// 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.

// @dart = 2.8

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

import 'input_decorator.dart';
import 'theme.dart';

/// Defines the visual properties of the widget displayed with [showTimePicker].
///
/// Descendant widgets obtain the current [TimePickerThemeData] object using
/// `TimePickerTheme.of(context)`. Instances of [TimePickerThemeData]
/// can be customized with [TimePickerThemeData.copyWith].
///
/// Typically a [TimePickerThemeData] is specified as part of the overall
/// [Theme] with [ThemeData.timePickerTheme].
///
/// All [TimePickerThemeData] properties are `null` by default. When null,
/// [showTimePicker] will provide its own defaults.
///
/// See also:
///
///  * [ThemeData], which describes the overall theme information for the
///    application.
///  * [TimePickerTheme], which describes the actual configuration of a time
///    picker theme.
@immutable
class TimePickerThemeData with Diagnosticable {

  /// Creates a theme that can be used for [TimePickerTheme] or
  /// [ThemeData.timePickerTheme].
  const TimePickerThemeData({
    this.backgroundColor,
    this.hourMinuteTextColor,
    this.hourMinuteColor,
    this.dayPeriodTextColor,
    this.dayPeriodColor,
    this.dialHandColor,
    this.dialBackgroundColor,
    this.dialTextColor,
    this.entryModeIconColor,
    this.hourMinuteTextStyle,
    this.dayPeriodTextStyle,
    this.helpTextStyle,
    this.shape,
    this.hourMinuteShape,
    this.dayPeriodShape,
    this.dayPeriodBorderSide,
    this.inputDecorationTheme,
  });

  /// The background color of a time picker.
  ///
  /// If this is null, the time picker defaults to the overall theme's
  /// [ColorScheme.background].
  final Color backgroundColor;

  /// The color of the header text that represents hours and minutes.
  ///
  /// If [hourMinuteTextColor] is a [MaterialStateColor], then the effective
  /// text color can depend on the [MaterialState.selected] state, i.e. if the
  /// text is selected or not.
  ///
  /// By default the overall theme's [ColorScheme.primary] color is used when
  /// the text is selected and [ColorScheme.onSurface] when it's not selected.
  final Color hourMinuteTextColor;

  /// The background color of the hour and minutes header segments.
  ///
  /// If [hourMinuteColor] is a [MaterialStateColor], then the effective
  /// background color can depend on the [MaterialState.selected] state, i.e.
  /// if the segment is selected or not.
  ///
  /// By default, if the segment is selected, the overall theme's
  /// `ColorScheme.primary.withOpacity(0.12)` is used when the overall theme's
  /// brightness is [Brightness.light] and
  /// `ColorScheme.primary.withOpacity(0.24)` is used when the overall theme's
  /// brightness is [Brightness.dark].
  /// If the segment is not selected, the overall theme's
  /// `ColorScheme.onSurface.withOpacity(0.12)` is used.
  final Color hourMinuteColor;

  /// The color of the day period text that represents AM/PM.
  ///
  /// If [dayPeriodTextColor] is a [MaterialStateColor], then the effective
  /// text color can depend on the [MaterialState.selected] state, i.e. if the
  /// text is selected or not.
  ///
  /// By default the overall theme's [ColorScheme.primary] color is used when
  /// the text is selected and `ColorScheme.onSurface.withOpacity(0.60)` when
  /// it's not selected.
  final Color dayPeriodTextColor;

  /// The background color of the AM/PM toggle.
  ///
  /// If [dayPeriodColor] is a [MaterialStateColor], then the effective
  /// background color can depend on the [MaterialState.selected] state, i.e.
  /// if the segment is selected or not.
  ///
  /// By default, if the segment is selected, the overall theme's
  /// `ColorScheme.primary.withOpacity(0.12)` is used when the overall theme's
  /// brightness is [Brightness.light] and
  /// `ColorScheme.primary.withOpacity(0.24)` is used when the overall theme's
  /// brightness is [Brightness.dark].
  /// If the segment is not selected, [Colors.transparent] is used to allow the
  /// [Dialog]'s color to be used.
  final Color dayPeriodColor;

  /// The color of the time picker dial's hand.
  ///
  /// If this is null, the time picker defaults to the overall theme's
  /// [ColorScheme.primary].
  final Color dialHandColor;

  /// The background color of the time picker dial.
  ///
  /// If this is null, the time picker defaults to the overall theme's
  /// [ColorScheme.primary].
  final Color dialBackgroundColor;

  /// The color of the dial text that represents specific hours and minutes.
  ///
  /// If [dialTextColor] is a [MaterialStateColor], then the effective
  /// text color can depend on the [MaterialState.selected] state, i.e. if the
  /// text is selected or not.
  ///
  /// By default the overall theme's `textTheme` color is used when the text is
  /// selected and `accentTextTheme` color is used when it's not selected.
  final Color dialTextColor;

  /// The color of the entry mode [IconButton].
  ///
  /// If this is null, the time picker defaults to
  /// ```
  /// Theme.of(context).colorScheme.onSurface.withOpacity(
  ///   Theme.of(context).colorScheme.brightness == Brightness.dark ? 1.0 : 0.6,
  /// )
  /// ```
  final Color entryModeIconColor;

  /// Used to configure the [TextStyle]s for the hour/minute controls.
  ///
  /// If this is null, the time picker defaults to the overall theme's
  /// [TextTheme.headline3].
  final TextStyle hourMinuteTextStyle;

  /// Used to configure the [TextStyle]s for the day period control.
  ///
  /// If this is null, the time picker defaults to the overall theme's
  /// [TextTheme.subtitle1].
  final TextStyle dayPeriodTextStyle;

  /// Used to configure the [TextStyle]s for the helper text in the header.
  ///
  /// If this is null, the time picker defaults to the overall theme's
  /// [TextTheme.overline].
  final TextStyle helpTextStyle;

  /// The shape of the [Dialog] that the time picker is presented in.
  ///
  /// If this is null, the time picker defaults to
  /// `RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(4.0)))`.
  final ShapeBorder shape;

  /// The shape of the hour and minute controls that the time picker uses.
  ///
  /// If this is null, the time picker defaults to
  /// `RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(4.0)))`.
  final ShapeBorder hourMinuteShape;

  /// The shape of the day period that the time picker uses.
  ///
  /// If this is null, the time picker defaults to:
  /// ```
  /// RoundedRectangleBorder(
  ///   borderRadius: BorderRadius.all(Radius.circular(4.0)),
  ///   side: BorderSide(),
  /// )
  /// ```
  final OutlinedBorder dayPeriodShape;

  /// The color and weight of the day period's outline.
  ///
  /// If this is null, the time picker defaults to:
  /// ```
  /// BorderSide(
  ///   color: Color.alphaBlend(colorScheme.onBackground.withOpacity(0.38), colorScheme.surface),
  /// )
  /// ```
  final BorderSide dayPeriodBorderSide;

  /// The input decoration theme for the [TextField]s in the time picker.
  ///
  /// If this is null, the time picker provides its own defaults.
  final InputDecorationTheme inputDecorationTheme;

  /// Creates a copy of this object with the given fields replaced with the
  /// new values.
  TimePickerThemeData copyWith({
    Color backgroundColor,
    Color hourMinuteTextColor,
    Color hourMinuteColor,
    Color hourMinuteUnselectedTextColor,
    Color hourMinuteUnselectedColor,
    Color dayPeriodTextColor,
    Color dayPeriodColor,
    Color dialHandColor,
    Color dialBackgroundColor,
    Color dialTextColor,
    Color entryModeIconColor,
    TextStyle hourMinuteTextStyle,
    TextStyle dayPeriodTextStyle,
    TextStyle helpTextStyle,
    ShapeBorder shape,
    ShapeBorder hourMinuteShape,
    OutlinedBorder dayPeriodShape,
    BorderSide dayPeriodBorderSide,
    InputDecorationTheme inputDecorationTheme,
  }) {
    return TimePickerThemeData(
      backgroundColor: backgroundColor ?? this.backgroundColor,
      hourMinuteTextColor: hourMinuteTextColor ?? this.hourMinuteTextColor,
      hourMinuteColor: hourMinuteColor ?? this.hourMinuteColor,
      dayPeriodTextColor: dayPeriodTextColor ?? this.dayPeriodTextColor,
      dayPeriodColor: dayPeriodColor ?? this.dayPeriodColor,
      dialHandColor: dialHandColor ?? this.dialHandColor,
      dialBackgroundColor: dialBackgroundColor ?? this.dialBackgroundColor,
      dialTextColor: dialTextColor ?? this.dialTextColor,
      entryModeIconColor: entryModeIconColor ?? this.entryModeIconColor,
      hourMinuteTextStyle: hourMinuteTextStyle ?? this.hourMinuteTextStyle,
      dayPeriodTextStyle: dayPeriodTextStyle ?? this.dayPeriodTextStyle,
      helpTextStyle: helpTextStyle ?? this.helpTextStyle,
      shape: shape ?? this.shape,
      hourMinuteShape: hourMinuteShape ?? this.hourMinuteShape,
      dayPeriodShape: dayPeriodShape ?? this.dayPeriodShape,
      dayPeriodBorderSide: dayPeriodBorderSide ?? this.dayPeriodBorderSide,
      inputDecorationTheme: inputDecorationTheme ?? this.inputDecorationTheme,
    );
  }

  /// Linearly interpolate between two time picker themes.
  ///
  /// The argument `t` must not be null.
  ///
  /// {@macro dart.ui.shadow.lerp}
  static TimePickerThemeData lerp(TimePickerThemeData a, TimePickerThemeData b, double t) {
    assert(t != null);

    // Workaround since BorderSide's lerp does not allow for null arguments.
    BorderSide lerpedBorderSide;
    if (a?.dayPeriodBorderSide == null && b?.dayPeriodBorderSide == null) {
      lerpedBorderSide = null;
    } else if (a?.dayPeriodBorderSide == null) {
      lerpedBorderSide = b?.dayPeriodBorderSide;
    } else if (b?.dayPeriodBorderSide == null) {
      lerpedBorderSide = a?.dayPeriodBorderSide;
    } else {
      lerpedBorderSide = BorderSide.lerp(a?.dayPeriodBorderSide, b?.dayPeriodBorderSide, t);
    }
    return TimePickerThemeData(
      backgroundColor: Color.lerp(a?.backgroundColor, b?.backgroundColor, t),
      hourMinuteTextColor: Color.lerp(a?.hourMinuteTextColor, b?.hourMinuteTextColor, t),
      hourMinuteColor: Color.lerp(a?.hourMinuteColor, b?.hourMinuteColor, t),
      dayPeriodTextColor: Color.lerp(a?.dayPeriodTextColor, b?.dayPeriodTextColor, t),
      dayPeriodColor: Color.lerp(a?.dayPeriodColor, b?.dayPeriodColor, t),
      dialHandColor: Color.lerp(a?.dialHandColor, b?.dialHandColor, t),
      dialBackgroundColor: Color.lerp(a?.dialBackgroundColor, b?.dialBackgroundColor, t),
      dialTextColor: Color.lerp(a?.dialTextColor, b?.dialTextColor, t),
      entryModeIconColor: Color.lerp(a?.entryModeIconColor, b?.entryModeIconColor, t),
      hourMinuteTextStyle: TextStyle.lerp(a?.hourMinuteTextStyle, b?.hourMinuteTextStyle, t),
      dayPeriodTextStyle: TextStyle.lerp(a?.dayPeriodTextStyle, b?.dayPeriodTextStyle, t),
      helpTextStyle: TextStyle.lerp(a?.helpTextStyle, b?.helpTextStyle, t),
      shape: ShapeBorder.lerp(a?.shape, b?.shape, t),
      hourMinuteShape: ShapeBorder.lerp(a?.hourMinuteShape, b?.hourMinuteShape, t),
      dayPeriodShape: ShapeBorder.lerp(a?.dayPeriodShape, b?.dayPeriodShape, t) as OutlinedBorder,
      dayPeriodBorderSide: lerpedBorderSide,
      inputDecorationTheme: t < 0.5 ? a.inputDecorationTheme : b.inputDecorationTheme,
    );
  }

  @override
  int get hashCode {
    return hashValues(
      backgroundColor,
      hourMinuteTextColor,
      hourMinuteColor,
      dayPeriodTextColor,
      dayPeriodColor,
      dialHandColor,
      dialBackgroundColor,
      dialTextColor,
      entryModeIconColor,
      hourMinuteTextStyle,
      dayPeriodTextStyle,
      helpTextStyle,
      shape,
      hourMinuteShape,
      dayPeriodShape,
      dayPeriodBorderSide,
      inputDecorationTheme,
    );
  }

  @override
  bool operator ==(Object other) {
    if (identical(this, other))
      return true;
    if (other.runtimeType != runtimeType)
      return false;
    return other is TimePickerThemeData
        && other.backgroundColor == backgroundColor
        && other.hourMinuteTextColor == hourMinuteTextColor
        && other.hourMinuteColor == hourMinuteColor
        && other.dayPeriodTextColor == dayPeriodTextColor
        && other.dayPeriodColor == dayPeriodColor
        && other.dialHandColor == dialHandColor
        && other.dialBackgroundColor == dialBackgroundColor
        && other.dialTextColor == dialTextColor
        && other.entryModeIconColor == entryModeIconColor
        && other.hourMinuteTextStyle == hourMinuteTextStyle
        && other.dayPeriodTextStyle == dayPeriodTextStyle
        && other.helpTextStyle == helpTextStyle
        && other.shape == shape
        && other.hourMinuteShape == hourMinuteShape
        && other.dayPeriodShape == dayPeriodShape
        && other.dayPeriodBorderSide == dayPeriodBorderSide
        && other.inputDecorationTheme == inputDecorationTheme;
  }

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties.add(ColorProperty('backgroundColor', backgroundColor, defaultValue: null));
    properties.add(ColorProperty('hourMinuteTextColor', hourMinuteTextColor, defaultValue: null));
    properties.add(ColorProperty('hourMinuteColor', hourMinuteColor, defaultValue: null));
    properties.add(ColorProperty('dayPeriodTextColor', dayPeriodTextColor, defaultValue: null));
    properties.add(ColorProperty('dayPeriodColor', dayPeriodColor, defaultValue: null));
    properties.add(ColorProperty('dialHandColor', dialHandColor, defaultValue: null));
    properties.add(ColorProperty('dialBackgroundColor', dialBackgroundColor, defaultValue: null));
    properties.add(ColorProperty('dialTextColor', dialTextColor, defaultValue: null));
    properties.add(ColorProperty('entryModeIconColor', entryModeIconColor, defaultValue: null));
    properties.add(DiagnosticsProperty<TextStyle>('hourMinuteTextStyle', hourMinuteTextStyle, defaultValue: null));
    properties.add(DiagnosticsProperty<TextStyle>('dayPeriodTextStyle', dayPeriodTextStyle, defaultValue: null));
    properties.add(DiagnosticsProperty<TextStyle>('helpTextStyle', helpTextStyle, defaultValue: null));
    properties.add(DiagnosticsProperty<ShapeBorder>('shape', shape, defaultValue: null));
    properties.add(DiagnosticsProperty<ShapeBorder>('hourMinuteShape', hourMinuteShape, defaultValue: null));
    properties.add(DiagnosticsProperty<ShapeBorder>('dayPeriodShape', dayPeriodShape, defaultValue: null));
    properties.add(DiagnosticsProperty<BorderSide>('dayPeriodBorderSide', dayPeriodBorderSide, defaultValue: null));
    properties.add(DiagnosticsProperty<InputDecorationTheme>('inputDecorationTheme', inputDecorationTheme, defaultValue: null));
  }
}

/// An inherited widget that defines the configuration for time pickers
/// displayed using [showTimePicker] in this widget's subtree.
///
/// Values specified here are used for time picker properties that are not
/// given an explicit non-null value.
class TimePickerTheme extends InheritedTheme {
  /// Creates a time picker theme that controls the configurations for
  /// time pickers displayed in its widget subtree.
  const TimePickerTheme({
    Key key,
    @required this.data,
    Widget child,
  }) : assert(data != null),
       super(key: key, child: child);

  /// The properties for descendant time picker widgets.
  final TimePickerThemeData data;

  /// The [data] value of the closest [TimePickerTheme] ancestor.
  ///
  /// If there is no ancestor, it returns [ThemeData.timePickerTheme].
  /// Applications can assume that the returned value will not be null.
  ///
  /// Typical usage is as follows:
  ///
  /// ```dart
  /// TimePickerThemeData theme = TimePickerTheme.of(context);
  /// ```
  static TimePickerThemeData of(BuildContext context) {
    final TimePickerTheme timePickerTheme = context.dependOnInheritedWidgetOfExactType<TimePickerTheme>();
    return timePickerTheme?.data ?? Theme.of(context).timePickerTheme;
  }

  @override
  Widget wrap(BuildContext context, Widget child) {
    final TimePickerTheme ancestorTheme = context.findAncestorWidgetOfExactType<TimePickerTheme>();
    return identical(this, ancestorTheme) ? child : TimePickerTheme(data: data, child: child);
  }

  @override
  bool updateShouldNotify(TimePickerTheme oldWidget) => data != oldWidget.data;
}