const timeZone = 'America/New_York';

interface HeatmapEntry {
	timestamp: number;
	contributions: number;
}

export interface GiteaProfile {
	baseUrl: string;
	username: string;
	profileUrl: string;
}

export function parseGiteaProfile(profileUrl: string | undefined): GiteaProfile | null {
	if (!profileUrl) return null;
	const url = new URL(profileUrl);
	const username = url.pathname.split('/').filter(Boolean)[0];
	return username ? { baseUrl: url.origin, username, profileUrl } : null;
}

function easternDate(timestampSeconds: number): string {
	return new Intl.DateTimeFormat('en-CA', { timeZone, year: 'numeric', month: '2-digit', day: '2-digit' }).format(
		new Date(timestampSeconds * 1000)
	);
}

export async function fetchGiteaDailyCounts({ baseUrl, username }: GiteaProfile): Promise<Map<string, number>> {
	const response = await fetch(`${baseUrl}/api/v1/users/${username}/heatmap`, { headers: { Accept: 'application/json' } });
	if (!response.ok) throw new Error(`Gitea heatmap returned ${response.status}`);

	const entries: HeatmapEntry[] = await response.json();
	const dailyCounts = new Map<string, number>();
	for (const { timestamp, contributions } of entries) {
		const date = easternDate(timestamp);
		dailyCounts.set(date, (dailyCounts.get(date) ?? 0) + contributions);
	}
	return dailyCounts;
}