web-player: share form limits between client and server and extract form parsers

web-player/src/lib/server/forms/albumForm.ts

@@ -0,0 +1,42 @@
+import { formString } from '$lib/server/api';
+import { ALBUM_EARLIEST_YEAR, LIMITS } from '$lib/validation';
+
+interface AlbumFormBody {
+	title: string;
+	description: string | null;
+	releaseYear: number | null;
+}
+
+export function parseAlbumForm(form: FormData): { body: AlbumFormBody } | { failMessage: string } {
+	const title = formString(form, 'title').trim();
+	if (title === '' || title.length > LIMITS.albumTitle) {
+		return { failMessage: `El título es obligatorio (máx. ${LIMITS.albumTitle} caracteres).` };
+	}
+
+	const description = formString(form, 'description').trim();
+	if (description.length > LIMITS.albumDescription) {
+		return {
+			failMessage: `La descripción no puede pasar de ${LIMITS.albumDescription} caracteres.`
+		};
+	}
+
+	const rawYear = formString(form, 'releaseYear').trim();
+	const latestYear = new Date().getFullYear() + 1;
+	let releaseYear: number | null = null;
+
+	if (rawYear !== '') {
+		const parsed = Number(rawYear);
+		if (!Number.isInteger(parsed) || parsed < ALBUM_EARLIEST_YEAR || parsed > latestYear) {
+			return { failMessage: `El año debe estar entre ${ALBUM_EARLIEST_YEAR} y ${latestYear}.` };
+		}
+		releaseYear = parsed;
+	}
+
+	return {
+		body: {
+			title,
+			description: description === '' ? null : description,
+			releaseYear
+		}
+	};
+}