import { app } from 'electron';
import * as fs from 'fs';
import * as fsp from 'fs/promises';
import * as path from 'path';
import { DataSource } from 'typeorm';
import {
  MessageEntity,
  UserEntity,
  RoomEntity,
  RoomChannelEntity,
  RoomMemberEntity,
  ReactionEntity,
  BanEntity,
  AttachmentEntity,
  MetaEntity
} from '../entities';
import { settings } from '../settings';

let applicationDataSource: DataSource | undefined;

export function getDataSource(): DataSource | undefined {
  return applicationDataSource;
}

export async function initializeDatabase(): Promise<void> {
  const userDataPath = app.getPath('userData');
  const dbDir = path.join(userDataPath, 'metoyou');

  await fsp.mkdir(dbDir, { recursive: true });
  const databaseFilePath = path.join(dbDir, settings.databaseName);

  let database: Uint8Array | undefined;

  if (fs.existsSync(databaseFilePath)) {
    database = fs.readFileSync(databaseFilePath);
  }

  applicationDataSource = new DataSource({
    type: 'sqljs',
    database,
    entities: [
      MessageEntity,
      UserEntity,
      RoomEntity,
      RoomChannelEntity,
      RoomMemberEntity,
      ReactionEntity,
      BanEntity,
      AttachmentEntity,
      MetaEntity
    ],
    migrations: [path.join(__dirname, '..', 'migrations', '*.js'), path.join(__dirname, '..', 'migrations', '*.ts')],
    synchronize: false,
    logging: false,
    autoSave: true,
    location: databaseFilePath
  });

  try {
    await applicationDataSource.initialize();
    console.log('[DB] Connection initialised at:', databaseFilePath);

    try {
      await applicationDataSource.runMigrations();
      console.log('[DB] Migrations executed');
    } catch (migErr) {
      console.error('[DB] Migration error:', migErr);
    }
  } catch (error) {
    console.error('[DB] Initialisation error:', error);
  }
}

export async function destroyDatabase(): Promise<void> {
  if (applicationDataSource?.isInitialized) {
    try {
      await applicationDataSource.destroy();
      console.log('[DB] Connection closed');
    } catch (error) {
      console.error('[DB] Error closing connection:', error);
    } finally {
      applicationDataSource = undefined;
    }
  }
}