# Message Recipients Backend

## Purpose

`message_recipients` is the per-organization store of per-recipient delivery records for messages
(one row per recipient, with delivery and read status). It is a generic-CRUD slice assembled from
the shared factories; the backend is the source of truth for these records. This is the
generic-CRUD slice for the `message_recipients` table; the higher-level parent-messaging workflow
is documented separately in `communications.md`.

## Slice Files (by layer)

- Route: `src/routes/message_recipients.ts` — `createCrudRouter(controller, { permission: 'message_recipients' })`.
- Controller: `src/api/controllers/message_recipients.controller.ts` — `createCrudController(service, { csvFields })`.
- Service (BLL): `src/services/message_recipients.ts` — `createCrudService(DbApi, { notFoundCode: 'message_recipientsNotFound' })`.
- Repository (DAL): `src/db/api/message_recipients.ts` (`Message_recipientsDBApi`) — entity-specific
  `create`/`bulkImport`/`update`/`findBy`/`findAll`; `remove`/`deleteByIds`/`findAllAutocomplete`
  delegate to `db/api/shared/repository.ts`.
- Model: `src/db/models/message_recipients.ts`.
- Shared used: CRUD factories (`services/shared/crud-service.ts`,
  `api/controllers/shared/crud-controller.ts`, `api/http/crud-router.ts`), repository helpers
  (`db/api/shared/repository.ts`), `shared/constants/pagination.ts` (`resolvePagination`).

## API

The standard generic-CRUD surface (all under `/api/message_recipients`, JWT +
`${METHOD}_MESSAGE_RECIPIENTS` permission, all `200`) — see `backend-architecture.md` for the
shared contract:

- `POST /` — body `{ data }`, returns `true`.
- `POST /bulk-import` — multipart CSV file, returns `true`.
- `PUT /:id` — body `{ data, id }` (the service reads the id from the **body**, not the path
  param), returns `true`.
- `DELETE /:id` — returns `true`.
- `POST /deleteByIds` — body `{ data: string[] }`, returns `true`.
- `GET /` — query filters, returns `{ rows, count }`; `?filetype=csv` streams a CSV of `csvFields`.
- `GET /count` — returns `{ rows: [], count }`.
- `GET /autocomplete` — `?query&limit&offset`, returns `[{ id, label }]` where `label` is
  `recipient_label`.
- `GET /:id` — returns the record with eager associations (see Data Contract).

`csvFields`: `id`, `recipient_label`, `destination`, `delivered_at`, `read_at`.

## Access Rules

- JWT required; the whole router is guarded by `checkCrudPermissions('message_recipients')`,
  deriving `READ_MESSAGE_RECIPIENTS` / `CREATE_MESSAGE_RECIPIENTS` /
  `UPDATE_MESSAGE_RECIPIENTS` / `DELETE_MESSAGE_RECIPIENTS` per HTTP method.
- Access is granted by role permission or per-user `custom_permissions` (see `permissions.md`).

## Tenant Scope

- `findAll` scopes `where.organizationId` to `currentUser.organizationId`; a `globalAccess`
  role clears the org filter (sees all tenants).
- `create` assigns the organization from `currentUser.organizationId`; `update` only reassigns
  organization for `globalAccess` users (otherwise it stays the caller's org).

## Data Contract

Model columns (`paranoid`, soft-delete via `deletedAt`):

- `id` (UUID PK), `recipient_label`, `destination` (TEXT, nullable).
- `recipient_type` — ENUM `user` | `student` | `guardian`.
- `delivery_status` — ENUM `pending` | `sent` | `delivered` | `failed` | `read`.
- `delivered_at`, `read_at` — DATE.
- `importHash` (unique), `organizationId`, `messageId`, `createdById`, `updatedById`, timestamps.

Associations: `belongsTo` organization, message, createdBy/updatedBy (users). `findBy`/`GET /:id`
eager-load organization and message in a single `Promise.all`.

List filters (`MessageRecipientsFilter`): `id`, `recipient_label`, `destination`,
`delivered_atRange`, `read_atRange`, `recipient_type`, `delivery_status`, `message` (id or
subject, `|`-separated), `organization`, `createdAtRange`, plus `field`/`sort` ordering and
`limit`/`page` pagination.

## Behavior / Notes

- This slice has no file relations.
- `bulkImport` offsets `createdAt` per row by `BULK_IMPORT_TIMESTAMP_STEP_MS` to preserve order.
- List pagination uses the shared `resolvePagination` defaults (page size 10, capped at 100).
- Note: `MessageRecipientsFilter` accepts an `active` flag the model has no column for; it is
  currently inert (kept for source accuracy).

## Tests

None yet.

## Related

- Generic-CRUD contract: `backend-architecture.md`; parent-messaging workflow:
  `communications.md`; related slices: `messages`, `permissions.md`.
