// C0R3 page entry (/core.html). The host/coordinator surface, its own
// standalone page so the dashboard tab strip stays lean: kept state
// (tombstones).
//
// Rebuild queue + meta inputs are tabs of /dashboard.html, not here. This
// page is its own esbuild bundle with its own runtime: it cold-loads
// /api/state and subscribes to /dashboard/stream (the same broker event
// channel the dashboard uses), maintaining its own copy of the tombstones
// state.

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

// ─── derived state (own copies; this bundle has its own runtime) ──────────
let tombstonesState = [];
function syncFromSnapshot(s) {
  tombstonesState = (s.tombstones || []).slice();
}

// ─── kept state (tombstones) ──────────────────────────────────────────────
function renderTombstones(s) {
  const root = $("tombstones-section");
  if (!root) return;
  root.replaceChildren();
  if (!s.tombstones || !s.tombstones.length) {
    root.append(el("p", { class: "empty" }, "no kept state — clean"));
    return;
  }
  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";
  };
  // 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 s.tombstones) {
    const li = el("li", { class: "container-row tombstone" });
    const head = el("div", { class: "head" });
    head.append(
      el("span", { class: "name" }, t.name),
      // Was `destroyed`, which the backend cannot actually know — see the
      // caveat above. `offline` is what the absence of a container proves.
      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);
}

// ─── render-all (cold load + any full re-render) ──────────────────────────
function renderAll() {
  renderTombstones({ tombstones: tombstonesState });
}

// ─── live SSE handlers ───────────────────────────────────────────────────
const SSE_HANDLERS = {
  tombstones_changed(ev) {
    tombstonesState = (ev.tombstones || []).slice();
    renderTombstones({ tombstones: tombstonesState });
  },
};

// ─── boot ─────────────────────────────────────────────────────────────────
// Re-fetch /api/state, re-sync the derived state, re-render. Used for the
// cold load and as the post-submit refresh for `data-async` forms whose
// mutation doesn't arrive via an SSE event (e.g. the meta-update / spawn /
// purge actions that opt out of `data-no-refresh`).
async function refreshState() {
  try {
    const resp = await fetch("/api/state");
    if (resp.ok) syncFromSnapshot(await resp.json());
  } catch {
    // best-effort: the page keeps its last-rendered state
  }
  renderAll();
}

async function init() {
  initServerWarnings();

  // `data-async` form submit interceptor — without this the meta-update /
  // cancel / respawn / purge buttons POST natively and the browser navigates
  // to the bare `ok` response page.
  bindAsyncForms(() => refreshState());

  await refreshState();

  // kinds= matches SSE_HANDLERS below verbatim — narrows the stream down
  // to the kinds this page acts on. This page was one
  // of 4 unfiltered `/api/dashboard/stream` subscribers before this
  // (subscription discipline, part 1 of the dashboard-event-stream-
  // split issue).
  const es = openStream("/api/dashboard/stream?kinds=tombstones_changed");
  if (es) {
    es.onmessage = (e) => {
      let ev;
      try {
        ev = JSON.parse(e.data);
      } catch {
        return;
      }
      const h = SSE_HANDLERS[ev.kind];
      if (h) h(ev);
    };
  }
}

init();