#!/usr/bin/env python
#-*- coding: utf-8 -*-
#  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
#
#  Use of this source code is governed by a BSD-style license
#  that can be found in the LICENSE file in the root of the source
#  tree. An additional intellectual property rights grant can be found
#  in the file PATENTS.  All contributing project authors may
#  be found in the AUTHORS file in the root of the source tree.

"""Contains functions for parsing the build master's transposed grid page.

   Compatible with build bot 0.8.4 P1.
"""

__author__ = 'phoglund@webrtc.org (Patrik Höglund)'

import re
import urllib


# This is here to work around a buggy build bot status message which makes no
# sense, but which means the build failed when the slave was lost.
BB_084_P1_BUGGY_STATUS = 'build<br/>successful<br/>exception<br/>slave<br/>lost'


class FailedToParseBuildStatus(Exception):
  pass


def _map_status(status):
  if status == 'exception' or status == BB_084_P1_BUGGY_STATUS:
    return 'failed'
  return status


def _parse_builds(revision, html):
  """Parses the bot list, which is a sequence of <td></td> lines.

     See contract for parse_tgrid_page for more information on how this function
     behaves.

     Example input:
     <td class="build success"><a href="builders/Android/builds/119">OK</a></td>
     The first regular expression group captures Android, second 119, third OK.
  """
  result = {}

  for match in re.finditer('<td.*?>.*?<a href="builders/(.+?)/builds/(\d+)">'
                           '(OK|failed|building|warnings|exception|' +
                           BB_084_P1_BUGGY_STATUS + ')'
                           '.*?</a>.*?</td>',
                           html, re.DOTALL):
    revision_and_bot_name = revision + "--" + urllib.unquote(match.group(1))
    build_number_and_status = match.group(2) + "--" + _map_status(
                                                          match.group(3))

    result[revision_and_bot_name] = build_number_and_status

  return result


def parse_tgrid_page(html):
  """Parses the build master's tgrid page.

     Example input:
     <tr>
       <td valign="bottom" class="sourcestamp">1568</td>
       LIST OF BOTS
     </tr>
     The first regular expression group captures 1568, second group captures
     everything in LIST OF BOTS. The list of bots is then passed into a
     separate function for parsing.

     Args:
         html: The raw HTML from the tgrid page.

     Returns: A dictionary with <svn revision>--<bot name> mapped to
         <bot build number>--<status>, where status is either OK, failed,
         building or warnings. The status may be 'exception' in the input, but
         we simply map that to failed.
  """
  result = {}

  for match in re.finditer('<td.*?class="sourcestamp">(\d+).*?</td>(.*?)</tr>',
                           html, re.DOTALL):
    revision = match.group(1)
    builds_for_revision_html = match.group(2)
    result.update(_parse_builds(revision, builds_for_revision_html))

  if not result:
    raise FailedToParseBuildStatus('Could not find any build statuses in %s.' %
                                   html)

  return result