Overdue invoice chaser

trigger:
  kind: schedule
  cron: "0 8 * * 1"
  timezone: America/Toronto
steps:
  - key: invoices
    name: Open invoices
    kind: tool
    tool: stripe.api_get
    args: { path: /invoices, params: { status: open, limit: 100 } }
  - key: overdue
    name: Find the overdue ones
    kind: javascript
    inputs: { invoices: "{{ steps.invoices.output.data }}", now: "{{ run.started_at }}" }
    outputs: { lines: array, count: integer, total: string }
    code: |
      function main({ invoices, now }) {
        const today = Date.parse(now) / 1000
        const late = invoices
          .filter(invoice => invoice.due_date && invoice.due_date < today)
          .map(invoice => ({ ...invoice, days: Math.floor((today - invoice.due_date) / 86400) }))
          .sort((a, b) => b.amount_due - a.amount_due)
        const cents = late.reduce((sum, invoice) => sum + invoice.amount_due, 0)
        const lines = late.map(i => `${i.number} · ${i.customer_name} · $${(i.amount_due / 100).toFixed(2)} · ${i.days} days late · ${i.hosted_invoice_url}`)
        console.log(`${late.length} of ${invoices.length} open invoices are overdue`)
        return { lines, count: late.length, total: `$${(cents / 100).toFixed(2)}` }
      }
  - key: write
    name: Write the email
    kind: llm
    model: fast
    if: { path: steps.overdue.output.count, gt: 0 }
    prompt: |
      Write a short email to the finance team about overdue Stripe invoices.
      Open with the total ({{ steps.overdue.output.total }} across {{ steps.overdue.output.count }} invoices),
      then list them as given, biggest first, and flag anything more than 30 days late.
      {{ steps.overdue.output.lines }}
    schema:
      type: object
      properties: { subject: { type: string }, text: { type: string } }
      required: [subject, text]
  - key: send
    name: Email finance
    kind: tool
    tool: email.send_email
    if: { path: steps.overdue.output.count, gt: 0 }
    args: { to: [finance@northwind.example], subject: "{{ steps.write.output.data.subject }}", text: "{{ steps.write.output.data.text }}" }