#!/usr/bin/python

# This is a program which will poll a (remote) SVN repository, looking for
# new revisions. It then uses the 'buildbot sendchange' command to deliver
# information about the Change to a (remote) buildmaster. It can be run from
# a cron job on a periodic basis, or can be told (with the 'watch' option) to
# automatically repeat its check every 10 minutes.

# This script does not store any state information, so to avoid spurious
# changes you must use the 'watch' option and let it run forever.

# You will need to provide it with the location of the buildmaster's
# PBChangeSource port (in the form hostname:portnum), and the svnurl of the
# repository to watch.


# 15.03.06 by John Pye
# 29.03.06 by Niklaus Giger, added support to run under windows,
# added invocation option
# 22.03.10 by Johnnie Pittman, added support for category and interval
# options.

import subprocess
import sys
import time
import xml.dom.minidom

from optparse import OptionParser
from xml.parsers.expat import ExpatError


if sys.platform == 'win32':
    import win32pipe


def getoutput(cmd):
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
    return p.stdout.read()


def sendchange_cmd(master, revisionData):
    cmd = [
        "buildbot",
        "sendchange",
        "--master=%s" % master,
        "--revision=%s" % revisionData['revision'],
        "--username=%s" % revisionData['author'],
        "--comments=%s" % revisionData['comments'],
        "--vc=%s" % 'svn',
    ]
    if opts.category:
        cmd.append("--category=%s" % opts.category)
    for path in revisionData['paths']:
        cmd.append(path)

    if opts.verbose:
        print cmd

    return cmd


def parseChangeXML(raw_xml):
    """Parse the raw xml and return a dict with key pairs set.

    Commmand we're parsing:

    svn log --non-interactive --xml --verbose --limit=1 <repo url>

    With an output that looks like this:

    <?xml version="1.0"?>
     <log>
      <logentry revision="757">
       <author>mwiggins</author>
       <date>2009-11-11T17:16:48.012357Z</date>
       <paths>
        <path kind="" copyfrom-path="/trunk" copyfrom-rev="756" action="A">/tags/Latest</path>
       </paths>
       <msg>Updates/latest</msg>
      </logentry>
     </log>
    """

    data = dict()

    # parse the xml string and grab the first log entry.
    try:
        doc = xml.dom.minidom.parseString(raw_xml)
    except ExpatError:
        print "\nError: Got an empty response with an empty changeset.\n"
        raise
    log_entry = doc.getElementsByTagName("logentry")[0]

    # grab the appropriate meta data we need
    data['revision'] = log_entry.getAttribute("revision")
    data['author'] = "".join([t.data for t in
                              log_entry.getElementsByTagName("author")[0].childNodes])
    data['comments'] = "".join([t.data for t in
                                log_entry.getElementsByTagName("msg")[0].childNodes])

    # grab the appropriate file paths that changed.
    pathlist = log_entry.getElementsByTagName("paths")[0]
    paths = []
    for path in pathlist.getElementsByTagName("path"):
        paths.append("".join([t.data for t in path.childNodes]))
    data['paths'] = paths

    return data


def checkChanges(repo, master, oldRevision=-1):
    cmd = ["svn", "log", "--non-interactive", "--xml", "--verbose",
           "--limit=1", repo]

    if opts.verbose:
        print "Getting last revision of repository: " + repo

    if sys.platform == 'win32':
        f = win32pipe.popen(cmd)
        xml1 = ''.join(f.readlines())
        f.close()
    else:
        xml1 = getoutput(cmd)

    if opts.verbose:
        print "XML\n-----------\n" + xml1 + "\n\n"

    revisionData = parseChangeXML(xml1)

    if opts.verbose:
        print "PATHS"
        print revisionData['paths']

    if revisionData['revision'] != oldRevision:

        cmd = sendchange_cmd(master, revisionData)

        if sys.platform == 'win32':
            f = win32pipe.popen(cmd)
            pretty_time = time.strftime("%H.%M.%S ")
            print "%s Revision %s: %s" % (pretty_time, revisionData['revision'],
                                          ''.join(f.readlines()))
            f.close()
        else:
            xml1 = getoutput(cmd)
    else:
        pretty_time = time.strftime("%H.%M.%S ")
        print "%s nothing has changed since revision %s" % (pretty_time,
                                                            revisionData['revision'])

    return revisionData['revision']


def build_parser():
    usagestr = "%prog [options] <repo url> <buildbot master:port>"
    parser = OptionParser(usage=usagestr)

    parser.add_option(
        "-c", "--category", dest="category", action="store", default="",
        help="""Store a category name to be associated with sendchange msg."""
    )

    parser.add_option(
        "-i", "--interval", dest="interval", action="store", default=0,
        help="Implies watch option and changes the time in minutes to the value specified.",
    )

    parser.add_option(
        "-v", "--verbose", dest="verbose", action="store_true", default=False,
        help="Enables more information to be presented on the command line.",
    )

    parser.add_option(
        "", "--watch", dest="watch", action="store_true", default=False,
        help="Automatically check the repo url every 10 minutes.",
    )

    return parser


def validate_args(args):
    """Validate our arguments and exit if we don't have what we want."""
    if not args:
        print "\nError: No arguments were specified.\n"
        parser.print_help()
        sys.exit(1)
    elif len(args) > 2:
        print "\nToo many arguments specified.\n"
        parser.print_help()
        sys.exit(2)


if __name__ == '__main__':

    # build our parser and validate our args
    parser = build_parser()
    (opts, args) = parser.parse_args()
    validate_args(args)
    if opts.interval:
        try:
            int(opts.interval)
        except ValueError:
            print "\nError: Value of the interval option must be a number."
            parser.print_help()
            sys.exit(3)

    # grab what we need
    repo_url = args[0]
    bbmaster = args[1]

    # if watch is specified, run until stopped
    if opts.watch or opts.interval:
        oldRevision = -1
        print "Watching for changes in repo %s for master %s." % (repo_url, bbmaster)
        while True:
            try:
                oldRevision = checkChanges(repo_url, bbmaster, oldRevision)
            except ExpatError:
                # had an empty changeset.  Trapping the exception and moving on.
                pass
            try:
                if opts.interval:
                    # Check the repository every interval in minutes the user specified.
                    time.sleep(int(opts.interval) * 60)
                else:
                    # Check the repository every 10 minutes
                    time.sleep(10 * 60)
            except KeyboardInterrupt:
                print "\nReceived interrupt via keyboard.  Shutting Down."
                sys.exit(0)

    # default action if watch isn't specified
    checkChanges(repo_url, bbmaster)
