import { humanize } from './string.js';

/**
 * Where one claim in a response comes from: a work, a place inside it, and the edition it was read in.
 *
 * @remarks
 * Structural rather than imported from one response type, because several schemas carry the same
 * object and a component should not have to name whichever one it happens to render. Every field is
 * optional here so a caller can pass what its own endpoint echoes.
 */
export interface SourceCitation {
	text?: string;
	chapter?: string | number;
	verse?: string;
	translation?: string | null;
	year?: number | null;
	publicDomain?: boolean;
	basis?: string;
}

/**
 * A verse reference that is a NUMBER or a range of them, rather than a sentence saying where a claim sits.
 *
 * @remarks
 * A range is written with a hyphen, and a citation can name a sub-verse with a point, so both belong
 * in the numeric shape. What must NOT match is a reference written as prose, which is the case that
 * decides how the two halves are joined below.
 */
const NUMERIC_VERSE = /^\d+(?:[.,]\d+)*(?:\s*-\s*\d+(?:[.,]\d+)*)?$/;

/**
 * One citation as a line: the work, the place inside it, and the edition where one is named.
 *
 * @remarks
 * **A verse is not always a number, so the two halves are never joined blindly.** A chapter and a
 * numbered verse read as `53.72`, which is how every printed edition is cited and how a reader finds
 * the passage. A verse that is a SENTENCE, because the claim sits in an appended note or a
 * commentary rather than in a numbered verse, reads as its own clause instead: joining it with a
 * point would manufacture a reference no edition contains.
 *
 * **A citation with no named translator is a reference, not a quotation, and it stays one.** The
 * translator and the year are printed only where the response carries them; a work with no
 * public-domain English is cited by work and verse and nothing more, so dropping the pair silently
 * would make a referenced-only claim look like a quoted one.
 *
 * The work title is humanized because the same field carries the literal value `convention` where no
 * verse states the rule, and that reads as a word rather than as an identifier.
 */
export function citationLine(c: SourceCitation): string {
	if (!c.text) return '';
	const chapter = c.chapter == null ? '' : String(c.chapter);
	const verse = c.verse ?? '';
	let where = chapter;
	if (verse) {
		where = !chapter
			? verse
			: NUMERIC_VERSE.test(verse.trim())
				? `${chapter}.${verse}`
				: `${chapter}, ${verse}`;
	}
	const edition = c.translation
		? [c.translation, c.year].filter(Boolean).join(' ')
		: '';
	const head = [humanize(c.text), where].filter(Boolean).join(' ');
	const parts = [head, edition, c.basis].filter(Boolean);
	return parts.join(' · ');
}