Add get_auth_token (#1)

* Android implementation of GetAuthToken

* Add firebase/installations.h

* Android Firebase Installations library

* iOS Firebase Installations libs

* Mention get_auth_token in documentation

* tabs -> spaces

* Add Gradle dependency

* Add get_auth_token to API file

* Rename auth token variables/functions for clarity

Author: dri-richard

docs/index.md

@@ -92,8 +92,14 @@ function init(self)
             print(err)
             return
         end
+        
         -- firebase is ready to use!
-	end
+        
+        -- installation auth token can be used for configuring test devices for A/B tests
+        firebase.get_installation_auth_token(function(self, token)
+            print("installation auth token is " .. token)
+        end)
+    end
 end
 ```
 

firebase/api/firebase.script_api

@@ -14,3 +14,12 @@
     - name: error
       type: string
       desc: Error message if initialisation failed
+
+  - name: get_installation_auth_token
+    type: function
+    desc: Get the Firebase Installation auth token
+
+    parameters:
+    - name: callback
+      type: function
+      desc: Function to invoke with the auth token (self, token)

firebase/lib/arm64-android/libfirebase_installations.a

@@ -1,4 +1,5 @@
 dependencies {
 	implementation 'com.google.firebase:firebase-analytics:18.0.3'
+	implementation 'com.google.firebase:firebase-installations:16.3.5'
 	implementation 'com.google.android.gms:play-services-base:17.6.0'
 }

firebase/lib/arm64-ios/libfirebase_installations.a

@@ -9,9 +9,10 @@
 #include "luautils.h"
 #include "platform_utils.h"
 #include "firebase/app.h"
-
+#include "firebase/installations.h"
 
 static firebase::App* firebase_app_;
+static dmScript::LuaCallbackInfo* g_InstallationAuthTokenCallback;
 
 using namespace firebase;
 
@@ -45,6 +46,50 @@ static int Firebase_Init(lua_State* L) {
 	return 2;
 }
 
+static int Firebase_GetInstallationAuthToken(lua_State* L) {
+	DM_LUA_STACK_CHECK(L, 0);
+
+	g_InstallationAuthTokenCallback = dmScript::CreateCallback(L, 1);
+
+	auto* installations_object = installations::Installations::GetInstance(firebase::App::GetInstance());
+
+	installations_object->GetToken(false)
+		.OnCompletion([](const Future< std::string >& completed_future) {
+		if (!dmScript::IsCallbackValid(g_InstallationAuthTokenCallback))
+		{
+			dmLogWarning("Firebase installation auth token callback is not valid");
+			return;
+		}
+
+		if (dmScript::SetupCallback(g_InstallationAuthTokenCallback))
+		{
+			lua_State* L = dmScript::GetCallbackLuaContext(g_InstallationAuthTokenCallback);
+
+			if (completed_future.error() == 0) {
+				lua_pushstring(L, completed_future.result()->c_str());
+				int ret = lua_pcall(L, 2, 0, 0);
+				if (ret != 0) {
+					lua_pop(L, 1);
+				}
+			}
+			else {
+				dmLogError("%d: %s", completed_future.error(), completed_future.error_message());
+				lua_pushnil(L);
+				lua_pushstring(L, completed_future.error_message());
+				int ret = lua_pcall(L, 3, 0, 0);
+				if (ret != 0) {
+					lua_pop(L, 2);
+				}
+			}
+			dmScript::TeardownCallback(g_InstallationAuthTokenCallback);
+		}
+
+		dmScript::DestroyCallback(g_InstallationAuthTokenCallback);
+		g_InstallationAuthTokenCallback = 0;
+			});
+	return 0;
+}
+
 
 firebase::App* Firebase_GetFirebaseApp()
 {
@@ -67,6 +112,7 @@ static void LuaInit(lua_State* L) {
 
 	// push functions on the firebase global table
 	lua_pushtablestringfunction(L, "init", Firebase_Init);
+	lua_pushtablestringfunction(L, "get_installation_auth_token", Firebase_GetInstallationAuthToken);
 
 	lua_pop(L, 1); // pop "firebase" global table
 }