defmodule Zig.Module do
  @moduledoc """
  this struct represents all information a zigler module bound to a
  nif should have.  WIP.
  """

  @enforce_keys [:file, :module, :otp_app]

  @default_imports [std: "std", e: "erl_nif.zig", beam: "beam.zig"]

  # libc is required to be linked in the case of *bsd based systems
  # because these operating systems do not have syscall stability and
  # ensure libc stability.
  link_libc =
    case :os.type() do
      {:unix, :linux} -> false
      {:unix, :freebsd} -> true
      {:unix, :darwin} -> true
      {_, :nt} -> false
    end

  defstruct @enforce_keys ++
              [
                zig_file: "",
                libs: [],
                system_libs: [],
                nifs: [],
                resources: [],
                zig_version: Version.parse!("0.9.1"),
                imports: @default_imports,
                c_includes: [],
                include_dirs: [],
                system_include_dirs: [],
                dry_run: false,
                code: [],
                version: Version.parse!("0.0.0"),
                link_libc: link_libc,
                link_libcpp: false,
                sources: [],
                test_dirs: nil
              ]

  @type t :: %__MODULE__{
          file: Path.t(),
          module: module,
          otp_app: atom,
          zig_file: Path.t(),
          libs: [Path.t()],
          system_libs: [String.t()],
          nifs: [Zig.Parser.Function.t()],
          resources: [Zig.Parser.Resource.t()],
          zig_version: Version.t(),
          imports: keyword(Path.t()),
          c_includes: keyword(Path.t() | [Path.t()]),
          include_dirs: [Path.t()],
          system_include_dirs: [Path.t()],
          link_libc: boolean,
          link_libcpp: boolean,
          dry_run: boolean,
          sources: [source],
          code: iodata,
          version: Version.t(),
          test_dirs: nil | [Path.t()]
        }

  @type source :: String.t() | {String.t(), [String.t()]}

  # takes the zigler imports option and turns it into the imports keyword

  def imports(nil), do: @default_imports
  def imports([:defaults | rest]), do: @default_imports ++ rest
  def imports(import_list), do: import_list
end