#!/usr/bin/ruby
# command line script that sends an HTTPS request to the WACC compiler web interface and interprets the JSON response

require "rest-client"
require "json"
require "optparse"


ARGV << "-h" if ARGV.empty?

$options = {}
$opts = []
OptionParser.new do |opts|
  opts.banner = "Usage: #{$0} [options] <target.s> \n  options:"
  
  $options[:assemble_only] = false
  opts.on("-a", "--assemble_only",
    "Assemble only. Check the input file for assembly errors, but do not execute the generated binary file.") do
    $opts << "-a" 
    $options[:assemble_only] = true
  end  

  $options[:directory] = false
  opts.on("-d", "--directory",
    "Give directory of ARM assembly files." ) do
    $options[:directory] = true
  end

  opts.on_tail("-h", "--help",
    "Show this message") do
    puts opts
    puts ""
    puts "  target.s: path to ARM assembly program file to emulate (or target directory if -dir option set)"
    exit
  end

end.parse!

# set up empty array of file_paths to process
files = []
puts ARGV[0]
if $options[:directory] then
  # add the results of a search to the array
  files += Dir.glob(File.join(ARGV[0], "**", "*.s"))
else
  # just add the target file to the array
  files << ARGV[0]
end

# check that there is at least one file to process
if files == [] then
  puts "Error: no file(s) targeted"
  exit 1
end

# now process each target file
files.each do |file_path|
  puts "calling the ARM emulator on #{file_path}"
  
  # get stdin from the user to pass to the ARM emulator
  stdin = ""
  unless $options[:assemble_only] then
    puts "please provide a stdin stream to use when emulating the program:"
    stdin = STDIN.gets
  end

  # make the call to the ARM emulator
  RestClient.post("https://teaching.doc.ic.ac.uk/wacc_compiler/emulate.cgi",
                    :stdin => stdin,
                    :options => $opts,
                    :testfile => File.new(file_path)
                   ) do |response|
    json = JSON.load(response)
    puts "-- Test: #{json['test']}"
    puts ""
    puts "-- Uploaded file: "
    puts "---------------------------------------------------------------"
    puts json['upload']
    puts "---------------------------------------------------------------"
    puts ""
    puts "-- Assembly Output:"
    puts json['assemble_out']
    puts ""
    unless $options[:assemble_only] then
      puts "-- Emulation Output:" 
      puts json['emulator_out']
      puts "---------------------------------------------------------------"
      puts "The exit code is: #{exit_code}."
      puts ""
    end
  end
  
end