class SandBox

def check_ruby_build_installed
  raise %(ruby-build not installed) unless ruby_build_installed?
end

def clean_sandbox
  system %(rm -rf #{base_dir})
end

def command_exists_on_path?(cmd)
  system("which #{cmd} > /dev/null 2>&1")
end

def ensure_base_dir_exists
  system %(mkdir -p #{base_dir}) unless Dir.exist?(base_dir)
end

def ensure_rubies_directories_exist
  rubies.each do |ruby|
    ruby_dir = File.join(@rubies_dir, ruby.version, ruby.gemset, ruby.name)
    system %(mkdir -p #{ruby_dir}) unless Dir.exist?(ruby_dir)
  end
end

def ensure_rubies_installed
  rubies.each do |ruby|
    ruby_dir = File.join(@rubies_dir, ruby.version, ruby.gemset, ruby.name)
    system %(#{@ruby_build_cmd} #{ruby.version} #{ruby_dir}) unless File.exist?(
      File.join(
        ruby_dir,
        %(.installed_by_pangea)
      )
    )
    system %(touch #{File.join(ruby_dir, %(.installed_by_pangea))}) unless File.exist?(
      File.join(
        ruby_dir,
        %(.installed_by_pangea)
      )
    )
  end
end

def initialize(
  name:,
  base_dir: %(~/.pangea/sandbox),
  rubies: []
)
  @base_dir = base_dir
  @name     = name
  @rubies   = rubies
  @rubies_dir = File.join(@base_dir, @name, %(rubies))
  @ruby_build_cmd = %(ruby-build)
end

def prepare_sandbox
  ensure_base_dir_exists
  ensure_rubies_directories_exist
  check_ruby_build_installed
  ensure_rubies_installed
end

def ruby_build_installed?
  command_exists_on_path?(@ruby_build_cmd)
end