// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/foundation.dart' show clampDouble;
import 'package:flutter/widgets.dart';

import 'chip.dart';
import 'chip_theme.dart';
import 'color_scheme.dart';
import 'colors.dart';
import 'debug.dart';
import 'icons.dart';
import 'material_state.dart';
import 'text_theme.dart';
import 'theme.dart';
import 'theme_data.dart';

enum _ChipVariant { flat, elevated }

/// A Material Design filter chip.
///
/// Filter chips use tags or descriptive words as a way to filter content.
///
/// Filter chips are a good alternative to [Checkbox] or [Switch] widgets.
/// Unlike these alternatives, filter chips allow for clearly delineated and
/// exposed options in a compact area.
///
/// Requires one of its ancestors to be a [Material] widget.
///
/// {@tool dartpad}
/// This example shows how to use [FilterChip]s to filter through exercises.
///
/// ** See code in examples/api/lib/material/filter_chip/filter_chip.0.dart **
/// {@end-tool}
///
/// ## Material Design 3
///
/// [FilterChip] can be used for multiple select Filter chip from
/// Material Design 3. If [ThemeData.useMaterial3] is true, then [FilterChip]
/// will be styled to match the Material Design 3 specification for Filter
/// chips. Use [ChoiceChip] for single select Filter chips.
///
/// See also:
///
///  * [Chip], a chip that displays information and can be deleted.
///  * [InputChip], a chip that represents a complex piece of information, such
///    as an entity (person, place, or thing) or conversational text, in a
///    compact form.
///  * [ChoiceChip], allows a single selection from a set of options. Choice
///    chips contain related descriptive text or categories.
///  * [ActionChip], represents an action related to primary content.
///  * [CircleAvatar], which shows images or initials of people.
///  * [Wrap], A widget that displays its children in multiple horizontal or
///    vertical runs.
///  * <https://material.io/design/components/chips.html>
class FilterChip extends StatelessWidget
    implements
        ChipAttributes,
        DeletableChipAttributes,
        SelectableChipAttributes,
        CheckmarkableChipAttributes,
        DisabledChipAttributes {
  /// Create a chip that acts like a checkbox.
  ///
  /// The [selected], [label], [autofocus], and [clipBehavior] arguments must
  /// not be null. When [onSelected] is null, the [FilterChip] will be disabled.
  /// The [pressElevation] and [elevation] must be null or non-negative. Typically,
  /// [pressElevation] is greater than [elevation].
  const FilterChip({
    super.key,
    this.avatar,
    required this.label,
    this.labelStyle,
    this.labelPadding,
    this.selected = false,
    required this.onSelected,
    this.deleteIcon,
    this.onDeleted,
    this.deleteIconColor,
    this.deleteButtonTooltipMessage,
    this.pressElevation,
    this.disabledColor,
    this.selectedColor,
    this.tooltip,
    this.side,
    this.shape,
    this.clipBehavior = Clip.none,
    this.focusNode,
    this.autofocus = false,
    this.color,
    this.backgroundColor,
    this.padding,
    this.visualDensity,
    this.materialTapTargetSize,
    this.elevation,
    this.shadowColor,
    this.surfaceTintColor,
    this.iconTheme,
    this.selectedShadowColor,
    this.showCheckmark,
    this.checkmarkColor,
    this.avatarBorder = const CircleBorder(),
    this.avatarBoxConstraints,
    this.deleteIconBoxConstraints,
  }) : assert(pressElevation == null || pressElevation >= 0.0),
       assert(elevation == null || elevation >= 0.0),
       _chipVariant = _ChipVariant.flat;

  /// Create an elevated chip that acts like a checkbox.
  ///
  /// The [selected], [label], [autofocus], and [clipBehavior] arguments must
  /// not be null. When [onSelected] is null, the [FilterChip] will be disabled.
  /// The [pressElevation] and [elevation] must be null or non-negative. Typically,
  /// [pressElevation] is greater than [elevation].
  const FilterChip.elevated({
    super.key,
    this.avatar,
    required this.label,
    this.labelStyle,
    this.labelPadding,
    this.selected = false,
    required this.onSelected,
    this.deleteIcon,
    this.onDeleted,
    this.deleteIconColor,
    this.deleteButtonTooltipMessage,
    this.pressElevation,
    this.disabledColor,
    this.selectedColor,
    this.tooltip,
    this.side,
    this.shape,
    this.clipBehavior = Clip.none,
    this.focusNode,
    this.autofocus = false,
    this.color,
    this.backgroundColor,
    this.padding,
    this.visualDensity,
    this.materialTapTargetSize,
    this.elevation,
    this.shadowColor,
    this.surfaceTintColor,
    this.iconTheme,
    this.selectedShadowColor,
    this.showCheckmark,
    this.checkmarkColor,
    this.avatarBorder = const CircleBorder(),
    this.avatarBoxConstraints,
    this.deleteIconBoxConstraints,
  }) : assert(pressElevation == null || pressElevation >= 0.0),
       assert(elevation == null || elevation >= 0.0),
       _chipVariant = _ChipVariant.elevated;

  @override
  final Widget? avatar;
  @override
  final Widget label;
  @override
  final TextStyle? labelStyle;
  @override
  final EdgeInsetsGeometry? labelPadding;
  @override
  final bool selected;
  @override
  final ValueChanged<bool>? onSelected;
  @override
  final Widget? deleteIcon;
  @override
  final VoidCallback? onDeleted;
  @override
  final Color? deleteIconColor;
  @override
  final String? deleteButtonTooltipMessage;
  @override
  final double? pressElevation;
  @override
  final Color? disabledColor;
  @override
  final Color? selectedColor;
  @override
  final String? tooltip;
  @override
  final BorderSide? side;
  @override
  final OutlinedBorder? shape;
  @override
  final Clip clipBehavior;
  @override
  final FocusNode? focusNode;
  @override
  final bool autofocus;
  @override
  final MaterialStateProperty<Color?>? color;
  @override
  final Color? backgroundColor;
  @override
  final EdgeInsetsGeometry? padding;
  @override
  final VisualDensity? visualDensity;
  @override
  final MaterialTapTargetSize? materialTapTargetSize;
  @override
  final double? elevation;
  @override
  final Color? shadowColor;
  @override
  final Color? surfaceTintColor;
  @override
  final Color? selectedShadowColor;
  @override
  final bool? showCheckmark;
  @override
  final Color? checkmarkColor;
  @override
  final ShapeBorder avatarBorder;
  @override
  final IconThemeData? iconTheme;
  @override
  final BoxConstraints? avatarBoxConstraints;
  @override
  final BoxConstraints? deleteIconBoxConstraints;

  @override
  bool get isEnabled => onSelected != null;

  final _ChipVariant _chipVariant;

  @override
  Widget build(BuildContext context) {
    assert(debugCheckHasMaterial(context));
    final ChipThemeData? defaults = Theme.of(context).useMaterial3
      ? _FilterChipDefaultsM3(context, isEnabled, selected, _chipVariant)
      : null;
    final Widget? resolvedDeleteIcon = deleteIcon
      ?? (Theme.of(context).useMaterial3 ? const Icon(Icons.clear, size: 18) : null);
    return RawChip(
      defaultProperties: defaults,
      avatar: avatar,
      label: label,
      labelStyle: labelStyle,
      labelPadding: labelPadding,
      onSelected: onSelected,
      deleteIcon: resolvedDeleteIcon,
      onDeleted: onDeleted,
      deleteIconColor: deleteIconColor,
      deleteButtonTooltipMessage: deleteButtonTooltipMessage,
      pressElevation: pressElevation,
      selected: selected,
      tooltip: tooltip,
      side: side,
      shape: shape,
      clipBehavior: clipBehavior,
      focusNode: focusNode,
      autofocus: autofocus,
      color: color,
      backgroundColor: backgroundColor,
      disabledColor: disabledColor,
      selectedColor: selectedColor,
      padding: padding,
      visualDensity: visualDensity,
      isEnabled: isEnabled,
      materialTapTargetSize: materialTapTargetSize,
      elevation: elevation,
      shadowColor: shadowColor,
      surfaceTintColor: surfaceTintColor,
      selectedShadowColor: selectedShadowColor,
      showCheckmark: showCheckmark,
      checkmarkColor: checkmarkColor,
      avatarBorder: avatarBorder,
      iconTheme: iconTheme,
      avatarBoxConstraints: avatarBoxConstraints,
      deleteIconBoxConstraints: deleteIconBoxConstraints,
    );
  }
}

// BEGIN GENERATED TOKEN PROPERTIES - FilterChip

// Do not edit by hand. The code between the "BEGIN GENERATED" and
// "END GENERATED" comments are generated from data in the Material
// Design token database by the script:
//   dev/tools/gen_defaults/bin/gen_defaults.dart.

class _FilterChipDefaultsM3 extends ChipThemeData {
  _FilterChipDefaultsM3(
    this.context,
    this.isEnabled,
    this.isSelected,
    this._chipVariant,
  ) : super(
        shape: const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(8.0))),
        showCheckmark: true,
      );

  final BuildContext context;
  final bool isEnabled;
  final bool isSelected;
  final _ChipVariant _chipVariant;
  late final ColorScheme _colors = Theme.of(context).colorScheme;
  late final TextTheme _textTheme = Theme.of(context).textTheme;

  @override
  double? get elevation => _chipVariant == _ChipVariant.flat
    ? 0.0
    : isEnabled ? 1.0 : 0.0;

  @override
  double? get pressElevation => 1.0;

  @override
  TextStyle? get labelStyle => _textTheme.labelLarge?.copyWith(
    color: isEnabled
      ? isSelected
        ? _colors.onSecondaryContainer
        : _colors.onSurfaceVariant
      : _colors.onSurface,
  );

  @override
  MaterialStateProperty<Color?>? get color =>
    MaterialStateProperty.resolveWith((Set<MaterialState> states) {
      if (states.contains(MaterialState.selected) && states.contains(MaterialState.disabled)) {
        return _chipVariant == _ChipVariant.flat
          ? _colors.onSurface.withOpacity(0.12)
          : _colors.onSurface.withOpacity(0.12);
      }
      if (states.contains(MaterialState.disabled)) {
        return _chipVariant == _ChipVariant.flat
          ? null
          : _colors.onSurface.withOpacity(0.12);
      }
      if (states.contains(MaterialState.selected)) {
        return _chipVariant == _ChipVariant.flat
          ? _colors.secondaryContainer
          : _colors.secondaryContainer;
      }
      return _chipVariant == _ChipVariant.flat
        ? null
        : _colors.surfaceContainerLow;
    });

  @override
  Color? get shadowColor => _chipVariant == _ChipVariant.flat
    ? Colors.transparent
    : _colors.shadow;

  @override
  Color? get surfaceTintColor => Colors.transparent;

  @override
  Color? get checkmarkColor => isEnabled
    ? isSelected
      ? _colors.onSecondaryContainer
      : _colors.primary
    : _colors.onSurface;

  @override
  Color? get deleteIconColor => isEnabled
    ? isSelected
      ? _colors.onSecondaryContainer
      : _colors.onSurfaceVariant
    : _colors.onSurface;

  @override
  BorderSide? get side => _chipVariant == _ChipVariant.flat && !isSelected
    ? isEnabled
      ? BorderSide(color: _colors.outline)
      : BorderSide(color: _colors.onSurface.withOpacity(0.12))
    : const BorderSide(color: Colors.transparent);

  @override
  IconThemeData? get iconTheme => IconThemeData(
    color: isEnabled
      ? isSelected
        ? _colors.onSecondaryContainer
        : _colors.primary
      : _colors.onSurface,
    size: 18.0,
  );

  @override
  EdgeInsetsGeometry? get padding => const EdgeInsets.all(8.0);

  /// The label padding of the chip scales with the font size specified in the
  /// [labelStyle], and the system font size settings that scale font sizes
  /// globally.
  ///
  /// The chip at effective font size 14.0 starts with 8px on each side and as
  /// the font size scales up to closer to 28.0, the label padding is linearly
  /// interpolated from 8px to 4px. Once the label has a font size of 2 or
  /// higher, label padding remains 4px.
  @override
  EdgeInsetsGeometry? get labelPadding {
    final double fontSize = labelStyle?.fontSize ?? 14.0;
    final double fontSizeRatio = MediaQuery.textScalerOf(context).scale(fontSize) / 14.0;
    return EdgeInsets.lerp(
      const EdgeInsets.symmetric(horizontal: 8.0),
      const EdgeInsets.symmetric(horizontal: 4.0),
      clampDouble(fontSizeRatio - 1.0, 0.0, 1.0),
    )!;
  }
}

// END GENERATED TOKEN PROPERTIES - FilterChip
