import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../app/load_state.dart';
import '../models/event_log_item.dart';
import '../providers/providers.dart';
import '../widgets/load_error_view.dart';

/// Экран просмотра лога событий.
class EventLogScreen extends ConsumerStatefulWidget {
  const EventLogScreen({super.key});

  @override
  ConsumerState<EventLogScreen> createState() => _EventLogScreenState();
}

class _EventLogScreenState extends ConsumerState<EventLogScreen> {
  int _limit = 100;

  @override
  void initState() {
    super.initState();
    _load();
  }

  Future<void> _load() async {
    await ref.read(eventLogProvider.notifier).load(limit: _limit);
  }

  @override
  Widget build(BuildContext context) {
    final eventsState = ref.watch(eventLogProvider);
    final events = eventsState.data;

    return Scaffold(
      appBar: AppBar(
        title: const Text('ЛОГ СОБЫТИЙ'),
        actions: [
          PopupMenuButton<int>(
            icon: const Icon(Icons.filter_list),
            tooltip: 'Количество записей',
            onSelected: (v) {
              _limit = v;
              _load();
            },
            itemBuilder: (_) => [50, 100, 200, 500]
                .map((n) => PopupMenuItem(value: n, child: Text('$n записей')))
                .toList(),
          ),
        ],
      ),
      body: _buildContent(eventsState, events),
    );
  }

  Widget _buildContent(
    LoadState<List<EventLogItem>> eventsState,
    List<EventLogItem> events,
  ) {
    if ((eventsState.isIdle || eventsState.isLoading) && events.isEmpty) {
      return const Center(
        child: CircularProgressIndicator(color: Colors.deepOrange),
      );
    }

    if (eventsState.hasError && events.isEmpty) {
      return LoadErrorView(
        title: 'Не удалось загрузить лог событий',
        message: eventsState.errorMessage,
        icon: Icons.list_alt,
        onRetry: _load,
      );
    }

    if (events.isEmpty) {
      return const Center(
        child: Text('Нет событий', style: TextStyle(color: Colors.white54)),
      );
    }

    final hasStatusHeader = eventsState.isLoading || eventsState.hasError;
    final statusHeaderCount = hasStatusHeader ? 1 : 0;

    return RefreshIndicator(
      color: Colors.deepOrange,
      onRefresh: _load,
      child: ListView.builder(
        physics: const AlwaysScrollableScrollPhysics(),
        padding: const EdgeInsets.all(8),
        itemCount: events.length + statusHeaderCount,
        itemBuilder: (context, index) {
          if (hasStatusHeader && index == 0) {
            if (eventsState.isLoading) {
              return const Padding(
                padding: EdgeInsets.only(bottom: 12),
                child: LinearProgressIndicator(color: Colors.deepOrange),
              );
            }

            return LoadErrorBanner(
              title: 'Не удалось обновить лог событий',
              message: eventsState.errorMessage,
              onRetry: _load,
            );
          }

          final eventIndex = index - statusHeaderCount;
          return _EventRow(event: events[eventIndex]);
        },
      ),
    );
  }
}

class _EventRow extends StatelessWidget {
  final EventLogItem event;

  const _EventRow({required this.event});

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: const EdgeInsets.only(bottom: 4),
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // Время
            SizedBox(
              width: 80,
              child: Text(
                event.formattedTime,
                style: const TextStyle(
                  fontSize: 11,
                  color: Colors.white38,
                  fontFamily: 'monospace',
                ),
              ),
            ),
            const SizedBox(width: 8),
            // Контент
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    event.title,
                    style: const TextStyle(
                      fontSize: 13,
                      fontWeight: FontWeight.w500,
                    ),
                  ),
                  if (event.paramsText.isNotEmpty)
                    Text(
                      event.paramsText,
                      style: const TextStyle(
                        fontSize: 11,
                        color: Colors.white38,
                      ),
                      maxLines: 2,
                      overflow: TextOverflow.ellipsis,
                    ),
                  if (event.actor.isNotEmpty)
                    Text(
                      event.actor,
                      style: const TextStyle(
                        fontSize: 10,
                        color: Colors.white24,
                      ),
                    ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}