import * as fs from 'fs-extra';

import { IEnvironment } from './environment';

export class Configuration {
  private config: any = {};
  private dirty = false;

  constructor(private env: IEnvironment, private file: string, private defaults?: any) {}

  public async load(): Promise<void> {
    if (!await fs.pathExists(this.file)) {
      this.saveDefaults();
      return;
    }

    const json = await fs.readJson(this.file);
    this.config = json;

    if (this.defaults) {
      this.config = Object.assign({}, this.defaults, json);
    }
  }

  public async save(force = false): Promise<void> {
    if (force) {
      return this.write();
    }

    this.dirty = true;
  }

  public get(key: string, defval?: any): any {
    if (!this.config[key]) {
      return defval;
    }
    return this.config[key];
  }

  private saveDefaults(): void {
    this.config = this.defaults || {};
    this.save(true);
  }

  private async write(): Promise<void> {
    return fs.writeJson(this.file, this.config);
  }

  private writeTask(): void {}
}