defmodule Mix.Tasks.Compile.Gin.Templates do
  use Mix.Task

  defstruct [:source]

  #######
  # API #
  #######

  def run(_) do
    Enum.map(Mix.Project.config[:"gin.templates"], &compile/1)
  end

  ###########
  # Private #
  ###########

  defp compile({source,data}) do
    target = String.trim_trailing(source, ".eex")
    head = head(source)
    body = EEx.eval_file(source, data)
    content = head <> body
    File.write(target, content)
  end

  defp head(source) do
    """
    *Note: Do not edit this file; it's autogenerated.  Instead, edit [#{source}](#{source}).*

    """
  end
end