import type { TaskRun, TaskRunPage } from "../../shared/tasks";

export const emptyTaskHistory: TaskRunPage = { runs: [], nextCursor: null };
export const activeRun = (run: TaskRun) =>
  ["dispatching", "pending", "running"].includes(run.status);

export function retainedRuns(latest: TaskRunPage, previous: TaskRunPage) {
  const overlap = latest.runs.some((run) =>
    previous.runs.some((item) => item.id === run.id),
  );
  return {
    overlap,
    runs: (overlap ? previous.runs : []).filter(
      (run) => !latest.runs.some((item) => item.id === run.id),
    ),
  };
}

export function unsettledCursor(retained: TaskRun[], previous: TaskRunPage) {
  const unfinished =
    retained.find(activeRun) ??
    retained.find((run) => run.status === "dispatch_error");
  const before =
    unfinished &&
    previous.runs[
      previous.runs.findIndex((run) => run.id === unfinished.id) - 1
    ];
  return before ? { id: before.id, createdAt: before.createdAt } : null;
}