mix.exs

defmodule Hello.MixProject do
  use Mix.Project

  def project() do
    {git_tag, description} = git_version()

    [
      app: :hello,
      version: git_tag,
      elixir: "~> 1.8",
      elixirc_paths: elixirc_paths(Mix.env()),
      compilers: [:phoenix, :gettext] ++ Mix.compilers(),
      description: "hello" <> description,
      start_permanent: Mix.env() == :prod,
      deps: deps()
    ]
  end

  # Configuration for the OTP application.
  #
  # Type `mix help compile.app` for more information.
  def application do
    [
      mod: {Hello.Application, []},
      extra_applications: [:logger, :runtime_tools]
    ]
  end

  # Specifies which paths to compile per environment.
  defp elixirc_paths(:test), do: ["lib", "test/support"]
  defp elixirc_paths(_), do: ["lib"]

  # Specifies your project dependencies.
  #
  # Type `mix help deps` for examples and options.
  defp deps do
    [
      {:distillery, "~> 2.0", runtime: false},
      {:phoenix, "~> 1.4.6"},
      {:phoenix_pubsub, "~> 1.1"},
      {:phoenix_html, "~> 2.11"},
      {:phoenix_live_reload, "~> 1.2", only: :dev},
      {:gettext, "~> 0.11"},
      {:jason, "~> 1.0"},
      {:plug_cowboy, "~> 2.0"}
    ]
  end

  defp git_version() do
    # pulls version information from "nearest" git tag or sha hash-ish
    {hashish, 0} =
      System.cmd("git", ~w[describe --dirty --abbrev=7 --tags --always --first-parent])

    full_version = String.trim(hashish)

    tag_version =
      hashish
      |> String.split("-")
      |> List.first()
      |> String.replace_prefix("v", "")
      |> String.trim()

    tag_version =
      case Version.parse(tag_version) do
        :error -> "0.0.0-#{tag_version}"
        _ -> tag_version
      end

    {tag_version, full_version}
  end

end