import 'package:flutter/material.dart';

import '../../../core/models/models.dart';
import '../../../core/models/severity_mapping.dart';
import '../../../core/theme/status_colors.dart';
import '../../../core/theme/theme_x.dart';
import '../../../core/utils/relative_time.dart';
import '../../../core/widgets/empty_state.dart';

class _FeedEntry {
  const _FeedEntry({
    required this.timestamp,
    required this.title,
    required this.subtitle,
    required this.severity,
    required this.icon,
  });

  final DateTime timestamp;
  final String title;
  final String subtitle;
  final Severity severity;
  final IconData icon;
}

/// Merges backup executions and OS update records from [NodeInfo] into one
/// reverse-chronological feed. There's no persisted scan-result log on the
/// server to fold in here — only these two histories actually exist.
class ActivityFeed extends StatelessWidget {
  const ActivityFeed({super.key, required this.node, this.maxEntries = 6});

  final NodeInfo node;
  final int maxEntries;

  List<_FeedEntry> _buildEntries() {
    final entries = <_FeedEntry>[
      for (final execution in node.backup.history)
        _FeedEntry(
          timestamp: execution.timestamp,
          title: execution.success ? 'Backup completed' : 'Backup failed',
          subtitle: execution.message.isEmpty
              ? '${execution.durationSeconds}s'
              : execution.message,
          severity: severityForSuccess(execution.success),
          icon: Icons.cloud_outlined,
        ),
      for (final update in node.updateHistory)
        _FeedEntry(
          timestamp: update.timestamp,
          title: update.success ? 'System update applied' : 'System update failed',
          subtitle: update.packages.isEmpty
              ? update.message
              : '${update.packages.length} package(s)${update.message.isEmpty ? '' : ' · ${update.message}'}',
          severity: severityForSuccess(update.success),
          icon: Icons.history_rounded,
        ),
    ]..sort((a, b) => b.timestamp.compareTo(a.timestamp));

    return entries.take(maxEntries).toList();
  }

  @override
  Widget build(BuildContext context) {
    final entries = _buildEntries();

    if (entries.isEmpty) {
      return const EmptyState(
        icon: Icons.history_rounded,
        title: 'No activity yet',
        message: 'Backup runs and system updates will show up here.',
      );
    }

    return Column(
      children: [
        for (var i = 0; i < entries.length; i++) ...[
          if (i > 0) const Divider(height: 1),
          _FeedRow(entry: entries[i]),
        ],
      ],
    );
  }
}

class _FeedRow extends StatelessWidget {
  const _FeedRow({required this.entry});

  final _FeedEntry entry;

  @override
  Widget build(BuildContext context) {
    final color = entry.severity.resolve(context.status, muted: context.colors.outline);

    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 11),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Container(
            width: 26,
            height: 26,
            decoration: BoxDecoration(
              color: Color.alphaBlend(color.withValues(alpha: 0.14), context.colors.surface),
              borderRadius: BorderRadius.circular(7),
            ),
            child: Icon(entry.icon, size: 14, color: color),
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(entry.title, style: context.text.labelLarge),
                Text(
                  entry.subtitle,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: context.text.bodySmall,
                ),
              ],
            ),
          ),
          const SizedBox(width: 12),
          Text(
            formatRelative(entry.timestamp),
            style: context.dataStyles.numericTabular.copyWith(fontSize: 12, color: context.colors.outline),
          ),
        ],
      ),
    );
  }
}