import 'dart:math' as math;

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

import 'package:notas/models/note.dart';

// NoteEditorScreen: unified UI for creating and editing notes.
// - Use `NoteEditorScreen.showDialog(context, note: existing)` to edit.
// - Use `NoteEditorScreen.showDialog(context)` to create a new note.
// The screen returns either a `Note` (saved) or the string `'delete'` when
// the user confirmed deletion. `null` indicates the user closed without saving.

class NoteEditorScreen extends StatefulWidget {
  const NoteEditorScreen({super.key, required this.note});

  final Note? note;

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

  static Future<dynamic> showDialog(BuildContext context, {Note? note}) {
    return showGeneralDialog<dynamic>(
      context: context,
      barrierDismissible: false,
      barrierColor: Colors.transparent,
      transitionDuration: const Duration(milliseconds: 200),
      pageBuilder: (context, animation, secondaryAnimation) {
        return NoteEditorScreen(note: note);
      },
      transitionBuilder: (context, animation, secondaryAnimation, child) {
        return ScaleTransition(scale: animation, child: child);
      },
    );
  }
}

class _NoteEditorScreenState extends State<NoteEditorScreen> {
  late TextEditingController _titleController;
  late TextEditingController _bodyController;
  late Note _currentNote;
  late bool _isNewNote;

  @override
  void initState() {
    super.initState();
    _isNewNote = widget.note?.id == null;

    if (_isNewNote) {
      final DateTime now = DateTime.now();
      _currentNote = Note(
        title: '',
        body: '',
        createdAt: now,
        updatedAt: now,
        index: 0,
      );
    } else {
      _currentNote = widget.note!;
    }

    _titleController = TextEditingController(text: _currentNote.title);
    _bodyController = TextEditingController(text: _currentNote.body);
  }

  @override
  void dispose() {
    _titleController.dispose();
    _bodyController.dispose();
    super.dispose();
  }

  void _closeWithoutSaving() {
    Navigator.of(context).pop();
  }

  void _saveNote() {
    final String title = _titleController.text.trim();
    final String body = _bodyController.text.trim();

    if (title.isEmpty && body.isEmpty) {
      Navigator.of(context).pop();
      return;
    }

    final Note updatedNote = _currentNote.copyWith(
      title: title.isEmpty ? 'Sin título' : title,
      body: body,
      updatedAt: DateTime.now(),
    );

    Navigator.of(context).pop(updatedNote);
  }

  void _deleteNote() {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          backgroundColor: const Color(0xFF303134),
          title: const Text(
            'Eliminar nota',
            style: TextStyle(color: Colors.white),
          ),
          content: const Text(
            '¿Estás seguro de que deseas eliminar esta nota?',
            style: TextStyle(color: Colors.white70),
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.of(context).pop(),
              child: const Text(
                'Cancelar',
                style: TextStyle(color: Colors.white70),
              ),
            ),
            TextButton(
              onPressed: () {
                Navigator.of(context).pop();
                Navigator.of(context).pop('delete');
              },
              child: const Text(
                'Eliminar',
                style: TextStyle(color: Colors.red),
              ),
            ),
          ],
        );
      },
    );
  }

  String _formatDate(DateTime date) {
    final DateTime now = DateTime.now();
    final DateTime today = DateTime(now.year, now.month, now.day);
    final DateTime yesterday = today.subtract(const Duration(days: 1));
    final DateTime noteDate = DateTime(date.year, date.month, date.day);

    if (noteDate == today) {
      return 'Hoy ${DateFormat('HH:mm').format(date)}';
    } else if (noteDate == yesterday) {
      return 'Ayer ${DateFormat('HH:mm').format(date)}';
    } else {
      return DateFormat('dd/MM/yyyy HH:mm').format(date);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Material(
      color: Colors.transparent,
      child: LayoutBuilder(
        builder: (BuildContext context, BoxConstraints constraints) {
          final double maxWidth = math.min(600, constraints.maxWidth - 48);
          final double maxHeight = math.min(constraints.maxHeight * 0.88, 720);
          final double overlayTop = MediaQuery.paddingOf(context).top + 32;

          return Stack(
            children: [
              Positioned.fill(
                top: overlayTop,
                child: Container(
                  color: const Color.fromARGB(127, 0, 0, 0).withValues(alpha: 0.5),
                ),
              ),
              SafeArea(
                child: Center(
                  child: Padding(
                    padding: EdgeInsets.only(top: overlayTop),
                    child: ConstrainedBox(
                      constraints: BoxConstraints(
                        maxWidth: maxWidth,
                        maxHeight: maxHeight,
                      ),
                      child: Container(
                        decoration: BoxDecoration(
                          color: const Color.fromRGBO(24, 25, 26, 1),
                          borderRadius: BorderRadius.circular(16),
                          border: Border.all(color: Colors.white24, width: 1),
                          boxShadow: [
                            BoxShadow(
                              color: Colors.black.withValues(alpha: 0.5),
                              blurRadius: 24,
                              offset: const Offset(0, 8),
                            ),
                          ],
                        ),
                        child: Column(
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            Container(
                              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
                              decoration: BoxDecoration(
                                border: Border(
                                  bottom: BorderSide(color: Colors.white12, width: 1),
                                ),
                              ),
                              child: Row(
                                children: [
                                  IconButton(
                                    onPressed: _closeWithoutSaving,
                                    icon: const Icon(Icons.close, color: Colors.white70),
                                    tooltip: 'Cerrar sin guardar',
                                  ),
                                  const SizedBox(width: 8),
                                  Expanded(
                                    child: Column(
                                      crossAxisAlignment: CrossAxisAlignment.start,
                                      mainAxisSize: MainAxisSize.min,
                                      children: [
                                        Text(
                                          'Creado: ${_formatDate(_currentNote.createdAt)}',
                                          style: const TextStyle(color: Colors.white54, fontSize: 12),
                                        ),
                                        if (_currentNote.updatedAt != _currentNote.createdAt)
                                          Text(
                                            'Modificado: ${_formatDate(_currentNote.updatedAt)}',
                                            style: const TextStyle(color: Colors.white54, fontSize: 12),
                                          ),
                                      ],
                                    ),
                                  ),
                                ],
                              ),
                            ),
                            Expanded(
                              child: SingleChildScrollView(
                                child: Padding(
                                  padding: const EdgeInsets.all(20),
                                  child: Column(
                                    crossAxisAlignment: CrossAxisAlignment.start,
                                    children: [
                                      TextField(
                                        controller: _titleController,
                                        style: const TextStyle(
                                          color: Colors.white,
                                          fontSize: 28,
                                          fontWeight: FontWeight.bold,
                                        ),
                                        decoration: const InputDecoration(
                                          hintText: 'Título',
                                          hintStyle: TextStyle(color: Colors.white30),
                                          border: InputBorder.none,
                                          contentPadding: EdgeInsets.zero,
                                        ),
                                      ),
                                      const SizedBox(height: 16),
                                      TextField(
                                        controller: _bodyController,
                                        maxLines: null,
                                        style: const TextStyle(
                                          color: Colors.white,
                                          fontSize: 16,
                                          height: 1.6,
                                        ),
                                        decoration: const InputDecoration(
                                          hintText: 'Escribe tu nota...',
                                          hintStyle: TextStyle(color: Colors.white30),
                                          border: InputBorder.none,
                                          contentPadding: EdgeInsets.zero,
                                        ),
                                      ),
                                    ],
                                  ),
                                ),
                              ),
                            ),
                            Container(
                              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
                              decoration: BoxDecoration(
                                border: Border(
                                  top: BorderSide(color: Colors.white12, width: 1),
                                ),
                              ),
                              child: Row(
                                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                children: [
                                  if (!_isNewNote)
                                    IconButton(
                                      onPressed: _deleteNote,
                                      icon: const Icon(Icons.delete_outline, color: Colors.red),
                                      tooltip: 'Eliminar nota',
                                    )
                                  else
                                    const SizedBox(width: 48),
                                  FilledButton(
                                    onPressed: _saveNote,
                                    child: const Text('Guardar'),
                                  ),
                                ],
                              ),
                            ),
                          ],
                        ),
                      ),
                    ),
                  ),
                ),
              ),
            ],
          );
        },
      ),
    );
  }
}