Improve app message types

app/src/bridge/messaging.ts

@@ -0,0 +1,172 @@
+"use strict";
+
+import { Receiver
+       , ReceiverSelectionCast
+       , ReceiverSelectionStop
+       , ReceiverStatus } from "./types";
+
+
+type MessageDefinitions = {
+      "shim:serviceUp": { id: Receiver["id"] }
+    , "shim:serviceDown": { id: Receiver["id"] }
+  
+    , "shim:launchApp": { receiver: Receiver }
+  
+      // Session messages
+    , "shim:session/stopped": {}
+    , "shim:session/connected": {
+          sessionId: string
+        , namespaces: Array<{ name: string }>
+        , displayName: string
+        , statusText: string
+      }
+    , "shim:session/updateStatus": { volume: any /* Volume */ }
+    , "shim:session/impl_addMessageListener": {
+          namespace: string
+        , data: string
+      }
+    , "shim:session/impl_sendMessage": {
+          messageId: string
+        , error: boolean
+      }
+    , "shim:session/impl_setReceiverMuted": {
+          volumeId: string
+        , error: boolean
+      }
+    , "shim:session/impl_setReceiverVolumeLevel": {
+          volumeId: string
+        , error: boolean
+      }
+    , "shim:session/impl_stop": {
+          stopId: string
+        , error: boolean
+      }
+  
+      // Bridge session messages
+    , "bridge:session/initialize": {
+          address: string
+        , port: number
+        , appId: string
+        , sessionId: string
+        , _id: string
+      }
+    , "bridge:session/close": {}
+    , "bridge:session/impl_leave": {
+          id: string
+        , _id: string
+      }
+    , "bridge:session/impl_sendMessage": {
+          namespace: string
+        , message: any
+        , messageId: string
+        , _id: string
+      }
+    , "bridge:session/impl_setReceiverMuted": {
+          muted: boolean
+        , volumeId: string
+        , _id: string
+      }
+    , "bridge:session/impl_setReceiverVolumeLevel": {
+          newLevel: number
+        , volumeId: string
+        , _id: string
+      }
+    , "bridge:session/impl_stop": {
+          stopId: string;
+          _id: string;
+      }
+    , "bridge:session/impl_addMessageListener": {
+          namespace: string;
+          _id: string;
+      }
+  
+      // Media messages
+    , "shim:media/update": {
+          currentTime: number
+        , _lastCurrentTime: number
+        , customData: any
+        , playbackRate: number
+        , playerState: string
+        , repeatMode: string
+        , _volumeLevel: number
+        , _volumeMuted: boolean
+        , media: unknown // MediaInfo
+        , mediaSessionId: number
+      }
+    , "shim:media/sendMediaMessageResponse": {
+          messageId: string
+        , error: boolean
+      }
+  
+      // Bridge media messages
+    , "bridge:media/initialize": {
+          sessionId: string
+        , mediaSessionId: number
+        , _internalSessionId: string
+        , _id: string
+      }
+    , "bridge:media/sendMediaMessage": {
+          message: any
+        , messageId: string
+        , _id: string
+      }
+  
+      // Bridge messages
+    , "main:receiverSelector/selected": ReceiverSelectionCast
+    , "main:receiverSelector/error": string
+    , "main:receiverSelector/close": {}
+    , "main:receiverSelector/stop": ReceiverSelectionStop
+  
+    , "bridge:getInfo": string
+    , "bridge:initialize": { shouldWatchStatus: boolean }
+  
+    , "bridge:receiverSelector/open": any
+    , "bridge:receiverSelector/close": {}
+  
+    , "bridge:stopReceiverApp": { receiver: Receiver }
+  
+    , "bridge:mediaServer/start": {
+          filePath: string
+        , port: number
+      }
+    , "bridge:mediaServer/stop": {}
+    , "mediaCast:mediaServer/started": {
+          mediaPath: string
+        , subtitlePaths: string[]
+        , localAddress: string
+      }
+    , "mediaCast:mediaServer/stopped": {}
+    , "mediaCast:mediaServer/error": {}
+  
+    , "main:serviceUp": Receiver
+    , "main:serviceDown": { id: string }
+  
+    , "main:receiverStatus": {
+          id: string
+        , status: ReceiverStatus
+      }
+}
+
+
+interface MessageBase<K extends keyof MessageDefinitions> {
+    subject: K;
+    data: MessageDefinitions[K];
+}
+
+type Messages = {
+    [K in keyof MessageDefinitions]: MessageBase<K>;
+}
+
+/**
+ * For better call semantics, make message data key optional if
+ * specified as blank or with all-optional keys.
+ */
+type NarrowedMessage<L extends MessageBase<keyof MessageDefinitions>> =
+    L extends any
+        ? {} extends L["data"]
+            ? Omit<L, "data"> & Partial<L>
+            : L
+        : never;
+
+        
+export type Message = NarrowedMessage<Messages[keyof Messages]>;