defmodule PaymentGatewayAppTest do
  use ExUnit.Case, async: true

  describe "start_payment/4" do
    test "successfully initiates a payment" do
      {:ok, payment} = PaymentGatewayApp.start_payment(50.0, "USD", "user_abc")

      assert is_map(payment)
      assert payment.amount == 50.0
      assert payment.currency == "USD"
      assert payment.user_id == "user_abc"
      assert is_binary(payment.id)
    end

    test "successfully initiates a payment with description" do
      {:ok, payment} = PaymentGatewayApp.start_payment(75.0, "USD", "user_def", description: "Test Payment")

      assert is_map(payment)
      assert payment.amount == 75.0
      assert payment.description == "Test Payment"
    end

    test "returns error for invalid input" do
      {:error, _reason} = PaymentGatewayApp.start_payment(-10, "USD", "user_abc")
    end
  end

  describe "get_payment_status/1" do
    test "retrieves payment status" do
      {:ok, status} = PaymentGatewayApp.get_payment_status("pay_test")

      assert is_map(status)
      assert status.id == "pay_test"
      assert is_binary(status.status)
    end

    test "returns error for invalid payment_id" do
      {:error, _reason} = PaymentGatewayApp.get_payment_status("")
    end
  end
end