Work in progress on subscriptions

models/confirmations.js

@@ -0,0 +1,51 @@
+'use strict';
+
+const knex = require('../lib/knex');
+const shortid = require('shortid');
+
+async function addConfirmation(listId, action, ip, data) {
+    const cid = shortid.generate();
+    await knex('confirmations').insert({
+        cid,
+        list: listId,
+        action,
+        ip,
+        data: JSON.stringify(data || {})
+    });
+
+    return cid;
+}
+
+/*
+ Atomically retrieves confirmation from the database, removes it from the database and returns it.
+ */
+async function takeConfirmation(cid) {
+    return await knex.transaction(async tx => {
+        const entry = await tx('confirmations').select(['cid', 'list', 'action', 'ip', 'data']).where('cid', cid).first();
+
+        if (!entry) {
+            return false;
+        }
+
+        await tx('confirmations').where('cid', cid).del();
+
+        let data;
+        try {
+            data = JSON.parse(entry.data);
+        } catch (err) {
+            data = {};
+        }
+
+        return {
+            list: entry.list,
+            action: entry.action,
+            ip: entry.ip,
+            data
+        };
+    });
+}
+
+module.exports = {
+    addConfirmation,
+    takeConfirmation
+};