#!/usr/bin/python

import os
import sys

class CompilerWrapper():
  def __init__(self, argv):
    self.args = argv
    self.execargs = []
    self.real_compiler = None
    self.argv0 = None
    self.append_flags = []
    self.prepend_flags = []
    self.custom_flags = {
      '--gomacc-path': None
    }

  def set_real_compiler(self):
    """Find the real compiler with the absolute path."""
    compiler_path = os.path.dirname(os.path.abspath(__file__))
    if os.path.islink(__file__):
      compiler = os.path.basename(os.readlink(__file__))
    else:
      compiler = os.path.basename(os.path.abspath(__file__))
    self.real_compiler = os.path.join(
        compiler_path,
        "real-" + compiler)
    self.argv0 = self.real_compiler

  def process_gomacc_command(self):
    """Return the gomacc command if '--gomacc-path' is set."""
    gomacc = self.custom_flags['--gomacc-path']
    if gomacc and os.path.isfile(gomacc):
      self.argv0 = gomacc
      self.execargs += [gomacc]

  def parse_custom_flags(self):
    i = 0
    args = []
    while i < len(self.args):
      if self.args[i] in self.custom_flags:
        self.custom_flags[self.args[i]] = self.args[i + 1]
        i = i + 2
      else:
        args.append(self.args[i])
        i = i + 1
    self.args = args

  def add_flags(self):
    self.args = self.prepend_flags + self.args + self.append_flags

  def invoke_compiler(self):
    self.set_real_compiler()
    self.parse_custom_flags()
    self.process_gomacc_command()
    self.add_flags()
    self.execargs += [self.real_compiler] + self.args
    os.execv(self.argv0, self.execargs)


def main(argv):
  cw = CompilerWrapper(argv[1:])
  cw.invoke_compiler()

if __name__ == "__main__":
  main(sys.argv)