import 'package:flutter/material.dart';

import '../../core/theme/design_tokens.dart';

class DetailHeaderActionItem<T> {
  const DetailHeaderActionItem({
    required this.value,
    required this.label,
    required this.icon,
    this.isDestructive = false,
    this.enabled = true,
  });

  final T value;
  final String label;
  final IconData icon;
  final bool isDestructive;
  final bool enabled;
}

class DetailHeaderActionMenu<T> extends StatefulWidget {
  const DetailHeaderActionMenu({
    super.key,
    required this.items,
    required this.onSelected,
  });

  final List<DetailHeaderActionItem<T>> items;
  final ValueChanged<T> onSelected;

  @override
  State<DetailHeaderActionMenu<T>> createState() =>
      _DetailHeaderActionMenuState<T>();
}

class _DetailHeaderActionMenuState<T> extends State<DetailHeaderActionMenu<T>> {
  static const double _buttonSize = AppSpacing.xl * 2;
  static const double _menuWidth = AppSpacing.xxl * 8;

  final LayerLink _layerLink = LayerLink();
  OverlayEntry? _menuEntry;

  bool get _isMenuOpen => _menuEntry != null;

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

  void _toggleMenu() {
    if (_isMenuOpen) {
      _hideMenu();
      return;
    }
    _showMenu();
  }

  void _showMenu() {
    final overlay = Overlay.of(context);
    _menuEntry = OverlayEntry(
      builder: (context) {
        return Stack(
          children: [
            Positioned.fill(
              child: GestureDetector(
                behavior: HitTestBehavior.opaque,
                onTap: _hideMenu,
                child: const SizedBox.expand(),
              ),
            ),
            CompositedTransformFollower(
              link: _layerLink,
              showWhenUnlinked: false,
              offset: Offset(
                _buttonSize - _menuWidth,
                _buttonSize + AppSpacing.sm,
              ),
              child: _buildMenuCard(),
            ),
          ],
        );
      },
    );

    overlay.insert(_menuEntry!);
    setState(() {});
  }

  void _removeOverlayEntry() {
    _menuEntry?.remove();
    _menuEntry = null;
  }

  void _hideMenu() {
    _removeOverlayEntry();
    if (mounted) {
      setState(() {});
    }
  }

  void _handleSelect(T value) {
    _hideMenu();
    widget.onSelected(value);
  }

  Widget _buildMenuCard() {
    final colorScheme = Theme.of(context).colorScheme;
    return Material(
      color: colorScheme.surface.withValues(alpha: 0),
      child: Container(
        width: _menuWidth,
        padding: const EdgeInsets.symmetric(vertical: AppSpacing.sm),
        decoration: BoxDecoration(
          color: colorScheme.surface,
          borderRadius: BorderRadius.circular(AppRadius.lg),
          border: Border.all(color: colorScheme.outlineVariant),
          boxShadow: [
            BoxShadow(
              color: colorScheme.shadow.withValues(alpha: 0.42),
              blurRadius: AppSpacing.xl,
              offset: const Offset(0, AppSpacing.sm),
            ),
          ],
        ),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            for (int i = 0; i < widget.items.length; i++) ...[
              _buildMenuItem(widget.items[i]),
              if (i < widget.items.length - 1)
                Padding(
                  padding: const EdgeInsets.symmetric(
                    horizontal: AppSpacing.md,
                  ),
                  child: Divider(
                    height: 1,
                    thickness: 1,
                    color: colorScheme.outlineVariant,
                  ),
                ),
            ],
          ],
        ),
      ),
    );
  }

  Widget _buildMenuItem(DetailHeaderActionItem<T> item) {
    final colorScheme = Theme.of(context).colorScheme;
    final textColor = item.isDestructive
        ? colorScheme.error
        : (item.enabled ? colorScheme.onSurface : colorScheme.onSurfaceVariant);
    final pressedColor = item.isDestructive
        ? colorScheme.errorContainer
        : colorScheme.primaryContainer;

    return SizedBox(
      height: AppSpacing.xxl * 2,
      child: Material(
        color: colorScheme.surface.withValues(alpha: 0),
        child: InkWell(
          borderRadius: BorderRadius.circular(AppRadius.md),
          splashColor: item.enabled
              ? pressedColor
              : colorScheme.surface.withValues(alpha: 0),
          highlightColor: item.enabled
              ? pressedColor
              : colorScheme.surface.withValues(alpha: 0),
          onTap: item.enabled ? () => _handleSelect(item.value) : null,
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: AppSpacing.md),
            child: Row(
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [
                Icon(
                  item.icon,
                  size: AppSpacing.lg + AppSpacing.xs,
                  color: textColor,
                ),
                const SizedBox(width: AppSpacing.md),
                Text(
                  item.label,
                  style: TextStyle(
                    fontSize: 14,
                    fontWeight: FontWeight.w600,
                    color: textColor,
                  ),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    if (widget.items.isEmpty) {
      return const SizedBox.shrink();
    }

    final colorScheme = Theme.of(context).colorScheme;
    return CompositedTransformTarget(
      link: _layerLink,
      child: GestureDetector(
        onTap: _toggleMenu,
        child: AnimatedContainer(
          duration: const Duration(milliseconds: 140),
          width: _buttonSize,
          height: _buttonSize,
          decoration: BoxDecoration(
            color: _isMenuOpen
                ? colorScheme.secondaryContainer
                : colorScheme.tertiaryContainer,
            borderRadius: BorderRadius.circular(AppRadius.md),
            border: Border.all(
              color: _isMenuOpen
                  ? colorScheme.outlineVariant
                  : colorScheme.outline,
            ),
          ),
          child: Icon(
            Icons.more_horiz,
            size: AppSpacing.lg + AppSpacing.xs,
            color: colorScheme.onSurfaceVariant,
          ),
        ),
      ),
    );
  }
}