import { DateTime, Duration } from "luxon";

class Hashable {
  public get hash(): string {
    const str = JSON.stringify(this);

    // source: https://gist.github.com/hyamamoto/fd435505d29ebfa3d9716fd2be8d42f0?permalink_comment_id=2775538#gistcomment-2775538
    let hash = 0;
    for (let i = 0; i < str.length; i++)
      hash = Math.imul(31, hash) + str.charCodeAt(i) | 0;

    return new Uint32Array([hash])[0].toString(36);
  }
}

export type EventJSONData = {
  summary: string;
  description: string;
  dtstart: string;
  dtend: string;
};

export class EventData extends Hashable {
  public summary: string;
  public description: string;
  public start: DateTime;
  public duration: Duration;

  public constructor(json_data: EventJSONData) {
    super();

    this.summary = json_data.summary;
    this.description = json_data.description;
    this.start = DateTime
      .fromISO(json_data.dtstart)
      .setLocale(navigator.language);
    const end = DateTime
      .fromISO(json_data.dtend)
      .setLocale(navigator.language);

    this.duration = end.diff(this.start);
  }
}

export type CalendarJSONData = {
  title: string;
  events: Array<EventJSONData>;
};

export class CalendarData extends Hashable {
  public title: string;
  public events: Array<EventData>;

  public constructor(json_data: CalendarJSONData) {
    super();

    this.title = json_data.title

    this.events = [];
    for (const event_data of json_data.events) {
      this.events.push(new EventData(event_data))
    }
  }
}