class ExecJS::GraalJSRuntime::Context

def call(source, *args)
  source = source.encode(Encoding::UTF_8)
  source = "(#{source})" if /\S/.match?(source)
  translate do
    function = eval_in_context(source)
    function.call(*convert_ruby_to_js(args))
  end
end

def convert_js_to_ruby(value)
  case value
  when true, false, Integer, Float
    value
  else
    if value.nil?
      nil
    elsif value.respond_to?(:call)
      nil
    elsif value.respond_to?(:to_str)
      value.to_str
    elsif value.respond_to?(:to_ary)
      value.to_ary.map do |e|
        if e.respond_to?(:call)
          nil
        else
          convert_js_to_ruby(e)
        end
      end
    else
      object = value
      h = {}
      object.instance_variables.each do |member|
        v = object[member]
        unless v.respond_to?(:call)
          h[member.to_s] = convert_js_to_ruby(v)
        end
      end
      h
    end
  end
end

def convert_ruby_to_js(value)
  case value
  when nil, true, false, Integer, Float
    value
  when String, Symbol
    Truffle::Interop.as_truffle_string value
  when Array
    value.map { |e| convert_ruby_to_js(e) }
  when Hash
    h = @js_object.new
    value.each_pair do |k,v|
      h[convert_ruby_to_js(k)] = convert_ruby_to_js(v)
    end
    h
  else
    raise TypeError, "Unknown how to convert to JS: #{value.inspect}"
  end
end

def eval(source, options = {})
  source = source.encode(Encoding::UTF_8)
  source = "(#{source})" if /\S/.match?(source)
  translate do
    eval_in_context(source)
  end
end

def exec(source, options = {})
  source = source.encode(Encoding::UTF_8)
  source = "(function(){#{source}})()" if /\S/.match?(source)
  translate do
    eval_in_context(source)
  end
end

def initialize(runtime, source = "", options = {})
  @context = Polyglot::InnerContext.new
  @context.eval('js', 'delete this.console')
  @js_object = @context.eval('js', 'Object')
  source = source.encode(Encoding::UTF_8)
  unless source.empty?
    translate do
      eval_in_context(source)
    end
  end
end

def translate
  convert_js_to_ruby yield
rescue ForeignException => e
  if e.message && e.message.start_with?('SyntaxError:')
    error_class = ExecJS::RuntimeError
  else
    error_class = ExecJS::ProgramError
  end
  backtrace = (e.backtrace || []).map { |line| line.sub('(eval)', '(execjs)') }
  raise error_class, e.message, backtrace
end