#!/usr/bin/env ruby

require 'fileutils'

##############################
#
# Standard Compile Script 
#
# Supported compilers: 
#   gcc, g++, and fpc.
#
##############################

def talk(str='')
  if ENV['TALKATIVE']!=nil
    puts str
  end
  if ENV['GRADER_LOGGING']!=nil
    log_fname = ENV['GRADER_LOGGING']
    fp = File.open(log_fname,"a")
    fp.puts("run: #{Time.new.strftime("%H:%M")} #{str}")
    fp.close
  end
end

C_COMPILER = "/usr/bin/gcc"
CPLUSPLUS_COMPILER = "/usr/bin/g++"
PASCAL_COMPILER = "/usr/bin/fpc"

C_OPTIONS = "-O2 -s -static -std=c99 -DCONTEST -lm -Wall"
CPLUSPLUS_OPTIONS = "-O2 -s -static -DCONTEST -lm -Wall"
PASCAL_OPTIONS = "-O1 -XS -dCONTEST"

# Check for the correct number of arguments. Otherwise, print usage.
if ARGV.length == 0 or ARGV.length > 4
  puts "Usage: compile <language> [<source-file>] [<output-file>] [<message-file>]"
  puts
  puts "<source-file>  is defaulted to \"source\"."
  puts "<output-file>  is defaulted to \"a.out\"."
  puts "<message-file> is defaulted to \"compiler_message\"."
  puts
  exit(127)
end

PARAMS = {
  :source_file => [1,'source'],
  :output_file => [2,'a.out'],
  :message_file => [3,'compiler_message']
}

params = {}
params[:prog_lang] = ARGV[0]
PARAMS.each_key do |param_name|
  index, default = PARAMS[param_name]
  if ARGV.length > index
    params[param_name] = ARGV[index]
  else
    params[param_name] = default
  end
  talk "#{param_name}: #{params[param_name]}"
end

# Remove any remaining output files or message files.
if FileTest.exists? params[:output_file]
  FileUtils.rm(params[:output_file])
end
if FileTest.exists? params[:message_file]
  FileUtils.rm(params[:message_file])
end

# Check if the source file exists before attempt compiling.
if !FileTest.exists? params[:source_file]
  talk("ERROR: The source file does not exist!")
  open(params[:message_file],"w") do |f|
    f.puts "ERROR: The source file did not exist."
  end
  exit(127)
end

if params[:prog_lang]=='cpp'
  params[:prog_lang] = 'c++'
end

# Compile.
case params[:prog_lang]

  when "c"
  command = "#{C_COMPILER} #{params[:source_file]} -o #{params[:output_file]} #{C_OPTIONS} 2> #{params[:message_file]}"
  system(command)

  when "c++"
  command = "#{CPLUSPLUS_COMPILER} #{params[:source_file]} -o #{params[:output_file]} #{CPLUSPLUS_OPTIONS} 2> #{params[:message_file]}"
  system(command)
  
  when "pas"
  command = "#{PASCAL_COMPILER} #{params[:source_file]} -ooutpas #{PASCAL_OPTIONS} > #{params[:message_file]}"
  system(command)
  FileUtils.mv("output", params[:output_file])
  
  else
  talk("ERROR: Invalid language specified!")
  open(params[:message_file],"w") do |f|
    f.puts "ERROR: Invalid language specified!"
  end
  exit(127)
end

# Report success or failure.
if FileTest.exists? params[:output_file]
  talk "Compilation was successful!"    
else
  talk "ERROR: Something was wrong during the compilation!"
end