yokutango-mobile-reader/lib/components/flashcard.dart

import 'dart:math';

import 'package:tangocard_reader/models/yokutango_entry.dart';
import 'package:flutter/material.dart';

class Flashcard extends StatelessWidget {
  final YokutangoEntry? card;
  final int? cardIndex;
  final bool isLeftSide;
  final bool languageFlipped;
  final int amountOfCardsOnStack;
  final double rotationAmount;

  const Flashcard({
    this.card,
    this.cardIndex,
    this.isLeftSide = false,
    this.languageFlipped = false,
    this.amountOfCardsOnStack = 10,
    this.rotationAmount = pi / 18,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final stackItems = <Widget>[];
    final rng = Random();

    for (int i = 0; i < amountOfCardsOnStack; i++) {
      stackItems.add(
        makeBlankCard(
          offset: (isLeftSide ? -1 : 1) * (amountOfCardsOnStack - i) * 2,
          rotationOrigin: isLeftSide ? 0.9 : 0.1,
          angle: rng.nextDouble() * rotationAmount - rotationAmount / 2,
        ),
      );
    }

    Widget? content;
    if (card != null) {
      if (isLeftSide && !languageFlipped || !isLeftSide && languageFlipped) {
        content = _NorwegianContent(card: card!);
      } else {
        content = _JapaneseContent(card: card!);
      }
    }

    stackItems.add(_FlashCardPaper(
      child: content,
      cardIndex: cardIndex,
    ));

    return Center(
      child: SizedBox(
        width: MediaQuery.of(context).size.width / 2 - 60,
        child: Stack(
          children: stackItems,
        ),
      ),
    );
  }

  Widget makeBlankCard({
    required double offset,
    required double rotationOrigin,
    required double angle,
  }) =>
      Transform.translate(
        offset: Offset(
          offset,
          0,
        ),
        child: Transform.rotate(
            angle: angle,
            alignment: FractionalOffset(
              rotationOrigin,
              0.5,
            ),
            child: const _FlashCardPaper()),
      );
}

class _FlashCardPaper extends StatelessWidget {
  final Widget? child;
  final int? cardIndex;

  const _FlashCardPaper({
    this.child,
    this.cardIndex,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    Widget? content;

    if (child != null) {
      content = Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Expanded(child: Container()),
          child!,
          Expanded(
            child: Row(
              crossAxisAlignment: CrossAxisAlignment.end,
              children: [
                Text((cardIndex != null) ? (cardIndex! + 1).toString() : "?")
              ],
            ),
          ),
        ],
      );
    }

    return AspectRatio(
      aspectRatio: 5 / 2,
      child: Container(
        padding: const EdgeInsets.all(10),
        decoration: BoxDecoration(
          color: Colors.white,
          border: Border.all(),
        ),
        child: content,
      ),
    );
  }
}

class _NorwegianContent extends StatelessWidget {
  final YokutangoEntry card;

  const _NorwegianContent({
    required this.card,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Expanded(
      child: FittedBox(
        fit: BoxFit.fitHeight,
        child: DefaultTextStyle.merge(
          style: const TextStyle(fontFamily: 'Heart Warming'),
          child: Column(
            children: card.norwegian.map((n) {
              final text = (n.hints == null)
                  ? n.word
                  : "${n.word} (${n.hints?.join(', ')})";
              return Text(text);
            }).toList(),
          ),
        ),
      ),
    );
  }
}

class _JapaneseContent extends StatelessWidget {
  final YokutangoEntry card;

  const _JapaneseContent({
    required this.card,
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Expanded(
      flex: 3,
      child: FittedBox(
        fit: BoxFit.fitHeight,
        child: DefaultTextStyle.merge(
          style: const TextStyle(fontFamily: 'K Gothic'),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: card.japanese
                .map((e) => Column(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: [
                          Text(e.word),
                          const Divider(),
                          Text(e.romaji ?? ""),
                        ]))
                .toList(),
          ),
        ),
      ),
    );
  }
}