import db from "external/mongo/db";
import CreateLogCtx from "lib/logger/logger";
import { FilterQuery } from "mongodb";
import {
	ChartDocument,
	IDStrings,
	IDStringToGame,
	integer,
	OrphanChart,
	SongDocument,
} from "tachi-common";
import { GetNextCounterValue } from "utils/db";
import { DedupeArr } from "utils/misc";

const logger = CreateLogCtx(__filename);

/**
 * Handles an orphan queue request.
 *
 * If the chart has never been seen before, add it to the orphan queue
 * and return null.
 *
 * If the chart has been seen before, and has less than N unique players
 * who have played it, return null.
 *
 * If the chart has been seen before, and has >= N unique players who have
 * played it, unorphan the chart, and return it.
 */
export async function HandleOrphanQueue<I extends IDStrings>(
	idString: I,
	game: IDStringToGame[I],
	chartDoc: ChartDocument<I>,
	songDoc: SongDocument<IDStringToGame[I]>,
	orphanMatchCriteria: FilterQuery<OrphanChart<I>>,
	queueSize: integer,
	userID: integer,
	chartName: string
) {
	logger.debug(`Received orphanqueue request for ${chartName}.`);

	const orphanChart = await db["orphan-chart-queue"].findOne(
		Object.assign({ idString }, orphanMatchCriteria),
		{
			projectID: true,
		}
	);

	if (!orphanChart) {
		logger.verbose(`Received unknown chart ${chartName}, orphaning.`);

		await db["orphan-chart-queue"].insert({
			idString,
			chartDoc,
			songDoc,
			userIDs: [userID],
		});

		return null;
	}

	orphanChart.userIDs.push(userID);

	const uniqueUsersArr = DedupeArr(orphanChart.userIDs);

	const playcount = uniqueUsersArr.length;
	// If N or more people have played this chart while orphaned, unorphan
	// it.
	if (playcount >= queueSize) {
		logger.info(`Song ${chartName} was unorphaned by userIDs ${uniqueUsersArr.join(", ")}.`);
		const songID = await GetNextCounterValue(`${game}-song-id`);

		logger.verbose(`${chartName} has been assigned songID ${songID}.`);

		const { songDoc, chartDoc } = orphanChart;

		songDoc.id = songID;
		chartDoc.songID = songID;

		await db.songs[game].insert(songDoc);
		await db.charts[game].insert(chartDoc);
		await db["orphan-chart-queue"].remove({
			_id: orphanChart._id,
		});

		return chartDoc as ChartDocument<I>;
	}

	// otherwise, update the state of this orphan.

	logger.verbose(`UserID ${userID} played ${chartName}, which is now at ${playcount} plays.`);
	await db["orphan-chart-queue"].update(
		{
			_id: orphanChart._id,
		},
		{
			$set: {
				userIDs: uniqueUsersArr,
			},
		}
	);

	return null;
}