frontend, api, db: add single sign-on

Closes https://gitlab.com/commento/commento/issues/90

frontend/js/dashboard-general.js

@@ -19,4 +19,27 @@
     });
   };
 
+  global.ssoProviderChangeHandler = function() {
+    var data = global.dashboard.$data;
+
+    if (data.domains[data.cd].ssoSecret === "") {
+      var json = {
+        "ownerToken": global.cookieGet("commentoOwnerToken"),
+        "domain": data.domains[data.cd].domain,
+      };
+
+      global.post(global.origin + "/api/domain/sso/new", json, function(resp) {
+        if (!resp.success) {
+          global.globalErrorShow(resp.message);
+          return;
+        }
+
+        data.domains[data.cd].ssoSecret = resp.ssoSecret;
+        $("#sso-secret").val(data.domains[data.cd].ssoSecret);
+      });
+    } else {
+      $("#sso-secret").val(data.domains[data.cd].ssoSecret);
+    }
+  };
+
 } (window.commento, document));