/**
* Server Registry
*
* Registers the WebSocket server port in SQLite for discovery by the Web UI.
* Uses heartbeat to detect stale entries from crashed processes.
*/
import { prisma } from '../db.js'
import { createLogger } from './logger.js'
const logger = createLogger('server-registry')
const HEARTBEAT_INTERVAL_MS = 5000 // 5 seconds
const STALE_THRESHOLD_MS = 15000 // Consider stale if no heartbeat for 15s
let heartbeatInterval: NodeJS.Timeout | null = null
/**
* Register the WebSocket server port in the database.
* This allows the Web UI to discover which port to connect to.
*/
export async function registerServerPort(port: number): Promise<void> {
const processId = process.pid
await prisma.serverInfo.upsert({
where: { id: 'singleton' },
create: {
id: 'singleton',
websocketPort: port,
startedAt: new Date(),
lastHeartbeat: new Date(),
processId,
},
update: {
websocketPort: port,
startedAt: new Date(),
lastHeartbeat: new Date(),
processId,
},
})
logger.info('Registered WebSocket port', { port, processId })
// Start heartbeat
startHeartbeat()
}
/**
* Update the heartbeat timestamp periodically.
* This allows clients to detect if the server is still alive.
*/
function startHeartbeat(): void {
if (heartbeatInterval) {
clearInterval(heartbeatInterval)
}
heartbeatInterval = setInterval(async () => {
try {
await prisma.serverInfo.update({
where: { id: 'singleton' },
data: { lastHeartbeat: new Date() },
})
} catch (error) {
logger.warn('Failed to update heartbeat', {
error: error instanceof Error ? error.message : String(error),
})
}
}, HEARTBEAT_INTERVAL_MS)
// Don't keep the process alive just for heartbeat
heartbeatInterval.unref()
}
/**
* Stop the heartbeat and unregister the server.
* Called during graceful shutdown.
*/
export async function unregisterServer(): Promise<void> {
if (heartbeatInterval) {
clearInterval(heartbeatInterval)
heartbeatInterval = null
}
try {
await prisma.serverInfo.delete({
where: { id: 'singleton' },
})
logger.info('Unregistered server')
} catch (error) {
logger.warn('Failed to unregister server', {
error: error instanceof Error ? error.message : String(error),
})
}
}
/**
* Get the current WebSocket port from the database.
* Returns null if no server is registered or if the entry is stale.
*/
export async function getActiveServerPort(): Promise<number | null> {
try {
const info = await prisma.serverInfo.findUnique({
where: { id: 'singleton' },
})
if (!info) {
return null
}
// Check if the entry is stale
const now = Date.now()
const lastHeartbeat = info.lastHeartbeat.getTime()
if (now - lastHeartbeat > STALE_THRESHOLD_MS) {
logger.warn('Stale entry detected', { lastHeartbeat: info.lastHeartbeat })
return null
}
return info.websocketPort
} catch {
return null
}
}
