"use client";

// The client's side of POST /api/report/timeline, and the event every part of
// a project page listens to after the manifest changed under it.
//
// The timeline editor, the structure editors and the On-screen section each
// hold a manifest TOKEN; a structural write changes the file, so after one
// every other holder must re-read before its next save would 409.

export const MANIFEST_CHANGED = "umtool:manifest-changed";

export function announceManifestChanged(project: string) {
  window.dispatchEvent(new CustomEvent(MANIFEST_CHANGED, { detail: { project } }));
}

export type TimelineResult = {
  ok: boolean;
  status: number;
  json: Record<string, unknown> & { error?: string; errors?: string[]; stale?: boolean; token?: string };
};

export async function timelineOp(project: string, token: string | null, op: string, args: Record<string, unknown> = {}): Promise<TimelineResult> {
  const r = await fetch("/api/report/timeline", {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({ project, token, op, ...args }),
    cache: "no-store",
  });
  const json = (await r.json().catch(() => ({ error: `HTTP ${r.status}` }))) as TimelineResult["json"];
  return { ok: r.ok, status: r.status, json };
}

/** A refusal in words: the build's sentences when there are several. */
export const refusalOf = (res: TimelineResult) =>
  res.json.stale
    ? "the manifest changed since this page read it — reloaded; try again"
    : res.json.errors?.length
      ? res.json.errors.join("; ")
      : String(res.json.error ?? `HTTP ${res.status}`);