/*
 * Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import 'package:meta/meta.dart';

import 'basic.dart';
import 'font.dart';
import 'icon.dart';
import 'text.dart';
import 'text_style.dart';
import 'widget.dart';

@immutable
class ThemeData extends Inherited {
  factory ThemeData({
    TextStyle? defaultTextStyle,
    TextStyle? paragraphStyle,
    TextStyle? header0,
    TextStyle? header1,
    TextStyle? header2,
    TextStyle? header3,
    TextStyle? header4,
    TextStyle? header5,
    TextStyle? bulletStyle,
    TextStyle? tableHeader,
    TextStyle? tableCell,
    bool? softWrap,
    TextAlign? textAlign,
    TextOverflow? overflow,
    int? maxLines,
    IconThemeData? iconTheme,
  }) {
    final base = ThemeData.base();
    return base.copyWith(
      defaultTextStyle: defaultTextStyle,
      paragraphStyle: paragraphStyle,
      bulletStyle: bulletStyle,
      header0: header0,
      header1: header1,
      header2: header2,
      header3: header3,
      header4: header4,
      header5: header5,
      tableHeader: tableHeader,
      tableCell: tableCell,
      softWrap: softWrap,
      overflow: overflow,
      textAlign: textAlign,
      maxLines: maxLines,
      iconTheme: iconTheme,
    );
  }

  ThemeData._({
    required this.defaultTextStyle,
    required this.paragraphStyle,
    required this.header0,
    required this.header1,
    required this.header2,
    required this.header3,
    required this.header4,
    required this.header5,
    required this.bulletStyle,
    required this.tableHeader,
    required this.tableCell,
    required this.softWrap,
    required this.overflow,
    required this.textAlign,
    required this.iconTheme,
    this.maxLines,
  })  : assert(defaultTextStyle.inherit == false),
        assert(paragraphStyle.inherit == false),
        assert(header0.inherit == false),
        assert(header1.inherit == false),
        assert(header2.inherit == false),
        assert(header3.inherit == false),
        assert(header4.inherit == false),
        assert(header5.inherit == false),
        assert(bulletStyle.inherit == false),
        assert(tableHeader.inherit == false),
        assert(tableCell.inherit == false),
        assert(maxLines == null || maxLines > 0);

  factory ThemeData.withFont({
    Font? base,
    Font? bold,
    Font? italic,
    Font? boldItalic,
    Font? icons,
  }) {
    final defaultStyle = TextStyle.defaultStyle().copyWith(
      font: base,
      fontNormal: base,
      fontBold: bold,
      fontItalic: italic,
      fontBoldItalic: boldItalic,
    );
    final fontSize = defaultStyle.fontSize!;

    return ThemeData._(
      defaultTextStyle: defaultStyle,
      paragraphStyle: defaultStyle.copyWith(lineSpacing: 5),
      bulletStyle: defaultStyle.copyWith(lineSpacing: 5),
      header0: defaultStyle.copyWith(fontSize: fontSize * 2.0),
      header1: defaultStyle.copyWith(fontSize: fontSize * 1.5),
      header2: defaultStyle.copyWith(fontSize: fontSize * 1.4),
      header3: defaultStyle.copyWith(fontSize: fontSize * 1.3),
      header4: defaultStyle.copyWith(fontSize: fontSize * 1.2),
      header5: defaultStyle.copyWith(fontSize: fontSize * 1.1),
      tableHeader: defaultStyle.copyWith(
          fontSize: fontSize * 0.8, fontWeight: FontWeight.bold),
      tableCell: defaultStyle.copyWith(fontSize: fontSize * 0.8),
      softWrap: true,
      overflow: TextOverflow.visible,
      textAlign: TextAlign.left,
      iconTheme: IconThemeData.fallback(icons),
    );
  }

  factory ThemeData.base() => ThemeData.withFont();

  ThemeData copyWith({
    TextStyle? defaultTextStyle,
    TextStyle? paragraphStyle,
    TextStyle? header0,
    TextStyle? header1,
    TextStyle? header2,
    TextStyle? header3,
    TextStyle? header4,
    TextStyle? header5,
    TextStyle? bulletStyle,
    TextStyle? tableHeader,
    TextStyle? tableCell,
    bool? softWrap,
    TextAlign? textAlign,
    int? maxLines,
    TextOverflow? overflow,
    IconThemeData? iconTheme,
  }) =>
      ThemeData._(
        defaultTextStyle: this.defaultTextStyle.merge(defaultTextStyle),
        paragraphStyle: this.paragraphStyle.merge(paragraphStyle),
        bulletStyle: this.bulletStyle.merge(bulletStyle),
        header0: this.header0.merge(header0),
        header1: this.header1.merge(header1),
        header2: this.header2.merge(header2),
        header3: this.header3.merge(header3),
        header4: this.header4.merge(header4),
        header5: this.header5.merge(header5),
        tableHeader: this.tableHeader.merge(tableHeader),
        tableCell: this.tableCell.merge(tableCell),
        softWrap: softWrap ?? this.softWrap,
        overflow: overflow ?? this.overflow,
        textAlign: textAlign ?? this.textAlign,
        maxLines: maxLines ?? this.maxLines,
        iconTheme: iconTheme ?? this.iconTheme,
      );

  final TextStyle defaultTextStyle;

  final TextStyle paragraphStyle;

  final TextStyle header0;
  final TextStyle header1;
  final TextStyle header2;
  final TextStyle header3;
  final TextStyle header4;
  final TextStyle header5;

  final TextStyle bulletStyle;

  final TextStyle tableHeader;

  final TextStyle tableCell;

  final TextAlign textAlign;
  final bool softWrap;
  final int? maxLines;
  final TextOverflow overflow;

  final IconThemeData iconTheme;
}

class Theme extends StatelessWidget {
  Theme({
    required this.data,
    required this.child,
  });

  final ThemeData data;

  final Widget child;

  static ThemeData of(Context context) {
    return context.dependsOn<ThemeData>()!;
  }

  @override
  Widget build(Context context) {
    return InheritedWidget(
      inherited: data,
      build: (Context context) => child,
    );
  }
}

class DefaultTextStyle extends StatelessWidget implements Inherited {
  DefaultTextStyle({
    required this.style,
    required this.child,
    this.textAlign,
    this.softWrap = true,
    this.overflow,
    this.maxLines,
  }) : assert(maxLines == null || maxLines > 0);

  static Widget merge({
    TextStyle? style,
    TextAlign? textAlign,
    bool? softWrap,
    int? maxLines,
    TextOverflow? overflow,
    required Widget child,
  }) {
    return Builder(
      builder: (Context context) {
        final parent = Theme.of(context);

        return DefaultTextStyle(
          style: parent.defaultTextStyle.merge(style),
          textAlign: textAlign ?? parent.textAlign,
          softWrap: softWrap ?? parent.softWrap,
          overflow: overflow ?? parent.overflow,
          maxLines: maxLines ?? parent.maxLines,
          child: child,
        );
      },
    );
  }

  final TextStyle style;

  final Widget child;

  final TextAlign? textAlign;

  final bool softWrap;

  final int? maxLines;

  final TextOverflow? overflow;

  @override
  Widget build(Context context) {
    final theme = Theme.of(context).copyWith(
      defaultTextStyle: style,
      textAlign: textAlign,
      softWrap: softWrap,
      overflow: overflow,
      maxLines: maxLines,
    );

    return InheritedWidget(
      inherited: theme,
      build: (Context context) => child,
    );
  }
}