#!/usr/bin/env ruby

$:.unshift(File.expand_path(File.join(File.dirname(__FILE__), "..", "lib")))

require "readline"
require "johnson"

RUNTIME = js = Johnson::Runtime.new
RUNTIME.evaluate(Johnson::CLI::JS)

EXIT_VERBS = [nil] + %w(exit quit)

local_binding = binding
ruby_readline = []

def copy_history
  new_history = []
  until Readline::HISTORY.empty?
    new_history.push(Readline::HISTORY.pop)
  end
  new_history
end

def paste_history(old_history)
  until old_history.empty?
    Readline::HISTORY << old_history.pop
  end
end

def handle_exit(input)
  if EXIT_VERBS.include?(input)
    puts if input.nil?
    exit
  end
end

def rescued(&block)
  yield
rescue Exception => e
  exit if SystemExit === e

  puts e.message
  puts e.backtrace.reject { |l| l =~ /bin\/johnson/ }
end

def eval_in_js(expression)
  rescued { puts "=> " + RUNTIME.evaluate(expression, "(console)").inspect }
end

def eval_in_ruby(expression, bind_to)
  rescued { puts "=> " + eval(expression, bind_to).inspect }
end

options = Johnson::CLI::Options.parse!(ARGV)

options.load_paths.each { |d| $LOAD_PATH << d }
options.paths_to_require.each { |p| RUNTIME.evaluate("Johnson.require('#{p}')") }
options.files_to_preload.each { |f| RUNTIME.load(f) }

unless options.expressions.empty?
  options.expressions.each { |e| RUNTIME.evaluate(e, '-e') }
  exit if options.files_to_evaluate.empty?
end

unless options.files_to_evaluate.empty?
  RUNTIME[:arguments] = options.arguments
  
  options.files_to_evaluate.each do |file|
    RUNTIME.load(file)
  end
  
  exit
end

loop do
  input = Readline.readline("js> ", true)
  handle_exit(input)
  
  if input =~ /^rb\s+(.+)$/
    eval_in_ruby($1, local_binding)
    next
  end
  
  if input == "rb"
    js_readline = copy_history
    paste_history(ruby_readline)
    
    loop do
      input = Readline.readline("rb> ", true)
      handle_exit(input)

      break if input == "js"

      if input =~ /^js\s+(.+)$/
        eval_in_js($1)
        next
      end

      eval_in_ruby(input, local_binding)
    end
    
    ruby_readline = copy_history
    paste_history(js_readline)
    next
  end
  
  eval_in_js(input)
end