import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_quill/flutter_quill.dart';

import 'package:notas/data/note_body.dart';
import 'package:notas/data/note_repository.dart';
import 'package:notas/models/note.dart';
import 'package:notas/theme/app_palette.dart';

class NoteEditorScreen extends StatefulWidget {
  const NoteEditorScreen({
    super.key,
    this.repository,
    this.saveNote,
    required this.note,
    this.embedded = false,
    this.onSaved,
  });

  final NoteRepository? repository;
  final Future<Note> Function(Note note)? saveNote;
  final Note note;
  final bool embedded;
  final ValueChanged<Note>? onSaved;

  @override
  State<NoteEditorScreen> createState() => _NoteEditorScreenState();
}

class _NoteEditorScreenState extends State<NoteEditorScreen> {
  static const Duration _debounceDuration = Duration(seconds: 1);

  late final TextEditingController _titleController;
  late final QuillController _bodyController;
  late final FocusNode _bodyFocusNode;
  late final ScrollController _bodyScrollController;

  Timer? _debounceTimer;
  bool _isSaving = false;
  bool _saveQueued = false;
  late Note _baselineNote;

  AppPalette _paletteOf(BuildContext context) {
    return Theme.of(context).extension<AppPalette>() ??
        AppPalette.fromBrightness(Theme.of(context).brightness);
  }

  @override
  void initState() {
    super.initState();
    _baselineNote = widget.note;
    _titleController = TextEditingController(text: widget.note.title)
      ..addListener(_scheduleSave);
    _bodyController = QuillController(
      document: noteBodyToDocument(widget.note.body),
      selection: const TextSelection.collapsed(offset: 0),
    )..addListener(_scheduleSave);
    _bodyFocusNode = FocusNode();
    _bodyScrollController = ScrollController();
  }

  @override
  void dispose() {
    _debounceTimer?.cancel();
    _titleController.dispose();
    _bodyController.dispose();
    _bodyFocusNode.dispose();
    _bodyScrollController.dispose();
    super.dispose();
  }

  String _bodyAsJson() {
    return noteDocumentToStorageJson(_bodyController.document);
  }

  void _scheduleSave() {
    _debounceTimer?.cancel();
    _debounceTimer = Timer(_debounceDuration, () {
      unawaited(_saveNow());
    });
  }

  Future<void> _saveNow() async {
    if (!mounted) {
      return;
    }

    final String title = _titleController.text.trim();
    final String body = _bodyAsJson();
    final Note draft = _baselineNote.copyWith(
      title: title.isEmpty ? 'Sin título' : title,
      body: body,
      categoryId: _baselineNote.categoryId,
      updatedAt: DateTime.now(),
      isDirty: true,
    );

    final bool hasChanges =
        draft.title != _baselineNote.title ||
        draft.body != _baselineNote.body ||
        draft.categoryId != _baselineNote.categoryId;

    if (!hasChanges) {
      return;
    }

    if (_isSaving) {
      _saveQueued = true;
      return;
    }

    _isSaving = true;
    try {
      final Note saved = widget.saveNote != null
          ? await widget.saveNote!(draft)
          : await widget.repository!.updateNote(draft);
      _baselineNote = saved;
      widget.onSaved?.call(saved);
    } catch (error) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('No se pudo guardar la nota: $error')),
        );
      }
    } finally {
      _isSaving = false;
      if (_saveQueued) {
        _saveQueued = false;
        unawaited(_saveNow());
      }
    }
  }

  Widget _buildEditorBody() {
    final AppPalette palette = _paletteOf(context);

    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        Row(
          children: [
            Expanded(
              child: Padding(
                padding: const EdgeInsets.only(left: 8),
                child: TextField(
                  controller: _titleController,
                  style: TextStyle(
                    color: palette.textPrimary,
                    fontSize: 26,
                    fontWeight: FontWeight.w700,
                  ),
                  decoration: InputDecoration(
                    hintText: 'Título',
                    hintStyle: TextStyle(color: palette.textHint),
                    border: InputBorder.none,
                  ),
                ),
              ),
            ),
          ],
        ),
        const SizedBox(height: 10),
        Expanded(
          child: Container(
            padding: const EdgeInsets.all(8),
            child: QuillEditor.basic(
              controller: _bodyController,
              focusNode: _bodyFocusNode,
              scrollController: _bodyScrollController,
              config: QuillEditorConfig(
                scrollable: true,
                padding: EdgeInsets.zero,
                autoFocus: false,
                expands: true,
                placeholder: 'Escribe tu nota...',
                keyboardAppearance: Theme.of(context).brightness,
              ),
            ),
          ),
        ),
        const SizedBox(height: 8),
        QuillSimpleToolbar(
          controller: _bodyController,
          config: const QuillSimpleToolbarConfig(
            color: Colors.transparent,
            showBoldButton: true,
            showItalicButton: true,
            showUnderLineButton: true,
            showStrikeThrough: false,
            showInlineCode: false,
            showColorButton: false,
            showBackgroundColorButton: false,
            showClearFormat: false,
            showAlignmentButtons: false,
            showHeaderStyle: false,
            showListNumbers: true,
            showListBullets: true,
            showListCheck: true,
            showCodeBlock: false,
            showQuote: false,
            showIndent: false,
            showLink: false,
            showUndo: false,
            showRedo: false,
            showDividers: false,
            showFontFamily: false,
            showFontSize: false,
            showDirection: false,
            showSearchButton: false,
            showSubscript: false,
            showSuperscript: false,
            multiRowsDisplay: false,
            axis: Axis.horizontal,
          ),
        ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    final AppPalette palette = _paletteOf(context);

    final Widget editor = Padding(
      padding: const EdgeInsets.all(8),
      child: _buildEditorBody(),
    );

    if (widget.embedded) {
      return editor;
    }

    return Scaffold(
      backgroundColor: palette.cardBackground,
      appBar: AppBar(title: const Text('Editar nota')),
      body: SafeArea(child: editor),
    );
  }
}