#!/usr/bin/env ruby
# The Rouge REPL/interpreter.
$: << "#{File.dirname(__FILE__)}/../lib"
require 'rouge'
require 'optparse'

# Boots Rouge and evaluates code in a new context. Prints non-nil results if
# print is true.
def evaluate(code, print = false)
  Rouge.boot!
  res = Rouge::Context.new(Rouge[:user]).readeval(code)

  if print && res
    puts Rouge.print(res, '')
  end
end

options = {:backtrace => true}

option_parser = OptionParser.new do |opts|
  opts.banner = "Usage: rouge [switch] [filename]"

  opts.on('-v', '--version', 'Print version number') do
    puts "Rouge #{Rouge::VERSION}"
    exit 0
  end

  opts.on('-e STR', '--eval STR',
          'Evaluate expressions in STR; print non-nil results') do |str|
    evaluate(str, true)
    exit 0
  end

  opts.on('--time-startup', 'Report boot up time') do
    start = Time.now
    Rouge.boot!
    puts Time.now - start
    exit 0
  end

  opts.on('--[no-]backtrace', 'Enable/disable backtracing in REPL') do |bool|
    options[:backtrace] = bool
  end
end

begin
  option_parser.parse!
rescue OptionParser::MissingArgument => e
  puts "rouge: #{e}"
end

# Using a standalone '-', which traditionally is the switch for indicating
# acceptance of standard input, causes some subtle issues with the
# OptionParser.
if ARGV.include?('-')
  code = ''
  while line = STDIN.gets
    code << line
  end
  evaluate(code, true)
  exit 0
end

if ARGV.length >= 1
  file = ARGV.shift

  if File.file?(file)
    code = File.read(file)
  else
    STDERR.puts "rouge: No such file -- #{file}"
    exit 1
  end

  # Permit shebangs at the top of the document.
  if code[0..1] == "#!"
    code = code[code.index("\n") + 1..-1]
  end

  evaluate(code)
  exit 0
end

Rouge.repl(options)