import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:stacked/stacked.dart';

import '../../about/internal/application/ServerProfile.dart';
import '../../about/internal/application/ServiceConfig.dart';
import '../../about/internal/application/TextType.dart';
import '../../comms/Comms.dart' show LogLine;
import '../../designs/LogConsole.dart';
import '../../designs/text/Text.dart';
import '../../utils/Colors.dart';
import 'ConnectLogs.dart';
import 'Logs.dart';
import 'ViewLogs.dart';

class LogsState extends State<Logs> implements ConnectLogs {
  ViewLogs? _model;

  StreamSubscription<LogLine>? _logSub;
  final _lines = <LogLine>[];
  final _searchController = TextEditingController();

  bool _loading = true;
  bool _following = false;
  bool _busy = false;
  String _status = 'unknown';
  String _query = '';
  DateTimeRange? _range;

  ServerProfile get _server => widget.server;
  ServiceConfig get _service => widget.service;

  List<LogLine> get _filtered {
    if (_query.trim().isEmpty) return _lines;
    final q = _query.toLowerCase();
    return _lines.where((l) => l.text.toLowerCase().contains(q)).toList();
  }

  @override
  void dispose() {
    _logSub?.cancel();
    _model?.stopLogs();
    _searchController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return ViewModelBuilder<ViewLogs>.reactive(
      viewModelBuilder: () => ViewLogs(context, this),
      onViewModelReady: _onReady,
      builder: (context, viewModel, child) => Scaffold(
        appBar: AppBar(
          title: text(
            '${_service.name} · logs',
            20,
            TextType.Bold,
            color: context.jp.text,
          ),
          actions: [
            IconButton(
              tooltip: _range == null ? 'Filter by date' : 'Change date range',
              onPressed: _busy ? null : _onPickRange,
              icon: Icon(
                Icons.date_range,
                color: _range != null ? PeachTheme.seed : null,
              ),
            ),
            IconButton(
              tooltip: 'Download logs',
              onPressed: _onDownload,
              icon: const Icon(Icons.download),
            ),
            IconButton(
              tooltip: 'Refresh',
              onPressed: _loading || _busy ? null : _onRefresh,
              icon: const Icon(Icons.refresh),
            ),
            const SizedBox(width: 4),
          ],
        ),
        body: Column(
          children: [
            _header(),
            _controlBar(),
            _searchBar(),
            if (_loading || _busy) const LinearProgressIndicator(minHeight: 3),
            Expanded(
              child: Padding(
                padding: const EdgeInsets.fromLTRB(12, 4, 12, 0),
                child: LogConsole(
                  logs: _filtered,
                  height: null,
                  live: _following,
                  totalCount: _query.isEmpty ? null : _lines.length,
                  emptyMessage: _loading
                      ? 'Loading…'
                      : (_query.isNotEmpty ? 'No matches.' : 'No log output.'),
                  onClear: _onClearBacklog,
                  onCopy: _onCopy,
                ),
              ),
            ),
            _bottomBar(),
          ],
        ),
      ),
    );
  }

  void _onReady(ViewLogs model) {
    _model = model;
    // onViewModelReady fires mid-build; a synchronous setState from the
    // first load would dirty this State while it is still being built.
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) _initiate();
    });
  }

  Future<void> _initiate() async {
    _logSub = _model?.logs.listen(_onLogLine);
    _model?.fetchLogs(_server, _service);
    _model?.loadStatus(_server, _service);
  }

  void _onLogLine(LogLine line) {
    if (!mounted) return;
    setState(() => _lines.add(line));
  }

  // ── status helpers ─────────────────────────────────────────────────────────

  bool get _isActive =>
      _status.contains('active') && !_status.contains('inactive');

  bool get _hasUnit => _status != 'no-unit';

  (Color, IconData) get _statusStyle {
    if (_status.contains('failed')) return (PeachTheme.danger, Icons.error);
    if (_isActive) return (PeachTheme.seed, Icons.play_circle);
    if (_status.contains('activating')) {
      return (PeachTheme.warn, Icons.hourglass_top);
    }
    return (context.jp.textFaint, Icons.stop_circle);
  }

  String _unitLabel() {
    if (_service.isWeb) {
      final unit = _service.nginxService.isEmpty
          ? 'nginx'
          : _service.nginxService;
      return 'nginx: $unit';
    }
    return _service.serviceName.isEmpty
        ? '(no unit)'
        : 'unit: ${_service.serviceName}';
  }

  // ── named handlers ─────────────────────────────────────────────────────────

  void _onRefresh() {
    setState(() {
      _loading = true;
      _following = false;
      _lines.clear();
    });
    _model?.fetchLogs(
      _server,
      _service,
      since: _range?.start,
      until: _range?.end,
    );
  }

  void _onStart() => _control('start');

  void _onStop() => _control('stop');

  void _onRestart() => _control('restart');

  void _control(String action) {
    setState(() {
      _busy = true;
      _following = false;
    });
    _model?.control(_server, _service, action);
  }

  Future<void> _onPickRange() async {
    final now = DateTime.now();
    final picked = await showDateRangePicker(
      context: context,
      firstDate: DateTime(now.year - 3),
      lastDate: now,
      initialDateRange: _range,
    );
    if (picked == null) return;
    setState(
      () => _range = DateTimeRange(
        start: DateTime(
          picked.start.year,
          picked.start.month,
          picked.start.day,
        ),
        end: DateTime(
          picked.end.year,
          picked.end.month,
          picked.end.day,
          23,
          59,
          59,
        ),
      ),
    );
    _onRefresh();
  }

  void _onClearRange() {
    setState(() => _range = null);
    _onRefresh();
  }

  void _onDownload() {
    final lines = _filtered.map((l) => l.text).toList();
    if (lines.isEmpty) {
      _notify('Nothing to download.');
      return;
    }
    _model?.saveLogs(_service.name, lines);
  }

  void _onToggleFollow() => _model?.toggleFollow(_server, _service, _following);

  void _onClearBacklog() => setState(() => _lines.clear());

  void _onCopy() {
    Clipboard.setData(
      ClipboardData(text: _filtered.map((l) => l.text).join('\n')),
    );
    _notify('Logs copied.');
  }

  void _onSearchChanged(String v) => setState(() => _query = v);

  void _onClearSearch() {
    _searchController.clear();
    setState(() => _query = '');
  }

  void _notify(String message) {
    if (!mounted) return;
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(message)));
  }

  // ── ConnectLogs ────────────────────────────────────────────────────────────

  @override
  void onLogsFetched() {
    if (!mounted) return;
    setState(() => _loading = false);
  }

  @override
  void onStatusLoaded(String status) {
    if (!mounted) return;
    setState(() => _status = status);
  }

  @override
  void onControlFinished(String message) {
    if (!mounted) return;
    setState(() => _busy = false);
    _notify(message);
  }

  @override
  void onFollowChanged(bool following) {
    if (!mounted) return;
    setState(() => _following = following);
  }

  @override
  void onLogsSaved(String? path) {
    _notify(path == null ? 'Download cancelled' : 'Saved to $path');
  }

  // ── screen-only widgets ────────────────────────────────────────────────────

  Widget _header() {
    final jp = context.jp;
    final (color, icon) = _statusStyle;
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.fromLTRB(16, 10, 16, 10),
      decoration: BoxDecoration(
        color: jp.surface,
        border: Border(bottom: BorderSide(color: jp.border)),
      ),
      child: Row(
        children: [
          const Icon(Icons.dns, size: 15, color: PeachTheme.seed),
          const SizedBox(width: 6),
          Expanded(
            child: text(
              '${_server.username}@${_server.host}  ·  ${_unitLabel()}',
              12.5,
              TextType.Regular,
              color: jp.textDim,
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
            ),
          ),
          const SizedBox(width: 8),
          Container(
            padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
            decoration: BoxDecoration(
              color: color.withValues(alpha: 0.16),
              borderRadius: BorderRadius.circular(20),
              border: Border.all(color: color.withValues(alpha: 0.5)),
            ),
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Icon(icon, size: 13, color: color),
                const SizedBox(width: 5),
                text(
                  _status.toUpperCase(),
                  10.5,
                  TextType.Bold,
                  color: color,
                  letterSpacing: 0.4,
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _controlBar() {
    if (!_hasUnit) return const SizedBox.shrink();
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.fromLTRB(12, 10, 12, 4),
      child: Wrap(
        spacing: 8,
        runSpacing: 8,
        children: [
          // Contextual: Start only when stopped, Stop only when running.
          if (!_isActive)
            _ctlButton(Icons.play_arrow, 'Start', PeachTheme.seed, _onStart),
          if (_isActive)
            _ctlButton(Icons.stop, 'Stop', PeachTheme.danger, _onStop),
          _ctlButton(
            Icons.restart_alt,
            _service.isWeb ? 'Reload' : 'Restart',
            PeachTheme.accent,
            _onRestart,
          ),
          if (_range != null) _rangeChip(),
        ],
      ),
    );
  }

  Widget _ctlButton(
    IconData icon,
    String label,
    Color color,
    VoidCallback onTap,
  ) {
    return OutlinedButton.icon(
      onPressed: _busy ? null : onTap,
      icon: Icon(icon, size: 18),
      label: text(label, 13, TextType.Bold, color: color),
      style: OutlinedButton.styleFrom(
        foregroundColor: color,
        side: BorderSide(color: color.withValues(alpha: 0.5)),
        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
      ),
    );
  }

  Widget _rangeChip() {
    String d(DateTime t) => '${t.month}/${t.day}';
    return InputChip(
      avatar: const Icon(Icons.date_range, size: 16),
      label: Text('${d(_range!.start)} – ${d(_range!.end)}'),
      onDeleted: _onClearRange,
      onPressed: _onPickRange,
    );
  }

  Widget _searchBar() {
    return Padding(
      padding: const EdgeInsets.fromLTRB(12, 4, 12, 8),
      child: TextField(
        controller: _searchController,
        onChanged: _onSearchChanged,
        decoration: InputDecoration(
          hintText: 'Search logs…',
          prefixIcon: const Icon(Icons.search, size: 20),
          suffixIcon: _query.isEmpty
              ? null
              : IconButton(
                  icon: const Icon(Icons.close, size: 18),
                  onPressed: _onClearSearch,
                ),
          isDense: true,
          contentPadding: const EdgeInsets.symmetric(vertical: 12),
        ),
      ),
    );
  }

  Widget _bottomBar() {
    return SafeArea(
      top: false,
      child: Padding(
        padding: const EdgeInsets.fromLTRB(12, 6, 12, 12),
        child: SizedBox(
          width: double.infinity,
          child: FilledButton.icon(
            onPressed: _busy ? null : _onToggleFollow,
            icon: Icon(_following ? Icons.stop_circle : Icons.stream),
            label: text(
              _following ? 'Stop live tail' : 'Live tail',
              14,
              TextType.Bold,
              color: colorWhite,
            ),
            style: _following
                ? FilledButton.styleFrom(
                    backgroundColor: PeachTheme.danger,
                    foregroundColor: colorWhite,
                  )
                : null,
          ),
        ),
      ),
    );
  }
}