import 'package:auto_route/auto_route.dart';
import 'package:collection/collection.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_keyboard_size/flutter_keyboard_size.dart';
import 'package:remever/common/functions.dart';
import 'package:remever/common/resources.dart';
import 'package:remever/common/widgets/typography.dart';
import 'package:remever/common/widgets/wspace.dart';
import 'package:remever/components/extensions/context.dart';
import 'package:remever/gen/assets.gen.dart';
import 'package:remever/screens/dialogs/alert_dialog.dart';

@RoutePage()
class CrudCollectionFullscreenField extends StatefulWidget {
  const CrudCollectionFullscreenField({
    super.key,
    this.title = '',
    this.hint,
    this.content,
    this.height = 92,
    required this.onEditingComplete,
  });

  final String title;
  final double height;
  final String? hint;
  final String? content;
  final void Function(String?) onEditingComplete;

  @override
  State<CrudCollectionFullscreenField> createState() =>
      _CrudCollectionFullscreenFieldState();
}

class _CrudCollectionFullscreenFieldState
    extends State<CrudCollectionFullscreenField> {
  final TextEditingController _controller = TextEditingController();

  @override
  void initState() {
    super.initState();
    if (widget.content != null) {
      _controller.text = widget.content!;
    }

    _controller.addListener(_handleTextChange);
  }

  @override
  void dispose() {
    _controller.removeListener(_handleTextChange);
    _controller.dispose();
    super.dispose();
  }

  String? _lastText;

  void _handleTextChange() {
    final currentText = _controller.text;

    // Если текст не изменился — выходим
    if (_lastText == currentText) return;

    // Находим позицию курсора
    final selection = _controller.selection;
    if (!selection.isValid) return;

    // Проверяем, был ли добавлен \n
    if (_lastText != null && currentText.length > _lastText!.length) {
      final addedChars = currentText.substring(_lastText!.length);
      if (addedChars == '\n') {
        _handleNewLineInserted(selection.start - 1);
      }
    }

    _lastText = currentText;
  }

  void _handleNewLineInserted(int newlinePosition) {
    final text = _controller.text;

    // Находим начало текущей строки (до \n)
    final lineStart = text.lastIndexOf('\n', newlinePosition - 1) + 1;
    final currentLine = text.substring(lineStart, newlinePosition);

    String? prefix;

    // Проверяем, начинается ли строка с префикса списка
    if (currentLine.startsWith('• ')) {
      prefix = '• ';
    } else {
      final match = RegExp(r'^(\d+)\.\s').firstMatch(currentLine);
      if (match != null) {
        final number = int.parse(match.group(1)!) + 1;
        prefix = '$number. ';
      }
    }

    // Если строка пустая (только префикс) — выходим из списка
    if (currentLine.trim().isEmpty && prefix != null) {
      _exitListAt(newlinePosition);
      return;
    }

    // Если есть префикс — добавляем новую строку с префиксом
    if (prefix != null) {
      final insertPos = newlinePosition + 1;
      final newText =
          text.substring(0, insertPos) + prefix + text.substring(insertPos);
      _controller.text = newText;

      // Перемещаем курсор после префикса
      _controller.selection = TextSelection.collapsed(
        offset: insertPos + prefix.length,
      );
      return;
    }

    // Иначе — просто оставляем \n
    _controller.selection = TextSelection.collapsed(
      offset: newlinePosition + 1,
    );
  }

  void _exitListAt(int newlinePosition) {
    final text = _controller.text;
    final insertPos = newlinePosition + 1;

    // Удаляем префикс из новой строки
    final lineStart = text.lastIndexOf('\n', newlinePosition - 1) + 1;
    final currentLine = text.substring(lineStart, newlinePosition);
    final trimmed = currentLine.trim();

    String replacement = '\n';
    if (trimmed.startsWith('•') || RegExp(r'^\d+\.').hasMatch(trimmed)) {
      replacement = '\n'; // просто перенос
    }

    final newText =
        text.substring(0, insertPos) + replacement + text.substring(insertPos);
    _controller.text = newText;
    _controller.selection = TextSelection.collapsed(offset: insertPos);
  }

  @override
  Widget build(BuildContext context) {
    return KeyboardSizeProvider(
      child: SafeArea(
        top: false,
        child: Scaffold(
          backgroundColor: AppColors.gray_bg,
          appBar: _buildAppBar(),
          body: _buildMainBody(),
        ),
      ),
    );
  }

  Widget _buildMainBody() {
    return Stack(
      children: [
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 16).r,
          child: SingleChildScrollView(
            physics: const BouncingScrollPhysics(),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                const HSpace(16),
                _buildField(),
                if (widget.hint != null) ...[
                  const HSpace(16),
                  AppTypography(
                    widget.hint!,
                    type: Regular14px(),
                    color: AppColors.disabled,
                  ),
                ],
                const HSpace(50),
              ],
            ),
          ),
        ),
        Align(alignment: Alignment.bottomCenter, child: _buildMenu()),
      ],
    );
  }

  Widget _buildMenu() {
    return Consumer<ScreenHeight>(
      builder: (_, screenHeight, __) {
        return AnimatedOpacity(
          opacity: 1,
          duration: const Duration(milliseconds: 500),
          child: Container(
            height: 64.h,
            decoration: BoxDecoration(
              color: AppColors.white,
              border: Border(
                top: BorderSide(color: AppColors.gray, width: 1.w),
              ),
            ),
            child: SingleChildScrollView(
              scrollDirection: Axis.horizontal,
              child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: [
                  const WSpace(8),
                  _buildPasteButton(),
                  _buildCopyButton(),
                  _buildBoldButton(),
                  _buildH1Button(),
                  _buildBulletListButton(),
                  _buildNumberedListButton(),
                  _buildSubmitButton(),
                  const WSpace(8),
                ],
              ),
            ),
          ),
        );
      },
    );
  }

  Widget _buildBoldButton() {
    return _MenuButton(
      icon: Icon(Icons.format_bold),
      onTap: () => _wrapSelection('**', '**'),
    );
  }

  Widget _buildH1Button() {
    return _MenuButton(
      icon: Icon(Icons.format_italic_outlined),
      onTap: () => _insertAtLineStart('# '),
    );
  }

  Widget _buildBulletListButton() {
    return _MenuButton(
      icon: Icon(Icons.list),
      onTap: () => _insertBulletList(),
    );
  }

  Widget _buildNumberedListButton() {
    return _MenuButton(
      icon: Icon(Icons.list_alt_outlined),
      onTap: () => _insertNumberedList(),
    );
  }

  void _wrapSelection(String before, String after) {
    final text = _controller.text;
    final selection = _controller.selection;

    if (!selection.isValid) {
      _controller.text = '$before${selection.textInside(text)}$after';
      _controller.selection = TextSelection.collapsed(
        offset: _controller.text.length - after.length,
      );
      return;
    }

    final newText = text.replaceRange(
      selection.start,
      selection.end,
      '$before${selection.textInside(text)}$after',
    );
    _controller.text = newText;

    final cursorPos =
        selection.start + before.length + selection.textInside(text).length;
    _controller.selection = TextSelection.collapsed(offset: cursorPos);
  }

  void _insertAtLineStart(String prefix) {
    final text = _controller.text;
    final selection = _controller.selection;
    int start = selection.start;

    // Находим начало строки
    int lineStart = text.lastIndexOf('\n', start - 1) + 1;
    if (lineStart == 0 && start == 0) lineStart = 0;

    final newText = text.replaceRange(lineStart, lineStart, prefix);
    _controller.text = newText;

    _controller.selection = TextSelection.collapsed(
      offset: lineStart + prefix.length + (selection.end - selection.start),
    );
  }

  void _insertBulletList() {
    _insertListPrefix('• ');
  }

  void _insertNumberedList() {
    _insertListPrefix('1. ');
  }

  void _insertListPrefix(String prefix) {
    final text = _controller.text;
    final selection = _controller.selection;

    String insertText;
    int newCursorPos;

    if (selection.isCollapsed) {
      // Вставляем в позицию курсора
      insertText = prefix;
      newCursorPos = selection.start + prefix.length;
    } else {
      // Оборачиваем выделение
      final selected = selection.textInside(text);
      final lines = selected.split('\n').where((l) => l.isNotEmpty).toList();

      final prefixed = lines
          .mapIndexed((index, line) {
            if (prefix == '• ') return '$prefix$line';
            final num = index + 1;
            return '$num. $line';
          })
          .join('\n');
      insertText = prefixed;
      newCursorPos = selection.start + prefixed.length;
    }

    final newText = text.replaceRange(
      selection.start,
      selection.end,
      insertText,
    );
    _controller.text = newText;
    _controller.selection = TextSelection.collapsed(offset: newCursorPos);
  }

  Widget _buildPasteButton() {
    return GestureDetector(
      onTap: _onPasteTap,
      child: Assets.icons.typePaste.image(height: 24.h, width: 24.w),
    );
  }

  Future<void> _onPasteTap() async {
    try {
      final data = await Clipboard.getData(Clipboard.kTextPlain);
      if (data?.text?.isEmpty ?? true) {
        showErrorToast('Не удалось получить текст из буфера обмена');
        return;
      }
      _controller.text += ' ${data!.text}';
      showSuccessToast('Текст вставлен из буфера обмена');
    } catch (e) {
      showErrorToast('Ошибка при вставке текста: $e');
    }
  }

  Widget _buildCopyButton() {
    return GestureDetector(
      onTap: _onCopyTap,
      child: Assets.icons.typeCopy.image(height: 24.h, width: 24.w),
    );
  }

  Future<void> _onCopyTap() async {
    if (_controller.text.isEmpty) {
      showErrorToast('Нет содержимого для отправки в буфер обмена');
      return;
    }
    try {
      await Clipboard.setData(ClipboardData(text: _controller.text));
      showSuccessToast('Текст скопирован в буфер обмена');
    } catch (e) {
      showErrorToast('Ошибка при копировании текста: $e');
    }
  }

  Widget _buildSubmitButton() {
    return GestureDetector(
      onTap: _onSubmitTap,
      child: SizedBox.square(
        dimension: 32.r,
        child: const DecoratedBox(
          decoration: BoxDecoration(
            shape: BoxShape.circle,
            color: AppColors.primary,
          ),
          child: Center(
            child: Icon(Icons.check, color: AppColors.white, size: 24),
          ),
        ),
      ),
    );
  }

  void _onSubmitTap() {
    widget.onEditingComplete(_controller.text);

    context.back();
  }

  Widget _buildField() {
    return SizedBox(
      height: widget.height.h,
      child: DecoratedBox(
        decoration: BoxDecoration(
          color: AppColors.white,
          borderRadius: BorderRadius.circular(12).r,
        ),
        child: Padding(
          padding: const EdgeInsets.all(12).r,
          child: TextField(
            autofocus: true,
            controller: _controller,
            textCapitalization: TextCapitalization.sentences,
            maxLines: 99,
            maxLength: 250,
            cursorColor: AppColors.danger,
            textInputAction: TextInputAction.newline,
            decoration: const InputDecoration.collapsed(
              hintText: 'Введите содержимое',
              hintStyle: TextStyle(color: AppColors.gray),
            ),
          ),
        ),
      ),
    );
  }

  AppBar _buildAppBar() {
    return AppBar(
      toolbarHeight: 56.h,
      backgroundColor: AppColors.white,
      shadowColor: Colors.transparent,
      leading: IconButton(
        onPressed: () => _handleBackPress(),
        icon: const Icon(CupertinoIcons.left_chevron, color: Colors.black),
      ),
      centerTitle: true,
      title: AppTypography(
        widget.title,
        type: SemiBold20px(),
        color: AppColors.body_text,
      ),
      actions: [
        Padding(
          padding: const EdgeInsets.only(right: 16).r,
          child: GestureDetector(
            onTap: _showResetDialog,
            child: Assets.icons.typeTrash.image(
              height: 24.h,
              width: 24.w,
              color: AppColors.danger,
            ),
          ),
        ),
      ],
    );
  }

  Future<void> _handleBackPress() async {
    final shouldExit = await _showExitDialog();
    if (shouldExit ?? false) {
      context.back();
    }
  }

  Future<bool?> _showExitDialog() async {
    final res = await showCuperModalBottomSheet<bool>(
      context: context,
      height: 262.h,
      builder:
          (_) => const AlertInfoDialog(
            title: 'У вас есть несохраненные изменения',
            acceptTitle: 'Выйти',
            declineTitle: 'Сохранить и выйти',
          ),
    );

    if (res == null) return false;
    if (res) return true;

    widget.onEditingComplete(_controller.text);
    return true;
  }

  Future<void> _showResetDialog() async {
    final res = await showCuperModalBottomSheet<bool>(
      context: context,
      height: 262.h,
      builder:
          (_) => AlertInfoDialog(
            title: 'Удалить вcе содержимое поля "${widget.title}"?',
            acceptTitle: 'Удалить',
            declineTitle: 'Отменить',
          ),
    );

    if (res == true) {
      _controller.clear();
    }
  }
}

class _MenuButton extends StatelessWidget {
  final Widget icon;
  final VoidCallback onTap;

  const _MenuButton({required this.icon, required this.onTap});

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: Container(padding: const EdgeInsets.all(8).r, child: icon),
    );
  }
}