Add find by headcode for train services

Signed-off-by: Fred Boniface <fred@fjla.uk>

src/services/trainService.services.js

@@ -0,0 +1,22 @@
+const log     = require('../utils/log.utils');
+const db      = require('./dbAccess.services');
+const clean   = require('../utils/sanitizer.utils');
+
+async function findByHeadcode(headcode) {
+  const sanitizedHeadcode = clean.removeNonAlphanumeric(headcode);
+  log.out(`trainServiceServices.findByHeadcode: Searching for headcode ${sanitizedHeadcode}`, 'dbug');
+  const now = new Date();
+  const dayMap = ['su', 'm', 't', 'w', 'th', 'f', 's'];
+  const shortDay = dayMap[now.getDay()]; // Fetch short day from map
+  const query = {
+    headcode: sanitizedHeadcode,
+    scheduleStartDate: {$lte: now},
+    scheduleEndDate: {$gte: now},
+    daysRun: {$in: [shortDay]}
+  };
+  return db.query('timetable', query);
+}
+
+module.exports = {
+  findByHeadcode,
+};