import 'dart:io';
import 'dart:isolate';
import 'package:famedlysdk/famedlysdk.dart';
import 'package:sqflite/sqflite.dart' show getDatabasesPath;
import 'package:path/path.dart' as p;
import 'package:flutter/material.dart';
import 'package:moor/moor.dart';
import 'package:moor/isolate.dart';
import 'cipher_db.dart' as cipher;

class DatabaseNoTransactions extends Database {
  DatabaseNoTransactions.connect(DatabaseConnection connection)
      : super.connect(connection);

  // moor transactions are sometimes rather weird and freeze. Until there is a
  // proper fix in moor we override that there aren't actually using transactions
  @override
  Future<T> transaction<T>(Future<T> Function() action) async {
    return action();
  }
}

bool _inited = false;

// see https://moor.simonbinder.eu/docs/advanced-features/isolates/
void _startBackground(_IsolateStartRequest request) {
  // this is the entry point from the background isolate! Let's create
  // the database from the path we received

  if (!_inited) {
    cipher.init();
    _inited = true;
  }
  final executor = cipher.VmDatabaseEncrypted(File(request.targetPath),
      password: request.password, logStatements: request.logStatements);
  // we're using MoorIsolate.inCurrent here as this method already runs on a
  // background isolate. If we used MoorIsolate.spawn, a third isolate would be
  // started which is not what we want!
  final moorIsolate = MoorIsolate.inCurrent(
    () => DatabaseConnection.fromExecutor(executor),
  );
  // inform the starting isolate about this, so that it can call .connect()
  request.sendMoorIsolate.send(moorIsolate);
}

// used to bundle the SendPort and the target path, since isolate entry point
// functions can only take one parameter.
class _IsolateStartRequest {
  final SendPort sendMoorIsolate;
  final String targetPath;
  final String password;
  final bool logStatements;

  _IsolateStartRequest(
      this.sendMoorIsolate, this.targetPath, this.password, this.logStatements);
}

Future<Database> constructDb(
    {bool logStatements = false,
    String filename = 'database.sqlite',
    String password = ''}) async {
  debugPrint('[Moor] using encrypted moor');
  final dbFolder = await getDatabasesPath();
  final targetPath = p.join(dbFolder, filename);
  final receivePort = ReceivePort();
  await Isolate.spawn(
    _startBackground,
    _IsolateStartRequest(
        receivePort.sendPort, targetPath, password, logStatements),
  );
  final isolate = (await receivePort.first as MoorIsolate);
  return DatabaseNoTransactions.connect(await isolate.connect());
}

Future<String> getLocalstorage(String key) async {
  return null;
}