/*
 * Copyright (c) 2024-2026 Fabian Freund.
 *
 * This file is part of WebLibre
 * (see https://weblibre.eu).
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
import 'package:flutter/material.dart';

class SlidingPillToggle extends StatelessWidget {
  final int selectedIndex;
  final List<String> labels;
  final ValueChanged<int> onChanged;

  const SlidingPillToggle({
    super.key,
    required this.selectedIndex,
    required this.labels,
    required this.onChanged,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;
    final disableAnimations = MediaQuery.disableAnimationsOf(context);

    return Container(
      height: 36,
      decoration: BoxDecoration(
        color: colorScheme.surfaceContainerHighest,
        borderRadius: BorderRadius.circular(18),
      ),
      child: Stack(
        children: [
          AnimatedAlign(
            alignment: Alignment(
              -1.0 + (2.0 * selectedIndex / (labels.length - 1)),
              0.0,
            ),
            duration: disableAnimations
                ? Duration.zero
                : const Duration(milliseconds: 250),
            curve: Curves.easeOutCubic,
            child: FractionallySizedBox(
              widthFactor: 1.0 / labels.length,
              child: Container(
                decoration: BoxDecoration(
                  color: colorScheme.primary,
                  borderRadius: BorderRadius.circular(18),
                ),
              ),
            ),
          ),
          Row(
            children: [
              for (var i = 0; i < labels.length; i++)
                Expanded(
                  child: GestureDetector(
                    behavior: HitTestBehavior.opaque,
                    onTap: () => onChanged(i),
                    child: Center(
                      child: Text(
                        labels[i],
                        style: theme.textTheme.labelMedium?.copyWith(
                          color: i == selectedIndex
                              ? colorScheme.onPrimary
                              : colorScheme.onSurfaceVariant,
                          fontWeight: i == selectedIndex
                              ? FontWeight.w600
                              : FontWeight.normal,
                        ),
                      ),
                    ),
                  ),
                ),
            ],
          ),
        ],
      ),
    );
  }
}