defmodule Mix.Tasks.Docs do
  use Mix.Task

  @shortdoc "Build docs with globally installed ex_doc to avoid conflicts"

  @moduledoc """

    ex_doc uses earmark. This means we can't have a dependency from
    earmark back to ex_doc, as this would be circular.

    Instead, we run ex_doc from the command line.

    ## Prerequisite

    ### Install `ex_doc` as an escript on your system ( Elixir >= 1.8 needed)

        mix escript.install hex ex_doc

    ### For ASDF

        Provide the location of where the ex_doc escript is by means of the
        EX_DOC_ESCRIPT environment variable.

    N.B. Launch the above command form anywhere else than your
    `Earmark` root directory.

  """

  def run(_) do
    ex_doc = System.get_env("EX_DOC_ESCRIPT") ||
      "#{System.get_env("HOME")}/.mix/escripts/ex_doc"
    System.cmd("rm", ~w( -rf doc ))
    IO.puts ex_doc
    System.cmd(ex_doc,
      ~w( Earmark #{current_version()} _build/dev/lib/earmark/ebin -m Earmark
          -u https://github/pragdave/earmark.html ))
  end

  defp current_version do
    Earmark.Mixfile.project() |> Keyword.get(:version)
  end
end


# SPDX-License-Identifier: Apache-2.0