defmodule PhoenixTest do
  @moduledoc """
    PhoenixTest is a testing library that allows you to run your feature tests the
    same way regardless of whether your page is a LiveView or a static view.

    It also handles navigation between LiveView and static pages seamlessly. So, you
    don't have to worry about what type of page you're visiting. Just write the
    tests from the user's perspective.

    Thus, you can test a flow going from static to LiveView pages and back without
    having to worry about the underlying implementation.

    This is a sample flow:

    ```elixir
    test "admin can create a user", %{conn: conn} do
      conn
      |> visit("/")
      |> click_link("Users")
      |> fill_form("#user-form", name: "Aragorn", email: "aragorn@dunedan.com")
      |> click_button("Create")
      |> assert_has(".user", "Aragorn")
    end
    ```

    Note that PhoenixTest does _not_ handle JavaScript. If you're looking for
    something that supports JavaScript, take a look at
    [Wallaby](https://hexdocs.pm/wallaby/readme.html).
  """

  alias PhoenixTest.Driver
  alias PhoenixTest.Assertions

  @endpoint Application.compile_env(:phoenix_test, :endpoint)
  import Phoenix.ConnTest

  @doc """
  Entrypoint to create a session.

  `visit/2` takes a `Plug.Conn` struct and the path to visit.

  It returns a `session` which the rest of the `PhoenixTest` functions can use.

  Note that `visit/2` is smart enough to know if the page you're visiting is a
  LiveView or a static view. You don't need to worry about which type of page
  you're visiting.
  """
  def visit(conn, path) do
    case get(conn, path) do
      %{assigns: %{live_module: _}} = conn ->
        PhoenixTest.Live.build(conn)

      conn ->
        PhoenixTest.Static.build(conn)
    end
  end

  @doc """
  Clicks a link with given text and performs the action.

  Here's how it handles different types of `a` tags:

  - With `href`: follows it to the next page
  - With `phx-submit`: it'll send the event to the appropriate LiveView
  - With live redirect: it'll follow the live navigation to the next LiveView
  - With live patch: it'll patch the current LiveView
  """
  defdelegate click_link(session, text), to: Driver

  @doc """
  Perfoms action defined by button.

  - If the button has a `phx-click` on it, it'll send the event to the LiveView.

  - If the button doesn't have a `phx-click` on it, it'll submit the parent form.

  This function can be preceded by `fill_form` to fill out a form and
  subsequently submit the form.

  Note that `fill_form/3` + `click_button/2` works for static and live pages.

  If `click_button/2` is used alone (without a `phx-click`), it is assumed it is a
  form with a single button (e.g. "Delete").

  ## Examples

  ```elixir
  # form with single button or button with `phx-click`
  session
  |> click_button("Delete")

  # fill out form and then submit
  session
  |> fill_form("#user-form", name: "Aragorn")
  |> click_button("Create")
  ```
  """
  defdelegate click_button(session, text), to: Driver

  @doc """
  Fills form data, validating that input fields are present.

  This can be used by both static and live pages.

  If it is a LiveView, and if the form has a `phx-change` attribute defined,
  `fill_form/3` will trigger the `phx-change` event.

  This can be followed by a `click_button/3` to submit the form.
  """
  defdelegate fill_form(session, selector, data), to: Driver

  @doc """
  Submits form in the same way one would do by pressing `<Enter>`.

  Note that this does not validate presence of the submit button.

  ## Examples

  ```elixir
  session
  |> submit_form("#user-form", name: "Aragorn")
  ```
  """
  defdelegate submit_form(session, selector, data), to: Driver

  @doc """
  Assert helper to ensure an element with given CSS selector and `text` is
  present.

  It'll raise an error if no elements are found, but it will not raise if more
  than one matching element is found.
  """
  defdelegate assert_has(session, selector, text), to: Assertions

  @doc """
  Opposite of `assert_has/3` helper. Verifies that element with
  given CSS selector and `text` is _not_ present.

  It'll raise an error if an element that matches selector and text is  found.
  """
  defdelegate refute_has(session, selector, text), to: Assertions
end