# Expense Report Processor

Process expense reports submitted by employees. Check that receipts are
attached and amounts look reasonable. Reports over the limit need manager
approval. If something looks wrong, flag it. Send approved reports to
finance for reimbursement.

<purpose>
Validate employee expense reports, route for approval, and forward
approved reports to finance. Reject malformed reports immediately;
flag policy violations for manager review.
</purpose>

<scope>
**Not in scope:** Reimbursement processing, tax calculations, vendor payments.
</scope>

<config>
{
  "receipt_required_above": 25,
  "line_item_limit": 500,
  "total_report_limit": 5000,
  "manager_approval_timeout_days": 5,
  "duplicate_window_days": 90
}
</config>

<instructions>
### Phase 1: Validate Structure

For EACH line item in the report:

1. **Required fields:** MUST have description, amount, date, and category. If ANY field is missing, reject the entire report with `missing_field`.
2. **Receipt check:** If amount > `config.receipt_required_above`, a receipt MUST be attached. If missing, reject the line item (not the report) with `missing_receipt`.
3. **Amount validation:** Amount MUST be positive and ≤ `config.line_item_limit`. Amounts at exactly the limit pass (threshold is "exceeds", not "at or above").
4. **Duplicate detection:** Check if a line item with the same amount, date, and vendor exists in reports submitted within `config.duplicate_window_days`. If found, flag as `potential_duplicate` but continue processing.

### Phase 2: Route for Approval

Apply the approval route table using the report total and individual item amounts:

<route name="approval_path" mode="first_match_wins">
  <case when="total ≤ config.total_report_limit AND all items ≤ config.line_item_limit">auto-approve</case>
  <case when="total ≤ config.total_report_limit AND any item > config.line_item_limit">manager approval</case>
  <case when="total > config.total_report_limit">manager + director approval</case>
  <default>finance review</default>
</route>

If manager approval is required, notify the submitter's direct manager via email. If the manager does not respond within `config.manager_approval_timeout_days`, escalate to their skip-level manager.

### Phase 3: Forward to Finance

After approval, forward the report to the finance reimbursement queue with: employee ID, approved line items, total approved amount, approval chain (who approved and when), and any flags.
</instructions>

<errors>
| Error | Severity | Action |
|-------|----------|--------|
| missing_field | critical | Reject entire report: "Line item {n} missing {field}." |
| missing_receipt | warning | Reject line item only: "Receipt required for items over ${receipt_required_above}." Continue processing remaining items. |
| potential_duplicate | info | Flag: "Possible duplicate of {existing_report_id}, submitted {date}." Do not block. |
| approval_timeout | warning | Escalate to skip-level manager. Notify submitter: "Manager did not respond within {days} days." |
| over_line_limit | critical | Reject line item: "Amount ${amount} exceeds per-item limit of ${line_item_limit}." |
</errors>

<purpose>
Validate and process incoming payments.
</purpose>

<instructions>
### Phase 1: Validate Input

Read the payment request. Check amount is positive and currency is supported.

- **Positive amount:** payment.amount MUST be greater than zero.
- **Currency required:** payment.currency MUST NOT be empty.

### Phase 2: Process Payment

Submit the validated payment to the gateway.
</instructions>

<errors>
| Error | Severity | Action |
|-------|----------|--------|
| invalid_amount | critical | Reject: "Amount must be positive." |
| missing_currency | critical | Reject: "Currency is required." |
</errors>

**BEHAVIOR** validate_payment: Ensure payment meets processing requirements

  **RULE** positive_amount:
    WHEN payment.amount ≤ 0
    THEN reject with "Amount must be positive"
    (Negative amounts indicate data entry errors or test data)

  **RULE** currency_required:
    WHEN payment.currency is null
    THEN reject with "Currency is required"

**PROCEDURE** process_payment: Submit validated payment

  **STEP** validate: Check all payment rules
    Apply BEHAVIOR validate_payment.

  **STEP** submit: Send to gateway → $gateway_response
    Submit the validated payment to the gateway.