Nexus API
###########

HTTP API
========

Authentication
--------------

**Every** request made to nexus must be authenticated
using the *HTTP basic auth* mechanism.

Users Management
----------------

.. http:post:: <nexus>/users

  Create a new user.  Only the super-user can call this API.

  **Request:**

  The body is a `User` object.

  **Response:**

  :status 409 Conflict: Username is not available.

  **Details:**

  .. ts:def:: User

     interface User {

       // User name
       username: string;

       // Shadow password
       shadowPassword: string;
     }

Bank Account Management
-----------------------

.. http:get:: <nexus>/bank-accounts
  
  **Response:**

  A list of `BankAccount` objects
  that belong to the requester.

  .. ts:def:: BankAccount
     
     interface BankAccount {
       // mnemonic name identifying this bank account.
       account: string; 
       // IBAN
       iban: string;
       // BIC
       bic: string;
       // Legal subject owning the account.
       holder: string;
     }

.. http:post:: <nexus>/bank-accounts/<my-acct>/submit-payment

  Ask nexus to submit one prepare payment at the bank.

  **Request:**

  .. ts:def:: SubmitPayment

     interface SubmitPayment {
       // Unique identifier of the (previously) prepared payment
       // to submit at the bank.
       uuid: string;

       // Optional field to specify the bank transport to use
       // for the submission.
       transport: string;
     }

  :status 404 Not Found: the unique identifier **or**
    the bank transport could not be found in the system


.. http:get:: <nexus>/bank-accounts/<my-acct>/prepared-payment/$uuid
   
   Ask the status of payment ``$uuid``.

   **Response:**

   .. ts:def:: PaymentStatus

      interface PaymentStatus {

        // Payment unique identifier
        uuid: string;

        // True for submitted payments
        submitted: boolean;

        // Creditor IBAN
        creditorIban: string;

        // Creditor BIC
        creditorBic: string;

        // Creditor legal name
        creditorName: string;

        // Amount
        amount: string;

        // Date of submission (in dashed form YYYY-MM-DD)
        submissionDate: string;

        // Date of preparation (in dashed form YYYY-MM-DD)
        preparationDate: string;
      }

.. http:post:: <nexus>/bank-accounts/<my-acct>/prepare-payment
  
  Ask nexus to prepare instructions for a new payment.
  Note that ``my-acct`` is the bank account that will be
  **debited** after this operation.

  **Request:**

  .. ts:def:: PreparedPaymentRequest

     interface PreparedPayment {
       // IBAN that will receive the payment.
       iban: string;
       // BIC hosting the IBAN.
       bic: string;
       // Legal subject that will receive the payment.
       name: string;

       // amount, in the format CURRENCY:XX.YY
       amount: string
     }

  **Response:**

  .. ts:def:: PreparedPaymentResponse
     
     interface PreparedPaymentResponse {

       // Opaque identifier to be communicated when
       // the user wants to submit the payment to the
       // bank.
       uuid: string;
     }

.. http:post:: <nexus>/bank-accounts/<my-acct>/collect-transactions

  Ask the default transport to download the latest transactions
  related to ``my-acct`` and store them locally.

  **Request:**

  .. ts:def:: CollectTransactions

     interface CollectTransactions {
       // Optional field to specify the bank transport to
       // use for such operation.
       bankTransport: string;
       // dashed date (YYYY-MM-DD) of the earliest payment
       // in the result. Optional, defaults to "earliest
       // possible" date.
       start: string;
       // dashed date (YYYY-MM-DD) of the earliest payment
       // in the result. Optional, defaults to "latest
       // possible" date.
       end: string;
     }

.. http:post:: <nexus>/collected-transactions

  Shows which transactions are stored locally at nexus.

  **Request:**

  .. ts:def:: TimeRange

     interface TimeRange {
       // start date of desired payments.  Optional,
       // defaults to "earliest possible" date.
       start: string;
       // end date of desired payments.  Optional,
       // defaults to "latest possible" date.
       end: string;
     }

  **Response:** A list of `Transaction` objects.

  .. ts:def:: Transaction

     interface Transaction {
       // local bank account involved in the transaction.
       account: string;

       // counterpart IBAN
       counterpartIban: string;

       // counterpart BIC
       counterpartBic: string;

       // counterpart holder name
       counterpartName: string;

       // amount, in the format [-]CURRENCY:XX.YY,
       // where the minus sign as prefix indicates
       // a debit for the user's bank account.
       amount: string
     }

Bank Transports
---------------

Bank transports connect the local LibEuFin bank account
to the real bank.

.. http:post:: <nexus>/bank-transports
  
  Activate a new bank transport for the requesting user.

  **Request:**
  Object of the type `BankTransport`

  **Response:**

  :status 409 Conflict: The ``name`` field exists already for
    the requesting user.

  **Details:**

  .. ts:def:: BankTransport

     interface BankTransport {

       // Mnemonic identifier for the transport bein created.
       name: string;

       // Optional field to restore a previous transport.
       backup: TransportBackup;

       // Type of the transport (ebics, fints, native, ..)
       type: string;
     }


  .. ts:def:: TransportBackup
     
     interface TransportBackup {

      // The information needed in this type depend entirely
      // on which transport is being restored.

     }

.. http:post:: <nexus>/bank-transports/<transport-name>/sendMSG.
  
  Perform the ``MSG`` operation offered by ``transport-name``
  **without** affecting the nexus database.

  **Response:**

  :status 404 Not Found: ``transport-name`` doesn't exist for
    the requesting user.

.. http:post:: <nexus>/bank-transports/<transport-name>/syncMSG.
  
  Some transports **do** have operations that aren't semantically
  related to a bank account but need to be stored locally at the nexus.
  One typical example is the downloading of the bank's keys vie the
  EBICS transport.  This API lets the user perform the ``MSG``
  operation that should result in new data being stored locally
  at the nexus.

  **Response:**

  :status 404 Not Found: ``transport-name`` doesn't exist for
    the requesting user.