import 'package:flutter/material.dart';

import '../data/mock.dart';

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

  @override
  State<AuditPage> createState() => _AuditPageState();
}

class _AuditPageState extends State<AuditPage> {
  String _typeFilter = 'all';

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final filtered = _typeFilter == 'all'
        ? mockEvents
        : mockEvents.where((e) => e.type.startsWith(_typeFilter)).toList();

    return Scaffold(
      appBar: AppBar(
        title: const Text('Audit Stream'),
        centerTitle: false,
        actions: [
          Padding(
            padding: const EdgeInsets.only(right: 16),
            child: DropdownButton<String>(
              value: _typeFilter,
              onChanged: (v) => setState(() => _typeFilter = v ?? 'all'),
              items: const [
                DropdownMenuItem(value: 'all', child: Text('all events')),
                DropdownMenuItem(value: 'flow.', child: Text('flow.*')),
                DropdownMenuItem(value: 'step.', child: Text('step.*')),
                DropdownMenuItem(value: 'module.', child: Text('module.*')),
              ],
            ),
          ),
        ],
      ),
      body: Column(
        children: [
          _StatusBar(eventCount: filtered.length),
          Expanded(
            child: ListView.separated(
              padding: const EdgeInsets.all(24),
              itemCount: filtered.length,
              separatorBuilder: (_, _) => const SizedBox(height: 8),
              itemBuilder: (context, i) {
                final e = filtered[i];
                final ts = e.timestamp;
                final tsStr =
                    '${ts.hour.toString().padLeft(2, '0')}:${ts.minute.toString().padLeft(2, '0')}:${ts.second.toString().padLeft(2, '0')}';
                final tone = _toneFor(e.type);
                return Card(
                  elevation: 0,
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(8),
                    side: BorderSide(
                      color: theme.colorScheme.outlineVariant,
                    ),
                  ),
                  child: Padding(
                    padding: const EdgeInsets.symmetric(
                      horizontal: 16,
                      vertical: 12,
                    ),
                    child: Row(
                      children: [
                        Container(
                          width: 4,
                          height: 32,
                          decoration: BoxDecoration(
                            color: tone,
                            borderRadius: BorderRadius.circular(2),
                          ),
                        ),
                        const SizedBox(width: 12),
                        SizedBox(
                          width: 90,
                          child: Text(
                            tsStr,
                            style: theme.textTheme.bodySmall?.copyWith(
                              fontFamily: 'monospace',
                              color: theme.colorScheme.onSurfaceVariant,
                            ),
                          ),
                        ),
                        SizedBox(
                          width: 180,
                          child: Text(
                            e.type,
                            style: theme.textTheme.bodyMedium?.copyWith(
                              fontFamily: 'monospace',
                              fontWeight: FontWeight.w500,
                            ),
                          ),
                        ),
                        Expanded(
                          child: Text(
                            _contextLine(e),
                            style: theme.textTheme.bodyMedium?.copyWith(
                              color: theme.colorScheme.onSurfaceVariant,
                            ),
                          ),
                        ),
                        if (e.durationMs != null)
                          Text(
                            '${e.durationMs}ms',
                            style: theme.textTheme.bodySmall?.copyWith(
                              fontFamily: 'monospace',
                              color: theme.colorScheme.onSurfaceVariant,
                            ),
                          ),
                      ],
                    ),
                  ),
                );
              },
            ),
          ),
        ],
      ),
    );
  }

  String _contextLine(AuditEvent e) {
    final parts = <String>[];
    if (e.flowName != null) parts.add(e.flowName!);
    if (e.stepId != null) parts.add(':${e.stepId}');
    if (e.moduleName != null) parts.add('  via ${e.moduleName}');
    if (e.error != null) parts.add('  [error: ${e.error}]');
    return parts.join('');
  }

  Color _toneFor(String type) {
    final scheme = Theme.of(context).colorScheme;
    if (type.endsWith('.failed')) return scheme.error;
    if (type.endsWith('.completed')) return scheme.primary;
    if (type.endsWith('.started')) return scheme.tertiary;
    return scheme.outline;
  }
}

class _StatusBar extends StatelessWidget {
  final int eventCount;

  const _StatusBar({required this.eventCount});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 8),
      color: theme.colorScheme.surfaceContainerHigh,
      child: Row(
        children: [
          Icon(
            Icons.fiber_manual_record,
            size: 12,
            color: theme.colorScheme.tertiary,
          ),
          const SizedBox(width: 8),
          Text(
            'live (mock data) — $eventCount events',
            style: theme.textTheme.bodySmall,
          ),
          const Spacer(),
          Text(
            'hash chain: verified',
            style: theme.textTheme.bodySmall?.copyWith(
              color: theme.colorScheme.primary,
            ),
          ),
        ],
      ),
    );
  }
}