name,
                            style: theme.textTheme.titleMedium?.copyWith(
                              fontWeight: FontWeight.w600,
                            ),
                          ),
                          const SizedBox(width: 8),
                          Container(
                            padding: const EdgeInsets.symmetric(
                              horizontal: 8,
                              vertical: 2,
                            ),
                            decoration: BoxDecoration(
                              color: theme.colorScheme.secondaryContainer,
                              borderRadius: BorderRadius.circular(4),
                            ),
                            child: Text(
                              'v${m.version}',
                              style: theme.textTheme.bodySmall?.copyWith(
                                color: theme.colorScheme.onSecondaryContainer,
                              ),
                            ),
                          ),
                        ],
                      ),
                      const SizedBox(height: 8),
                      _ChipRow(label: 'Capabilities', items: m.capabilities),
                    ],
                  ),
                ),
              );
            },
          );
        },
      ),
    );
  }
}

class _ChipRow extends StatelessWidget {
  final String label;
  final List<String> items;

  const _ChipRow({required this.label, required this.items});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        SizedBox(
          width: 140,
          child: Text(
            label,
            style: theme.textTheme.bodySmall?.copyWith(
              color: theme.colorScheme.onSurfaceVariant,
            ),
          ),
        ),
        Expanded(
          child: Wrap(
            spacing: 6,
            runSpacing: 6,
            children: items
                .map(
                  (s) => Container(
                    padding: const EdgeInsets.symmetric(
                      horizontal: 8,
                      vertical: 3,
                    ),
                    decoration: BoxDecoration(
                      color: theme.colorScheme.surfaceContainerHighest,
                      borderRadius: BorderRadius.circular(4),
                    ),
                    child: Text(
                      s,
                      style: theme.textTheme.bodySmall?.copyWith(
                        fontFamily: 'monospace',
                      ),
                    ),
                  ),
                )
                .toList(),
          ),
        ),
      ],
    );
  }
}

class _ConnectionError extends StatelessWidget {
  final String message;
  final VoidCallback onRetry;

  const _ConnectionError({required this.message, required this.onRetry});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Center(
      child: Padding(
        padding: const EdgeInsets.all(32),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(
              Icons.cloud_off_outlined,
              size: 48,
              color: theme.colorScheme.error,
            ),
            const SizedBox(height: 16),
            Text(
              message,
              textAlign: TextAlign.center,
              style: theme.textTheme.bodyMedium,
            ),
            const SizedBox(height: 8),
            Text(
              'Start the hub with `fai serve`.',
              style: theme.textTheme.bodySmall?.copyWith(
                color: theme.colorScheme.onSurfaceVariant,
              ),
            ),
            const SizedBox(height: 16),
            FilledButton.tonal(
              onPressed: onRetry,
              child: const Text('Retry'),
            ),
          ],
        ),
      ),
    );
  }
}