/**
 * Server start hook — Next runs register() once per server process, before
 * it serves the first request (a root instrumentation.ts is picked up with no
 * config in Next 15+).
 *
 * It boots the trading background work eagerly. getClients() in lib/clients.ts
 * starts the broker clients, the contract resolver, the reporter, the master
 * link, the client supervisor and the persisted-schedule resume — and it used
 * to run only on the first HTTP request. So a restarted instance (a crash, an
 * update, pm2 after a reboot) sat idle, not trading and invisible to the
 * master, until someone opened the dashboard or start-all's warm-up curl
 * happened to reach it.
 *
 * The boot must never take the server down with it: a failure is logged, and
 * if the boot never got going the first request still starts it through the
 * same lazy getClients() path as before.
 *
 * This module is its own server bundle, so it can hold its own instances of
 * lib/ modules, separate from the route handlers'. Anything the two must share
 * (the client pool, the scheduler, timers) lives on globalThis for that reason.
 */

export async function register(): Promise<void> {
    // The nodejs check is the documented shape for a Node-only import, kept
    // exactly: the edge compile (Turbopack always builds one) inlines
    // NEXT_RUNTIME and drops the block, so lib/clients — sqlite, sockets —
    // never reaches the edge bundle, where it would fail the build. The build
    // check is defense in depth (Next itself doesn't call register() during
    // `next build`) — a build must never dial brokers or resume the scheduler.
    if (process.env.NEXT_RUNTIME === 'nodejs') {
        if (process.env.NEXT_PHASE === 'phase-production-build') return;
        try {
            const { getClients } = await import('./lib/clients');
            getClients();
        } catch (err) {
            const message = err instanceof Error ? err.message : String(err);
            console.error(`[instrumentation] eager boot failed — clients will start on the first request: ${message}`);
        }
    }
}