// SPDX-FileCopyrightText: 2022 Iconica
//
// SPDX-License-Identifier: BSD-3-Clause

import 'package:flutter/material.dart';

enum IntroductionScreenMode { showNever, showAlways, showOnce }

enum IntroductionScreenButtonMode { text, icon, disabled, singleFinish }

enum IntroductionLayoutStyle {
  imageCenter,
  imageTop,
  imageBottom,
}

enum IndicatorMode { dot, dash, custom }

enum IntroductionDisplayMode {
  singleScrollablePageVertical,
  multiPageHorizontal
}

enum IntroductionControlMode {
  previousNextButton,
  singleButton,
}

enum IntroductionButtonType {
  next,
  previous,
  finish,
  skip,
}

class IntroductionPage {
  /// Creates an introduction page with data used in the introduction screen for
  /// each page.
  ///
  /// The values for [title] and [text] are optional in this, but will use a
  /// default translation key when built.
  ///
  /// The [background] is fully optional and if not provided will show the
  /// [ThemeData.colorScheme.background] as default.
  IntroductionPage({
    this.title,
    this.text,
    this.graphic,
    this.decoration,
    this.layoutStyle,
  });
  final Widget? title;
  final Widget? text;
  final Widget? graphic;
  final BoxDecoration? decoration;
  final IntroductionLayoutStyle? layoutStyle;
}

class IntroductionOptions {
  const IntroductionOptions({
    this.introductionTranslations = const IntroductionTranslations(),
    this.introductionButtonTextstyles = const IntroductionButtonTextstyles(),
    this.indicatorMode = IndicatorMode.dash,
    this.indicatorBuilder,
    this.layoutStyle = IntroductionLayoutStyle.imageCenter,
    this.pages = const [],
    this.buttonMode = IntroductionScreenButtonMode.disabled,
    this.tapEnabled = false,
    this.mode = IntroductionScreenMode.showNever,
    this.textAlign = TextAlign.center,
    this.displayMode = IntroductionDisplayMode.multiPageHorizontal,
    this.skippable = false,
    this.buttonBuilder,
    this.controlMode = IntroductionControlMode.previousNextButton,
  }) : assert(
          !(identical(indicatorMode, IndicatorMode.custom) &&
              indicatorBuilder == null),
          'When indicator mode is set to custom, '
          'make sure to define indicatorBuilder',
        );

  /// Determine when the introduction screens needs to be shown.
  ///
  /// [IntroductionScreenMode.showNever] To disable introduction screens.
  ///
  /// [IntroductionScreenMode.showAlways] To always show the introduction
  /// screens on startup.
  ///
  /// [IntroductionScreenMode.showOnce] To only show the introduction screens
  /// once on startup.
  final IntroductionScreenMode mode;

  /// List of introduction pages to set the text, icons or images for the
  /// introduction screens.
  final List<IntroductionPage> pages;

  /// Determines whether the user can tap the screen to go to the next
  /// introduction screen.
  final bool tapEnabled;

  /// Determines what kind of buttons are used to navigate to the next
  /// introduction screen.
  /// Introduction screens can always be navigated by swiping (or tapping if
  /// [tapEnabled] is enabled).
  ///
  /// [IntroductionScreenButtonMode.text] Use text buttons (text can be set by
  /// setting the translation key or using the default appshell translations).
  ///
  /// [IntroductionScreenButtonMode.icon] Use icon buttons (icons can be
  /// changed by providing a icon library)
  ///
  /// [IntroductionScreenButtonMode.disabled] Disable buttons.
  final IntroductionScreenButtonMode buttonMode;

  /// Determines the position of the provided images or icons that are set
  /// using [pages].
  /// Every introduction page provided with a image or icon will use the same
  /// layout setting.
  ///
  /// [IntroductionLayoutStyle.imageCenter] Image/icon will be at the center of the introduction page.
  ///
  /// [IntroductionLayoutStyle.imageTop] Image/icon will be at the top of the introduction page.
  ///
  /// [IntroductionLayoutStyle.imageBottom] Image/icon will be at the bottom of the introduction page.
  final IntroductionLayoutStyle layoutStyle;

  /// Determines the style of the page indicator shown at the bottom on the
  /// introduction pages.
  ///
  /// [IndicatorMode.dot] Shows a dot for each page.
  ///
  /// [IndicatorMode.dash] Shows a dash for each page.
  ///
  /// [IndicatorMode.custom] calls indicatorBuilder for the indicator
  final IndicatorMode indicatorMode;

  /// Builder that is called when [indicatorMode] is set
  /// to [IndicatorMode.custom]
  final Widget Function(
    BuildContext,
    PageController,
    int,
    int,
  )? indicatorBuilder;

  /// Determines whether the user can skip the introduction pages using a button
  /// in the header
  final bool skippable;

  /// Determines whether the introduction screens should be shown in a single
  final TextAlign textAlign;

  /// [IntroductionDisplayMode.multiPageHorizontal] Configured introduction
  /// pages will be shown on seperate screens and can be navigated using using
  /// buttons (if enabled) or swiping.
  ///
  /// !Unimplemented! [IntroductionDisplayMode.singleScrollablePageVertical]
  /// All configured introduction pages will be shown on a single scrollable
  /// page.
  ///
  final IntroductionDisplayMode displayMode;

  /// When [IntroductionDisplayMode.multiPageHorizontal] is selected multiple
  /// controlMode can be selected.
  ///
  /// [IntroductionControlMode.previousNextButton] shows two buttons at the
  /// bottom of the screen to return or proceed. The skip button is placed at
  /// the top left of the screen.
  ///
  /// [IntroductionControlMode.singleButton] contains one button at the bottom
  /// of the screen to proceed. Underneath is clickable text to skip if the
  /// current page is the first page. If the current page is any different it
  /// return to the previous screen.
  ///
  final IntroductionControlMode controlMode;

  /// A builder that can be used to replace the default text buttons when
  /// [IntroductionScreenButtonMode.text] is provided to [buttonMode]
  final Widget Function(
    BuildContext,
    VoidCallback,
    Widget,
    IntroductionButtonType,
  )? buttonBuilder;

  /// The translations for all buttons on the introductionpages
  ///
  /// See [IntroductionTranslations] for more information
  /// The following buttons have a translation:
  /// - Skip
  /// - Next
  /// - Previous
  /// - Finish
  final IntroductionTranslations introductionTranslations;

  /// The textstyles for all buttons on the introductionpages
  ///
  /// See [IntroductionButtonTextstyles] for more information
  /// The following buttons have a textstyle:
  /// - Skip
  /// - Next
  /// - Previous
  /// - Finish
  final IntroductionButtonTextstyles introductionButtonTextstyles;

  IntroductionOptions copyWith({
    IntroductionScreenMode? mode,
    List<IntroductionPage>? pages,
    bool? tapEnabled,
    IntroductionScreenButtonMode? buttonMode,
    IntroductionLayoutStyle? layoutStyle,
    IndicatorMode? indicatorMode,
    Widget Function(
      BuildContext,
      PageController,
      int,
      int,
    )? indicatorBuilder,
    bool? skippable,
    TextAlign? textAlign,
    IntroductionDisplayMode? displayMode,
    IntroductionControlMode? controlMode,
    Widget Function(BuildContext, VoidCallback, Widget, IntroductionButtonType)?
        buttonBuilder,
    IntroductionTranslations? introductionTranslations,
    IntroductionButtonTextstyles? introductionButtonTextstyles,
  }) =>
      IntroductionOptions(
        mode: mode ?? this.mode,
        pages: pages ?? this.pages,
        tapEnabled: tapEnabled ?? this.tapEnabled,
        buttonMode: buttonMode ?? this.buttonMode,
        layoutStyle: layoutStyle ?? this.layoutStyle,
        indicatorMode: indicatorMode ?? this.indicatorMode,
        indicatorBuilder: indicatorBuilder ?? this.indicatorBuilder,
        skippable: skippable ?? this.skippable,
        textAlign: textAlign ?? this.textAlign,
        displayMode: displayMode ?? this.displayMode,
        controlMode: controlMode ?? this.controlMode,
        buttonBuilder: buttonBuilder ?? this.buttonBuilder,
        introductionTranslations:
            introductionTranslations ?? this.introductionTranslations,
        introductionButtonTextstyles:
            introductionButtonTextstyles ?? this.introductionButtonTextstyles,
      );
}

class IntroductionTranslations {
  const IntroductionTranslations({
    this.skipButton = 'skip',
    this.nextButton = 'next',
    this.previousButton = 'previous',
    this.finishButton = 'finish',
  });
  final String skipButton;
  final String nextButton;
  final String previousButton;
  final String finishButton;
}

class IntroductionButtonTextstyles {
  const IntroductionButtonTextstyles({
    this.skipButtonStyle,
    this.nextButtonStyle,
    this.previousButtonStyle,
    this.finishButtonStyle,
  });
  final TextStyle? skipButtonStyle;
  final TextStyle? nextButtonStyle;
  final TextStyle? previousButtonStyle;
  final TextStyle? finishButtonStyle;
}