feat(cli): add preview server daemon

packages/cli/src/framework/runtime.ts

@@ -0,0 +1,77 @@
+import * as Effect from "effect/Effect"
+import * as Command from "effect/unstable/cli/Command"
+import { Spec } from "./spec"
+import { Daemon } from "../services/daemon"
+
+export type Input<Value> =
+  Value extends Spec.Node<infer _Name, infer Command, infer _Commands>
+    ? Input<Command>
+    : Value extends Command.Command<infer _Name, infer Input, infer _Context, infer _Error, infer _Requirements>
+      ? Input
+      : never
+
+type RuntimeHandler = (input: unknown) => Effect.Effect<void, unknown, Daemon.Service>
+type Loader<Node extends Spec.Any> = () => Promise<{ default: (input: Input<Node>) => Effect.Effect<void, any, Daemon.Service> }>
+type ProvidedCommand = Command.Command<string, unknown, unknown, unknown, Daemon.Service>
+
+export type Handlers<Node extends Spec.Any> = keyof Node["commands"] extends never
+  ? Loader<Node>
+  : { readonly $?: Loader<Node> } & { readonly [Key in keyof Node["commands"]]: Handlers<Node["commands"][Key]> }
+
+interface LazyHandler {
+  readonly spec: Command.Command.Any
+  readonly load: () => Promise<{ default: RuntimeHandler }>
+}
+
+type RuntimeHandlers =
+  | (() => Promise<{ default: RuntimeHandler }>)
+  | {
+      readonly $?: () => Promise<{ default: RuntimeHandler }>
+      readonly [key: string]: RuntimeHandlers | (() => Promise<{ default: RuntimeHandler }>) | undefined
+    }
+
+export function handler<const Node extends Spec.Any, Error, Requirements>(
+  _node: Node,
+  run: (input: Input<Node>) => Effect.Effect<void, Error, Requirements>,
+) {
+  return run
+}
+
+export function handlers<const Root extends Spec.Any>(root: Root, handlers: Handlers<Root>) {
+  const result: LazyHandler[] = []
+
+  function add(node: Spec.Any, value: RuntimeHandlers) {
+    if (typeof value === "function") {
+      result.push({ spec: node.spec, load: value as () => Promise<{ default: RuntimeHandler }> })
+      return
+    }
+    if (value.$) result.push({ spec: node.spec, load: value.$ as () => Promise<{ default: RuntimeHandler }> })
+    for (const [name, child] of Object.entries(node.commands)) add(child, value[name] as RuntimeHandlers)
+  }
+
+  add(root, handlers as RuntimeHandlers)
+  return result
+}
+
+export function run(commands: Spec.Any, handlers: ReadonlyArray<LazyHandler>, options: { readonly version: string }) {
+  return Command.run(provide(commands, handlers), options) as Effect.Effect<void, unknown, Command.Environment>
+}
+
+function provide(node: Spec.Any, handlers: ReadonlyArray<LazyHandler>): ProvidedCommand {
+  const spec: Command.Command.Any = Object.keys(node.commands).length
+    ? (node.spec as Command.Command<string, unknown>).pipe(
+        Command.withSubcommands(Object.values(node.commands).map((child) => provide(child, handlers))),
+      )
+    : node.spec
+  const handler = handlers.find((handler) => handler.spec === node.spec)
+  if (!handler) return spec as ProvidedCommand
+  return spec.pipe(
+    Command.withHandler((input) =>
+      Effect.gen(function* () {
+        yield* Effect.flatMap(Effect.promise(handler.load), (module) => module.default(input))
+      }),
+    ),
+  ) as ProvidedCommand
+}
+
+export * as Runtime from "./runtime"