defmodule Securion do
  @moduledoc """
  Elixir client library to the [SecurionPay](https://securionpay.com) payment
  gateway REST APIs.

  > Please refer to the [docs](https://securionpay.com/docs/api) of the original REST
  APIs when in doubt. This client library is a thin wrapper around it and
  most details are left unchanged.
  However, some API shortcuts (e.g. on-the-go card creation for new
  subscriptions, see the
  [https://securionpay.com/docs/api#subscription-create](docs))
  were removed in favor of simpler, composable APIs.

  `securion` doesn't fully cover the original APIs yet, possibly ever. Only
  core features are available. Most notably, subscriptions, plans, and events
  are *not* supported.

  ## Installation

  Add `securion` as dependency in `mix.exs`:

      defp deps do
      [
        {:securion, "~> x.y.z"}
      ]
      end

  ## Configuration

  You must provide your SecurionPay API secret key. The public key is **not** required.

      # config/config.exs

      config :securion,
        secret_key: "sk_ ..."

  You should also run your tests with test-only API keys, like so:

      # config/test.exs

      config :securion,
        secret_key: "sk_test_ ..."

  ## Overview

  - `Securion.Customer` - Customers APIs.
  - `Securion.Card` - Payment cards APIs.
  - `Securion.Token` - One-time only tokens for safely handling payment
  cards.
  - `Securion.Charge` - Transactions APIs.
  """

  import Securion.Resource

  @default_limit 10

  @doc """
  Fetches a page of SecurionPay resources (`list`). `limit`
  determines the maximum number of resources.
  """
  def fetch_list(list, limit \\ @default_limit) do
    get(list.path, list.params ++ [limit: limit])
  end

  @doc """
  Fetches a page of SecurionPay resources (`list`). `limit`
  determines the maximum number of resources.

  **Only resources that follow `cursor` will be selected.**
  """
  def fetch_list_after(list, cursor, limit \\ @default_limit) do
    get(list.path, list.params ++ [limit: limit, startingAfterId: cursor])
  end

  @doc """
  Fetches a page of SecurionPay resources (`list`). `limit`
  determines the maximum number of resources.

  **Only resources that precede `cursor` will be selected.**
  """
  def fetch_list_before(list, cursor, limit \\ @default_limit) do
    get(list.path, list.params ++ [limit: limit, startingBeforeId: cursor])
  end
end