"""Produces a api_version.txt file with the plugin API version.
"""

import argparse
import re
from xml.dom.minidom import parseString
import zipfile

parser = argparse.ArgumentParser()

parser.add_argument(
    "--application_info_jar",
    help="The jar file containing the application info xml",
    required=True,)
parser.add_argument(
    "--application_info_name",
    help="A .txt file containing the application info xml name",
    required=True,)


def _parse_build_number(build_number):
  """Parses the build number.

  Args:
    build_number: The build number as text.
  Returns:
    build_number, build_number_without_product_code.
  Raises:
    ValueError: if the build number is invalid.
  """
  match = re.match(r"^([A-Z]+-)?([0-9]+)((\.[0-9]+)*)", build_number)
  if match is None:
    raise ValueError("Invalid build number: " + build_number)

  return match.group(1) + match.group(2) + match.group(3)


def main():

  args = parser.parse_args()

  with open(args.application_info_name) as f:
    application_info_name = f.read().strip()

  with zipfile.ZipFile(args.application_info_jar, "r") as zf:
    try:
      data = zf.read(application_info_name)
    except:
      raise ValueError("Could not read application info file: " +
                       application_info_name)
    component = parseString(data)

    build_elements = component.getElementsByTagName("build")
    if not build_elements:
      raise ValueError("Could not find <build> element.")
    if len(build_elements) > 1:
      raise ValueError("Ambiguous <build> element.")
    build_element = build_elements[0]

    attrs = build_element.attributes
    if attrs.has_key("apiVersion"):
      api_version_attr = attrs.get("apiVersion")
    else:
      api_version_attr = attrs.get("number")

  if not api_version_attr:
    raise ValueError("Could not find api version in application info")

  api_version = _parse_build_number(api_version_attr.value)
  print api_version


if __name__ == "__main__":
  main()