import {IIndexingManager} from "../interfaces/IIndexingManager";
import {IndexingProgressDTO} from "../../../common/entities/settings/IndexingProgressDTO";
import {ObjectManagerRepository} from "../ObjectManagerRepository";
import {ISQLGalleryManager} from "./IGalleryManager";
import * as path from "path";
import {SQLConnection} from "./SQLConnection";
import {DirectoryEntity} from "./enitites/DirectoryEntity";
import {Logger} from "../../Logger";

const LOG_TAG = "[IndexingManager]";

export class IndexingManager implements IIndexingManager {
  directoriesToIndex: string[] = [];
  indexingProgress = null;
  enabled = false;
  private indexNewDirectory = async () => {
    if (this.directoriesToIndex.length == 0) {
      this.indexingProgress = null;
      if (global.gc) {
        global.gc();
      }
      return;
    }
    const directory = this.directoriesToIndex.shift();
    this.indexingProgress.current = directory;
    this.indexingProgress.left = this.directoriesToIndex.length;
    const scanned = await (<ISQLGalleryManager>ObjectManagerRepository.getInstance().GalleryManager).indexDirectory(directory);
    if (this.enabled == false) {
      return;
    }
    this.indexingProgress.indexed++;
    for (let i = 0; i < scanned.directories.length; i++) {
      this.directoriesToIndex.push(path.join(scanned.directories[i].path, scanned.directories[i].name))
    }
    process.nextTick(this.indexNewDirectory);
  };

  startIndexing(): void {
    if (this.directoriesToIndex.length == 0 && this.enabled == false) {
      Logger.info(LOG_TAG, "Starting indexing");
      this.indexingProgress = <IndexingProgressDTO>{
        indexed: 0,
        left: 0,
        current: ""
      };
      this.directoriesToIndex.push("/");
      this.enabled = true;
      this.indexNewDirectory();
    } else {
      Logger.info(LOG_TAG, "Already indexing..");
    }
  }

  getProgress(): IndexingProgressDTO {
    return this.indexingProgress;
  }

  cancelIndexing(): void {
    Logger.info(LOG_TAG, "Canceling indexing");
    this.directoriesToIndex = [];
    this.indexingProgress = null;
    this.enabled = false;
    if (global.gc) {
      global.gc();
    }
  }

  async reset(): Promise<void> {
    Logger.info(LOG_TAG, "Resetting DB");
    this.directoriesToIndex = [];
    this.indexingProgress = null;
    this.enabled = false;
    const connection = await SQLConnection.getConnection();
    return connection
      .getRepository(DirectoryEntity)
      .createQueryBuilder("directory")
      .delete()
      .execute();
  }
}