feat(web): move connection downlinks to WebSocket

packages/client/connection/src/index.ts

@@ -2,13 +2,14 @@
 import type { Context } from 'cordis'
 import z from 'schemastery'
 // Activates the httpServer Context merge used below.
-import type { WebRoute } from '@deepseek-ai/dsh-host-webserver'
+import type { WebRoute, WebUpgradeRoute } from '@deepseek-ai/dsh-host-webserver'
 import { toFetchHandler } from '@deepseek-ai/dsh-host-apiproxy'
-import { API_PATH } from './api-path.ts'
+import { API_PATH, HOST_EVENTS_PATH, MUX_EVENTS_PATH } from './api-path.ts'
 import { bridge } from './http-bridge.ts'
 import { assertTrustedAuthority, isTrustedApiRequest } from './api-request-trust.ts'
+import { rejectWebSocketUpgrade, WebSocketDownlinks } from './websocket-downlink.ts'
 
-export { API_PATH } from './api-path.ts'
+export { API_PATH, HOST_EVENTS_PATH, MUX_EVENTS_PATH } from './api-path.ts'
 
 /** Stable Cordis plugin name. */
 export const name = 'client-connection'
@@ -76,6 +77,7 @@ export function apply(ctx: Context, config?: ConnectionConfig): void {
   // silently authorizing its hostname prefix at request time.
   for (const entry of trustedHosts) assertTrustedAuthority(entry)
   const apiHandler = toFetchHandler(ctx.apiProxy)
+  const downlinks = new WebSocketDownlinks(ctx.apiProxy)
   const route: WebRoute = {
     kind: 'prefix',
     path: API_PATH,
@@ -92,8 +94,31 @@ export function apply(ctx: Context, config?: ConnectionConfig): void {
         res.end('forbidden')
         return
       }
+      if (req.method === 'GET' && (pathname === MUX_EVENTS_PATH || pathname === HOST_EVENTS_PATH)) {
+        res.writeHead(426, { connection: 'Upgrade', upgrade: 'websocket' })
+        res.end('upgrade required')
+        return
+      }
       await bridge(req, res, apiHandler)
     },
   }
   ctx.effect(() => ctx.httpServer.register(route), 'client-connection: /api route')
+  const registerDownlink = (
+    path: string,
+    handle: WebUpgradeRoute['handler'],
+  ): void => {
+    ctx.effect(() => ctx.httpServer.registerUpgrade({
+      path,
+      handler: (req, socket, head) => {
+        if (!isTrustedApiRequest(req, trustedHosts)) {
+          rejectWebSocketUpgrade(socket)
+          return
+        }
+        return handle(req, socket, head)
+      },
+    }), `client-connection: ${path} WebSocket`)
+  }
+  ctx.effect(() => () => downlinks.close(), 'client-connection: WebSocket downlinks')
+  registerDownlink(MUX_EVENTS_PATH, (req, socket, head) => { downlinks.handleMux(req, socket, head) })
+  registerDownlink(HOST_EVENTS_PATH, (req, socket, head) => { downlinks.handleHost(req, socket, head) })
 }