defmodule Phoenix.UI.Components.Drawer do
  @moduledoc """
  Provides drawer component.
  """
  import Phoenix.UI.Components.{Backdrop, Paper}

  use Phoenix.UI, :component

  @default_anchor "left"
  @default_open false
  @default_square true
  @default_variant "temporary"

  @doc """
  Renders drawer component.

  ## Examples

      ```
      <.drawer id="basic_drawer">
        content
      </.drawer>
      ```

  """
  @spec drawer(Socket.assigns()) :: Rendered.t()
  def drawer(raw_assigns) do
    assigns =
      raw_assigns
      |> assign_new(:anchor, fn -> @default_anchor end)
      |> assign_new(:open, fn -> @default_open end)
      |> assign_new(:square, fn -> @default_square end)
      |> assign_new(:variant, fn -> @default_variant end)
      |> assign_new("phx-click-away", fn -> hide_drawer("##{raw_assigns[:id]}") end)
      |> assign_new("phx-key", fn -> "escape" end)
      |> assign_new("phx-window-keydown", fn -> hide_drawer("##{raw_assigns[:id]}") end)
      |> build_drawer_attrs()

    ~H"""
    <.backdrop
      id={"#{@id}_drawer_backdrop"}
      open={@open}
      variant="visible"
      phx-click={hide_drawer("##{@id}")}
    >
    </.backdrop>
    <.paper variant="elevated" {@drawer_attrs}>
      <%= render_slot(@inner_block) %>
    </.paper>
    """
  end

  ### JS Interactions ##########################

  @doc """
  Hides drawer matching selector.

  ## Examples

      iex> hide_drawer(selector)
      %JS{}

      iex> hide_drawer(js, selector)
      %JS{}

  """
  @spec hide_drawer(String.t()) :: struct()
  def hide_drawer(selector), do: hide_drawer(%JS{}, selector)

  @spec hide_drawer(struct(), String.t()) :: struct()
  def hide_drawer(%JS{} = js, selector) do
    js
    |> JS.remove_attribute("open", to: selector)
    |> hide_backdrop("#{selector}_drawer_backdrop")
  end

  @doc """
  Shows drawer matching selector.

  ## Examples

      iex> show_drawer(selector)
      %JS{}

      iex> show_drawer(js, selector)
      %JS{}

  """
  @spec show_drawer(String.t()) :: struct()
  def show_drawer(selector), do: show_drawer(%JS{}, selector)

  @spec show_drawer(struct(), String.t()) :: struct()
  def show_drawer(%JS{} = js, selector) do
    js
    |> JS.set_attribute({"open", "true"}, to: selector)
    |> show_backdrop("#{selector}_drawer_backdrop")
  end

  ### Drawer Attrs ##########################

  defp build_drawer_attrs(assigns) do
    extend_class = build_class(~w(
      fixed overflow-hidden z-50 invisible open:visible
      transition-all ease-in-out duration-300
      #{classes(:anchor, assigns)}
      #{classes(:open, assigns)}
      #{Map.get(assigns, :extend_class)}
    ))

    attrs =
      assigns
      |> assigns_to_attributes([:anchor, :extend_class, :variant])
      |> Keyword.put(:extend_class, extend_class)

    assign(assigns, :drawer_attrs, attrs)
  end

  ### CSS Classes ##########################

  # Anchor
  defp classes(:anchor, %{anchor: "bottom"}), do: "bottom-0 left-0 right-0"
  defp classes(:anchor, %{anchor: "left"}), do: "bottom-0 left-0 top-0"
  defp classes(:anchor, %{anchor: "right"}), do: "bottom-0 right-0 top-0"
  defp classes(:anchor, %{anchor: "top"}), do: "left-0 right-0 top-0"

  # Open
  defp classes(:open, %{anchor: "bottom"}), do: "max-h-0 open:max-h-full"
  defp classes(:open, %{anchor: "left"}), do: "max-w-0 open:max-w-full"
  defp classes(:open, %{anchor: "right"}), do: "max-w-0 open:max-w-full"
  defp classes(:open, %{anchor: "top"}), do: "max-h-0 open:max-h-full"

  defp classes(_rule_group, _assigns), do: nil
end