import 'dart:io';

import 'package:aves/utils/android_file_utils.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:path/path.dart';

class CreateAlbumDialog extends StatefulWidget {
  @override
  _CreateAlbumDialogState createState() => _CreateAlbumDialogState();
}

class _CreateAlbumDialogState extends State<CreateAlbumDialog> {
  final TextEditingController _nameController = TextEditingController();
  final ValueNotifier<bool> _existsNotifier = ValueNotifier(false);
  Set<StorageVolume> _allVolumes;
  StorageVolume _primaryVolume, _selectedVolume;

  @override
  void initState() {
    super.initState();
    _allVolumes = androidFileUtils.storageVolumes;
    _primaryVolume = _allVolumes.firstWhere((volume) => volume.isPrimary, orElse: () => _allVolumes.first);
    _selectedVolume = _primaryVolume;
    _initAlbumName();
  }

  @override
  void dispose() {
    _nameController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text('New Album'),
      content: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          if (_allVolumes.length > 1) ...[
            Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Text('Storage:'),
                SizedBox(width: 8),
                Expanded(
                  child: DropdownButton<StorageVolume>(
                    isExpanded: true,
                    items: _allVolumes
                        .map((volume) => DropdownMenuItem(
                              value: volume,
                              child: Text(
                                volume.description,
                                softWrap: false,
                                overflow: TextOverflow.fade,
                                maxLines: 1,
                              ),
                            ))
                        .toList(),
                    value: _selectedVolume,
                    onChanged: (volume) {
                      _selectedVolume = volume;
                      _checkAlbumExists();
                      setState(() {});
                    },
                  ),
                ),
              ],
            ),
            SizedBox(height: 16),
          ],
          ValueListenableBuilder<bool>(
              valueListenable: _existsNotifier,
              builder: (context, exists, child) {
                return TextField(
                  controller: _nameController,
                  decoration: InputDecoration(
                    helperText: exists ? 'Album already exists' : '',
                  ),
                  onChanged: (_) => _checkAlbumExists(),
                  onSubmitted: (_) => _submit(context),
                );
              }),
        ],
      ),
      contentPadding: EdgeInsets.fromLTRB(24, 20, 24, 0),
      actions: [
        FlatButton(
          onPressed: () => Navigator.pop(context),
          child: Text('Cancel'.toUpperCase()),
        ),
        FlatButton(
          onPressed: () => _submit(context),
          child: Text('Create'.toUpperCase()),
        ),
      ],
    );
  }

  String _buildAlbumPath(String name) {
    if (name == null || name.isEmpty) return '';
    return join(_selectedVolume.path, 'Pictures', name);
  }

  Future<void> _initAlbumName() async {
    var count = 1;
    while (true) {
      var name = 'Album $count';
      if (!await Directory(_buildAlbumPath(name)).exists()) {
        _nameController.text = name;
        return;
      }
      count++;
    }
  }

  Future<void> _checkAlbumExists() async {
    final path = _buildAlbumPath(_nameController.text);
    _existsNotifier.value = path.isEmpty ? false : await Directory(path).exists();
  }

  void _submit(BuildContext context) => Navigator.pop(context, _buildAlbumPath(_nameController.text));
}