Auth Adapters refactoring (#3177)

* Moves all authentication providers to Adapter/Auth

* refactors specs

* Deprecates oauth option in favor of auth option

- Deprecates facebookAppIds option (in favor of auth.facebook.appIds)
- Adds warnings about the deprecated options

* nits

src/Adapters/Auth/google.js

@@ -0,0 +1,70 @@
+// Helper functions for accessing the google API.
+var https = require('https');
+var Parse = require('parse/node').Parse;
+
+function validateIdToken(id, token) {
+  return request("tokeninfo?id_token="+token)
+    .then((response) => {
+      if (response && (response.sub == id || response.user_id == id)) {
+        return;
+      }
+      throw new Parse.Error(
+        Parse.Error.OBJECT_NOT_FOUND,
+        'Google auth is invalid for this user.');
+    });
+}
+
+function validateAuthToken(id, token) {
+  return request("tokeninfo?access_token="+token)
+    .then((response) => {
+      if (response &&  (response.sub == id || response.user_id == id)) {
+        return;
+      }
+      throw new Parse.Error(
+        Parse.Error.OBJECT_NOT_FOUND,
+        'Google auth is invalid for this user.');
+    });
+}
+
+// Returns a promise that fulfills if this user id is valid.
+function validateAuthData(authData) {
+  if (authData.id_token) {
+    return validateIdToken(authData.id, authData.id_token);
+  } else {
+    return validateAuthToken(authData.id, authData.access_token).then(() => {
+      // Validation with auth token worked
+      return;
+    }, () => {
+      // Try with the id_token param
+      return validateIdToken(authData.id, authData.access_token);
+    });
+  }
+}
+
+// Returns a promise that fulfills if this app id is valid.
+function validateAppId() {
+  return Promise.resolve();
+}
+
+// A promisey wrapper for api requests
+function request(path) {
+  return new Promise(function(resolve, reject) {
+    https.get("https://www.googleapis.com/oauth2/v3/" + path, function(res) {
+      var data = '';
+      res.on('data', function(chunk) {
+        data += chunk;
+      });
+      res.on('end', function() {
+        data = JSON.parse(data);
+        resolve(data);
+      });
+    }).on('error', function() {
+      reject('Failed to validate this access token with Google.');
+    });
+  });
+}
+
+module.exports = {
+  validateAppId: validateAppId,
+  validateAuthData: validateAuthData
+};