/*
 * Copyright 2020 Adobe. All rights reserved.
 * This file is licensed to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. You may obtain a copy
 * of the License at http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under
 * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
 * OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */

"use strict";

const { AdobeIOEvents, AdobeIOEventEmitter } = require("@adobe/asset-compute-events-client");
const EventEmitter = require("events");

/**
 * Sent for each successfully processed and uploaded rendition.
 *
 * @typedef {Object} AssetComputeRenditionCreatedEvent
 * @property {String} type Event type (rendition_created)
 * @property {String} date Timestamp when event was sent in simplified extended ISO-8601 format.
 * @property {String} requestId AssetCompute job ID
 * @property {AssetComputeSource} source Source passed in to the process request
 * @property {Object} userData User data passed in to the process request (if provided)
 * @property {AssetComputeRendition} rendition Rendition passed in to the process request
 * @property {Object} metadata Rendition metadata (optional, tiff:ImageWidth, tiff:ImageHeight, repo:size)
 * @property {String} errorReason Rendition failure reason (if any)
 * @property {String} errorMessage Text giving more detail about the rendition failure (if any)
 */
/**
 * Sent for each rendition that failed to process or upload.
 *
 * @typedef {Object} AssetComputeRenditionFailedEvent
 * @property {String} type Event type (rendition_failed)
 * @property {String} date Timestamp when event was sent in simplified extended ISO-8601 format.
 * @property {String} requestId AssetCompute job ID
 * @property {AssetComputeSource} source Source passed in to the process request
 * @property {Object} userData User data passed in to the process request (if provided)
 * @property {AssetComputeRendition} rendition Rendition passed in to the process request
 * @property {String} errorReason Rendition failure reason (if any)
 * @property {String} errorMessage Text giving more detail about the rendition failure (if any)
 */
/**
 * Sent for each successfully processed and uploaded rendition.
 *
 * @event AssetCompute#rendition_created
 * @type {AssetComputeRenditionCreatedEvent}
 */
/**
 * Sent for each rendition that failed to process or upload.
 *
 * @event AssetCompute#rendition_failed
 * @type {AssetComputeRenditionFailedEvent}
 */
/**
 * Error event fired on polling failure.
 *
 * @event AssetCompute#error
 * @type {Error}
 */
class AssetComputeEventEmitter extends EventEmitter {

    /**
     * @typedef {Object} AssetComputeEventEmitterOptions
     * @property {String} accessToken JWT access token
     * @property {String} org IMS organization
     * @property {String} journal Journal URL
     * @property {Number} [interval=] Override interval at which to poll I/O events (optional)
     */
    /**
     * Construct Asset Compute client
     *
     * @param {AssetComputeIntegration} integration Asset Compute Integration
     * @param {AssetComputeEventEmitterOptions} options Options
     */
    constructor(options) {
        super();

        this.accessToken = options.accessToken;
        this.org = options.org;
        this.journal = options.journal;
        this.interval = options.interval;

        // always latest, because we are listening for events that are generated by us only
        this.ioEvents = new AdobeIOEvents({
            accessToken: this.accessToken,
            orgId: this.org
        });
        this.ioEventsEmitter = new AdobeIOEventEmitter(this.ioEvents, this.journal, {
            latest: true,
            interval: this.interval
        });

        // forward events
        const self = this;
        this.ioEventsEmitter.on('event', event => {
            if (event && event.event) {
                const assetComputeEvent = event.event;
                this.emit(assetComputeEvent.type, assetComputeEvent);
            } else {
                this.emit(
                    "error",
                    Error(`Event is missing 'event' object: ${JSON.stringify(event)}`)
                );
            }
        });
        this.ioEventsEmitter.on('error', error => self.emit("error", error));
    }

    /**
     * Stop the AssetComputeEventEmitter
     */
    async close() {
        return this.ioEventsEmitter.stop();
    }

}

module.exports = {
    AssetComputeEventEmitter
};