From 5b303dd6c62bddb04f1aa6cfe86263267d97952b Mon Sep 17 00:00:00 2001
From: karishmas6 <carishmashukla28@gmail.com>
Date: Wed, 11 Sep 2024 23:33:04 +0530
Subject: [PATCH] feat: cron expressions

---
 server/src/routes/storage.ts | 95 +++++++++++++++++++++++++++++++-----
 1 file changed, 84 insertions(+), 11 deletions(-)

diff --git a/server/src/routes/storage.ts b/server/src/routes/storage.ts
index 07db5c19..1f90372b 100644
--- a/server/src/routes/storage.ts
+++ b/server/src/routes/storage.ts
@@ -11,6 +11,8 @@ import { browserPool } from "../server";
 import fs from "fs";
 import { uuid } from "uuidv4";
 import { workflowQueue } from '../workflow-management/scheduler';
+import moment from 'moment-timezone';
+import cron from 'node-cron';
 
 export const router = Router();
 
@@ -194,27 +196,98 @@ router.post('/runs/run/:fileName/:runId', async (req, res) => {
 
 router.put('/schedule/:fileName/', async (req, res) => {
   try {
-    const runId = uuid();
-
     const { fileName } = req.params;
-    const { scheduleTime } = req.body;
-    
-    if (!fileName || !runId || !scheduleTime) {
+    const { 
+      frequency, 
+      frequencyUnit, 
+      startDay, 
+      time, 
+      timezone 
+    } = req.body;
+
+    if (!fileName || !frequency || !frequencyUnit || !startDay || !time || !timezone) {
       return res.status(400).json({ error: 'Missing required parameters' });
     }
 
-    const delay = new Date(scheduleTime).getTime() - Date.now();
-    
-    // Add job to the queue with delay
-    await workflowQueue.add('run workflow', { fileName, runId }, { delay: Math.max(0, delay) });
-    
-    res.status(200).json({ message: 'Workflow scheduled successfully' });
+    // Validate inputs
+    if (!['HOURS', 'DAYS', 'WEEKS', 'MONTHS'].includes(frequencyUnit)) {
+      return res.status(400).json({ error: 'Invalid frequency unit' });
+    }
+
+    if (!moment.tz.zone(timezone)) {
+      return res.status(400).json({ error: 'Invalid timezone' });
+    }
+
+    const [hours, minutes] = time.split(':').map(Number);
+    if (isNaN(hours) || isNaN(minutes) || hours < 0 || hours > 23 || minutes < 0 || minutes > 59) {
+      return res.status(400).json({ error: 'Invalid time format' });
+    }
+
+    const days = ['SUNDAY', 'MONDAY', 'TUESDAY', 'WEDNESDAY', 'THURSDAY', 'FRIDAY', 'SATURDAY'];
+    if (!days.includes(startDay)) {
+      return res.status(400).json({ error: 'Invalid start day' });
+    }
+
+    // Generate cron expression
+    let cronExpression;
+    switch (frequencyUnit) {
+      case 'HOURS':
+        cronExpression = `${minutes} */${frequency} * * *`;
+        break;
+      case 'DAYS':
+        cronExpression = `${minutes} ${hours} */${frequency} * *`;
+        break;
+      case 'WEEKS':
+        const dayIndex = days.indexOf(startDay);
+        cronExpression = `${minutes} ${hours} * * ${dayIndex}/${7 * frequency}`;
+        break;
+      case 'MONTHS':
+        cronExpression = `${minutes} ${hours} 1-7 */${frequency} *`;
+        if (startDay !== 'SUNDAY') {
+          const dayIndex = days.indexOf(startDay);
+          cronExpression += ` ${dayIndex}`;
+        }
+        break;
+    }
+
+    if (!cronExpression || !cron.validate(cronExpression)) {
+      return res.status(400).json({ error: 'Invalid cron expression generated' });
+    }
+
+    const runId = uuid();
+
+    // Schedule the recurring job
+    await workflowQueue.add(
+      'run workflow',
+      { fileName, runId },
+      { 
+        repeat: {
+          pattern: cronExpression,
+          tz: timezone
+        }
+      }
+    );
+
+    res.status(200).json({ 
+      message: 'Workflow scheduled successfully', 
+      runId,
+      cronExpression,
+      // nextRunTime: getNextRunTime(cronExpression, timezone)
+    });
+
   } catch (error) {
     console.error('Error scheduling workflow:', error);
     res.status(500).json({ error: 'Failed to schedule workflow' });
   }
 });
 
+// function getNextRunTime(cronExpression, timezone) {
+//   const schedule = cron.schedule(cronExpression, () => {}, { timezone });
+//   const nextDate = schedule.nextDate();
+//   schedule.stop();
+//   return nextDate.toDate();
+// }
+
 /**
  * POST endpoint for aborting a current interpretation of the run.
  */