defmodule Htmx do
  @moduledoc """
  Provides a custom sigil for working with HTMX components.

  ## Example
    
    def render(assigns) do
      ~HTMX"<div><%= @some_key %></div>"
    end
  """

  defmacro sigil_HTMX({:<<>>, _meta, [expr]}, []) do
    unless Macro.Env.has_var?(__CALLER__, {:assigns, nil}) do
      raise "~HTMX requires a variable named \"assigns\" to exist and be set to a map"
    end

    options = [
      engine: Phoenix.HTML.Engine,
      source: expr
    ]

    ast = EEx.compile_string(expr, options)

    quote do
      unquote(ast)
      |> Phoenix.HTML.Engine.encode_to_iodata!()
      |> IO.iodata_to_binary()
    end
  end
end