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/StepTracker.dart';
import '../../../about/internal/application/TextType.dart';
import '../../../comms/Comms.dart' show LogLine;
import '../../../designs/LogConsole.dart';
import '../../../designs/StepList.dart';
import '../../../designs/text/Text.dart';
import '../../../utils/Colors.dart';
import 'BatchDeploy.dart';
import 'ConnectBatchDeploy.dart';
import 'ViewBatchDeploy.dart';

enum BatchMode { buildDeploy, buildOnly }

class BatchDeployState extends State<BatchDeploy>
    implements ConnectBatchDeploy {
  ViewBatchDeploy? _model;

  final _subscriptions = <StreamSubscription>[];
  final _lines = <LogLine>[];
  List<DeployStep> _steps = [];

  final Set<String> _selected = {};
  final Map<String, BatchState> _status = {};
  final Map<String, String> _detail = {};

  late List<ServiceConfig> _ordered;
  BatchMode _mode = BatchMode.buildDeploy;
  bool _running = false;

  ServerProfile get _server => widget.server;

  /// A service can join a batch only if Peach knows how to build it.
  bool _eligible(ServiceConfig s) => s.canBuild;

  int get _eligibleCount => _ordered.where(_eligible).length;

  int get _doneCount =>
      _status.values.where((s) => s == BatchState.done).length;

  int get _failCount =>
      _status.values.where((s) => s == BatchState.failed).length;

  @override
  void initState() {
    super.initState();
    _ordered = _server.orderedServices;
    for (final service in _ordered) {
      if (_eligible(service)) _selected.add(service.id);
    }
  }

  @override
  void dispose() {
    for (final s in _subscriptions) {
      s.cancel();
    }
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return ViewModelBuilder<ViewBatchDeploy>.reactive(
      viewModelBuilder: () => ViewBatchDeploy(context, this),
      onViewModelReady: _onReady,
      builder: (context, viewModel, child) => Scaffold(
        appBar: AppBar(
          title: text(
            'Build & deploy · ${_server.name}',
            20,
            TextType.Bold,
            color: context.jp.text,
          ),
        ),
        body: Column(
          children: [
            _header(),
            Expanded(
              child: ListView(
                padding: const EdgeInsets.fromLTRB(16, 8, 16, 16),
                children: [
                  _reorderHint(),
                  ReorderableListView.builder(
                    shrinkWrap: true,
                    physics: const NeverScrollableScrollPhysics(),
                    buildDefaultDragHandles: false,
                    onReorderItem: _onReorder,
                    itemCount: _ordered.length,
                    itemBuilder: (context, i) => Padding(
                      key: ValueKey(_ordered[i].id),
                      padding: const EdgeInsets.only(bottom: 10),
                      child: _serviceTile(_ordered[i], i),
                    ),
                  ),
                  if (_steps.isNotEmpty) ...[
                    const SizedBox(height: 14),
                    StepList(steps: _steps),
                  ],
                  if (_lines.isNotEmpty) ...[
                    const SizedBox(height: 14),
                    LogConsole(
                      logs: _lines,
                      height: 300,
                      onClear: _onClearLogs,
                      onCopy: _onCopyLogs,
                    ),
                  ],
                ],
              ),
            ),
            _bottomBar(),
          ],
        ),
      ),
    );
  }

  void _onReady(ViewBatchDeploy 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 {
    final model = _model;
    if (model == null) return;
    _subscriptions.addAll([
      model.logs.listen(_onLogLine),
      model.buildLogs.listen(_onLogLine),
      model.steps.listen(_onSteps),
      model.buildSteps.listen(_onSteps),
    ]);
  }

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

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

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

  /// [newIndex] already accounts for the removed item — `onReorderItem` does
  /// that adjustment for us, unlike the older `onReorder`.
  void _onReorder(int oldIndex, int newIndex) {
    setState(() {
      final moved = _ordered.removeAt(oldIndex);
      _ordered.insert(newIndex, moved);
    });
    _model?.saveDeployOrder(_server, _ordered.map((s) => s.id).toList());
  }

  void _onRun() {
    final batch = _ordered.where((s) => _selected.contains(s.id)).toList();
    if (batch.isEmpty) {
      _notify('Select at least one service.');
      return;
    }
    setState(() {
      _running = true;
      _lines.clear();
    });
    _model?.runBatch(
      _server,
      batch,
      deployAfterBuild: _mode == BatchMode.buildDeploy,
    );
  }

  void _onStop() => _model?.requestCancel();

  void _onSelectMode(BatchMode mode) => setState(() => _mode = mode);

  void _onToggleService(ServiceConfig service, bool? selected) {
    setState(() {
      if (selected == true) {
        _selected.add(service.id);
      } else {
        _selected.remove(service.id);
      }
    });
  }

  void _onToggleAll() {
    final eligible = _ordered.where(_eligible).map((s) => s.id).toSet();
    setState(() {
      if (_selected.length >= eligible.length) {
        _selected.clear();
      } else {
        _selected
          ..clear()
          ..addAll(eligible);
      }
    });
  }

  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)));
  }

  // ── ConnectBatchDeploy ─────────────────────────────────────────────────────

  @override
  void onBatchStarted(List<String> serviceIds) {
    if (!mounted) return;
    setState(() {
      for (final id in serviceIds) {
        _status[id] = BatchState.queued;
        _detail.remove(id);
      }
    });
  }

  @override
  void onServiceState(String serviceId, BatchState state, {String? detail}) {
    if (!mounted) return;
    setState(() {
      _status[serviceId] = state;
      if (detail != null) _detail[serviceId] = detail;
    });
  }

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

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

  Widget _header() {
    final jp = context.jp;
    final allSelected =
        _selected.length >= _eligibleCount && _eligibleCount > 0;
    return Container(
      padding: const EdgeInsets.fromLTRB(16, 14, 16, 14),
      decoration: BoxDecoration(
        color: jp.surface,
        border: Border(bottom: BorderSide(color: jp.border)),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              text('Mode', 13, TextType.Bold, color: jp.textDim),
              const Spacer(),
              if (_running || _doneCount + _failCount > 0)
                text(
                  '${_doneCount + _failCount}/${_selected.length} · '
                  '$_doneCount ok · $_failCount failed',
                  12,
                  TextType.Regular,
                  color: jp.textFaint,
                ),
            ],
          ),
          const SizedBox(height: 8),
          Row(
            children: [
              _modeChip(
                BatchMode.buildDeploy,
                'Build & deploy',
                Icons.rocket_launch,
              ),
              const SizedBox(width: 8),
              _modeChip(BatchMode.buildOnly, 'Build only', Icons.build),
              const Spacer(),
              TextButton.icon(
                onPressed: _running ? null : _onToggleAll,
                icon: Icon(
                  allSelected ? Icons.remove_done : Icons.done_all,
                  size: 16,
                ),
                label: text(
                  allSelected ? 'Clear' : 'Select all',
                  13,
                  TextType.Bold,
                  color: colorPrimary,
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }

  Widget _reorderHint() => Padding(
    padding: const EdgeInsets.only(left: 4, bottom: 8, top: 2),
    child: Row(
      children: [
        Icon(Icons.drag_indicator, size: 15, color: context.jp.textFaint),
        const SizedBox(width: 4),
        text(
          'Drag to set deployment order — saved automatically',
          12,
          TextType.Regular,
          color: context.jp.textFaint,
        ),
      ],
    ),
  );

  Widget _modeChip(BatchMode mode, String label, IconData icon) {
    final jp = context.jp;
    final active = _mode == mode;
    return GestureDetector(
      onTap: _running ? null : () => _onSelectMode(mode),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        decoration: BoxDecoration(
          color: active ? PeachTheme.seed.withValues(alpha: 0.14) : jp.surface2,
          borderRadius: BorderRadius.circular(10),
          border: Border.all(color: active ? PeachTheme.seed : jp.border),
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(icon, size: 15, color: active ? PeachTheme.seed : jp.textDim),
            const SizedBox(width: 6),
            text(
              label,
              12.5,
              TextType.Bold,
              color: active ? PeachTheme.seed : jp.textDim,
            ),
          ],
        ),
      ),
    );
  }

  Widget _serviceTile(ServiceConfig service, int index) {
    final jp = context.jp;
    final eligible = _eligible(service);
    final selected = _selected.contains(service.id);
    final state = _status[service.id];
    return Container(
      padding: const EdgeInsets.fromLTRB(8, 12, 12, 12),
      decoration: PeachTheme.panel(context, radius: 14),
      child: Row(
        children: [
          Container(
            width: 24,
            height: 24,
            alignment: Alignment.center,
            decoration: BoxDecoration(
              color: PeachTheme.seed.withValues(alpha: 0.12),
              borderRadius: BorderRadius.circular(7),
            ),
            child: text(
              '${index + 1}',
              12,
              TextType.Bold,
              color: PeachTheme.seed,
            ),
          ),
          const SizedBox(width: 4),
          if (eligible)
            Checkbox(
              value: selected,
              onChanged: _running ? null : (v) => _onToggleService(service, v),
            )
          else
            const SizedBox(width: 40, child: Icon(Icons.block, size: 18)),
          Icon(
            service.isWeb
                ? Icons.language
                : (service.isGeneric ? Icons.terminal : Icons.settings_suggest),
            size: 18,
            color: jp.textDim,
          ),
          const SizedBox(width: 10),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                text(
                  service.name,
                  14,
                  TextType.Bold,
                  color: jp.text,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                ),
                text(
                  eligible
                      ? (_detail[service.id] ??
                            '${service.kind.label} · builds from source')
                      : 'Add a source path to include',
                  11.5,
                  TextType.Regular,
                  color: jp.textFaint,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                ),
              ],
            ),
          ),
          const SizedBox(width: 8),
          _statusPill(state),
          if (!_running) ...[
            const SizedBox(width: 4),
            ReorderableDragStartListener(
              index: index,
              child: Icon(Icons.drag_handle, size: 20, color: jp.textFaint),
            ),
          ],
        ],
      ),
    );
  }

  Widget _statusPill(BatchState? state) {
    if (state == null) return const SizedBox.shrink();
    final jp = context.jp;
    final (color, label, spinning) = switch (state) {
      BatchState.queued => (jp.textFaint, 'QUEUED', false),
      BatchState.building => (PeachTheme.warn, 'BUILDING', true),
      BatchState.deploying => (PeachTheme.accent, 'DEPLOYING', true),
      BatchState.done => (PeachTheme.seed, 'DONE', false),
      BatchState.failed => (PeachTheme.danger, 'FAILED', false),
      BatchState.skipped => (jp.textFaint, 'SKIPPED', false),
    };
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 9, vertical: 4),
      decoration: BoxDecoration(
        color: color.withValues(alpha: 0.16),
        borderRadius: BorderRadius.circular(20),
        border: Border.all(color: color.withValues(alpha: 0.4)),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          if (spinning)
            SizedBox(
              width: 11,
              height: 11,
              child: CircularProgressIndicator(strokeWidth: 2, color: color),
            )
          else
            Icon(
              state == BatchState.done
                  ? Icons.check
                  : state == BatchState.failed
                  ? Icons.close
                  : Icons.circle,
              size: 11,
              color: color,
            ),
          const SizedBox(width: 5),
          text(label, 10, TextType.Bold, color: color),
        ],
      ),
    );
  }

  Widget _bottomBar() {
    return SafeArea(
      top: false,
      child: Padding(
        padding: const EdgeInsets.fromLTRB(16, 8, 16, 12),
        child: Row(
          children: [
            Expanded(
              child: FilledButton.icon(
                onPressed: _running || _selected.isEmpty ? null : _onRun,
                icon: _running
                    ? SizedBox(
                        width: 18,
                        height: 18,
                        child: CircularProgressIndicator(
                          strokeWidth: 2,
                          color: colorWhite,
                        ),
                      )
                    : Icon(
                        _mode == BatchMode.buildOnly
                            ? Icons.build
                            : Icons.rocket_launch,
                      ),
                label: text(
                  _running
                      ? 'Running…'
                      : (_mode == BatchMode.buildOnly
                            ? 'Build ${_selected.length} selected'
                            : 'Build & deploy ${_selected.length} selected'),
                  14,
                  TextType.Bold,
                  color: colorWhite,
                ),
              ),
            ),
            if (_running) ...[
              const SizedBox(width: 10),
              OutlinedButton.icon(
                onPressed: _onStop,
                icon: const Icon(Icons.cancel, size: 18),
                label: text(
                  'Stop',
                  13,
                  TextType.Bold,
                  color: PeachTheme.danger,
                ),
                style: OutlinedButton.styleFrom(
                  foregroundColor: PeachTheme.danger,
                  side: BorderSide(
                    color: PeachTheme.danger.withValues(alpha: 0.6),
                  ),
                  padding: const EdgeInsets.symmetric(
                    horizontal: 16,
                    vertical: 16,
                  ),
                ),
              ),
            ],
          ],
        ),
      ),
    );
  }
}