Rework to remove Alexa voiceagent dependencies

Changes include:
- The previous somewhat hard-coded Alexa voiceagent configuration in the
  app controller definition has been replaced with a scheme that allows
  instead specifying voiceagent configuration via the configuration file
  /etc/xdg/AGL/voice-high.json, and individual per-voiceagent
  configuration via JSON files in the directory
  /etc/xdg/AGL/voiceagents. See the updated README.md for more details.
- The new file reading code for the above change was facilitated by
  bumping the C++ standard option to 17 (from 11) to allow use of the
  new standard library filesystem classes.
- The configured voiceagents' APIs are now loaded dynamically using the
  afb_api_require_api call enabled by the recently exposed
  platform:apis:auto-ws widget permission. The widget configuration has
  been updated to add the permission, and also remove the previously
  hard-code dependency on the "alexa-voiceagent" API.
- App controller event hooks are created dynamically for the events from
  the configured voiceagents. This is done by calling back into the
  app controller API at the appropriate place during initialization,
  replacing the previous hard-coding of events from "alexa-voiceagent".
  If future use cases require dynamic removal of voiceagents, then this
  scheme will need to be revisited, as the app controller API currently
  has no provision for removing events.
- The IAFBApi interdace and AFBApiImpl implementation classes have been
  extended with additional getApi and requireApi calls to enable the
  above changes in a straightforward manner.

Bug-AGL: SPEC-2898

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: Iae8b99a6286174510e88d8eeffd51718db64f2f4

1 files changed, 184 insertions, 48 deletions

diff --git a/src/plugins/VshlCoreApi.cpp b/src/plugins/VshlCoreApi.cpp
index 05c894d..4c32391 100644
--- a/src/plugins/VshlCoreApi.cpp
+++ b/src/plugins/VshlCoreApi.cpp
@@ -17,7 +17,10 @@
 
 #include <list>
 #include <sstream>
+#include <fstream>
+#include <filesystem>
 #include <json.hpp>
+#include <json-c/json.h>
 
 #include "afb/AFBApiImpl.h"
 #include "afb/AFBRequestImpl.h"
@@ -49,6 +52,10 @@ static std::string STARTLISTENING_JSON_ATTR_REQUEST = "request_id";
 static std::string EVENTS_JSON_ATTR_VA_ID = "va_id";
 static std::string EVENTS_JSON_ATTR_EVENTS = "events";
 
+static std::string CONFIG_JSON_FILE = "/etc/xdg/AGL/voice-high.json";
+static std::string JSON_EXT = ".json";
+static std::string VA_CONFIG_JSON_DIR = "/etc/xdg/AGL/voiceagents";
+
 static std::shared_ptr<vshlcore::utilities::logging::Logger> sLogger;
 static std::shared_ptr<vshlcore::common::interfaces::IAFBApi> sAfbApi;
 static std::unique_ptr<vshlcore::core::VRRequestProcessor> sVRRequestProcessor;
@@ -151,69 +158,198 @@ CTLP_CAPI(onDialogStateEvent, source, argsJ, eventJ) {
     return 0;
 }
 
-CTLP_CAPI(loadVoiceAgentsConfig, source, argsJ, eventJ) {
-    if (sVoiceAgentsDataManager == nullptr) {
-        sLogger->log(Level::WARNING, TAG, "loadVoiceAgentsConfig: Voice service not initialized.");
+// Helper function to add events for voice agent to controller
+// configuration.  It relies on the controller configuration being
+// available via the userdata of the API pointer.
+static int AddVoiceAgentEvents(std::string &agentApi) {
+    // Retrieve section config from api handle
+    CtlConfigT *ctrlConfig = (CtlConfigT*) afb_api_get_userdata(sAfbApi->getApi());
+    if (ctrlConfig == nullptr) {
+        sLogger->log(Level::ERROR, TAG, "AddVoiceAgentEvents: ctrlConfig == nullptr");
         return -1;
     }
 
-    if (argsJ == nullptr) {
-        sLogger->log(Level::WARNING, TAG, "loadVoiceAgentsConfig: No arguments supplied.");
+    CtlSectionT* section = nullptr;
+    for (int idx = 0; ctrlConfig->sections[idx].key != NULL; ++idx) {
+        if (!strcasecmp(ctrlConfig->sections[idx].key, "events")) {
+            section = &(ctrlConfig->sections[idx]);
+            break;
+        }
+    }
+    if (section == nullptr) {
+        sLogger->log(Level::ERROR, TAG, "AddVoiceAgentEvents: events section not found");
         return -1;
     }
 
-    json agentsConfigJson = json::parse(json_object_to_json_string(argsJ));
-    if (agentsConfigJson.find(VA_JSON_ATTR_AGENTS) == agentsConfigJson.end()) {
-        sLogger->log(Level::ERROR, TAG, "loadVoiceAgentsConfig: No agents object found in agents json");
-        return -1;
+    // Fill out events JSON array to pass to the controller
+    json_object* eventsJ = json_object_new_array();
+
+    json_object *eventJ = json_object_new_object();
+    std::string uid = agentApi + "/voice_authstate_event";
+    json_object *uidJ = json_object_new_string(uid.c_str());
+    json_object_object_add(eventJ, "uid", uidJ);
+    json_object *actionJ = json_object_new_string("plugin://vshl-core#onAuthStateEvent");
+    json_object_object_add(eventJ, "action", actionJ);
+    json_object_array_add(eventsJ, eventJ);
+
+    eventJ = json_object_new_object();
+    uid = agentApi + "/voice_connectionstate_event";
+    uidJ = json_object_new_string(uid.c_str());
+    json_object_object_add(eventJ, "uid", uidJ);
+    actionJ = json_object_new_string("plugin://vshl-core#onConnectionStateEvent");
+    json_object_object_add(eventJ, "action", actionJ);
+    json_object_array_add(eventsJ, eventJ);
+
+    eventJ = json_object_new_object();
+    uid = agentApi + "/voice_dialogstate_event";
+    uidJ = json_object_new_string(uid.c_str());
+    json_object_object_add(eventJ, "uid", uidJ);
+    actionJ = json_object_new_string("plugin://vshl-core#onDialogStateEvent");
+    json_object_object_add(eventJ, "action", actionJ);
+    json_object_array_add(eventsJ, eventJ);
+
+    // Call into controller to add event actions
+    // NOTE: AFAICT the JSON objects end up reused by the controller data
+    //       structures, so eventsJ should not be freed with a put after
+    //       this call.
+    int rc = AddActionsToSection(sAfbApi->getApi(), section, eventsJ, 0);
+    if (rc != 0) {
+        stringstream message;
+        message << "AddVoiceAgentEvents: AddActionsToSection rc = " << rc;
+        sLogger->log(Level::WARNING, TAG, message.str().c_str());
     }
+    return rc;
+}
 
-    json agentsJson = agentsConfigJson[VA_JSON_ATTR_AGENTS];
-    for (auto agentIt = agentsJson.begin(); agentIt != agentsJson.end(); ++agentIt) {
-        json agentJson = *agentIt;
-
-        if (agentJson.find(VA_JSON_ATTR_ID) == agentJson.end() ||
-            agentJson.find(VA_JSON_ATTR_ACTIVE) == agentJson.end() ||
-            agentJson.find(VA_JSON_ATTR_NAME) == agentJson.end() ||
-            agentJson.find(VA_JSON_ATTR_API) == agentJson.end() ||
-            agentJson.find(VA_JSON_ATTR_WWS) == agentJson.end() ||
-            agentJson.find(VA_JSON_ATTR_ACTIVE_WW) == agentJson.end() ||
-            agentJson.find(VA_JSON_ATTR_DESCRIPTION) == agentJson.end() ||
-            agentJson.find(VA_JSON_ATTR_VENDOR) == agentJson.end()) {
-            std::stringstream error;
-            error << "loadVoiceAgentsConfig: One or more missing params in agent "
-                     "config "
-                  << agentJson.dump();
-            sLogger->log(Level::WARNING, TAG, error.str().c_str());
-            continue;
-        }
+// Helper function to parse a voiceagent's configuration
+static bool parseVoiceAgentConfig(const json &agentJson) {
+    if (agentJson.find(VA_JSON_ATTR_ID) == agentJson.end() ||
+	agentJson.find(VA_JSON_ATTR_ACTIVE) == agentJson.end() ||
+	agentJson.find(VA_JSON_ATTR_NAME) == agentJson.end() ||
+	agentJson.find(VA_JSON_ATTR_API) == agentJson.end() ||
+	agentJson.find(VA_JSON_ATTR_WWS) == agentJson.end() ||
+	agentJson.find(VA_JSON_ATTR_ACTIVE_WW) == agentJson.end() ||
+	agentJson.find(VA_JSON_ATTR_DESCRIPTION) == agentJson.end() ||
+	agentJson.find(VA_JSON_ATTR_VENDOR) == agentJson.end()) {
+	stringstream error;
+	error << "loadVoiceAgentConfig: One or more missing params in agent "
+	    "config "
+	      << agentJson.dump();
+	sLogger->log(Level::WARNING, TAG, error.str().c_str());
+	return false;
+    }
 
-        std::string id(agentJson[VA_JSON_ATTR_ID].get<string>());
-        std::string name(agentJson[VA_JSON_ATTR_NAME].get<string>());
-        std::string api(agentJson[VA_JSON_ATTR_API].get<string>());
-        std::string description(agentJson[VA_JSON_ATTR_DESCRIPTION].get<string>());
-        std::string vendor(agentJson[VA_JSON_ATTR_VENDOR].get<string>());
-        std::string activeWakeword(agentJson[VA_JSON_ATTR_ACTIVE_WW].get<string>());
-        bool isActive(agentJson[VA_JSON_ATTR_ACTIVE].get<bool>());
-
-        shared_ptr<unordered_set<string>> wakewords = std::make_shared<unordered_set<string>>();
-        json wakewordsJson = agentJson[VA_JSON_ATTR_WWS];
-        for (auto wwIt = wakewordsJson.begin(); wwIt != wakewordsJson.end(); ++wwIt) {
-            wakewords->insert(wwIt->get<string>());
-        }
+    std::string id(agentJson[VA_JSON_ATTR_ID].get<string>());
+    std::string name(agentJson[VA_JSON_ATTR_NAME].get<string>());
+    std::string api(agentJson[VA_JSON_ATTR_API].get<string>());
+    std::string description(agentJson[VA_JSON_ATTR_DESCRIPTION].get<string>());
+    std::string vendor(agentJson[VA_JSON_ATTR_VENDOR].get<string>());
+    std::string activeWakeword(agentJson[VA_JSON_ATTR_ACTIVE_WW].get<string>());
+    bool isActive(agentJson[VA_JSON_ATTR_ACTIVE].get<bool>());
+
+    shared_ptr<unordered_set<string>> wakewords = std::make_shared<unordered_set<string>>();
+    json wakewordsJson = agentJson[VA_JSON_ATTR_WWS];
+    for (auto wwIt = wakewordsJson.begin(); wwIt != wakewordsJson.end(); ++wwIt) {
+	wakewords->insert(wwIt->get<string>());
+    }
+
+    if (sAfbApi->requireApi(api, true) != 0) {
+	stringstream error;
+	error << "loadVoiceAgentConfig: Failed to require API \""
+	      << api
+	      << "\" for voiceagent \""
+	      << name
+	      << "\".";
+	sLogger->log(Level::ERROR, TAG, error.str().c_str());
+	return false;
+    }
+
+    if (AddVoiceAgentEvents(api) != 0) {
+	stringstream error;
+	error << "loadVoiceAgentConfig: Failed to add events for voiceagent \""
+	      << name
+	      << "\".";
+	sLogger->log(Level::ERROR, TAG, error.str().c_str());
+	return false;
+    }
+
+    return sVoiceAgentsDataManager->addNewVoiceAgent(
+	id, name, description, api, vendor, activeWakeword, isActive, wakewords);
+}
 
-        sVoiceAgentsDataManager->addNewVoiceAgent(
-            id, name, description, api, vendor, activeWakeword, isActive, wakewords);
+// Helper function to parse voiceagents configuration
+static void parseVoiceAgentsConfig(const json &agentsConfigJson, std::string &defaultVoiceAgent) {
+    if (agentsConfigJson.find(VA_JSON_ATTR_AGENTS) != agentsConfigJson.end()) {
+	json agentsJson = agentsConfigJson[VA_JSON_ATTR_AGENTS];
+	for (auto agentIt = agentsJson.begin(); agentIt != agentsJson.end(); ++agentIt) {
+	    json agentJson = *agentIt;
+	    parseVoiceAgentConfig(agentJson);
+	}
     }
 
-    // Set the default agent.
-    if (agentsConfigJson.find(VA_JSON_ATTR_DEFAULT) == agentsConfigJson.end()) {
-        sLogger->log(Level::ERROR, TAG, "loadVoiceAgentsConfig: No default agent found in agents json");
+    // Save the default agent if specified
+    if (agentsConfigJson.find(VA_JSON_ATTR_DEFAULT) != agentsConfigJson.end()) {
+	defaultVoiceAgent = agentsConfigJson[VA_JSON_ATTR_DEFAULT].get<string>();
+    }
+}
+
+CTLP_CAPI(loadVoiceAgentsConfig, source, argsJ, eventJ) {
+    if (sVoiceAgentsDataManager == nullptr) {
+        sLogger->log(Level::WARNING, TAG, "loadVoiceAgentsConfig: Voice service not initialized.");
         return -1;
     }
-    std::string defaultAgentId(agentsConfigJson[VA_JSON_ATTR_DEFAULT].get<string>());
-    sVoiceAgentsDataManager->setDefaultVoiceAgent(defaultAgentId);
 
+    string defaultVoiceAgent;
+
+    if (argsJ != nullptr) {
+	// Parse any agent configs from controller arguments
+	json agentsConfigJson = json::parse(json_object_to_json_string(argsJ));
+	parseVoiceAgentsConfig(agentsConfigJson, defaultVoiceAgent);
+    }
+
+    // Load external configuration if present
+    filesystem::path agentsConfigFile = CONFIG_JSON_FILE;
+    if(filesystem::exists(agentsConfigFile)) {
+	stringstream message;
+	message << "loadVoiceAgentsConfig: reading " << agentsConfigFile.string();;
+	sLogger->log(Level::INFO, TAG, message.str().c_str());
+
+	ifstream agentsConfigJsonFile(agentsConfigFile.string());
+	json agentsConfigJson;
+	agentsConfigJsonFile >> agentsConfigJson;
+	parseVoiceAgentsConfig(agentsConfigJson, defaultVoiceAgent);
+    }
+
+    // Load any external individual voiceagent configurations
+    error_code ec;
+    for (const auto& entry : filesystem::directory_iterator(VA_CONFIG_JSON_DIR, ec)) {
+	if (entry.is_regular_file(ec) &&
+	    entry.path().extension().string() == JSON_EXT) {
+	    const auto filename = entry.path().string();
+
+	    stringstream message;
+	    message << "loadVoiceAgentsConfig: reading " << filename;
+	    sLogger->log(Level::INFO, TAG, message.str().c_str());
+
+	    ifstream jsonFile(filename);
+	    json agentJson;
+	    jsonFile >> agentJson;
+	    parseVoiceAgentConfig(agentJson);
+	}
+    }
+
+    // Set the default agent if specified
+    if (!defaultVoiceAgent.empty()) {
+	stringstream message;
+	message << "loadVoiceAgentsConfig: setting default agent to " << defaultVoiceAgent;
+	sLogger->log(Level::INFO, TAG, message.str().c_str());
+
+	sVoiceAgentsDataManager->setDefaultVoiceAgent(defaultVoiceAgent);
+    } else {
+        sLogger->log(Level::WARNING, TAG, "loadVoiceAgentsConfig: No default agent found");
+    }
+
+    // Always return zero so service will start
     return 0;
 }