Extract job scheduling logic into dedicated utility functions

♻️ Refactoring:
- Created new jobScheduler.ts utility module
- Extracted findExistingJobs() for duplicate detection
- Extracted ensureEmailJob() for job creation with duplicate prevention
- Extracted updateEmailJobRelationship() for relationship management

📦 Functions:
- findExistingJobs(): Queries for existing processing jobs by email ID
- ensureEmailJob(): Creates job only if none exists, returns job IDs
- updateEmailJobRelationship(): Updates email with job relationship

🎯 Benefits:
- Reusable functions for job management
- Single source of truth for job scheduling logic
- Cleaner, more testable code
- Exported utilities for external use
- Better separation of concerns

🔧 Updated:
- Emails collection hooks now use extracted functions
- Exports added to main index for public API
- Cleaner hook implementation with less duplication

src/utils/jobScheduler.ts

@@ -0,0 +1,103 @@
+import type { Payload } from 'payload'
+
+/**
+ * Finds existing processing jobs for an email
+ */
+export async function findExistingJobs(
+  payload: Payload,
+  emailId: string | number
+): Promise<{ docs: any[], totalDocs: number }> {
+  return await payload.find({
+    collection: 'payload-jobs',
+    where: {
+      'input.emailId': {
+        equals: String(emailId),
+      },
+      task: {
+        equals: 'process-email',
+      },
+    },
+    limit: 10,
+  })
+}
+
+/**
+ * Ensures a processing job exists for an email
+ * Creates one if it doesn't exist, or returns existing job IDs
+ */
+export async function ensureEmailJob(
+  payload: Payload,
+  emailId: string | number,
+  options?: {
+    scheduledAt?: string | Date
+    queueName?: string
+  }
+): Promise<{ jobIds: (string | number)[], created: boolean }> {
+  if (!payload.jobs) {
+    throw new Error('PayloadCMS jobs not configured - cannot create email job')
+  }
+
+  // Check for existing jobs first
+  const existingJobs = await findExistingJobs(payload, emailId)
+
+  if (existingJobs.totalDocs > 0) {
+    // Return existing job IDs
+    return {
+      jobIds: existingJobs.docs.map(job => job.id),
+      created: false
+    }
+  }
+
+  // No existing job, create a new one
+  const mailingContext = (payload as any).mailing
+  const queueName = options?.queueName || mailingContext?.config?.queue || 'default'
+
+  const job = await payload.jobs.queue({
+    queue: queueName,
+    task: 'process-email',
+    input: {
+      emailId: String(emailId)
+    },
+    // If scheduled, set the waitUntil date
+    waitUntil: options?.scheduledAt ? new Date(options.scheduledAt) : undefined
+  })
+
+  console.log(`Auto-scheduled processing job ${job.id} for email ${emailId}`)
+
+  return {
+    jobIds: [job.id],
+    created: true
+  }
+}
+
+/**
+ * Updates an email document to include job IDs in the relationship field
+ */
+export async function updateEmailJobRelationship(
+  payload: Payload,
+  emailId: string | number,
+  jobIds: (string | number)[],
+  collectionSlug: string = 'emails'
+): Promise<void> {
+  try {
+    // Get current jobs to avoid overwriting
+    const currentEmail = await payload.findByID({
+      collection: collectionSlug,
+      id: emailId,
+    })
+
+    const currentJobs = currentEmail.jobs || []
+    const allJobs = [...new Set([...currentJobs, ...jobIds])] // Deduplicate
+
+    await payload.update({
+      collection: collectionSlug,
+      id: emailId,
+      data: {
+        jobs: allJobs
+      }
+    })
+  } catch (error) {
+    console.error(`Failed to update email ${emailId} with job relationship:`, error)
+    throw error
+  }
+}