import { AggregateRoot } from '@nestjs/cqrs';

export class DailyActiveStats extends AggregateRoot {
  private _day: Date;
  private _dauCount: number;
  private _dauByProvince: Map<string, number>;
  private _dauByCity: Map<string, number>;
  private _calculatedAt: Date;
  private _version: number;

  private constructor() { super(); }

  get day(): Date { return this._day; }
  get dauCount(): number { return this._dauCount; }
  get dauByProvince(): Map<string, number> { return new Map(this._dauByProvince); }
  get dauByCity(): Map<string, number> { return new Map(this._dauByCity); }
  get calculatedAt(): Date { return this._calculatedAt; }
  get version(): number { return this._version; }

  static create(props: {
    day: Date;
    dauCount: number;
    dauByProvince?: Map<string, number>;
    dauByCity?: Map<string, number>;
  }): DailyActiveStats {
    const stats = new DailyActiveStats();
    stats._day = props.day;
    stats._dauCount = props.dauCount;
    stats._dauByProvince = props.dauByProvince ?? new Map();
    stats._dauByCity = props.dauByCity ?? new Map();
    stats._calculatedAt = new Date();
    stats._version = 1;
    return stats;
  }

  recalculate(newDauCount: number, byProvince?: Map<string, number>, byCity?: Map<string, number>): void {
    this._dauCount = newDauCount;
    if (byProvince) this._dauByProvince = byProvince;
    if (byCity) this._dauByCity = byCity;
    this._calculatedAt = new Date();
    this._version++;
  }

  static reconstitute(props: {
    day: Date;
    dauCount: number;
    dauByProvince: Map<string, number>;
    dauByCity: Map<string, number>;
    calculatedAt: Date;
    version: number;
  }): DailyActiveStats {
    const stats = new DailyActiveStats();
    stats._day = props.day;
    stats._dauCount = props.dauCount;
    stats._dauByProvince = props.dauByProvince;
    stats._dauByCity = props.dauByCity;
    stats._calculatedAt = props.calculatedAt;
    stats._version = props.version;
    return stats;
  }
}