Blacklist functionality

Some API improvements

models/blacklist.js

@@ -0,0 +1,61 @@
+'use strict';
+
+const knex = require('../lib/knex');
+const dtHelpers = require('../lib/dt-helpers');
+const shares = require('./shares');
+const tools = require('../lib/tools-async');
+
+async function listDTAjax(context, params) {
+    shares.enforceGlobalPermission(context, 'manageBlacklist');
+
+    return await dtHelpers.ajaxList(
+        params,
+        builder => builder
+            .from('blacklist'),
+        ['blacklist.email']
+    );
+}
+
+async function add(context, email) {
+    return await knex.transaction(async tx => {
+        shares.enforceGlobalPermission(context, 'manageBlacklist');
+
+        const existing = await tx('blacklist').where('email', email).first();
+        if (!existing) {
+            await tx('blacklist').insert({email});
+        }
+    });
+}
+
+async function remove(context, email) {
+    shares.enforceGlobalPermission(context, 'manageBlacklist');
+    await knex('blacklist').where('email', email).del();
+}
+
+async function isBlacklisted(email) {
+    const existing = await knex('blacklist').where('email', email).first();
+    return !!existing;
+}
+
+async function serverValidate(context, data) {
+    shares.enforceGlobalPermission(context, 'manageBlacklist');
+    const result = {};
+
+    if (data.email) {
+        const user = await knex('blacklist').where('email', data.email).first();
+
+        result.email = {};
+        result.email.invalid = await tools.validateEmail(data.email) !== 0;
+        result.email.exists = !!user;
+    }
+
+    return result;
+}
+
+module.exports = {
+    listDTAjax,
+    add,
+    remove,
+    isBlacklisted,
+    serverValidate
+};