import type { AuditRow } from "./api";

// The audit log's scheduler noise, folded (the owner's pick): the background jobs write a row per
// run that changed something, so an hour of "enrichment done" filled the first screen and pushed the
// admins' own actions down. A job's SUCCESSFUL runs become one row that names how many there were and
// opens to each — whatever ran between them (another job, an admin's action): the owner read a fold
// that broke at every other job as the same row five times. Only that job's own failed or skipped run
// breaks it: that row stays on its own, at its moment, where it is seen, and the job's older successes
// start a new fold below it. Rows arrive newest first; a fold stands at its newest run's place.

/** An audit row as the table lists it: a lone row, or the newest of a job's folded runs (`runs`, the
 *  whole fold newest first, the row itself included). */
export type AuditListRow = AuditRow & { runs?: AuditRow[] };

/** The job a row is a run of, or null for any other row. */
function jobOf(row: AuditRow): string | null {
  return row.action === "job_run" && row.target_type === "job" && row.target_id
    ? row.target_id
    : null;
}

export function foldJobRuns(rows: readonly AuditRow[]): AuditListRow[] {
  const out: AuditListRow[] = [];
  // Each job's open fold: the row its next older success joins.
  const open = new Map<string, AuditListRow>();
  for (const row of rows) {
    const job = jobOf(row);
    if (job === null) {
      out.push(row);
      continue;
    }
    if (row.after?.status !== "ok") {
      // A failure or a skip stands alone and closes the job's fold.
      open.delete(job);
      out.push(row);
      continue;
    }
    const head = open.get(job);
    if (head) {
      head.runs = [...(head.runs ?? [head]), row];
      continue;
    }
    const fresh: AuditListRow = { ...row };
    open.set(job, fresh);
    out.push(fresh);
  }
  return out;
}