module SassC::Util

def abstract(obj)
  raise NotImplementedError.new("#{obj.class} must implement ##{caller_info[2]}")
end

def caller_info(entry = nil)
  # JRuby evaluates `caller` incorrectly when it's in an actual default argument.
  entry ||= caller[1]
  info = entry.scan(/^((?:[A-Za-z]:)?.*?):(-?.*?)(?::.*`(.+)')?$/).first
  info[1] = info[1].to_i
  # This is added by Rubinius to designate a block, but we don't care about it.
  info[2].sub!(/ \{\}\Z/, '') if info[2]
  info
end

def clamp(value, min, max)
  return min if value < min
  return max if value > max
  return value
end

def deprecated(obj, message = nil)
  obj_class = obj.is_a?(Class) ? "#{obj}." : "#{obj.class}#"
  full_message = "DEPRECATION WARNING: #{obj_class}#{caller_info[2]} " +
    "will be removed in a future version of Sass.#{("\n" + message) if message}"
  SassC::Util.sass_warn full_message
end

def ironruby?
  return @ironruby if defined?(@ironruby)
  @ironruby = RUBY_ENGINE == "ironruby"
end

def jruby?
  return @jruby if defined?(@jruby)
  @jruby = RUBY_PLATFORM =~ /java/
end

def jruby_version
  @jruby_version ||= ::JRUBY_VERSION.split(".").map {|s| s.to_i}
end

def map_keys(hash)
  map_hash(hash) {|k, v| [yield(k), v]}
end

def paths(arrs)
  arrs.inject([[]]) do |paths, arr|
    arr.map {|e| paths.map {|path| path + [e]}}.flatten(1)
  end
end

def rails_env
  return ::Rails.env.to_s if defined?(::Rails.env)
  return RAILS_ENV.to_s if defined?(RAILS_ENV)
  nil
end

def rails_root
  if defined?(::Rails.root)
    return ::Rails.root.to_s if ::Rails.root
    raise "ERROR: Rails.root is nil!"
  end
  return RAILS_ROOT.to_s if defined?(RAILS_ROOT)
  nil
end

def rbx?
  return @rbx if defined?(@rbx)
  @rbx = RUBY_ENGINE == "rbx"
end

def relative_path_from(path, from)
  pathname(path.to_s).relative_path_from(pathname(from.to_s))
rescue NoMethodError => e
  raise e unless e.name == :zero?
  # Work around https://github.com/ruby/ruby/pull/713.
  path = path.to_s
  from = from.to_s
  raise ArgumentError("Incompatible path encodings: #{path.inspect} is #{path.encoding}, " +
    "#{from.inspect} is #{from.encoding}")
end

def round(value)
  # If the number is within epsilon of X.5, round up (or down for negative
  # numbers).
  mod = value % 1
  mod_is_half = (mod - 0.5).abs < SassC::Script::Value::Number.epsilon
  if value > 0
    !mod_is_half && mod < 0.5 ? value.floor : value.ceil
  else
    mod_is_half || mod < 0.5 ? value.floor : value.ceil
  end
end

def sass_warn(msg)
  Sass.logger.warn("#{msg}\n")
end

def silence_sass_warnings
  old_level, Sass.logger.log_level = Sass.logger.log_level, :error
  yield
ensure
  SassC.logger.log_level = old_level
end

def windows?
  return @windows if defined?(@windows)
  @windows = (RbConfig::CONFIG['host_os'] =~ /mswin|windows|mingw/i)
end