website/src/lib/worldtodo/shared.ts

// Shared (client + server) constants and types for the Worldwide Todo List.

export const WORLDTODO_SCALES = ['planet', 'region', 'country', 'city', 'street'] as const;
export type Scale = (typeof WORLDTODO_SCALES)[number];
export const WORLDTODO_STATUSES = ['open', 'in_progress', 'done'] as const;
export type Status = (typeof WORLDTODO_STATUSES)[number];
export const WORLDTODO_REQUEST_KINDS = ['add', 'edit', 'delete'] as const;
export type RequestKind = (typeof WORLDTODO_REQUEST_KINDS)[number];
export const WORLDTODO_REQUEST_STATUSES = ['pending', 'approved', 'rejected'] as const;
export type RequestStatus = (typeof WORLDTODO_REQUEST_STATUSES)[number];
export const WORLDTODO_LOCATION_PRECISIONS = ['exact', 'approximate', 'none'] as const;
export type LocationPrecision = (typeof WORLDTODO_LOCATION_PRECISIONS)[number];

/** Same rule as the tasks_location_precision trigger: what kind of pin a task gets. */
export function precisionFor(
	scale: Scale,
	lat: number | null | undefined,
	lon: number | null | undefined
): LocationPrecision {
	if (lat === null || lat === undefined || lon === null || lon === undefined) return 'none';
	if (scale === 'planet') return 'none';
	return scale === 'street' || scale === 'city' ? 'exact' : 'approximate';
}

/** The only keys a request payload may carry (checked server-side). */
export const EDITABLE_FIELDS = [
	'title',
	'description',
	'scale',
	'category',
	'location_name',
	'country_code',
	'lat',
	'lon',
	'status',
	'source_urls'
] as const;
export type EditableField = (typeof EDITABLE_FIELDS)[number];

export const FIELD_LABELS: Record<EditableField, string> = {
	title: 'Title',
	description: 'Description',
	scale: 'Scale',
	category: 'Category',
	location_name: 'Location',
	country_code: 'Country code',
	lat: 'Latitude',
	lon: 'Longitude',
	status: 'Status',
	source_urls: 'Sources'
};

export const SCALE_INFO: Record<Scale, { label: string; emoji: string }> = {
	planet: { label: 'Planet', emoji: '🌍' },
	region: { label: 'Region', emoji: '🗺️' },
	country: { label: 'Country', emoji: '🏳️' },
	city: { label: 'City', emoji: '🏙️' },
	street: { label: 'Street', emoji: '🛣️' }
};

export const STATUS_LABELS: Record<Status, string> = {
	open: 'Open',
	in_progress: 'In progress',
	done: 'Done'
};

/** Slugs that are routes under /projects/worldwide-todo, never task slugs. */
export const RESERVED_SLUGS = new Set(['request', 'requests', 'queue', 'api']);

/** A task as the public sees it (list, detail, realtime events). */
export type PublicTask = {
	id: number;
	slug: string;
	title: string;
	description: string;
	scale: Scale;
	category: string;
	locationName: string;
	countryCode: string | null;
	lat: number | null;
	lon: number | null;
	/** Map pin kind (see precisionFor). */
	locationPrecision: LocationPrecision;
	status: Status;
	sourceUrls: string[];
	sourceDate: string | null;
	confidence: 'high' | 'medium';
	verificationNote: string | null;
	asOf: string;
	createdAt: string;
	updatedAt: string;
	pending?: number;
};

export type Category = { slug: string; label: string; icon: string; colour: string };

export type LiveEvent = {
	type: 'task.added' | 'task.updated' | 'task.deleted';
	slug: string;
	task: PublicTask | null;
	at: string;
};

/** Field values in the editable shape (snake_case keys, as in payloads). */
export type TaskFields = {
	title: string;
	description: string;
	scale: Scale;
	category: string;
	location_name: string;
	country_code: string | null;
	lat: number | null;
	lon: number | null;
	status: Status;
	source_urls: string[];
};

export function fieldsOf(task: PublicTask): TaskFields {
	return {
		title: task.title,
		description: task.description,
		scale: task.scale,
		category: task.category,
		location_name: task.locationName,
		country_code: task.countryCode,
		lat: task.lat,
		lon: task.lon,
		status: task.status,
		source_urls: task.sourceUrls
	};
}

const same = (a: unknown, b: unknown) => JSON.stringify(a ?? null) === JSON.stringify(b ?? null);

/** Only the fields of `next` that differ from `current`. */
export function changedFields(current: TaskFields, next: Partial<TaskFields>): Partial<TaskFields> {
	const out: Record<string, unknown> = {};
	for (const key of EDITABLE_FIELDS) {
		if (key in next && !same(current[key], next[key])) out[key] = next[key];
	}
	return out as Partial<TaskFields>;
}

export function formatValue(key: EditableField, value: unknown): string {
	if (value === null || value === undefined || value === '') return '—';
	if (key === 'source_urls' && Array.isArray(value)) return value.join('\n');
	if (key === 'status') return STATUS_LABELS[value as Status] ?? String(value);
	if (key === 'scale') return SCALE_INFO[value as Scale]?.label ?? String(value);
	return String(value);
}

/** Does a task match the list filters (used for live updates on open list pages)? */
export function matchesFilters(
	task: PublicTask,
	f: { scale: string; category: string; status: string; q: string }
): boolean {
	if (f.scale && task.scale !== f.scale) return false;
	if (f.category && task.category !== f.category) return false;
	if (f.status === 'todo' && task.status === 'done') return false;
	if (['open', 'in_progress', 'done'].includes(f.status) && task.status !== f.status) return false;
	if (f.q) {
		const hay = `${task.title} ${task.description} ${task.locationName}`.toLowerCase();
		if (
			!f.q
				.toLowerCase()
				.split(/\s+/)
				.filter(Boolean)
				.every((w) => hay.includes(w))
		)
			return false;
	}
	return true;
}

export function relativeTime(iso: string, now = Date.now()): string {
	const s = Math.round((now - new Date(iso).getTime()) / 1000);
	if (s < 60) return 'just now';
	const units: [number, string][] = [
		[60, 'minute'],
		[3600, 'hour'],
		[86400, 'day'],
		[2592000, 'month'],
		[31536000, 'year']
	];
	let label = '';
	for (let i = units.length - 1; i >= 0; i--) {
		const [size, name] = units[i];
		if (s >= size) {
			const n = Math.floor(s / size);
			label = `${n} ${name}${n === 1 ? '' : 's'} ago`;
			break;
		}
	}
	return label;
}