Integration with mix about protobuf HOT 8 CLOSED

defmodule Mix.Tasks.Compiler.ProtocGen do
  use Mix.Task.Compiler

  def run(_args) do
    protobuf_dir = Application.get_env(:bootstrap, :protobuf_path, "priv/protobuf")

    if is_binary(protobuf_dir) and File.dir?(protobuf_dir) and
         not Enum.empty?(File.ls!(protobuf_dir)) do
      with {:ok, protoc_path} <- find_executable("protoc"),
           {:ok, _elixir_protoc_path} <- find_executable("protoc-gen-elixir") do
        protoc_files = File.ls!(protobuf_dir) |> Enum.map(&Path.join(protobuf_dir, &1))
        IO.puts("Compiling protoc files: #{inspect(protoc_files)}")

        # Create the directory where we'll store protobuf generated files, if it doesn't exist
        File.mkdir_p!("./lib/protoc_gen")
        compile_while_successful(protoc_files, protoc_path)
      else
        {:error, {name, :not_found}} ->
          warn_without_stacktrace("Failed to find the #{name} exectuable on the path")
          {:error, []}
      end
    else
      warn_without_stacktrace(
        "Expected the #{inspect(protobuf_dir)} directory to contain at least one file, skipping Elixir protoc generation."
      )
    end
  end

  def clean do
    IO.puts("Cleaned up protoc module generation")
  end

  defp compile_while_successful(protoc_files, protoc_executable_path)
       when is_list(protoc_files) and is_binary(protoc_executable_path) do
    Enum.reduce_while(protoc_files, :ok, fn file_path, _acc ->
      case System.cmd(protoc_executable_path, ["--elixir_out=./lib/protoc_gen", file_path]) do
        {_, 0} ->
          {:cont, :ok}

        # Usually the message is printed by the command anyway
        {_message, nonzero_exit_code} ->
          warn_without_stacktrace(
            "Failed to generate Elixir protobuf modules for #{file_path} with exit code: #{
              nonzero_exit_code
            }"
          )

          {:halt, {:error, []}}
      end
    end)
  end

  defp warn_without_stacktrace(message) do
    IO.warn(message, [])
  end

  defp find_executable(name) do
    case System.find_executable(name) do
      nil -> {:error, {name, :not_found}}
      path -> {:ok, path}
    end
  end
end

def project do
  [
    # Be sure to add the compiler before the standard Mix compilers
    # This ensures that Protobuf-generated code is available before
    # the project's Elixir source is compiled.
    compilers: [:protoc_gen] ++ Mix.compilers()

    # ... Other project configuration
  ]
end