/**
 * @file Starts and reports on the "Update all" batch: every registered
 * marketplace, then every installed plugin, then a reload of the Claude Code
 * sessions the dashboard has open.
 *
 * Why a detached worker with an on-disk journal instead of a plain request
 * handler: the batch includes AgentHub ITSELF when the dashboard runs from the
 * plugin cache. Updating that plugin ends in `plugin-bootstrap.js --force`,
 * which SIGTERMs this very server, so an in-process loop would die partway
 * through with the remaining steps unrun and no way to report anything. The
 * worker outlives the swap, keeps going, and writes each step's outcome to
 * `cc-update-all.json` under the runtime directory — outside the plugin cache,
 * which the update replaces — so whichever server is alive can serve progress
 * from it. AgentHub is ordered LAST for the same reason: every other plugin is
 * already done by the time the restart happens.
 *
 * The reload step comes after all updates, not per-plugin, because that is what
 * "update everything, then reload" means for a session: one `/reload-plugins`
 * picks up every pending change at once, where N of them would just re-scan the
 * same directory N times. A single-plugin update reloads immediately instead —
 * see the `reload` flag on `POST /api/cc-config/plugins/action`.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const fs = require("fs");
const path = require("path");
const { spawn } = require("child_process");
const { getDataDir } = require("./claude-home");

const JOURNAL_NAME = "cc-update-all.json";
/** A batch still "running" after this long is treated as abandoned, so a worker
 *  killed by a reboot can't wedge the button forever. */
const STALE_MS = 60 * 60 * 1000;

function runtimeDir() {
  return path.join(getDataDir(), "runtime");
}

function journalPath(rt = runtimeDir()) {
  return path.join(rt, JOURNAL_NAME);
}

/**
 * Current (or last) batch state, or null when none has ever run.
 *
 * A `running` journal older than `STALE_MS` is reported as `abandoned` rather
 * than `running`: the worker is detached, so a host reboot leaves no one to
 * write the terminal entry and the UI would otherwise show a spinner forever.
 *
 * @returns {{status: string, steps: object[], started_at?: string,
 *   finished_at?: string} | null}
 */
function readUpdateAll(rt = runtimeDir()) {
  let parsed;
  try {
    parsed = JSON.parse(fs.readFileSync(journalPath(rt), "utf8"));
  } catch {
    return null; // never run, unreadable, or malformed — all "nothing to report"
  }
  if (!parsed || typeof parsed !== "object" || !Array.isArray(parsed.steps)) return null;
  if (parsed.status === "running") {
    const started = Date.parse(parsed.started_at || "");
    if (Number.isFinite(started) && Date.now() - started > STALE_MS) {
      return { ...parsed, status: "abandoned" };
    }
  }
  return parsed;
}

/** True when a batch is in flight — used to refuse a concurrent start rather
 *  than run two `claude plugin update` chains over the same config dir. */
function isRunning(rt = runtimeDir()) {
  return readUpdateAll(rt)?.status === "running";
}

/**
 * Spawn the detached batch worker.
 *
 * The caller must have written its HTTP response first: when `selfPlugin` is
 * set, this process is going to be stopped before the batch finishes.
 *
 * @param {{plugins: string[], selfPlugin: {marketplace: string, plugin: string}|null,
 *   selfRoot: string|null, reload: boolean}} plan
 *   `plugins` are `name@marketplace` ids, already validated by the caller.
 * @returns {{spawned: true, runtime_dir: string}}
 */
function startUpdateAll(plan) {
  const rt = runtimeDir();
  fs.mkdirSync(rt, { recursive: true });
  // Clear the previous batch so a stale terminal state is never read as this
  // run's progress in the window before the worker writes its first entry.
  try {
    fs.rmSync(journalPath(rt), { force: true });
  } catch {
    /* best effort */
  }

  const helper = path.join(__dirname, "..", "..", "scripts", "cc-update-all-helper.js");
  const child = spawn(process.execPath, [helper, rt, JSON.stringify(plan)], {
    // Never the plugin root: when selfPlugin is set that directory is replaced
    // mid-run, and a cwd inside a replaced directory can wedge the process.
    cwd: rt,
    detached: true,
    stdio: "ignore",
    env: process.env,
  });
  child.unref();
  return { spawned: true, runtime_dir: rt };
}

module.exports = { startUpdateAll, readUpdateAll, isRunning, runtimeDir, journalPath, STALE_MS };