export enum JobStatisticsType {
	SUCCESSFUL = "successful",
	FAILED = "failed",
	TOTAL = "total",
	CONSTRUCTED = "constructed",
	QUEUED = "queued",
	DURATION = "duration"
}

export class JobStatistics {
	private _stats: Record<
		string,
		Record<
			| Exclude<JobStatisticsType, "duration">
			| "averageTime"
			| "totalTime",
			number
		>
	>;

	public constructor() {
		this._stats = {};
	}

	/**
	 * getStats - Get statistics of job queue
	 *
	 * @returns Job queue statistics
	 */
	public getStats() {
		const total = Object.values(this._stats).reduce(
			(a, b) => ({
				successful: a.successful + b.successful,
				failed: a.failed + b.failed,
				total: a.total + b.total,
				constructed: a.constructed + b.constructed,
				queued: a.queued + b.queued,
				averageTime: -1,
				totalTime: a.totalTime + b.totalTime
			}),
			{
				successful: 0,
				failed: 0,
				total: 0,
				constructed: 0,
				queued: 0,
				averageTime: -1,
				totalTime: 0
			}
		);
		total.averageTime = total.totalTime / total.total;

		return {
			...this._stats,
			total
		};
	}

	/**
	 * updateStats - Update job statistics
	 *
	 * @param jobName - Job name
	 * @param type - Stats type
	 * @param duration - Duration of job, for average time stats
	 */
	public updateStats(
		jobName: string,
		type: JobStatisticsType,
		duration?: number
	) {
		if (!this._stats[jobName])
			this._stats[jobName] = {
				successful: 0,
				failed: 0,
				total: 0,
				constructed: 0,
				queued: 0,
				averageTime: 0,
				totalTime: 0
			};
		if (type === "duration") {
			if (!duration) throw new Error("No duration specified");

			this._stats[jobName].totalTime += duration;

			this._stats[jobName].averageTime =
				this._stats[jobName].totalTime / this._stats[jobName].total;
		} else this._stats[jobName][type] += 1;
	}
}

export default new JobStatistics();