module YAMLScript::LibYS

def self.extension
  case RUBY_PLATFORM
  when /darwin/
    'dylib'
  when /linux/
    'so'
  else
    raise Error, "Unsupported platform #{RUBY_PLATFORM} for yamlscript."
  end
end

def self.find_libys_path
  name = libys_name
  path = ld_library_paths.map {
    |dir| File.join(dir, name) }.detect { |file| File.exist?(file)
  }
  vers = YAMLSCRIPT_VERSION
  raise Error, <<-ERROR unless path
ed library file `#{name}` not found
 curl https://yamlscript.org/install | VERSION=#{vers} LIB=1 bash
 https://github.com/yaml/yamlscript/wiki/Installing-YAMLScript
R
  path
end

def self.ld_library_paths
  env_value = ENV.fetch('LD_LIBRARY_PATH', '')
  paths = env_value.split(':')
  paths << '/usr/local/lib'
  paths << ENV.fetch('HOME', '') + '/.local/lib'
end

def self.libys_name
  "libys.#{extension}.#{YAMLSCRIPT_VERSION}"
end