invoice/lib/data/file_storage.dart

104 lines
2.4 KiB
Dart

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'package:archive/archive.dart';
import 'package:flutter/foundation.dart';
import 'package:shared_preferences/shared_preferences.dart';
class FileStorage {
const FileStorage(
this.tag,
this.getDirectory,
);
static const GZIP_TAG = '_gzip';
final String tag;
final Future<Directory> Function() getDirectory;
Future<File> _getLocalFile() async {
final dir = await getDirectory();
return File('${dir.path}/invoiceninja__$tag.json');
}
Future<dynamic> load() async {
if (kIsWeb) {
final prefs = await SharedPreferences.getInstance();
String value = prefs.getString(tag);
if (value != null) {
return value;
}
value = prefs.getString(tag + GZIP_TAG);
if (value != null) {
final decoded = base64Decode(value);
final unzipped = GZipDecoder().decodeBytes(decoded);
return utf8.decode(unzipped);
}
return null;
} else {
final file = await _getLocalFile();
final contents = await file.readAsString();
return contents;
}
}
Future<File> save(String data) async {
if (kIsWeb) {
final prefs = await SharedPreferences.getInstance();
try {
await prefs.setString(tag, data);
} catch (e) {
if ('$e'.contains('QuotaExceededError')) {
await prefs.remove(tag);
final gzipBytes = GZipEncoder().encode(utf8.encode(data));
final zipped = base64Encode(gzipBytes);
try {
await prefs.setString(tag + GZIP_TAG, zipped);
} catch (e) {
if ('$e'.contains('QuotaExceededError')) {
await prefs.remove(tag + GZIP_TAG);
}
}
}
}
return null;
} else {
final file = await _getLocalFile();
return file.writeAsString(data);
}
}
Future<FileSystemEntity> delete() async {
if (kIsWeb) {
final prefs = await SharedPreferences.getInstance();
prefs.remove(tag);
prefs.remove(tag + GZIP_TAG);
return null;
} else {
final file = await _getLocalFile();
return file.delete();
}
}
Future<bool> exists() async {
if (kIsWeb) {
final prefs = await SharedPreferences.getInstance();
return prefs.containsKey(tag) || prefs.containsKey(tag + GZIP_TAG);
} else {
final file = await _getLocalFile();
return file.existsSync();
}
}
}