Restrict the brightness sink to one app, picked by name not typed

Confirmed the brightness command applies globally, not per-LED
(serverinfo showed exactly one adjustment object, "id": "default",
covering the whole string), so no LED-count configuration is needed
for this at all -- that question resolved itself once the mechanism
was actually inspected instead of assumed.

For "only react while Spotify is running": only one app can be in the
foreground on webOS at a time, so a "capture the current app" button
in this app's own UI can never work -- pressing it means this app is
foreground, not Spotify. The only workable UI is picking a target from
every *installed* app by name, regardless of what's currently running.

That needed a new native capability this service never had: calling
OUT to another Luna service, not just being called. Two additions:

  foreground_app.c   subscribes once, at startup, to
                      com.webos.applicationManager/getForegroundAppInfo
                      and keeps a thread-safe cache the audio thread can
                      read without a blocking Luna call
  service.c           new listApps method, bridging to
                      com.webos.applicationManager/listApps so the
                      frontend never has to call another service
                      directly -- same rule as everywhere else here

Until the subscription has delivered at least one reply, a restricted
sink treats the target app as inactive, not active -- reacting to
audio when the user explicitly restricted it to one app would be the
wrong failure mode. Verified end to end on the host: engine_smoke.c
opens the sink with a restriction set, confirms it reports itself
correctly inactive against the stub Luna bus (which always "fails" to
call out, exactly like a real host with no bus).

Needed real, linkable stub bodies for LSCall/LSCallOneReply/
LSCallCancel/LSMessageGetPayload/LSErrorInit/LSErrorFree
(test/stubs/luna-service2/lunaservice_stub.c) since foreground_app.c
is the first source file here that's actually linked into a host test
binary rather than only syntax-checked -- service.c/main.c's existing
stub declarations were never called, only compiled against. Confirmed
those really are the correct symbol names by cross-compiling clean
against the real webOS SDK's actual libluna-service2, not just the
stub.

Bumped to 1.0.5.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

test/engine_smoke.c

@@ -204,12 +204,22 @@ static void test_status(engine_t* e)
         check(json_len(json_get(levels, "bands")) == DSP_BANDS, "all bands reported");
 
         const json_value_t* sinks = json_get(v, "sinks");
-        check(json_len(sinks) == 2, "two sinks reported");
+        check(json_len(sinks) == 3, "three sinks reported");
         for (size_t i = 0; i < json_len(sinks); i++) {
             const json_value_t* s = json_at(sinks, i);
             char label[64];
             snprintf(label, sizeof(label), "sink '%s' started cleanly", json_str(s, "id", "?"));
             check(json_bool(s, "ok", false), label);
+
+            if (strcmp(json_str(s, "id", ""), "hyperhdrAdjust") == 0) {
+                // A host has no Luna bus (see lunaservice_stub.c), so the
+                // sink can never confirm the restricted app is foreground.
+                // The correct failure mode is inactive, not "assume yes".
+                check(strcmp(json_str(s, "restrictToApp", ""), "some.other.app") == 0,
+                    "restriction target reported back");
+                check(json_bool(s, "restrictedAppActive", true) == false,
+                    "restricted app correctly reported as not active (fail-closed)");
+            }
         }
         json_free(v);
     }
@@ -224,9 +234,11 @@ int main(void)
     char cfg_text[512];
     snprintf(cfg_text, sizeof(cfg_text),
         "{\"capture\":{\"backend\":\"tone\",\"rate\":48000,\"channels\":2},"
-        "\"sinks\":[\"tcp\",\"http\"],"
+        "\"sinks\":[\"tcp\",\"http\",\"hyperhdrAdjust\"],"
         "\"tcp\":{\"port\":%d},"
-        "\"http\":{\"port\":%d}}",
+        "\"http\":{\"port\":%d},"
+        "\"hyperhdrAdjust\":{\"host\":\"127.0.0.1\",\"port\":19444,"
+        "\"restrictToApp\":\"some.other.app\"}}",
         TCP_PORT, HTTP_PORT);
 
     json_value_t* cfg = json_parse(cfg_text);

test/run-tests.sh

@@ -13,12 +13,14 @@ export PYTHONDONTWRITEBYTECODE=1
 OUT=$(mktemp -d)
 trap 'rm -rf "$OUT"' EXIT
 
-CFLAGS=(-std=c11 -Wall -Wextra -Wno-unused-parameter -D_GNU_SOURCE -Inative/src -O1 -g)
+CFLAGS=(-std=c11 -Wall -Wextra -Wno-unused-parameter -D_GNU_SOURCE -Inative/src -Itest/stubs -O1 -g)
 
 SOURCES=(
   native/src/engine.c
   native/src/config.c
   native/src/dsp.c
+  native/src/foreground_app.c
+  test/stubs/luna-service2/lunaservice_stub.c
   native/src/common/log.c
   native/src/common/json.c
   native/src/common/ringbuf.c
@@ -41,7 +43,7 @@ SOURCES=(
 
 echo "== Syntax-checking the webOS-only sources against stub headers"
 for f in native/src/service.c native/src/main.c; do
-  "$CC" "${CFLAGS[@]}" -Itest/stubs -fsyntax-only "$f"
+  "$CC" "${CFLAGS[@]}" -fsyntax-only "$f"
   echo "  ok   $f"
 done
 

test/stubs/luna-service2/lunaservice.h

@@ -20,6 +20,8 @@ typedef struct {
 } LSError;
 
 typedef bool (*LSMethodFunction)(LSHandle* sh, LSMessage* msg, void* category_context);
+typedef bool (*LSFilterFunc)(LSHandle* sh, LSMessage* reply, void* ctx);
+typedef unsigned long LSMessageToken;
 
 typedef enum {
     LUNA_METHOD_FLAGS_NONE = 0,
@@ -58,6 +60,17 @@ bool LSGmainAttach(LSHandle* handle, GMainLoop* loop, LSError* error);
 const char* LSMessageGetPayload(LSMessage* message);
 bool LSMessageIsSubscription(LSMessage* message);
 bool LSMessageReply(LSHandle* sh, LSMessage* message, const char* reply, LSError* error);
+void LSMessageRef(LSMessage* message);
+void LSMessageUnref(LSMessage* message);
 
 bool LSSubscriptionAdd(LSHandle* sh, const char* key, LSMessage* message, LSError* error);
 bool LSSubscriptionReply(LSHandle* sh, const char* key, const char* payload, LSError* error);
+
+// Client-call API: this service acting as a caller of another service, not
+// just a callee. LSCall keeps calling `callback` for every reply (used for
+// subscribe:true); LSCallOneReply auto-cancels after the first one.
+bool LSCall(LSHandle* sh, const char* uri, const char* payload, LSFilterFunc callback,
+    void* ctx, LSMessageToken* ret_token, LSError* error);
+bool LSCallOneReply(LSHandle* sh, const char* uri, const char* payload, LSFilterFunc callback,
+    void* ctx, LSMessageToken* ret_token, LSError* error);
+bool LSCallCancel(LSHandle* sh, LSMessageToken token, LSError* error);

test/stubs/luna-service2/lunaservice_stub.c

@@ -0,0 +1,58 @@
+// Linkable bodies for the handful of luna-service2 client-call functions
+// foreground_app.c calls. service.c/main.c only ever get -fsyntax-only'd, so
+// declarations alone are enough for them; foreground_app.c is linked into
+// real host test binaries (engine_smoke, rtp_send) via SOURCES[] in
+// run-tests.sh, so those symbols need bodies too, or the link fails.
+//
+// A host has no Luna bus, so "the call failed" is exactly the right
+// simulated behaviour -- every caller here already treats that as
+// "foreground app tracking unavailable" and degrades accordingly, which is
+// also genuinely exercised by the test suite (see the fail-closed check in
+// engine_smoke.c).
+#include "luna-service2/lunaservice.h"
+
+#include <string.h>
+
+void LSErrorInit(LSError* error)
+{
+    memset(error, 0, sizeof(*error));
+}
+
+void LSErrorFree(LSError* error)
+{
+    (void)error;
+}
+
+bool LSCall(LSHandle* sh, const char* uri, const char* payload, LSFilterFunc callback,
+    void* ctx, LSMessageToken* ret_token, LSError* error)
+{
+    (void)sh;
+    (void)uri;
+    (void)payload;
+    (void)callback;
+    (void)ctx;
+    (void)ret_token;
+    if (error)
+        error->message = (char*)"no Luna bus on this host";
+    return false;
+}
+
+bool LSCallOneReply(LSHandle* sh, const char* uri, const char* payload, LSFilterFunc callback,
+    void* ctx, LSMessageToken* ret_token, LSError* error)
+{
+    return LSCall(sh, uri, payload, callback, ctx, ret_token, error);
+}
+
+bool LSCallCancel(LSHandle* sh, LSMessageToken token, LSError* error)
+{
+    (void)sh;
+    (void)token;
+    (void)error;
+    return true;
+}
+
+const char* LSMessageGetPayload(LSMessage* message)
+{
+    (void)message;
+    return NULL;
+}

test/ui_smoke.js

@@ -133,6 +133,16 @@ async function main() {
   check('hyperhdr card is first and marked',
     doc.querySelector('.sink-card .badge').textContent === 'Recommended');
   check('hyperhdr host field exists', !!doc.querySelector('[data-path="hyperhdr.host"]'));
+  const restrictPicker = doc.querySelector('[data-path="hyperhdrAdjust.restrictToApp"]');
+  check('restrict-to-app picker exists', !!restrictPicker);
+  eq('restrict-to-app picker starts on Always active', restrictPicker.textContent, 'Always active');
+  // Always active -> the first installed app alphabetically by title
+  // ("Live TV", ahead of Netflix/Spotify/YouTube in the mock's list).
+  click(restrictPicker);
+  await wait(600);
+  eq('picking an app reaches settings by id, not a typed value',
+    window.App.state.settings.hyperhdrAdjust.restrictToApp, 'com.webos.app.livetv');
+  eq('picker now shows the app name, not the id', restrictPicker.textContent, 'Live TV');
   check('backend choice exists', !!doc.querySelector('[data-path="capture.backend"]'));
   check('log level choice exists', !!doc.querySelector('[data-path="logLevel"]'));
   check('boot toggle exists', !!doc.querySelector('[data-path="autoStart"]'));