fetch.ts

import moment from 'moment-timezone';

import { CanvasClient } from '../apis/canvas';
import { Storage } from '../apis/storage';

import { EmojiRequest } from '../types/notion';

export interface IFetchedAssignment {
	name: string;
	description: string | null;
	points: number;
	course: string;
	icon: EmojiRequest | null;
	url: string;
	available: string | null;
	due: string | null;
}

export interface SavedAssignments {
	[course: string]: IFetchedAssignment[];
}

function roundToNextHour(date: Date): Date {
	if (date.getMinutes() === 0) return date;
	date.setHours(date.getHours() + 1, 0, 0, 0);
	return date;
}

function reformatDate(dateString: string | null, timeZone: string | null): string | null {
	if (!dateString) return null;

	/*
		Problem:  Notion does not convert times into the correct timezone,
				  even when supplied a timezone, Notion will show the user the
				  UTC time (incorrect time, unless you live in UTC region), labeled
				  with the supplied timezone.
		Solution: Re-format the ISO date string to give Notion a 'false' date string based
				  on the timezone provided by the user. This is a misuse of ISO time/date strings,
				  but it will result in the correct date being shown in Notion.
	 */
	const date = new Date(dateString);
	const offset = moment.tz.zone(timeZone ?? moment.tz.guess())?.utcOffset(date.valueOf()) ?? 0;
	date.setMinutes(date.getMinutes() - offset);
	return date.toISOString();
}

(async function fetchAssignments(): Promise<SavedAssignments | void> {
	try {
		const { origin, pathname } = window.location;
		const courseId = pathname.match(/\/courses\/([^/]+)\/?/)?.[1];

		if (!courseId) {
			throw 'This is an invalid Canvas course page.\n\nPlease navigate to a Canvas course page (or any subpage), and try again.\n\nExample: https://canvas.auckland.ac.nz/courses/72763/...';
		}

		const canvasClient = new CanvasClient({ origin, courseId });

		const [course, assignmentGroups] = await Promise.all([
			canvasClient.fetchCourse(),
			canvasClient.fetchAssignmentGroups(),
		]);

		if (!course || !assignmentGroups) {
			throw `Failed to fetch ${(!course) ? 'course' : 'assignments'}.\n\nPlease try again later.\n\nIf this issue persists, please open an Issue on GitHub or report it in the Discord Server.`;
		}

		const options = await Storage.getOptions();

		const courseCode = options.canvas.courseCodeOverrides[course.course_code] ?? course.course_code;
		const courseIcon = options.notion.courseEmojis[courseCode] ?? null;

		const emojiedCourseCode = `${(courseIcon) ? `${courseIcon} ` : ''}${courseCode}`;

		const timeNow = new Date();

		const canvasAssignments = assignmentGroups.flatMap(group => group.assignments)
			.filter(assignment => options.canvas.importMissingDueDates || assignment.due_at)
			.sort(({ due_at: a }, { due_at: b }) => {
				return Date.parse(a ?? timeNow.toISOString()) - Date.parse(b ?? timeNow.toISOString());
			})
			.map(assignment => ({
				name: assignment.name,
				description: assignment.description,
				points: assignment.points_possible,
				course: courseCode,
				icon: courseIcon,
				url: assignment.html_url,
				available: (assignment.unlock_at)
					? reformatDate(assignment.unlock_at, options.notion.timeZone)
					// If the due date is in the past, set the available date to be one month before that.
					// See #388.
					: (assignment.due_at && (timeNow < new Date(assignment.due_at)))
						? reformatDate(roundToNextHour(timeNow).toISOString(), options.notion.timeZone)
						: reformatDate(moment(assignment.due_at ?? 0).subtract(1, 'month').format(), options.notion.timeZone),
				due: reformatDate(assignment.due_at, options.notion.timeZone),
			}));

		const savedAssignments = await Storage.getSavedAssignments();

		savedAssignments[emojiedCourseCode] = canvasAssignments;

		await Promise.all([
			Storage.setSavedAssignments(savedAssignments),
			Storage.setSavedCourse(emojiedCourseCode),
		]);

		return savedAssignments;
	}

	catch (error) {
		alert(error);
		return Storage.setSavedCourse(null);
	}
})();