# Invoice Behaviors

## Overview

Invoices are the core entity of the Integreat accounts payable system. They represent bills from vendors that clients must pay. The invoice subsystem supports full lifecycle management from creation/import through payment and voiding, with comprehensive filtering, bulk operations, and OCR-based automated entry via Glimpse.

**User value:**
- Track all vendor bills in one place
- Pay invoices individually or in bulk via checks, debits, cash, or credit
- Import invoices from CSV/PDF files with automatic data extraction
- Spread expenses across multiple locations
- Manage invoice status (unpaid, paid, voided, scheduled)

## Routes & Pages

| Route | Handler | Purpose |
|-------|---------|---------|
| `GET /invoices` | `::all-page` | List all invoices |
| `GET /invoices/unpaid` | `::unpaid-page` | List unpaid invoices |
| `GET /invoices/paid` | `::paid-page` | List paid invoices |
| `GET /invoices/voided` | `::voided-page` | List voided invoices |
| `GET /invoices/table` | `::table` | HTMX table refresh |
| `GET /invoices/new` | `::new-wizard` | Create new invoice wizard |
| `POST/PUT /invoices/new` | `::new-invoice-submit` | Submit new/edit invoice |
| `PUT /invoices/new/navigate` | `::new-wizard-navigate` | Wizard step navigation |
| `PUT /invoices/new/due-date` | `::due-date` | Calculate due date from vendor terms |
| `PUT /invoices/new/scheduled-payment-date` | `::scheduled-payment-date` | Calculate scheduled payment from vendor autopay |
| `PUT /invoices/new/account/prediction` | `::account-prediction` | Show vendor default account suggestion |
| `PUT /invoices/new/total` | `::expense-account-total` | Calculate expense account total |
| `PUT /invoices/new/balance` | `::expense-account-balance` | Calculate balance vs invoice total |
| `GET /invoices/new/account/new` | `::new-wizard-new-account` | Add new expense account row |
| `GET /invoices/new/account/location-select` | `::location-select` | Location dropdown for account |
| `GET /invoices/pay-button` | `::pay-button` | Render pay button with selected invoice totals |
| `GET /invoices/pay` | `::pay-wizard` | Pay selected invoices wizard |
| `POST /invoices/pay` | `::pay-submit` | Submit payment |
| `POST /invoices/pay/using-credit` | `::pay-using-credit` | Pay using vendor credit balance |
| `PUT /invoices/pay/navigate` | `::pay-wizard-navigate` | Pay wizard step navigation |
| `GET /invoices/bulk-delete` | `::bulk-delete` | Bulk void confirmation dialog |
| `DELETE /invoices/bulk-delete` | `::bulk-delete-confirm` | Execute bulk void |
| `GET /invoices/bulk-edit` | `::bulk-edit` | Bulk edit expense accounts wizard |
| `PUT /invoices/bulk-edit` | `::bulk-edit-submit` | Submit bulk edit |
| `GET /invoices/bulk-edit/account` | `::bulk-edit-new-account` | Add new account row in bulk edit |
| `PUT /invoices/bulk-edit/total` | `::bulk-edit-total` | Calculate percentage total |
| `PUT /invoices/bulk-edit/balance` | `::bulk-edit-balance` | Calculate percentage balance |
| `DELETE /invoices/:id` | `::delete` | Void single invoice |
| `PUT /invoices/:id/undo-autopay` | `::undo-autopay` | Undo scheduled autopay |
| `PUT /invoices/:id/unvoid` | `::unvoid` | Restore voided invoice |
| `PUT /invoices/:id/edit` | `::edit-wizard` | Edit existing invoice |
| `GET /invoices/import` | `::import-page` | Import invoices page |
| `POST /invoices/import/upload` | `::import-file` | Upload and parse invoice files |
| `GET /invoices/import/table` | `::import-table` | Import table refresh |
| `DELETE /invoices/import/:id/disapprove` | `::disapprove` | Remove pending imported invoice |
| `PUT /invoices/import/:id/approve` | `::approve` | Approve pending imported invoice |
| `DELETE /invoices/import/disapprove` | `::bulk-disapprove` | Bulk remove pending imports |
| `PUT /invoices/import/approve` | `::bulk-approve` | Bulk approve pending imports |

## Behaviors by Page

### Invoice List Page

#### Unit Tests
- `fetch-ids` generates correct Datomic queries for all filter combinations
- `fetch-page` returns `[results count outstanding-sum total-sum]` tuple
- `sum-outstanding` and `sum-total-amount` calculate aggregates correctly
- `selected->ids` resolves "all selected" vs individual selection
- `hydrate-results` groups and orders pulled entities by input IDs
- `payable-ids` filters to only unpaid, non-scheduled invoices
- `can-undo-autopayment` validates invoice state for undo eligibility

#### Integration Tests
- **Happy path:** Load list page with invoices, verify table renders
- **Filter by vendor:** Select vendor, table refreshes with filtered results
- **Filter by account:** Select account, table refreshes
- **Filter by date range:** Apply date range, results filtered
- **Filter by amount range:** Set min/max amounts, results filtered
- **Filter by invoice number:** Partial match on invoice number
- **Filter by check number:** Search by check number
- **Exact match:** Navigate from notification to specific invoice via `exact-match-id`
- **Sort by each column:** Click column headers (client, vendor, date, due, invoice-number, total, outstanding-balance, location, description-original)
- **Pagination:** Navigate pages, change per-page (default 25)
- **Selection:** Check individual rows, select all, select all filtered
- **Action buttons appear conditionally:** Based on permissions and selection state
- **Legacy redirects:** Old routes redirect to new SSR routes

#### UI Tests (SSR)
- Table renders with correct columns: Client, Vendor, Invoice #, Date, Due, Status, Account, Outstanding, Links
- Status pills display correctly: Paid (primary), Voided (red), Scheduled (yellow), Unpaid (secondary)
- Due date shows relative time: "today", "in X days", "X days ago" with color coding
- Outstanding shows partial payment indicator when balance != total
- Links dropdown shows payments, transactions, ledger entries, source files
- Client column hidden when single client with single location
- Row action buttons: Void (unpaid), Edit (unpaid/paid), Unvoid (voided), Undo autopay (eligible)
- Pay button tooltip explains why disabled: no selection, multiple clients, mixed debit/credit
- Break table grouping by vendor name when sorting by vendor

### New Invoice Wizard

#### Unit Tests
- `new-form-schema` validates required fields, money amounts, entity IDs
- Vendor must have default expense account (`check-vendor-default-account`)
- `clientize-vendor` applies client-specific terms, account overrides, autopay settings
- `assert-no-conflicting` prevents duplicate invoice numbers per vendor/client
- `assert-invoice-amounts-add-up` validates expense accounts sum to total
- `maybe-spread-locations` spreads "Shared" location across all client locations
  - Existing tests in `new_invoice_wizard_test.clj` cover:
    - Equal spread across 2 locations
    - Negative amount spreading
    - Remainder distribution (33.34, 33.33, 33.33)
    - Negative remainder distribution
    - Single cent leftover tolerance (`apply-total-delta-to-account`)
- `$->cents` and `cents->$` round correctly
- `calculate-spread` distributes base amount + remainder

#### Integration Tests
- **Happy path create:**
  1. Open wizard, select client, vendor, date, invoice number, total
  2. Due date auto-calculates from vendor terms when client+date+vendor selected
  3. Scheduled payment auto-calculates from vendor autopay setting
  4. Save with default account → invoice created with vendor's default account
  5. Wizard navigates to "Next Steps" with Pay now / Add another / Close options
- **Happy path customize accounts:**
  1. Select "Customize accounts" on basic details
  2. Add multiple expense account rows
  3. Select account, location (auto-populated from account or Shared), amount
  4. Total and balance update dynamically via HTMX
  5. Location dropdown updates when account changes
  6. Save validates totals match
- **Edit existing invoice:**
  1. Open edit wizard for unpaid/paid invoice
  2. Vendor field disabled (cannot change)
  3. Modify amounts, add/remove accounts
  4. Save updates row in place

#### UI Tests (SSR)
- Wizard renders as modal with Basic Details → Expense Accounts (optional) → Next Steps
- Client typeahead searches companies
- Vendor typeahead searches vendors, disabled when editing
- Date inputs use normal date format
- "Add due / scheduled payment date" link appears when dates not set
- Account prediction radio shows vendor default account name
- Expense account grid: Account, Location, Amount columns
- New account row button adds empty row
- Remove row button with Alpine.js transition
- Total/Balance rows update on amount change
- Validation errors display per field

### Pay Wizard

#### Unit Tests
- `payment-form-schema` validates payment structure
- `does-amount-exceed-outstanding?` catches over/under payments
- `can-handwrite?` validates single vendor and positive balance for handwritten checks
- `credit-only?` detects when all vendor totals are negative (credit scenario)
- `pay-button*` calculates vendor totals and detects credit payment scenarios

#### Integration Tests
- **Happy path - debit:**
  1. Select unpaid invoices from same client
  2. Click Pay → Choose Payment Method modal opens
  3. Select bank account → click Debit
  4. Confirm "Pay in full" or switch to "Customize payments"
  5. Submit → payments created, checks printed if applicable
- **Happy path - print check:**
  1. Select check-type bank account
  2. Choose "Print check"
  3. Payment processed, PDF URL returned for printing
- **Happy path - cash:**
  1. Select cash-type bank account
  2. Payment processed immediately
- **Happy path - handwrite check:**
  1. Single vendor, positive balance required
  2. Enter check number and date
  3. Payment created with pending status
- **Happy path - credit payment:**
  1. Select invoices where vendor total is 0 (credit + debit balance)
  2. Pay button shows "Pay invoices using credit"
  3. Credit invoices offset payment invoices
  4. Balance payment created
- **Validation:**
  - Cannot pay invoices from multiple clients
  - Cannot pay with mixed vendor debit/credit totals
  - Custom payment amounts cannot exceed outstanding balance
  - Handwritten check requires check number
  - Locked client dates blocked

#### UI Tests (SSR)
- Pay button shows count and total amount
- Warning pill appears when some selected invoices are locked/scheduled
- Bank account cards show type-appropriate icons (cash=green, check=blue, credit=purple)
- Tooltip on Pay button explains disabled state
- Payment method selection buttons: Print check, With cash, Debit, Handwrite check
- Payment details step shows invoice grid with vendor, number, total, pay amount
- Mode toggle: "Pay in full" vs "Customize payments"
- Success modal shows thumbs up, PDF download link for checks, scaling reminder

### Bulk Edit

#### Unit Tests
- `assert-percentages-add-up` validates percentages sum to 100%
- `maybe-code-accounts` distributes expense accounts by percentage
  - Shared location spreads across all client locations
  - Rounds cents correctly with remainder handling
  - Validates account location matches

#### Integration Tests
- **Happy path:**
  1. Select invoices via checkboxes
  2. Click "Bulk Edit" → wizard opens
  3. Add expense account rows with account, location, percentage
  4. Submit → all selected invoices coded with new expense accounts
- **Locked invoices excluded:** Only invoices with date >= client locked-until are processed
- **Validation:**
  - Percentages must sum to 100%
  - Account location must match account's configured location

#### UI Tests (SSR)
- Wizard shows count of invoices to be edited
- Account typeahead with location dropdown
- Percentage input (displayed as whole number, stored as decimal)
- Total/Balance percentage display
- New account row button

### Bulk Delete/Void

#### Unit Tests
- `void-invoices-internal`:
  - Voids cash payments linked to selected invoices
  - Only voids invoices without linked invoice-payments
  - Only voids invoices with date >= client locked-until
  - Sets total, outstanding-balance, and expense account amounts to 0

#### Integration Tests
- **Happy path:**
  1. Select invoices
  2. Click "Void selected" → confirmation modal
  3. Confirm → invoices voided, table refreshes with notification
- **Admin only:** Bulk delete requires admin permission
- **Validation:**
  - Paid invoices with linked payments require voiding payments first
  - Locked dates blocked

#### UI Tests (SSR)
- Red alert icon in confirmation modal
- Shows count of invoices to void
- Modal closes on success with notification

### Import Page

#### Unit Tests
- `import->invoice` maps parsed data to invoice entity
- `validate-invoice` checks required keys and client access
- `match-vendor` finds vendor by code or throws with search hint
- `admin-only-if-multiple-clients` flags source-url for admin-only when multiple clients
- `upload-schema` validates force-client, force-vendor, force-location, force-chatgpt

#### Integration Tests
- **Happy path CSV/PDF import:**
  1. Upload file(s) via drag-and-drop or file input
  2. File parsed (CSV direct, PDF via OCR when allowed)
  3. Invoices created with pending import status
  4. Results table shows success/failure per file
- **Force overrides:**
  - Force client overrides parsed client
  - Force vendor overrides parsed vendor
  - Force location overrides parsed location
  - Force ChatGPT restricts to GPT-only parsing
- **Approve/disapprove:**
  - Individual approve → status changes to imported
  - Individual disapprove → invoice deleted
  - Bulk approve/disapprove with selection
- **Validation:**
  - Missing client, vendor, date, total → error
  - No client access → error
  - Vendor not found → error with search hint

#### UI Tests (SSR)
- Upload zone with drag-and-drop styling (blue idle, green hover)
- File list shows selected files
- Force client/vendor/location typeaheads
- "Only use ChatGPT" checkbox
- Results table: File, Result, Template, Sample columns
- Green/red styling for success/error
- Error list shows first 5 errors
- Import table shows pending invoices with approve/disapprove buttons
- Filters: vendor, date range, check number, invoice number, amount range

### Glimpse (OCR Import)

#### Unit Tests
- `textract->textract-invoice` extracts fields from AWS Textract response
- `stack-rank` sorts field descriptors by confidence
- `clean-customer` normalizes customer names for search
- `deduplicate` removes duplicate parsed values
- `textract-invoice->invoice` converts to invoice with vendor terms and autopay

#### Integration Tests
- **Happy path:**
  1. Upload PDF to Glimpse page
  2. File uploaded to S3, Textract job started
  3. Poll every 5s while IN_PROGRESS
  4. On SUCCESS, display extracted fields with alternatives
  5. User selects client, vendor, date, total, invoice number from alternatives
  6. Save creates invoice and links to textract job
- **Field extraction:**
  - Total: from AMOUNT_DUE or TOTAL fields
  - Customer: from CUSTOMER_NUMBER or RECEIVER_NAME (with Solr fallback)
  - Vendor: from VENDOR_NAME with Solr search
  - Date: from INVOICE_RECEIPT_DATE, ORDER_DATE, DELIVERY_DATE
  - Invoice number: from INVOICE_RECEIPT_ID or PO_NUMBER

#### UI Tests (SSR)
- Upload form with Dropzone integration (PDF only)
- Progress indicator while analyzing
- Side-by-side layout: PDF preview iframe + form
- Form fields: Client, Location, Vendor, Date, Total, Invoice Number
- Alternatives shown as clickable pills below each field
- Disabled fields for client and vendor (must select from alternatives)
- Success notification with link to view new invoice

## Cross-Cutting Behaviors

### Filtering
All list pages support these filters (applied via HTMX with debounce):

- **Vendor:** Typeahead search, filters to specific vendor
- **Account:** Typeahead search, filters invoices with that expense account
- **Date range:** Start/end date for invoice date (uses `scan-invoices` for performance)
- **Due date range:** Start/end due date
- **Amount range:** Min/max total amount (inclusive)
- **Invoice number:** Partial string match via `.contains`
- **Check number:** Text search
- **Status:** Route-param based (all, unpaid, paid, voided) or query-param
- **Import status:** Filter by pending/imported
- **Exact match:** Navigate to specific invoice by ID (bypasses other filters)
- **Scheduled payments:** Filter to invoices with scheduled payment date
- **Unresolved:** Invoices missing expense accounts or with unassigned accounts
- **Location:** Filter by expense account location

### Sorting
Click column headers to sort. Supported sort keys:
- client (by client name)
- vendor (by vendor name)
- description-original
- location (by expense account location)
- date
- due (nulls last with default 2050-01-01)
- invoice-number
- total
- outstanding-balance

Default sort: descending by scan-invoices default. Toggle asc/desc.

### Pagination
- Default 25 per page
- Configurable per-page
- Offset-based pagination
- Import table supports up to 250 for "all selected" operations

### Selection
- Individual row checkboxes
- "Select all" checkbox selects all visible
- "Select all filtered" selects all matching current filters (up to 250)
- Selection state maintained via Alpine.js
- Pay/Void/Edit/Bulk-Edit buttons use selection

### Permissions
All invoice operations check permissions via `can?`:

| Activity | Required Permission |
|----------|-------------------|
| Create invoice | `{:subject :invoice :activity :create}` |
| Edit invoice | `{:subject :invoice :activity :edit}` |
| Delete/Void invoice | `{:subject :invoice :activity :delete}` |
| Pay invoice | `{:subject :invoice :activity :pay}` |
| Bulk delete | `{:subject :invoice :activity :bulk-delete}` |
| Bulk edit | `{:subject :invoice :activity :bulk-edit}` |
| Import | `{:subject :invoice :activity :import}` |

Additional checks:
- `assert-can-see-client` - user must have access to invoice's client
- `assert-not-locked` - invoice date must be >= client's locked-until date
- Admin-only for bulk delete confirmation

## Edge Cases

### Voiding Paid Invoices
- Single void: Blocked if invoice has linked non-voided payments. User must void payments first.
- Bulk void: Automatically voids linked cash payments before voiding invoices.

### Unvoiding
- Restores invoice to original status, total, outstanding balance, and expense accounts
- Uses Datomic history to reconstruct previous state
- Requires edit permission and client access

### Undo Autopay
- Only available for paid invoices with scheduled payment and no linked payments
- Resets status to unpaid, outstanding to total, clears scheduled payment
- Locked dates blocked

### Paying with Credit
- Triggered when selected invoices for single vendor have net 0 balance (credit invoices + payment invoices)
- Credit invoices (negative balance) offset payment invoices
- Creates balance-credit payment

### Location Spreading
- "Shared" location in expense accounts spreads across all client locations
- Base amount = total / location count (integer division in cents)
- Remainder distributed 1 cent at a time to first N locations
- Total delta applied to first account to handle rounding

### Negative Amounts
- Supported throughout (credit memos, overpayments)
- Spread calculations handle negative totals
- Pay button validates all-credits-or-debits (can't mix positive and negative vendor totals)

### Zero Balances
- Invoices with 0 outstanding balance show as paid
- Zero-balance selections excluded from payment

### Duplicate Invoice Numbers
- `assert-no-conflicting` prevents same invoice number for same vendor/client
- Edit wizard preserves existing invoice number unless changed

### Missing Vendor/Account
- New invoice wizard requires vendor with default expense account
- Import validation fails if vendor not found
- Unresolved filter finds invoices missing expense accounts

### Locked Clients
- Client has `locked-until` date
- Invoices with date < locked-until cannot be: edited, paid, voided, imported, approved
- Bulk operations filter out locked invoices
- Pay wizard shows warning when some selections are locked

### Large Invoice Counts
- `scan-invoices` Datomic query used for efficient date/client filtering
- Pagination limits to 25 per page by default
- "All selected" capped at 250 for bulk operations
- Outstanding/total sums calculated from all-ids, not just page

## Test Data Requirements

### Entities Needed
- **Clients:** Multiple clients with different locations, some with locked-until dates
- **Vendors:** With/without default accounts, terms, autopay settings, account overrides, terms overrides
- **Accounts:** Expense accounts with/without invoice allowance, different locations
- **Bank Accounts:** Check, cash, credit types, visible/hidden
- **Invoices:** Various statuses, dates, amounts, with/without payments, with/without scheduled payments

### Specific Test Scenarios
- Client with multiple locations (for spreading)
- Client with single location (client column hidden)
- Vendor with terms (auto-due date) and autopay (auto-scheduled payment)
- Invoice with partial payment (outstanding < total)
- Invoice with linked payment (void blocked)
- Voided invoice with history (unvoid test)
- Paid invoice with scheduled payment, no linked payment (undo autopay)
- Negative balance invoice (credit)
- Imported pending invoice (approve/disapprove)
- Locked client with pre/post-lock invoices

### File Upload Test Data
- Valid CSV with proper headers
- PDF with embedded text
- PDF requiring OCR
- File with multiple clients (admin-only source-url)
- File with missing required fields
- File with unmatchable vendor

## Dependencies

- **Datomic:** Primary data store, history for unvoid
- **AWS S3:** File storage for imports and Glimpse PDFs
- **AWS Textract:** OCR for Glimpse PDF processing
- **Solr:** Search for vendor/client matching in Glimpse
- **HTMX/Alpine.js:** Frontend interactivity
- **Bidi:** Route generation
- **Malli:** Schema validation for forms and query params
- **clj-time:** Date parsing and manipulation

## Existing Tests to Preserve

### Unit Tests
- `test/clj/auto_ap/ssr/invoice/new_invoice_wizard_test.clj`
  - `maybe-spread-locations-test` - 6 test cases for location spreading logic

### Integration Tests
- `test/clj/auto_ap/integration/routes/invoice_test.clj`
  - `import-uploaded-invoices` - import single, duplicate prevention, location override, coded invoice
- `test/clj/auto_ap/integration/graphql/invoices.clj`
  - `test-add-invoice` - add with valid/invalid accounts, vendor special accounts
  - `edit-invoice` - edit fields, vendor change blocked, conflicting invoice numbers
  - `edit-expense-accounts` - modify expense accounts
  - `bulk-change-invoices` - bulk coding with percentages
  - `void-invoices` - bulk void and unvoid
  - `void-invoice` - single void and unvoid