effect: add RuntimeFlags service (#27181)

packages/opencode/src/effect/runtime-flags.ts

@@ -0,0 +1,27 @@
+import { Config, ConfigProvider, Context, Effect, Layer } from "effect"
+import { ConfigService } from "@/effect/config-service"
+
+export class Service extends ConfigService.Service<Service>()("@opencode/RuntimeFlags", {
+  pure: Config.boolean("OPENCODE_PURE").pipe(Config.withDefault(false)),
+  disableDefaultPlugins: Config.boolean("OPENCODE_DISABLE_DEFAULT_PLUGINS").pipe(Config.withDefault(false)),
+}) {}
+
+export type Info = Context.Service.Shape<typeof Service>
+
+const emptyConfigLayer = Service.defaultLayer.pipe(
+  Layer.provide(ConfigProvider.layer(ConfigProvider.fromUnknown({}))),
+  Layer.orDie,
+)
+
+export const layer = (overrides: Partial<Info> = {}) =>
+  Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      const flags = yield* Service
+      return Service.of({ ...flags, ...overrides })
+    }),
+  ).pipe(Layer.provide(emptyConfigLayer))
+
+export const defaultLayer = Service.defaultLayer.pipe(Layer.orDie)
+
+export * as RuntimeFlags from "./runtime-flags"