# vim: set ts=8 sts=2 sw=2 tw=99 et:
import re
import os, sys
import subprocess

argv = sys.argv[1:]
if len(argv) < 2:
  sys.stderr.write('Usage: generate_headers.py <source_path> <output_folder>\n')
  sys.exit(1)

SourceFolder = os.path.abspath(os.path.normpath(argv[0]))
OutputFolder = os.path.normpath(argv[1])

class FolderChanger:
  def __init__(self, folder):
    self.old = os.getcwd()
    self.new = folder

  def __enter__(self):
    if self.new:
      os.chdir(self.new)

  def __exit__(self, type, value, traceback):
    os.chdir(self.old)

def run_and_return(argv):
  # Python 2.6 doesn't have check_output.
  if hasattr(subprocess, 'check_output'):
    text = subprocess.check_output(argv)
    if str != bytes:
      text = str(text, 'utf-8')
  else:
    p = subprocess.Popen(argv, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    output, ignored = p.communicate()
    rval = p.poll()
    if rval:
      raise subprocess.CalledProcessError(rval, argv)
    text = output.decode('utf8')
  return text.strip()

def get_git_version():
  revision_count = run_and_return(['git', 'rev-list', '--count', 'HEAD'])
  revision_hash = run_and_return(['git', 'log', '--pretty=format:%h:%H', '-n', '1'])
  shorthash, longhash = revision_hash.split(':')

  return revision_count, shorthash, longhash

def output_version_header():
  with FolderChanger(SourceFolder):
    count, shorthash, longhash = get_git_version()

  with open(os.path.join(SourceFolder, 'product.version')) as fp:
    contents = fp.read()
  m = re.match(r'(\d+)\.(\d+)\.(\d+)-?(.*)', contents)
  if m == None:
    raise Exception('Could not detremine product version')
  major, minor, release, tag = m.groups()
  product = "{0}.{1}.{2}".format(major, minor, release)
  fullstring = product
  if tag != "":
    fullstring += "-{0}".format(tag)
    if tag == "dev":
      fullstring += "+{0}".format(count)

  with open(os.path.join(OutputFolder, 'metamod_version_auto.h'), 'w') as fp:
    fp.write("""
#ifndef _METAMOD_AUTO_VERSION_INFORMATION_H_
#define _METAMOD_AUTO_VERSION_INFORMATION_H_

#define MMS_BUILD_TAG		\"{0}\"
#define MMS_BUILD_CSET		\"{1}\"
#define MMS_BUILD_MAJOR		\"{2}\"
#define MMS_BUILD_MINOR		\"{3}\"
#define MMS_BUILD_RELEASE	\"{4}\"
#define MMS_BUILD_LOCAL_REV      \"{6}\"

#define MMS_BUILD_UNIQUEID       "{6}:" MMS_BUILD_CSET

#define MMS_VERSION_STRING	\"{5}\"
#define MMS_VERSION_FILE	{2},{3},{4},0

#endif /* _METAMOD_AUTO_VERSION_INFORMATION_H_ */
    """.format(tag, shorthash, major, minor, release, fullstring, count))

output_version_header()