export interface StorageValue {
  id: string;
}

export class DataStorage<T extends StorageValue> {
  constructor(private storageKey: string) {}

  private readValues(): T[] {
    const objects = JSON.parse(window.localStorage.getItem(this.storageKey) || "[]");
    if (!Array.isArray(objects)) {
      return Object.values(objects);
    }
    return objects;
  }

  private writeValues(values: T[]) {
    window.localStorage.setItem(this.storageKey, JSON.stringify(values));
  }

  getAll(): T[] {
    return this.readValues();
  }

  add(value: T): boolean {
    const values = this.readValues();
    for (const v of values) {
      if (v.id == value.id) {
        return false;
      }
    }
    values.push(value);
    this.writeValues(values);
    return true;
  }

  remove(id: string) {
    const values = this.readValues();
    for (let i = 0; i < values.length; i++) {
      if (values[i].id == id) {
        values.splice(i, 1);
        this.writeValues(values);
        return;
      }
    }
  }
}