Files
familienarchiv/frontend/src/lib/document/filename.ts
2026-05-05 14:35:15 +02:00

88 lines
3.0 KiB
TypeScript

import { isoToGerman } from '$lib/shared/utils/date';
export interface FilenameParseResult {
/** ISO format: YYYY-MM-DD */
dateIso?: string;
/** "Firstname Lastname" — order reversed from filename convention */
personName?: string;
/** Ready-to-use title, e.g. "Hans Mueller (12.03.1965)" */
suggestedTitle?: string;
}
// A date token is either YYYY-MM-DD or YYYYMMDD with a plausible month/day range.
function tryParseDate(s: string): string | undefined {
if (/^\d{4}-\d{2}-\d{2}$/.test(s)) {
const m = parseInt(s.slice(5, 7));
const d = parseInt(s.slice(8, 10));
if (m >= 1 && m <= 12 && d >= 1 && d <= 31) return s;
} else if (/^\d{8}$/.test(s)) {
const m = parseInt(s.slice(4, 6));
const d = parseInt(s.slice(6, 8));
if (m >= 1 && m <= 12 && d >= 1 && d <= 31)
return `${s.slice(0, 4)}-${s.slice(4, 6)}-${s.slice(6, 8)}`;
}
return undefined;
}
const NAME_PART = /^\p{L}+$/u;
/**
* Parses a structured filename and extracts a date and person name.
*
* Supported conventions (date-first or date-last, compound last names supported):
* YYYY-MM-DD_Lastname_Firstname.ext
* YYYYMMDD_Lastname_Firstname.ext
* YYYYMMDD_de_Gruyter_Walter.ext ← compound last name: lastName="de Gruyter"
* Lastname_Firstname_YYYY-MM-DD.ext
* Lastname_Firstname_YYYYMMDD.ext
* de_Gruyter_Walter_YYYYMMDD.ext ← compound last name: lastName="de Gruyter"
*
* Algorithm: split on "_", identify the date token (first or last segment),
* treat the outermost remaining segment as firstName, rest as lastName parts.
* Returns {} for anything that doesn't match cleanly.
*/
export function parseFilename(filename: string): FilenameParseResult {
const dot = filename.lastIndexOf('.');
if (dot < 0) return {}; // no extension — not a real file
const stem = filename.slice(0, dot);
const parts = stem.split('_');
// Minimum: date + at least one lastName segment + firstName = 3 parts
if (parts.length < 3) return {};
let dateIso: string;
let nameParts: string[];
const dateFromFirst = tryParseDate(parts[0]);
if (dateFromFirst) {
dateIso = dateFromFirst;
nameParts = parts.slice(1);
} else {
const dateFromLast = tryParseDate(parts[parts.length - 1]);
if (!dateFromLast) return {};
dateIso = dateFromLast;
nameParts = parts.slice(0, -1);
}
// Need at least lastName + firstName after removing the date
if (nameParts.length < 2) return {};
// All name segments must be pure letters (covers umlauts via \p{L})
if (!nameParts.every((p) => NAME_PART.test(p))) return {};
const firstName = nameParts[nameParts.length - 1];
const lastName = nameParts.slice(0, -1).join(' ');
const personName = `${firstName} ${lastName}`;
const suggestedTitle = `${personName} (${isoToGerman(dateIso)})`;
return { dateIso, personName, suggestedTitle };
}
export function stripExtension(filename: string): string {
return filename.replace(/\.[^/.]+$/, '');
}
export function bulkTitleFromFilename(filename: string): string {
return stripExtension(filename).replace(/[_-]+/g, ' ').trim();
}