import 'dart:async';

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

import '../../../about/external/data/EnvCheck.dart';
import '../../../about/internal/application/ServerProfile.dart';
import '../../../about/internal/application/StepTracker.dart';
import '../../../about/internal/application/TextType.dart';
import '../../../comms/Comms.dart' show DeployResult, LogLine;
import '../../../designs/LogConsole.dart';
import '../../../designs/StepList.dart';
import '../../../designs/text/Text.dart';
import '../../../utils/Colors.dart';
import 'ConnectServerSetup.dart';
import 'ServerSetup.dart';
import 'ViewServerSetup.dart';

class ServerSetupState extends State<ServerSetup>
    implements ConnectServerSetup {
  static const _labels = ['Connect', 'Choose', 'Install', 'Done'];

  ViewServerSetup? _model;

  StreamSubscription<LogLine>? _logSub;
  StreamSubscription<List<DeployStep>>? _stepSub;

  final _lines = <LogLine>[];
  List<DeployStep> _steps = [];
  final Map<String, String> _versions = {};
  final Set<String> _selected = {};

  int _step = 0; // 0 connect · 1 choose · 2 install · 3 done
  bool _connecting = true;
  bool _connected = false;
  String? _connectError;
  String _packageManager = 'unknown';
  bool _installing = false;
  DeployResult? _result;

  ServerProfile get _server => widget.server;

  bool _installed(String key) => (_versions[key] ?? '').trim().isNotEmpty;

  List<EnvTool> get _toInstall =>
      kEnvTools.where((t) => _selected.contains(t.key)).toList();

  int get _presentCount => kEnvTools.where((t) => _installed(t.key)).length;

  @override
  void dispose() {
    _logSub?.cancel();
    _stepSub?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return ViewModelBuilder<ViewServerSetup>.reactive(
      viewModelBuilder: () => ViewServerSetup(context, this),
      onViewModelReady: _onReady,
      builder: (context, viewModel, child) => Scaffold(
        appBar: AppBar(
          title: text(
            'Set up ${_server.name}',
            20,
            TextType.Bold,
            color: context.jp.text,
          ),
          actions: [
            TextButton(
              onPressed: _onSkip,
              child: text('Skip', 13, TextType.Bold, color: colorPrimary),
            ),
            const SizedBox(width: 8),
          ],
        ),
        body: Column(
          children: [
            _progressBar(),
            Expanded(
              child: switch (_step) {
                0 => _connectStep(),
                1 => _chooseStep(viewModel),
                2 => _installStep(viewModel),
                _ => _doneStep(),
              },
            ),
          ],
        ),
      ),
    );
  }

  void _onReady(ViewServerSetup 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);
    _stepSub = _model?.steps.listen(_onSteps);
    _model?.probeServer(_server);
  }

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

  void _onSteps(List<DeployStep> steps) {
    if (!mounted) return;
    setState(() => _steps = steps);
  }

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

  void _onSkip() => Navigator.of(context).pop();

  void _onFinish() => Navigator.of(context).pop(true);

  void _onRetryConnect() {
    setState(() {
      _connecting = true;
      _connectError = null;
    });
    _model?.probeServer(_server);
  }

  void _onGoToChoose() => setState(() => _step = 1);

  void _onGoToConnect() => setState(() => _step = 0);

  void _onGoToInstall() => setState(() => _step = 2);

  void _onToggleTool(EnvTool tool, bool? selected) {
    setState(() {
      if (selected == true) {
        _selected.add(tool.key);
      } else {
        _selected.remove(tool.key);
      }
    });
  }

  void _onInstall(ViewServerSetup model) {
    setState(() {
      _installing = true;
      _lines.clear();
      _result = null;
    });
    model.installEnvironment(
      _server,
      _toInstall,
      model.buildInstallCommand(_toInstall, _packageManager),
    );
  }

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

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

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

  // ── ConnectServerSetup ─────────────────────────────────────────────────────

  @override
  void onServerProbed(String packageManager, Map<String, String> versions) {
    if (!mounted) return;
    setState(() {
      _packageManager = packageManager;
      _versions
        ..clear()
        ..addAll(versions);
      _connected = true;
      _connecting = false;
      _connectError = null;
    });
  }

  @override
  void onProbeFailed(String message) {
    if (!mounted) return;
    setState(() {
      _connected = false;
      _connecting = false;
      _connectError = message;
    });
  }

  @override
  void onInstallFinished(DeployResult result, Map<String, String> versions) {
    if (!mounted) return;
    setState(() {
      _installing = false;
      _result = result;
      _versions.addAll(versions);
      if (result.ok) _step = 3;
    });
  }

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

  Widget _progressBar() {
    final jp = context.jp;
    return Container(
      padding: const EdgeInsets.fromLTRB(16, 14, 16, 14),
      decoration: BoxDecoration(
        color: jp.surface,
        border: Border(bottom: BorderSide(color: jp.border)),
      ),
      child: Row(
        children: [
          for (var i = 0; i < _labels.length; i++) ...[
            _dot(i, _labels[i]),
            if (i < _labels.length - 1)
              Expanded(
                child: Container(
                  height: 2,
                  margin: const EdgeInsets.symmetric(horizontal: 6),
                  color: i < _step ? PeachTheme.seed : jp.border,
                ),
              ),
          ],
        ],
      ),
    );
  }

  Widget _dot(int index, String label) {
    final jp = context.jp;
    final done = index < _step;
    final active = index == _step;
    final color = done || active ? PeachTheme.seed : jp.textFaint;
    return Row(
      children: [
        Container(
          width: 26,
          height: 26,
          alignment: Alignment.center,
          decoration: BoxDecoration(
            color: color.withValues(alpha: active ? 0.18 : (done ? 0.14 : 0.0)),
            shape: BoxShape.circle,
            border: Border.all(color: color.withValues(alpha: 0.6)),
          ),
          child: done
              ? const Icon(Icons.check, size: 14, color: PeachTheme.seed)
              : text('${index + 1}', 12, TextType.Bold, color: color),
        ),
        const SizedBox(width: 6),
        text(
          label,
          12.5,
          active ? TextType.Bold : TextType.Regular,
          color: active ? jp.text : jp.textFaint,
        ),
      ],
    );
  }

  Widget _connectStep() {
    final jp = context.jp;
    return ListView(
      padding: const EdgeInsets.all(20),
      children: [
        Container(
          padding: const EdgeInsets.all(20),
          decoration: PeachTheme.panel(context, glowColor: PeachTheme.seed),
          child: Column(
            children: [
              if (_connecting) ...[
                const SizedBox(
                  width: 40,
                  height: 40,
                  child: CircularProgressIndicator(strokeWidth: 3),
                ),
                const SizedBox(height: 16),
                text(
                  'Connecting to ${_server.host} …',
                  14,
                  TextType.Regular,
                  color: jp.textDim,
                ),
              ] else if (_connected) ...[
                const Icon(
                  Icons.check_circle,
                  color: PeachTheme.seed,
                  size: 44,
                ),
                const SizedBox(height: 12),
                text('Connected', 18, TextType.Bold, color: jp.text),
                const SizedBox(height: 6),
                text(
                  'Package manager: $_packageManager · '
                  '$_presentCount/${kEnvTools.length} tools present',
                  14,
                  TextType.Regular,
                  color: jp.textDim,
                  align: TextAlign.center,
                ),
              ] else ...[
                const Icon(Icons.error, color: PeachTheme.danger, size: 44),
                const SizedBox(height: 12),
                text(
                  'Could not connect',
                  14,
                  TextType.Bold,
                  color: PeachTheme.danger,
                ),
                const SizedBox(height: 6),
                text(
                  _connectError ?? '',
                  12,
                  TextType.Regular,
                  color: jp.textDim,
                  align: TextAlign.center,
                ),
              ],
            ],
          ),
        ),
        const SizedBox(height: 20),
        Row(
          children: [
            if (!_connected && !_connecting) ...[
              Expanded(
                child: OutlinedButton.icon(
                  onPressed: _onRetryConnect,
                  icon: const Icon(Icons.refresh),
                  label: text('Retry', 14, TextType.Bold, color: jp.textDim),
                ),
              ),
              const SizedBox(width: 10),
            ],
            Expanded(
              child: FilledButton.icon(
                onPressed: _connected ? _onGoToChoose : null,
                icon: const Icon(Icons.arrow_forward),
                label: text(
                  'Choose environment',
                  14,
                  TextType.Bold,
                  color: colorWhite,
                ),
              ),
            ),
          ],
        ),
      ],
    );
  }

  Widget _chooseStep(ViewServerSetup model) {
    final jp = context.jp;
    return Column(
      children: [
        Expanded(
          child: ListView(
            padding: const EdgeInsets.all(20),
            children: [
              text(
                'What should this server run?',
                18,
                TextType.Bold,
                color: jp.text,
              ),
              const SizedBox(height: 4),
              text(
                'Tick anything missing you want Peach to install '
                '(via $_packageManager). Installed tools are already ready.',
                13,
                TextType.Regular,
                color: jp.textDim,
              ),
              const SizedBox(height: 16),
              for (final tool in kEnvTools) _toolTile(tool),
            ],
          ),
        ),
        _bottomBar(
          back: _onGoToConnect,
          nextLabel: _selected.isEmpty
              ? 'Nothing to install'
              : 'Review & install',
          onNext: _selected.isEmpty ? null : _onGoToInstall,
        ),
      ],
    );
  }

  Widget _toolTile(EnvTool tool) {
    final jp = context.jp;
    final installed = _installed(tool.key);
    final selected = _selected.contains(tool.key);
    return Container(
      margin: const EdgeInsets.only(bottom: 10),
      padding: const EdgeInsets.all(12),
      decoration: PeachTheme.panel(context, radius: 14),
      child: Row(
        children: [
          Container(
            width: 40,
            height: 40,
            decoration: BoxDecoration(
              color: (installed ? PeachTheme.seed : jp.textFaint).withValues(
                alpha: 0.14,
              ),
              borderRadius: BorderRadius.circular(11),
            ),
            child: Icon(
              tool.icon,
              color: installed ? PeachTheme.seed : jp.textDim,
              size: 20,
            ),
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                text(tool.label, 14, TextType.Bold, color: jp.text),
                text(
                  installed
                      ? (_versions[tool.key] ?? 'installed')
                      : 'not installed',
                  11.5,
                  TextType.Regular,
                  color: installed ? jp.textDim : jp.textFaint,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                ),
              ],
            ),
          ),
          if (installed)
            const Padding(
              padding: EdgeInsets.only(right: 6),
              child: Icon(Icons.check_circle, color: PeachTheme.seed),
            )
          else
            Checkbox(value: selected, onChanged: (v) => _onToggleTool(tool, v)),
        ],
      ),
    );
  }

  Widget _installStep(ViewServerSetup model) {
    final jp = context.jp;
    final command = model.buildInstallCommand(_toInstall, _packageManager);
    return Column(
      children: [
        Expanded(
          child: ListView(
            padding: const EdgeInsets.all(20),
            children: [
              text('Review', 18, TextType.Bold, color: jp.text),
              const SizedBox(height: 4),
              text(
                'These will be installed${_server.useSudo ? ' via sudo' : ''}:',
                13,
                TextType.Regular,
                color: jp.textDim,
              ),
              const SizedBox(height: 12),
              Wrap(
                spacing: 8,
                runSpacing: 8,
                children: _toInstall
                    .map(
                      (t) => Chip(
                        avatar: Icon(t.icon, size: 16),
                        label: Text(t.label),
                      ),
                    )
                    .toList(),
              ),
              const SizedBox(height: 14),
              Container(
                width: double.infinity,
                padding: const EdgeInsets.all(12),
                decoration: BoxDecoration(
                  color: jp.consoleBg,
                  borderRadius: BorderRadius.circular(12),
                  border: Border.all(color: ConsoleColors.frame),
                ),
                child: SelectableText(
                  command,
                  style: const TextStyle(
                    fontFamily: 'monospace',
                    fontSize: 12.5,
                    color: ConsoleColors.body,
                  ),
                ),
              ),
              if (_steps.isNotEmpty) ...[
                const SizedBox(height: 16),
                StepList(steps: _steps),
              ],
              if (_result != null && !_result!.ok) ...[
                const SizedBox(height: 12),
                _banner(_result!),
              ],
              if (_lines.isNotEmpty) ...[
                const SizedBox(height: 14),
                LogConsole(
                  logs: _lines,
                  height: 240,
                  onClear: _onClearLogs,
                  onCopy: _onCopyLogs,
                ),
              ],
            ],
          ),
        ),
        _bottomBar(
          back: _installing ? null : _onGoToChoose,
          nextLabel: _installing ? 'Installing…' : 'Install now',
          onNext: _installing ? null : () => _onInstall(model),
          nextIcon: Icons.download,
        ),
      ],
    );
  }

  Widget _doneStep() {
    final jp = context.jp;
    return ListView(
      padding: const EdgeInsets.all(20),
      children: [
        Container(
          padding: const EdgeInsets.all(24),
          decoration: PeachTheme.panel(context, glowColor: PeachTheme.seed),
          child: Column(
            children: [
              Container(
                width: 72,
                height: 72,
                decoration: BoxDecoration(
                  gradient: PeachTheme.brandGradient,
                  borderRadius: BorderRadius.circular(20),
                  boxShadow: PeachTheme.glow(
                    PeachTheme.seed,
                    opacity: 0.5,
                    blur: 28,
                  ),
                ),
                child: Icon(Icons.check, color: colorWhite, size: 38),
              ),
              const SizedBox(height: 16),
              text(
                '${_server.name} is ready',
                20,
                TextType.Bold,
                color: jp.text,
              ),
              const SizedBox(height: 6),
              text(
                '$_presentCount/${kEnvTools.length} tools installed. '
                'Add a service to start deploying.',
                14,
                TextType.Regular,
                color: jp.textDim,
                align: TextAlign.center,
              ),
            ],
          ),
        ),
        const SizedBox(height: 20),
        FilledButton.icon(
          onPressed: _onFinish,
          icon: const Icon(Icons.check),
          label: text('Finish', 14, TextType.Bold, color: colorWhite),
        ),
      ],
    );
  }

  Widget _bottomBar({
    VoidCallback? back,
    required String nextLabel,
    VoidCallback? onNext,
    IconData nextIcon = Icons.arrow_forward,
  }) {
    return SafeArea(
      top: false,
      child: Padding(
        padding: const EdgeInsets.fromLTRB(16, 8, 16, 14),
        child: Row(
          children: [
            OutlinedButton(
              onPressed: back,
              child: text('Back', 13, TextType.Bold, color: context.jp.textDim),
            ),
            const SizedBox(width: 10),
            Expanded(
              child: FilledButton.icon(
                onPressed: onNext,
                icon: _installing
                    ? SizedBox(
                        width: 18,
                        height: 18,
                        child: CircularProgressIndicator(
                          strokeWidth: 2,
                          color: colorWhite,
                        ),
                      )
                    : Icon(nextIcon),
                label: text(nextLabel, 14, TextType.Bold, color: colorWhite),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _banner(DeployResult result) {
    final color = result.ok ? PeachTheme.seed : PeachTheme.danger;
    return Container(
      padding: const EdgeInsets.fromLTRB(14, 12, 12, 12),
      decoration: BoxDecoration(
        color: color.withValues(alpha: 0.10),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: color.withValues(alpha: 0.5)),
      ),
      child: Row(
        children: [
          Icon(result.ok ? Icons.check_circle : Icons.error, color: color),
          const SizedBox(width: 10),
          Expanded(
            child: text(result.message, 14, TextType.Regular, color: color),
          ),
        ],
      ),
    );
  }
}