import type { UserIdentity } from './identity';

export interface ActivityHistoryEntry {
	date: number;
	amount: number;
}

export const fillMissingDays = (
	inputActivities: ActivityHistoryEntry[],
	startOfYear = false
): ActivityHistoryEntry[] => {
	if (inputActivities.length === 0)
		return startOfYear
			? fillDateRange(
					new Date(new Date().getUTCFullYear(), 0, 1),
					new Date(new Date().getUTCFullYear() + 1, 0, 1)
			  )
			: [];

	const sortedActivities = [...inputActivities].sort((a, b) => a.date - b.date);
	const endDate = new Date(sortedActivities[sortedActivities.length - 1].date * 1000);

	endDate.setUTCDate(endDate.getUTCDate() + 1);

	return fillDateRange(
		startOfYear
			? new Date(new Date().getUTCFullYear(), 0, 1)
			: new Date(sortedActivities[0].date * 1000),
		endDate,
		sortedActivities
	);
};

const fillDateRange = (
	startDate: Date,
	endDate: Date,
	existingActivities: ActivityHistoryEntry[] = []
): ActivityHistoryEntry[] => {
	const outputActivities: ActivityHistoryEntry[] = [];

	for (let dt = new Date(startDate); dt < endDate; dt.setUTCDate(dt.getUTCDate() + 1)) {
		const dateString = dt.toDateString();

		if (
			!new Set(
				existingActivities.map((activity) => new Date(activity.date * 1000).toDateString())
			).has(dateString)
		) {
			outputActivities.push({ date: Math.floor(dt.getTime() / 1000), amount: 0 });
		} else {
			const activity = existingActivities.find(
				(activity) => new Date(activity.date * 1000).toDateString() === dateString
			);

			if (activity) outputActivities.push(activity);
		}
	}

	return outputActivities;
};

export const activityHistory = async (
	userIdentity: UserIdentity
): Promise<ActivityHistoryEntry[]> => {
	return (
		await (
			await fetch('https://graphql.anilist.co', {
				method: 'POST',
				headers: {
					'Content-Type': 'application/json',
					Accept: 'application/json'
				},
				body: JSON.stringify({
					query: `{ User(id: ${userIdentity.id}) {
					stats { activityHistory { date amount } }
        } }`
				})
			})
		).json()
	)['data']['User']['stats']['activityHistory'];
};

export const lastActivityDate = async (userIdentity: UserIdentity): Promise<Date> => {
	const history = await activityHistory(userIdentity);
	const date = new Date(
		Number(history[history.length - 1]['date']) * 1000 + new Date().getTimezoneOffset()
	);

	date.setDate(date.getDate() + 1);

	return date;
};