"use strict";

const Promise = require("bluebird");
const consumable = require("@joepie91/consumable");
const syncpipe = require("syncpipe");

const createMutationAPIWrapper = require("./mutation-api/wrapper");

module.exports = function (state) {
	const createDatabaseMutationAPI = require("./mutation-api/database")(state);

	return function createDatabaseQueue(context) {
		let databaseMutationAPI = createDatabaseMutationAPI(context);
		let mutationAPI = createMutationAPIWrapper(context, databaseMutationAPI);
	
		let queue = consumable([]);
	
		return {
			api: syncpipe(Object.keys(mutationAPI), [
				(_) => _.map((method) => [ method, function() { queue.peek().push([ method, arguments ]); } ]),
				(_) => Object.fromEntries(_)
			]),
			execute: function () {
				if (!queue.peek().some((method) => method[0] === "updateMetadata")) {
					// Doing an updateMetadata call is necessary to mark a task 'completed', so we inject a dummy call that doesn't actually change the metadata itself
					// FIXME: Split apart 'markTaskCompleted' and 'updateMetadata' queries so that this hack is no longer necessary
					queue.peek().push([ "updateMetadata", [ (data) => data ]]);
				}

				return Promise.each(queue.consume(), ([ method, args ]) => {
					return mutationAPI[method](... args);
				});
			}
		};
	};
};