import { readObj } from '@rsdk/common.node';
import { LoggerFactory } from '@rsdk/logging';
import { watch } from 'node:fs';

import { DeclareProperty, InjectProperty } from '../../metadata';
import { FsPathParser } from '../../parsers';
import { ReloadEvents } from '../../reload';
import { ReloadableConfigSource } from '../base';
import { Source } from '../config-source.decorator';

@Source('reloadable')
@DeclareProperty('CONFIG_PATH', new FsPathParser('file'), {
  description: 'Path to some configuration file',
})
export class ReloadableFileSource extends ReloadableConfigSource {
  constructor(
    @InjectProperty('CONFIG_PATH') private readonly path: string,
    reloadEvents: ReloadEvents,
  ) {
    super(LoggerFactory.create(ReloadableFileSource), reloadEvents);
  }

  override name(): string {
    return `Configuration file: ${this.path}`;
  }

  override loadRaw(): Promise<unknown> {
    return readObj(this.path);
  }

  override init(): void {
    watch(this.path, (event) => {
      if (event !== 'change') {
        return;
      }

      this.logger.info('Changes detected', { source: this.name });

      this.reload();
    });
  }
}