import 'dart:async';

import 'package:clide/kernel/kernel.dart';
import 'package:clide/widgets/widgets.dart';
import 'package:flutter/services.dart';
import 'package:flutter/widgets.dart';

class GitStatusItem extends StatefulWidget {
  const GitStatusItem({super.key});

  @override
  State<GitStatusItem> createState() => _GitStatusItemState();
}

class _GitStatusItemState extends State<GitStatusItem> {
  String? _branch;
  int _ahead = 0;
  int _behind = 0;
  StreamSubscription<DaemonEvent>? _sub;

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    if (_sub != null) return;
    final kernel = ClideKernel.of(context);
    _sub = kernel.events.on<DaemonEvent>().listen(_onEvent);
    unawaited(_load(kernel.ipc));
  }

  Future<void> _load(DaemonClient ipc) async {
    final r = await ipc.request('git.status');
    if (!r.ok || !mounted) return;
    setState(() {
      _branch = r.data['branch'] as String?;
      _ahead = (r.data['ahead'] as num?)?.toInt() ?? 0;
      _behind = (r.data['behind'] as num?)?.toInt() ?? 0;
    });
  }

  void _onEvent(DaemonEvent e) {
    if (e.subsystem != 'git' || e.kind != 'git.changed') return;
    final kernel = ClideKernel.of(context);
    unawaited(_load(kernel.ipc));
  }

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

  void _openBranchPicker() {
    final kernel = ClideKernel.of(context);
    kernel.dialog.show<String>(
      (ctx, dismiss) => _BranchPicker(
        ipc: kernel.ipc,
        currentBranch: _branch,
        onDismiss: dismiss,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final tokens = ClideTheme.of(context).surface;
    if (_branch == null) return const SizedBox.shrink();
    final parts = <String>[_branch!];
    if (_ahead > 0) parts.add('↑$_ahead');
    if (_behind > 0) parts.add('↓$_behind');
    return Semantics(
      button: true,
      label: 'switch branch — $_branch',
      child: GestureDetector(
        onTap: _openBranchPicker,
        child: MouseRegion(
          cursor: SystemMouseCursors.click,
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 8),
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                ClideIcon(
                  const GitBranchIcon(),
                  size: 12,
                  color: tokens.statusBarForeground,
                ),
                const SizedBox(width: 4),
                ClideText(
                  parts.join(' '),
                  fontSize: clideFontCaption,
                  color: tokens.statusBarForeground,
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class _BranchPicker extends StatefulWidget {
  const _BranchPicker({
    required this.ipc,
    required this.currentBranch,
    required this.onDismiss,
  });

  final DaemonClient ipc;
  final String? currentBranch;
  final void Function([String?]) onDismiss;

  @override
  State<_BranchPicker> createState() => _BranchPickerState();
}

class _BranchPickerState extends State<_BranchPicker> {
  List<Map<String, Object?>> _branches = const [];
  bool _loading = true;
  String? _error;
  late final FocusNode _focus;

  @override
  void initState() {
    super.initState();
    _focus = FocusNode()..requestFocus();
    unawaited(_load());
  }

  @override
  void dispose() {
    _focus.dispose();
    super.dispose();
  }

  Future<void> _load() async {
    final r = await widget.ipc.request('git.branches');
    if (!mounted) return;
    setState(() {
      _loading = false;
      if (r.ok) {
        _branches = [
          for (final b in (r.data['branches'] as List? ?? const [])) (b as Map).cast<String, Object?>(),
        ];
      } else {
        _error = r.error?.message ?? 'failed to load branches';
      }
    });
  }

  Future<void> _checkout(String branch) async {
    await widget.ipc.request('git.checkout', args: {'branch': branch});
    widget.onDismiss();
  }

  KeyEventResult _onKey(FocusNode node, KeyEvent event) {
    if (event is KeyDownEvent && event.logicalKey == LogicalKeyboardKey.escape) {
      widget.onDismiss();
      return KeyEventResult.handled;
    }
    return KeyEventResult.ignored;
  }

  @override
  Widget build(BuildContext context) {
    final tokens = ClideTheme.of(context).surface;
    return Focus(
      focusNode: _focus,
      onKeyEvent: _onKey,
      child: Container(
        width: 320,
        constraints: const BoxConstraints(maxHeight: 320),
        decoration: BoxDecoration(
          color: tokens.dropdownBackground,
          border: Border.all(color: tokens.dropdownBorder),
          borderRadius: BorderRadius.circular(6),
        ),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
              child: Row(
                children: [
                  Expanded(
                    child: ClideText('Switch branch', fontSize: clideFontCaption, color: tokens.globalTextMuted, fontFamily: clideMonoFamily),
                  ),
                  GestureDetector(
                    onTap: () => widget.onDismiss(),
                    child: MouseRegion(
                      cursor: SystemMouseCursors.click,
                      child: ClideIcon(PhosphorIcons.xMark, size: 12, color: tokens.globalTextMuted),
                    ),
                  ),
                ],
              ),
            ),
            if (_loading) const Padding(padding: EdgeInsets.all(12), child: ClideText('Loading…', muted: true)),
            if (_error != null) Padding(padding: const EdgeInsets.all(12), child: ClideText(_error!, muted: true)),
            if (!_loading && _error == null && _branches.isEmpty)
              const Padding(padding: EdgeInsets.all(12), child: ClideText('No branches found.', muted: true)),
            if (_branches.isNotEmpty)
              Flexible(
                child: ListView.builder(
                  shrinkWrap: true,
                  padding: EdgeInsets.zero,
                  itemCount: _branches.length,
                  itemBuilder: (ctx, i) {
                    final b = _branches[i];
                    final name = b['name'] as String? ?? '';
                    final current = b['current'] as bool? ?? false;
                    return _BranchRow(
                      name: name,
                      current: current,
                      onTap: current ? null : () => unawaited(_checkout(name)),
                    );
                  },
                ),
              ),
          ],
        ),
      ),
    );
  }
}

class _BranchRow extends StatelessWidget {
  const _BranchRow({
    required this.name,
    required this.current,
    this.onTap,
  });

  final String name;
  final bool current;
  final VoidCallback? onTap;

  @override
  Widget build(BuildContext context) {
    final tokens = ClideTheme.of(context).surface;
    return ClideTappable(
      onTap: onTap,
      cursor: onTap != null ? SystemMouseCursors.click : MouseCursor.defer,
      builder: (context, hovered, _) => Container(
        color: hovered ? tokens.listItemHoverBackground : null,
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
        child: Row(
          children: [
            if (current)
              Padding(
                padding: const EdgeInsets.only(right: 8),
                child: ClideIcon(
                  const CheckIcon(),
                  size: 12,
                  color: tokens.statusSuccess,
                ),
              )
            else
              const SizedBox(width: 20),
            Expanded(
              child: ClideText(
                name,
                fontFamily: clideMonoFamily,
                fontSize: clideFontMono,
                color: current ? tokens.globalForeground : tokens.listItemForeground,
              ),
            ),
          ],
        ),
      ),
    );
  }
}