// K3PT ST4T3 tab of the dashboard: kept state from agents whose container
// is absent (tombstones), with a purge button per row. Owns its slice of
// state like agents.js / builds.js do; tabs.js feeds it the /api/state
// snapshot and the `tombstones_changed` stream event.

import { $, form } from "./common.js";
import { el } from "@hive/shared/dom.js";

let tombstonesState = [];

const fmtBytes = (n) => {
  if (n < 1024) return n + " B";
  if (n < 1024 * 1024) return (n / 1024).toFixed(1) + " KB";
  if (n < 1024 * 1024 * 1024) return (n / (1024 * 1024)).toFixed(1) + " MB";
  return (n / (1024 * 1024 * 1024)).toFixed(2) + " GB";
};

const fmtAgeDays = (ts) => {
  if (!ts) return "?";
  const d = Math.floor((Date.now() / 1000 - ts) / 86400);
  if (d <= 0) return "today";
  if (d === 1) return "1 day ago";
  return d + " days ago";
};

/** Number of kept-state entries, for the tab's count pill. */
export function keptCount() {
  return tombstonesState.length;
}

export function syncKeptFromSnapshot(s) {
  tombstonesState = (s.tombstones || []).slice();
}

export function renderKept() {
  const root = $("tombstones-section");
  if (!root) return;
  root.replaceChildren();
  if (!tombstonesState.length) {
    root.append(el("p", { class: "empty" }, "no kept state — clean"));
    return;
  }
  // Only shown alongside actual rows — a caveat over an empty list is noise.
  // Wording is deliberately about what the list *is* rather than what it
  // isn't: nothing records a destroy, so "container absent" is the only thing
  // the backend can actually tell.
  const warn = el("hive-warn", { level: "warning" });
  warn.append(
    el("strong", {}, "shows every agent whose container is absent"),
    " — not only destroyed ones. An agent part-way through being spawned " +
      "looks identical here, because nothing records a destroy. Check it is " +
      "really gone before you PURG3.",
  );
  root.append(warn);
  const ul = el("ul", { class: "containers" });
  for (const t of tombstonesState) {
    const li = el("li", { class: "container-row tombstone" });
    const head = el("div", { class: "head" });
    head.append(
      el("span", { class: "name" }, t.name),
      // `offline` is what the absence of a container proves; `destroyed`
      // is something the backend cannot know — see the caveat above.
      el("span", { class: "hive-pill-sm badge-muted" }, "offline"),
    );
    if (t.has_creds)
      head.append(
        el("span", { class: "hive-pill-sm badge-muted" }, "creds kept"),
      );
    head.append(
      el(
        "span",
        { class: "meta" },
        `${fmtBytes(t.state_bytes)} · ${fmtAgeDays(t.last_seen)}`,
      ),
    );
    li.append(head);

    const actions = el("div", { class: "actions" });
    actions.append(
      form(
        "/api/purge-tombstone/" + t.name,
        "btn-destroy",
        "PURG3",
        "PURGE " +
          t.name +
          "? config history, claude creds, " +
          "and notes are all WIPED. no undo.",
        {},
        { noRefresh: true },
      ),
    );
    li.append(actions);
    ul.append(li);
  }
  root.append(ul);
}

/** `tombstones_changed` stream event: replace the list and re-render. */
export function applyTombstonesChanged(ev) {
  tombstonesState = (ev.tombstones || []).slice();
  renderKept();
}