Added volume_changed event plus verbs

New subscribe and unsubscribe verbs to get the volume_changed event.

Bug: SPEC-2053

Change-Id: Iedeb542c7c3d880f0d6294b0310d2662e0ac11f1
Signed-off-by: Loïc Collignon <loic.collignon@iot.bzh>

3 files changed, 118 insertions, 20 deletions

diff --git a/ahl-binding/ahl-binding.cpp b/ahl-binding/ahl-binding.cpp
index 036ed88..98d36b6 100644
--- a/ahl-binding/ahl-binding.cpp
+++ b/ahl-binding/ahl-binding.cpp
@@ -89,6 +89,24 @@ void ahl_api_get_roles(afb_req_t req)
 }
 
 /**
+ * @brief Callback invoked when clients call the verb 'subscribe'.
+ * @param[in] req Request to handle.
+ */
+void ahl_api_subscribe(afb_req_t req)
+{
+    ahl_binding_t::instance().subscribe(req);
+}
+
+/**
+ * @brief Callback invoked when clients call the verb 'unsubscribe'.
+ * @param[in] req Request to handle.
+ */
+void ahl_api_unsubscribe(afb_req_t req)
+{
+    ahl_binding_t::instance().unsubscribe(req);
+}
+
+/**
  * @brief Callback invoked when clients call a 'role' verb.
  * @param[in] req Request to handle.
  *
@@ -166,6 +184,13 @@ int ahl_binding_t::init()
     afb_api_seal(handle_);
     AFB_API_NOTICE(handle_, "API is now sealed!");
 
+    volume_changed_ = afb_api_make_event(handle_, "volume_changed");
+    if(!afb_event_is_valid(volume_changed_))
+    {
+        AFB_API_ERROR(handle_, "Failed to create the \"volume_changed\" event!");
+        return -2;
+    }
+
     if (update_streams()) return -1;
     return 0;
 }
@@ -283,6 +308,30 @@ void ahl_binding_t::load_static_verbs()
     {
         throw std::runtime_error("Failed to add 'get_role' verb to the API.");
     }
+
+    if (afb_api_add_verb(
+            handle_,
+            "subscribe",
+            "Subscribe to \"volume_changed\" event",
+            ahl_api_subscribe,
+            nullptr,
+            nullptr,
+            AFB_SESSION_NONE_X2, 0))
+    {
+        throw std::runtime_error("Failed to add 'subscribe' verb to the API.");
+    }
+
+    if (afb_api_add_verb(
+            handle_,
+            "unsubscribe",
+            "Unsubscribe to \"volume_changed\" event",
+            ahl_api_unsubscribe,
+            nullptr,
+            nullptr,
+            AFB_SESSION_NONE_X2, 0))
+    {
+        throw std::runtime_error("Failed to add 'unsubscribe' verb to the API.");
+    }
 }
 
 void ahl_binding_t::load_controller_configs()
@@ -381,26 +430,51 @@ int ahl_binding_t::create_api_verb(role_t* r)
     return 0;
 }
 
-void ahl_binding_t::get_roles(afb_req_t req)
+void ahl_binding_t::get_roles(afb_req_t req) const
 {
-	json_bool verbose = FALSE;
-	json_object* arg = afb_req_json(req);
+    json_bool verbose = FALSE;
+    json_object* arg = afb_req_json(req);
     json_object* jverbose;
     if (arg != nullptr)
     {
-		json_bool ret = json_object_object_get_ex(arg, "verbose", &jverbose);
-		if (ret) verbose = json_object_get_boolean(jverbose);
+        json_bool ret = json_object_object_get_ex(arg, "verbose", &jverbose);
+        if (ret) verbose = json_object_get_boolean(jverbose);
     }
 
     json_object* result = json_object_new_array();
     for(const auto& r : roles_)
-	{
-		if (verbose == TRUE || r.device_uri().size())
-        	json_object_array_add(result, json_object_new_string(r.uid().c_str()));
-	}
+    {
+        if (verbose == TRUE || r.device_uri().size())
+        json_object_array_add(result, json_object_new_string(r.uid().c_str()));
+    }
     afb_req_success(req, result, nullptr);
 }
 
+void ahl_binding_t::subscribe(afb_req_t req) const
+{
+    if (afb_req_subscribe(req, volume_changed_))
+        afb_req_fail(req, "Failed to subscribe to \"volume_changed\" event!", nullptr);
+    else
+        afb_req_success(req, nullptr, "Subscribed to \"volume_changed\" event!");
+}
+
+void ahl_binding_t::unsubscribe(afb_req_t req) const
+{
+    if (afb_req_unsubscribe(req, volume_changed_))
+        afb_req_fail(req, "Failed to unsubscribe from \"volume_changed\" event!", nullptr);
+    else
+        afb_req_success(req, nullptr, "Unsubscribed from \"volume_changed\" event!");
+}
+
+int ahl_binding_t::emit_volume_changed(const std::string& role, int volume) const
+{
+    json_object* data = json_object_new_object();
+    json_object_object_add(data, "role", json_object_new_string(role.c_str()));
+    json_object_object_add(data, "volume", json_object_new_int(volume));
+
+    return afb_event_push(volume_changed_, data);
+}
+
 const std::vector<role_t> ahl_binding_t::roles() const
 {
     return roles_;
diff --git a/ahl-binding/ahl-binding.hpp b/ahl-binding/ahl-binding.hpp
index 0e7bd63..24f4acb 100644
--- a/ahl-binding/ahl-binding.hpp
+++ b/ahl-binding/ahl-binding.hpp
@@ -40,6 +40,7 @@ class ahl_binding_t
 
 private:
     afb_api_t handle_;
+    afb_event_t volume_changed_;
     std::vector<role_t> roles_;
 
     explicit ahl_binding_t();
@@ -60,7 +61,10 @@ public:
     int preinit(afb_api_t handle);
     int init();
     void event(std::string name, json_object* arg);
-    void get_roles(afb_req_t req);
+    void get_roles(afb_req_t req) const;
+    void subscribe(afb_req_t req) const;
+    void unsubscribe(afb_req_t req) const;
+    int emit_volume_changed(const std::string& role, int volume) const;
 
     const std::vector<role_t> roles() const;
     afb_api_t handle() const;
diff --git a/ahl-binding/role.cpp b/ahl-binding/role.cpp
index 06caa98..7d35889 100644
--- a/ahl-binding/role.cpp
+++ b/ahl-binding/role.cpp
@@ -229,18 +229,18 @@ void role_t::close(afb_req_t r, json_object* o)
 }
 
 void role_t::mute(afb_req_t r, json_object* o) {
-	do_mute(r, true);
+    do_mute(r, true);
 }
 
 void role_t::unmute(afb_req_t r, json_object  *o) {
-	do_mute(r, false);
+    do_mute(r, false);
 }
 
 void role_t::do_mute(afb_req_t r, bool v) {
 
-	json_object* a = json_object_new_object();
+    json_object* a = json_object_new_object();
     json_object_object_add(a, "mute", json_object_new_boolean(v));
-	afb_api_t api = ahl_binding_t::instance().handle();
+    afb_api_t api = ahl_binding_t::instance().handle();
 
     afb_api_call(
         api,
@@ -260,9 +260,15 @@ void role_t::do_mute(afb_req_t r, bool v) {
         afb_req_addref(r));
 }
 
+struct volumeclosure
+{
+    std::string role;
+    afb_req_t req;
+};
+
 void role_t::volume(afb_req_t r, json_object* o)
 {
-	afb_api_t api = ahl_binding_t::instance().handle();
+    afb_api_t api = ahl_binding_t::instance().handle();
 
     if(!afb_req_has_permission(r, "urn:AGL:permission::public:4a-audio-mixer"))
     {
@@ -296,6 +302,10 @@ void role_t::volume(afb_req_t r, json_object* o)
     json_object* a = json_object_new_object();
     json_object_object_add(a, "volume", value);
 
+    volumeclosure* userdata = new volumeclosure();
+    userdata->role = uid_;
+    userdata->req = afb_req_addref(r);
+
     afb_api_call(
         api,
         hal_.c_str(),
@@ -304,14 +314,24 @@ void role_t::volume(afb_req_t r, json_object* o)
         [](void* closure, json_object* result, const char* error, const char* info, afb_api_t handle)
         {
             AFB_API_DEBUG(handle, "Got the following answer: %s", json_object_to_json_string(result));
-            afb_req_t r = (afb_req_t)closure;
+            volumeclosure* r = reinterpret_cast<volumeclosure*>(closure);
 
             json_object_get(result);
-            if (error) afb_req_fail(r, json_object_to_json_string(result), nullptr);
-            else afb_req_success(r, result, nullptr);
-            afb_req_unref(r);
+            if (error) afb_req_fail(r->req, json_object_to_json_string(result), nullptr);
+            else
+            {
+                json_object* volnew;
+                if (json_object_object_get_ex(result, "volnew", &volnew))
+                {
+                    ahl_binding_t::instance().emit_volume_changed(r->role, json_object_get_int(volnew));
+                }
+                afb_req_success(r->req, result, nullptr);
+            }
+            afb_req_unref(r->req);
+            delete r;
         },
-        afb_req_addref(r));
+        userdata
+    );
 }
 
 void role_t::interrupt(afb_req_t r, json_object* o)