feat: expose background service lifecycle (#36895)

packages/server/src/service-status.ts

@@ -0,0 +1,57 @@
+export * as Status from "./service-status"
+
+import { InstallationVersion } from "@opencode-ai/core/installation/version"
+import { ServiceStatus } from "@opencode-ai/protocol/groups/health"
+import { Effect, Ref } from "effect"
+
+export interface Interface {
+  readonly health: Effect.Effect<ServiceStatus.Health>
+  readonly current: Effect.Effect<ServiceStatus.State>
+  readonly ready: Effect.Effect<void>
+  readonly fail: (failure: { readonly message: string; readonly action: string }) => Effect.Effect<void>
+  readonly beginStopping: (targetVersion?: string) => Effect.Effect<void>
+  readonly requestStop: (request: ServiceStatus.StopRequest) => Effect.Effect<boolean>
+}
+
+export const make = Effect.fnUntraced(function* (options: {
+  readonly instanceID: string
+  readonly managed: boolean
+  readonly initial?: ServiceStatus.State
+}) {
+  const current = yield* Ref.make(options.initial ?? ({ type: "starting" } satisfies ServiceStatus.State))
+  const transitionToStopping = (targetVersion?: string) =>
+    Ref.update(current, (status) => {
+      if (status.type === "stopping") return status
+      return (
+        targetVersion === undefined || targetVersion === InstallationVersion
+          ? { type: "stopping" }
+          : { type: "stopping", targetVersion }
+      ) satisfies ServiceStatus.State
+    })
+
+  return {
+    current: Ref.get(current),
+    health: Effect.gen(function* () {
+      return {
+        healthy: true as const,
+        version: InstallationVersion,
+        pid: process.pid,
+        instanceID: options.instanceID,
+        status: yield* Ref.get(current),
+      }
+    }),
+    ready: Ref.update(current, (status) =>
+      status.type === "starting" ? ({ type: "ready" } satisfies ServiceStatus.State) : status,
+    ),
+    fail: (failure) =>
+      Ref.update(current, (status) =>
+        status.type === "starting" ? ({ type: "failed", ...failure } satisfies ServiceStatus.State) : status,
+      ),
+    beginStopping: transitionToStopping,
+    requestStop: (request) => {
+      if (!options.managed || request.instanceID !== options.instanceID)
+        return Effect.succeed(false)
+      return transitionToStopping(request.targetVersion).pipe(Effect.as(true))
+    },
+  } satisfies Interface
+})