import pick from 'lodash/pick';
import sum from 'lodash/sum';
import {removeByIndex, replaceByIndex} from '../../../util/array';

import EventSelector from './event-selector';
import {LabelPart, MPEvent, SerializedCustomEvent} from './types';

export default class MPCustomEvent {
  public static fromSerializedCustomEvent({alternatives, name, id}: SerializedCustomEvent): MPCustomEvent {
    const eventSelectors = alternatives.map(alternative => EventSelector.fromAlternative(alternative));
    return new MPCustomEvent({id, name, eventSelectors});
  }

  public id?: number;
  public name: string;
  public eventSelectors: Array<EventSelector>;
  public custom = true;

  constructor(options: Partial<MPCustomEvent> = {}) {
    const {id, name = ``, eventSelectors = null} = options;
    if (id) {
      this.id = id;
    }

    this.name = name;
    this.eventSelectors = eventSelectors ? eventSelectors.map(s => new EventSelector(s)) : [new EventSelector()];
  }

  static get CUSTOM_EVENT_PREFIX(): string {
    return `$custom_event:`;
  }

  public getSerializedName(): string {
    return `${MPCustomEvent.CUSTOM_EVENT_PREFIX}${this.id}`;
  }

  public getLabelParts(): Array<LabelPart> {
    return this.eventSelectors.reduce((parts, selector, index, arr) => {
      const operator = index !== arr.length - 1 ? [{label: `\nOR`, highlight: false}] : [];
      return [...parts, ...selector.getLabelParts(), ...operator];
    }, []);
  }

  public toSerializedCustomEvent(): SerializedCustomEvent {
    const alternatives = this.eventSelectors
      .filter(eventSelector => eventSelector.isValid())
      .map(eventSelector => eventSelector.toAlternative());
    return {
      ...pick(this, [`id`]),
      alternatives,
      name: this.name.trim(),
    };
  }

  public isValid(): boolean {
    return (
      this.eventSelectors.some(eventSelector => eventSelector.isValid()) &&
      this.eventSelectors.every((eventSelector, idx, arr) => eventSelector.isValid() || idx === arr.length - 1)
    );
  }

  public addEventSelector(): MPCustomEvent {
    return new MPCustomEvent({
      ...this.getAttrs(),
      eventSelectors: [...this.eventSelectors, new EventSelector()],
    });
  }

  public updateEventSelectorAtIndex(eventSelector: EventSelector, idx: number): MPCustomEvent {
    return new MPCustomEvent({
      ...this.getAttrs(),
      eventSelectors: replaceByIndex(this.eventSelectors, idx, eventSelector),
    });
  }

  public updateEventAtIndex(event: MPEvent, idx: number): MPCustomEvent {
    const eventSelector = this.eventSelectors[idx].updateEvent(event);
    return new MPCustomEvent({
      ...this.getAttrs(),
      eventSelectors: replaceByIndex(this.eventSelectors, idx, eventSelector),
    });
  }

  public removeEventSelectorAtIndex(idx: number): MPCustomEvent {
    return new MPCustomEvent({
      ...this.getAttrs(),
      eventSelectors: removeByIndex(this.eventSelectors, idx),
    });
  }

  public updateName(name: string): MPCustomEvent {
    return new MPCustomEvent({...this.getAttrs(), name});
  }

  public toTrackingData(): object {
    return {
      '# alternatives': this.eventSelectors.length,
      '# property filters': sum(this.eventSelectors.map(selector => selector.propertyFilters.length)),
      'custom event id': this.id,
      'name': this.name,
    };
  }

  public getAttrs(): Partial<MPCustomEvent> {
    return pick(this, [
      `eventSelectors`,
      `id`,
      `name`,
    ]);
  }
}