defmodule <%= @mod %>.Scene.Transforms do
  use Scenic.Scene
  alias Scenic.Graph

  import Scenic.Primitives
  import Scenic.Components

  alias <%= @mod %>.Component.Nav
  alias <%= @mod %>.Component.Notes

  @notes """
    \"Transforms\" demonstrates using transforms to position, rotate and scale.
    The upper sliders apply transforms to the group containing the inset UI.
    The lower slider rotates the quad independantly of the upper sliders.
  """

  @start_x 150
  @start_y 300
  @start_scale 1.0

  @graph Graph.build(font: :roboto, font_size: 20)
         |> group(
           fn g ->
             g
             |> group(
               fn g ->
                 g
                 |> text("X")
                 |> text("Y", translate: {0, 20})
                 |> text("Scale", translate: {0, 40})
                 |> text("Angle", translate: {0, 60})
               end,
               translate: {60, 20},
               text_align: :right
             )
             |> group(
               fn g ->
                 g
                 |> slider({{00, 500}, @start_x}, id: :pos_x)
                 |> slider({{180, 400}, @start_y}, id: :pos_y, translate: {0, 20})
                 |> slider({{0.2, 3.0}, @start_scale}, id: :scale, translate: {0, 40})
                 |> slider({{-1.5708, 1.5708}, 0}, id: :rotate_ui, translate: {0, 60})
               end,
               translate: {70, 6}
             )
           end,
           translate: {0, 70}
         )
         |> group(
           fn g ->
             g
             |> text("Inner UI group", translate: {0, 30})
             |> quad({{0, 20}, {30, 0}, {36, 26}, {25, 40}},
               id: :quad,
               fill: {:linear, {0, 0, 40, 40, :yellow, :purple}},
               stroke: {2, :khaki},
               # pin: {400,310}
               translate: {140, 0},
               scale: 1.4
             )
             |> slider({{-1.5708, 1.5708}, 0}, id: :rotate_quad, translate: {0, 50}, width: 200)
           end,
           translate: {@start_x, @start_y},
           pin: {100, 25},
           id: :ui_group
         )

         # Nav and Notes are added last so that they draw on top
         |> Nav.add_to_graph(__MODULE__)
         |> Notes.add_to_graph(@notes)

  # ============================================================================
  # setup

  # --------------------------------------------------------
  @doc false
  @impl Scenic.Scene
  def init(scene, _param, _opts) do
    graph = @graph

    scene =
      scene
      |> assign(graph: graph, x: @start_x, y: @start_y)
      |> push_graph(graph)

    {:ok, scene}
  end

  # --------------------------------------------------------
  @doc false
  @impl Scenic.Scene
  def handle_event({:value_changed, :pos_x, x}, _, %{assigns: %{graph: graph, y: y}} = scene) do
    graph = Graph.modify(graph, :ui_group, &update_opts(&1, translate: {x, y}))

    scene =
      scene
      |> assign(graph: graph, x: x)
      |> push_graph(graph)

    {:halt, scene}
  end

  def handle_event({:value_changed, :pos_y, y}, _, %{assigns: %{graph: graph, x: x}} = scene) do
    graph = Graph.modify(graph, :ui_group, &update_opts(&1, translate: {x, y}))

    scene =
      scene
      |> assign(graph: graph, y: y)
      |> push_graph(graph)

    {:halt, scene}
  end

  def handle_event({:value_changed, :scale, scale}, _, %{assigns: %{graph: graph}} = scene) do
    graph = Graph.modify(graph, :ui_group, &update_opts(&1, scale: scale))

    scene =
      scene
      |> assign(graph: graph)
      |> push_graph(graph)

    {:halt, scene}
  end

  def handle_event({:value_changed, :rotate_ui, angle}, _, %{assigns: %{graph: graph}} = scene) do
    graph = Graph.modify(graph, :ui_group, &update_opts(&1, rotate: angle))

    scene =
      scene
      |> assign(graph: graph)
      |> push_graph(graph)

    {:halt, scene}
  end

  def handle_event({:value_changed, :rotate_quad, angle}, _, %{assigns: %{graph: graph}} = scene) do
    graph = Graph.modify(graph, :quad, &update_opts(&1, rotate: angle))

    scene =
      scene
      |> assign(graph: graph)
      |> push_graph(graph)

    {:halt, scene}
  end
end