/** Dev fixture prefixes (import script / dev_fixture.php). */
export function isDevTestClientCode(code) {
    const c = String(code ?? '').trim();
    return c.toUpperCase().startsWith('DEV-CL-');
}

export function isDevTestUsername(username) {
    return String(username ?? '').trim().toLowerCase().startsWith('dev_');
}

export function testDataRowClassForClient(clientCode) {
    return isDevTestClientCode(clientCode) ? ' row-test-data' : '';
}

export function testDataRowClassForUser(username) {
    return isDevTestUsername(username) ? ' row-test-data' : '';
}

const STABLE_KEY_RE = /^[a-zA-Z][a-zA-Z0-9_]*$/;

/** Local question id from full questionID (hash__q5 → q5). */
export function questionLocalKey(questionID, fallback = '') {
    const id = String(questionID ?? '');
    const sep = id.lastIndexOf('__');
    if (sep >= 0) return id.slice(sep + 2);
    return fallback || id;
}

function parseQuestionConfig(q) {
    if (!q || typeof q !== 'object') return {};
    let cfg = q.configJson;
    if (typeof cfg === 'string') {
        try {
            cfg = JSON.parse(cfg);
        } catch {
            cfg = {};
        }
    }
    return cfg && typeof cfg === 'object' ? cfg : {};
}

/** Stable question key for table headers / CSV (matches server qdb_question_column_label). */
export function questionDisplayKey(q) {
    if (!q) return '';
    if (q.questionKey) return String(q.questionKey);
    const cfg = parseQuestionConfig(q);
    const fromCfg = String(cfg.questionKey || '').trim();
    if (fromCfg && STABLE_KEY_RE.test(fromCfg)) return fromCfg;
    const dt = String(q.defaultText || '').trim();
    if (dt && STABLE_KEY_RE.test(dt)) return dt;
    return questionLocalKey(q.questionID, dt);
}

/** German question text for header tooltips. */
export function questionGermanLabel(q) {
    const dt = String(q?.defaultText || '').trim();
    const key = questionDisplayKey(q);
    if (dt && dt !== key) return dt;
    return '';
}

/** header_order.json column id → question key (questionnaire_x-y → y). */
export function headerColumnQuestionKey(headerId) {
    const id = String(headerId ?? '');
    if (id === 'client_code') return 'client_code';
    const dash = id.indexOf('-');
    if (dash < 0) return id;
    return id.slice(dash + 1);
}