// The only values ever interpolated into SQL (sort column and direction) come
// from the whitelists here; everything else is a bind parameter.

const SORT_COLUMNS = {
  agreementUuid: '"agreementUuid"',
  eventUuid: '"eventUuid"',
  sender: "sender",
  date: "date",
  size: '"size"',
};

export const SORTABLE_KEYS = Object.keys(SORT_COLUMNS);

export function sortClause(sort, dir) {
  const col = SORT_COLUMNS[sort] || "date";
  const direction = String(dir).toLowerCase() === "asc" ? "ASC" : "DESC";
  return `ORDER BY ${col} ${direction} NULLS LAST`;
}

export function eventSearchClause(idx) {
  return (
    `(e.event_id_uuid::text ILIKE '%'||$${idx}||'%'` +
    ` OR agr.agreement_id_uuid::text ILIKE '%'||$${idx}||'%'` +
    ` OR e.sender_id ILIKE '%'||$${idx}||'%'` +
    ` OR e.recipient_id ILIKE '%'||$${idx}||'%')`
  );
}

export const DEFAULT_LIMIT = 50;
const MAX_LIMIT = 200;

// Server-side bound, applied on every request regardless of what the UI sends.
export function clampLimit(v) {
  const n = parseInt(v, 10);
  if (!Number.isFinite(n)) return DEFAULT_LIMIT;
  return Math.min(Math.max(n, 1), MAX_LIMIT);
}

export function clampOffset(v) {
  const n = parseInt(v, 10);
  if (!Number.isFinite(n) || n < 0) return 0;
  return n;
}

export function pageCount(total, perPage = DEFAULT_LIMIT) {
  return Math.max(1, Math.ceil((Number(total) || 0) / (perPage || DEFAULT_LIMIT)));
}

const MAX_WINDOW_DAYS = 366;

// Enforced server-side on every request, not in the UI.
export function windowParams(query = {}) {
  const iso = (d) => d.toISOString().slice(0, 10);
  const valid = (s) => typeof s === "string" && /^\d{4}-\d{2}-\d{2}$/.test(s);

  const today = new Date();
  today.setUTCHours(0, 0, 0, 0);

  const to = valid(query.to) ? query.to : iso(today);
  let from = valid(query.from) ? query.from : null;
  if (!from) {
    const d = new Date(`${to}T00:00:00Z`);
    d.setUTCDate(d.getUTCDate() - 29);
    from = iso(d);
  }

  let fromD = new Date(`${from}T00:00:00Z`);
  const toD = new Date(`${to}T00:00:00Z`);
  if (fromD > toD) {
    from = to;
    fromD = new Date(toD);
  }
  if ((toD - fromD) / 86_400_000 > MAX_WINDOW_DAYS) {
    const capped = new Date(toD);
    capped.setUTCDate(capped.getUTCDate() - MAX_WINDOW_DAYS);
    from = iso(capped);
  }
  return { from, to };
}