module V8::CLI

def self.load(cxt, libfile)
  begin
    cxt.load(libfile)
  rescue V8::JavascriptError => e
    puts e.javascript_stacktrace
  rescue StandardError => e
    puts e
  end      
end

def self.repl(cxt, exename)
  require 'readline'
  puts "help() for help. quit() to quit."
  puts "The Ruby Racer #{V8::VERSION}"
  puts "Vroom Vroom!"      
  trap("SIGINT") do
    puts "^C"
  end        
  loop do
    line = Readline.readline("#{exename}> ", true)
    begin
      result = cxt.eval(line, '<shell>')
      puts(result) unless result.nil?                
    rescue V8::JavascriptError => e
      puts e.javascript_stacktrace
    rescue StandardError => e
      puts e
    end
  end          
end            

def self.run(exename = 'v8', args = [])      
  options = OpenStruct.new
  options.libs = []
  options.libdirs = []
  parser = OptionParser.new
  parser.banner = "Usage: #{exename} [options]"
  parser.on("-r", "--require FILE", "load and execute FILE as JavaScript source") {|r| options.libs << r}
  parser.on("-i", "--interactive", "interactive mode") {options.interactive = true}
  parser.on("-e", "--execute JAVASCRIPT", String, "evaluate JAVASCRIPT and exit") {|src| options.execute = src}
  parser.on("--selftest", "check that therubyracer is functioning properly") {options.selftest = true}
  parser.on_tail("-v", "--version", "Show version and exit") {options.version_info = true}
  parser.on_tail("-h", "--help", "Show this message") do
    puts parser
    exit
  end
  begin
    parser.parse!(args.dup)
  rescue OptionParser::InvalidOption => e
    puts "#{exename}: #{e.message}"
    exit(1)
  end
  if options.version_info
    puts "The Ruby Racer #{V8::VERSION}"
    puts "V8 Version 2.1.10"
    exit
  elsif options.selftest
    self.test        
  end
  Context.open(:with => Shell.new) do |cxt|
    for libfile in options.libs do
      load(cxt,libfile)
    end        
    if options.interactive
      repl(cxt, exename)
    elsif options.execute
      cxt.eval(options.execute, '<execute>')
    else
      begin
        cxt.eval($stdin, '<stdin>')
      rescue Interrupt => e
        puts; exit
      end
    end
  end
end

def self.test
  begin
    require 'rubygems'
    require 'spec'
    parser = ::Spec::Runner::OptionParser.new($stderr, $stdout)
    parser.order!([File.dirname(__FILE__) + '/../../spec/'])
    ::Spec::Runner.use(parser.options)  
    exit parser.options.run_examples
  rescue LoadError => e
    puts "selftest requires rspec to be installed (gem install rspec)"
    exit(1)
  end
  
end