module RBS
  # Copies RBS files loaded through `loader` under `vendor_dir`.
  #
  # Core libraries and library RBS files will be copied.
  #
  # ```rb
  # loader = RBS::EnvironmentLoader.new()
  #
  # loader.add(library: set)               # Libraries will be copied.
  # loader.add(library: "minitest", version: "1.2.3")
  #
  # loader.add(path: Pathname("sig"))      # Dirs will be ignored.
  #
  # vendorer = RBS::Vendorer.new(vendor_dir: Pathname("vendor/rbs"), loader: loader)
  # vendorer.clean!
  # vendorer.copy!
  # ```
  #
  # The result will be:
  #
  # ```
  # vendor/rbs/core            => Will include core RBSs
  # vendor/rbs/set-0           => Will include `set` library RBSs.
  # vendor/rbs/minitest-1.2.3  => Will include `minitest` library RBSs.
  # ```
  #
  # The vendorerd RBSs will be loaded through :dir source.
  #
  # ```rb
  # loader = RBS::EnvironmentLoader.new(core_root: nil, repository: RBS::Repository.new(no_stdlib: true))
  # loader.add(path: Pathname("vendor/rbs"))
  # loader.add(path: Pathname("sig"))
  # ```
  #
  class Vendorer
    attr_reader vendor_dir: Pathname
    attr_reader loader: EnvironmentLoader

    def initialize: (vendor_dir: Pathname, loader: EnvironmentLoader) -> void

    # Copy RBS files into `vendor_dir`.
    # Ensures the `vendor_dir` exists.
    def copy!: () -> void

    # Deletes `vendor_dir` and its content if exists.
    #
    def clean!: () -> void

    def ensure_dir: [A] () { () -> A } -> A
  end
end