#!/usr/bin/python
# Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

'''Reads the Webkit Version.xcconfig file looking for MAJOR_VERSION and
MINOR_VERSION, emitting them into a webkit_version.h header file as
WEBKIT_MAJOR_VERSION and WEBKIT_MINOR_VERSION macros.
'''

import os
import re
import sys

def ReadVersionFile(fname):
  '''Reads the Webkit Version.xcconfig file looking for MAJOR_VERSION and
     MINOR_VERSION.  This function doesn't attempt to support the full syntax
     of xcconfig files.'''
  re_major = re.compile('MAJOR_VERSION\s*=\s*(\d+).*')
  re_minor = re.compile('MINOR_VERSION\s*=\s*(\d+).*')
  major = -1
  minor = -1
  f = open(fname, 'rb')
  line = "not empty"
  while line and not (major >= 0 and minor >= 0):
    line = f.readline()
    if major == -1:
      match = re_major.match(line)
      if match:
        major = int(match.group(1))
        continue
    if minor == -1:
      match = re_minor.match(line)
      if match:
        minor = int(match.group(1))
        continue
  assert(major >= 0 and minor >= 0)
  return (major, minor)

def EmitVersionHeader(version_file, output_dir):
  '''Given webkit's version file, emit a header file that we can use from
  within webkit_glue.cc.
  '''
  (major, minor) = ReadVersionFile(version_file)
  fname = os.path.join(output_dir, "webkit_version.h")
  f = open(fname, 'wb')
  template = """// webkit_version.h
// generated from %s

#define WEBKIT_VERSION_MAJOR %d
#define WEBKIT_VERSION_MINOR %d
""" % (version_file, major, minor)
  f.write(template)
  f.close()

def main():
  EmitVersionHeader(sys.argv[1], sys.argv[2])


if __name__ == "__main__":
  main()