import { LocalEvent } from "../commons/types/local-event";
import { Runner } from "../commons/types/runner";
import { CookieUtils } from "../commons/utils/cookie-utils";
import { EventEmitter } from "../commons/utils/event-emitter";
import { BatchEventBuilder } from "../event/core/batch-event-builder";
import { Event, EventType } from "../event/core/event";

/**
 * GA Runner to send GA events when some biggy events occur.
 *
 * @export
 * @class GARunner
 * @extends {Runner}
 */
export class GARunner extends Runner {
    /**
     * Run all event processing code.
     *
     * @protected
     * @memberof GARunner
     */
    protected run(): Promise<void> {
        EventEmitter.on(LocalEvent.EventPush, (event) => this.processEventPush(event));
        EventEmitter.on(LocalEvent.EventBatch, (batch) => this.processEventBatch(batch));
        return;
    }

    /**
     * Process a batch of events.
     *
     * @private
     * @param {BatchEventBuilder} batch Batch of events.
     * @memberof GARunner
     */
    private processEventBatch(batch: BatchEventBuilder) {
        batch.events.forEach((event) => this.processEventPush(event));
    }

    /**
     * Process a single event.
     *
     * @private
     * @param {Event} event Event to be processed.
     * @memberof GARunner
     */
    private processEventPush(event: Event) {
        let conversion: ConversionCookie = { front: false, search: false };
        const cookie = CookieUtils.get(window._RecSys.Bundle.Properties.cookies.ga.key);

        if (cookie !== undefined && cookie.length > 0) {
            conversion = JSON.parse(atob(cookie));
        }

        if (event.type === EventType.FrontClick) {
            conversion.front = true;
        } else if (event.type === EventType.SearchClick) {
            conversion.search = true;
        } else if (event.type === EventType.PageConfirmation) {
            if (conversion.search) {
                window.dataLayer.push({
                    event: "biggy.search.conversion",
                } as ConversionEvent);
            }

            if (conversion.front) {
                window.dataLayer.push({
                    event: "biggy.front.conversion",
                } as ConversionEvent);
            }
        }

        CookieUtils.set(window._RecSys.Bundle.Properties.cookies.ga.key, btoa(JSON.stringify(conversion)), {
            ttl: window._RecSys.Bundle.Properties.cookies.ga.ttl,
        });
    }
}

/**
 * DataLayer event for client-side conversion.
 *
 * @interface ConversionEvent
 */
interface ConversionEvent {
    event: "biggy.front.conversion" | "biggy.search.conversion";
}

/**
 * Tracking cookie for client-side conversion.
 *
 * @interface ConversionCookie
 */
interface ConversionCookie {
    front: boolean;
    search: boolean;
}