store.ts

import * as SQLite3 from "sqlite3";
import * as log from "npmlog";
import * as Bluebird from "bluebird";
import * as fs from "fs";
import { IDbSchema } from "./db/schema/dbschema";
import { IDbData} from "./db/dbdatainterface";
const CURRENT_SCHEMA = 7;
/**
 * Stores data for specific users and data not specific to rooms.
 */
export class DiscordStore {
  /**
   * @param  {string} filepath Location of the SQLite database file.
   */
  public db: any;
  private version: number;
  private filepath: string;
  constructor (filepath: string) {
    this.version = null;
    this.filepath = filepath;
  }

  public backup_database(): Promise<null> {
    if (this.filepath === ":memory:") {
      log.info("DiscordStore", "Can't backup a :memory: database.");
      return Promise.resolve();
    }
    const BACKUP_NAME = this.filepath + ".backup";

    return new Promise((resolve, reject) => {
      // Check to see if a backup file already exists.
      fs.access(BACKUP_NAME, (err) => {
        return resolve(err === null);
      });
    }).then((result) => {
      return new Promise((resolve, reject) => {
        if (!result) {
          log.warn("DiscordStore", "NOT backing up database while a file already exists");
          resolve(true);
          return;
        }
        const rd = fs.createReadStream(this.filepath);
        rd.on("error", reject);
        const wr = fs.createWriteStream(BACKUP_NAME);
        wr.on("error", reject);
        wr.on("close", resolve);
        rd.pipe(wr);
      });
    });
  }

  /**
   * Checks the database has all the tables needed.
   */
  public async init (overrideSchema: number = 0) {
    log.info("DiscordStore", "Starting DB Init");
    await this.open_database();
    let version = await this.getSchemaVersion();
    const targetSchema = overrideSchema || CURRENT_SCHEMA;
    while (version < targetSchema) {
      version++;
      const schemaClass = require(`./db/schema/v${version}.js`).Schema;
      const schema = (new schemaClass() as IDbSchema);
      log.info("DiscordStore", `Updating database to v${version}, "${schema.description}"`);
      try {
        await schema.run(this);
        log.info("DiscordStore", "Updated database to version %s", version);
      } catch (ex) {
        log.error("DiscordStore", "Couldn't update database to schema %s", version);
        log.error("DiscordStore", ex);