ecto_sql.ex

defmodule Mix.EctoSQL do
  @moduledoc false

  @doc """
  Ensures the given repository's migrations paths exists on the file system.

  This function checks for migrations paths in the following order:
  1. Command-line options (`--migrations_path`)
  2. Repository configuration (`:migrations_paths`)
  3. Default path based on `:priv` configuration or "priv/repo/migrations"
  """
  @spec ensure_migrations_paths(Ecto.Repo.t(), Keyword.t()) :: [String.t()]
  def ensure_migrations_paths(repo, opts) do
    paths = Keyword.get_values(opts, :migrations_path)

    paths =
      if paths == [] do
        # Use repo config if available, otherwise fall back to default
        config = repo.config()

        case config[:migrations_paths] do
          nil ->
            [Path.join(source_repo_priv(repo), "migrations")]

          config_paths when is_list(config_paths) ->
            app = Keyword.fetch!(config, :otp_app)
            # In Mix context, we use deps_paths or cwd for path resolution
            base_dir = Mix.Project.deps_paths()[app] || File.cwd!()

            Enum.map(config_paths, fn path ->
              if Path.type(path) == :absolute do
                path
              else
                Path.join(base_dir, path)
              end
            end)

          other ->
            raise ArgumentError,
                  ":migrations_paths must be a list of paths, got: #{inspect(other)}"
        end
      else
        paths
      end

    if not Mix.Project.umbrella?() do
      for path <- paths, not File.dir?(path) do
        raise_missing_migrations(Path.relative_to_cwd(path), repo)
      end
    end

    paths
  end

  defp raise_missing_migrations(path, repo) do
    Mix.raise("""
    Could not find migrations directory #{inspect(path)}
    for repo #{inspect(repo)}.

    This may be because you are in a new project and the
    migration directory has not been created yet. Creating an
    empty directory at the path above will fix this error.

    If you expected existing migrations to be found, please
    make sure your repository has been properly configured
    and the configured path exists.
    """)
  end

  @doc """
  Returns the private repository path relative to the source.
  """
  def source_repo_priv(repo) do
    config = repo.config()
    priv = config[:priv] || "priv/#{repo |> Module.split() |> List.last() |> Macro.underscore()}"
    app = Keyword.fetch!(config, :otp_app)
    Path.join(Mix.Project.deps_paths()[app] || File.cwd!(), priv)
  end
end