import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../core/models/models.dart';
import '../../core/models/severity_mapping.dart';
import '../../core/network/api_exception.dart';
import '../../core/theme/status_colors.dart';
import '../../core/theme/theme_x.dart';
import '../../core/utils/relative_time.dart';
import '../../core/widgets/error_banner.dart';
import '../../core/widgets/stat_tile.dart';
import '../../data/repositories/nodes_repository.dart';
import 'providers/dashboard_summary.dart';
import 'providers/dashboard_summary_provider.dart';
import 'widgets/activity_feed.dart';
import 'widgets/quick_actions_row.dart';

class DashboardScreen extends ConsumerWidget {
  const DashboardScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final summaryAsync = ref.watch(dashboardSummaryProvider);
    final fleetAsync = ref.watch(aggregatedNodesProvider);

    return summaryAsync.when(
      loading: () => const Center(child: CircularProgressIndicator()),
      error: (error, stackTrace) => Center(
        child: ErrorBanner(
          message: error is ApiException ? error.userMessage : error.toString(),
          onRetry: () => ref.invalidate(dashboardSummaryProvider),
        ),
      ),
      data: (summary) => ListView(
        padding: const EdgeInsets.all(24),
        children: [
          _StatRow(summary: summary, fleetAsync: fleetAsync),
          const SizedBox(height: 22),
          Text('QUICK ACTIONS', style: context.text.titleSmall),
          const SizedBox(height: 10),
          const QuickActionsRow(),
          const SizedBox(height: 22),
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Text('RECENT ACTIVITY', style: context.text.titleSmall),
            ],
          ),
          const SizedBox(height: 10),
          Card(child: ActivityFeed(node: summary.node)),
        ],
      ),
    );
  }
}

class _StatRow extends StatelessWidget {
  const _StatRow({required this.summary, required this.fleetAsync});

  final DashboardSummary summary;
  final AsyncValue<List<AggregatedNodeStatus>> fleetAsync;

  @override
  Widget build(BuildContext context) {
    final services = summary.services;
    final up = services.where((s) => s.status == 'up').length;
    final down = services.where((s) => s.status == 'down').length;
    final unknown = services.length - up - down;

    final servicesSeverity = down > 0
        ? Severity.critical
        : unknown > 0
        ? Severity.warning
        : Severity.good;
    final servicesCaption = services.isEmpty
        ? 'No services discovered yet'
        : [
            if (down > 0) '$down down',
            if (unknown > 0) '$unknown unknown',
          ].isEmpty
        ? 'All running'
        : [if (down > 0) '$down down', if (unknown > 0) '$unknown unknown'].join(' · ');

    final history = [...summary.node.backup.history]
      ..sort((a, b) => b.timestamp.compareTo(a.timestamp));
    final lastBackup = history.isEmpty ? null : history.first;

    final updates = [...summary.node.updateHistory]..sort((a, b) => b.timestamp.compareTo(a.timestamp));
    final lastUpdate = updates.isEmpty ? null : updates.first;

    return Wrap(
      spacing: 12,
      runSpacing: 12,
      children: [
        SizedBox(
          width: 260,
          child: StatTile(
            label: 'Services',
            value: '$up',
            valueQualifier: '/ ${services.length} up',
            caption: servicesCaption,
            severity: services.isEmpty ? Severity.neutral : servicesSeverity,
          ),
        ),
        SizedBox(
          width: 260,
          child: StatTile(
            label: 'Last backup',
            value: lastBackup == null ? 'Never' : formatRelative(lastBackup.timestamp),
            caption: lastBackup == null
                ? 'No backups run yet'
                : (lastBackup.success ? '${lastBackup.durationSeconds}s' : lastBackup.message),
            severity: lastBackup == null ? Severity.neutral : severityForSuccess(lastBackup.success),
          ),
        ),
        SizedBox(
          width: 260,
          child: StatTile(
            label: 'Last system update',
            value: lastUpdate == null ? 'Never' : formatRelative(lastUpdate.timestamp),
            caption: lastUpdate == null
                ? 'No updates recorded yet'
                : '${lastUpdate.packages.length} package(s)',
            severity: lastUpdate == null ? Severity.neutral : severityForSuccess(lastUpdate.success),
          ),
        ),
        SizedBox(width: 260, child: _FleetTile(fleetAsync: fleetAsync)),
      ],
    );
  }
}

class _FleetTile extends StatelessWidget {
  const _FleetTile({required this.fleetAsync});

  final AsyncValue<List<AggregatedNodeStatus>> fleetAsync;

  @override
  Widget build(BuildContext context) {
    return fleetAsync.when(
      loading: () => const StatTile(
        label: 'Fleet',
        value: '…',
        severity: Severity.neutral,
      ),
      error: (error, stackTrace) => StatTile(
        label: 'Fleet',
        value: '—',
        caption: error is ApiException ? error.userMessage : error.toString(),
        severity: Severity.critical,
      ),
      data: (nodes) {
        if (nodes.isEmpty) {
          return const StatTile(
            label: 'Fleet',
            value: '0',
            caption: 'No nodes registered',
            severity: Severity.neutral,
          );
        }
        final online = nodes.where((n) => n.error == null).length;
        final unreachable = nodes.where((n) => n.error != null).toList();
        return StatTile(
          label: 'Fleet',
          value: '$online',
          valueQualifier: '/ ${nodes.length} online',
          caption: unreachable.isEmpty
              ? 'All nodes reachable'
              : 'unreachable: ${unreachable.map((n) => n.node.name).join(', ')}',
          severity: unreachable.isEmpty ? Severity.good : Severity.critical,
        );
      },
    );
  }
}