import { Injectable, EventEmitter } from "@angular/core";

@Injectable()
export class PermissionService {
  private _permissionStore: Array<string> = [];
  private _permissionStoreChange: EventEmitter<any> = new EventEmitter();

  constructor() {}

  public define(permissions: Array<string>): void {
    if (!Array.isArray(permissions))
      throw "permissions parameter is not array.";

    this.clearStore();
    for (let permission of permissions) this.add(permission);
  }

  public add(permission: string): void {
    if (
      typeof permission === "string" &&
      !this.hasDefined(permission.toLocaleLowerCase())
    ) {
      this._permissionStore.push(permission.toLocaleLowerCase());
      this._permissionStoreChange.emit(null);
    }
  }

  public remove(permission: string): void {
    if (typeof permission !== "string") return;

    let index = this._permissionStore.indexOf(permission.toLowerCase());
    if (index < 0) return;

    this._permissionStore.splice(index, 1);
    this._permissionStoreChange.emit(null);
  }

  public hasDefined(permission: string): boolean {
    if (typeof permission !== "string") return false;

    let index = this._permissionStore.indexOf(permission.toLowerCase());
    return index > -1;
  }

  public hasOneDefined(permissions: Array<string>): boolean {
    if (!Array.isArray(permissions))
      throw "permissions parameter is not array.";

    return permissions.some((v) => {
      if (typeof v === "string")
        return this._permissionStore.indexOf(v.toLowerCase()) >= 0;
      return false;
    });
  }

  public clearStore(): void {
    this._permissionStore = [];
  }

  get store(): Array<string> {
    return this._permissionStore;
  }

  get permissionStoreChangeEmitter(): EventEmitter<any> {
    return this._permissionStoreChange;
  }
}