#!/usr/local/bin/python
"""Canonicalize domain names.

We maintain an in-memory data structure mapping domains to canonical domains.
Whenever the web directory changes, we rebuild our data structure

"""
import os
import stat
import sys
import traceback
from commands import getoutput
from os.path import basename, islink, isfile, join, realpath
from pprint import pprint

WWW = "/usr/local/www"


class Base(object):

    __modtime = 0


    def main(self, command):
        """Main loop per mod_rewrite > RewriteMap > prg.
        """
        rebuild = self._canonizer if (command == 'canonizer') else self._porter
        while 1:
            host = sys.stdin.readline().strip()
            if self.isstale():
                map_ = rebuild()
            print map_.get(host, 'NULL')
            sys.stdout.flush()


    def dump(self):
        """Build and print a domain map.
        """
        pprint(self._canonizer())
        pprint(self._porter())


    def isstale(self):
        """Return a boolean based on whether the WWW directory has changed.
        """
        _modtime = os.stat(WWW)[stat.ST_MTIME]
        if _modtime != self.__modtime:
            self.__modtime = _modtime
            return True
        else:
            return False


    def _canonizer(self):
        """Build a domain map from filesystem links.
        """
        domain_map = dict()

        for name in os.listdir(WWW):
            if name.endswith('.flanderous.com'):
                canonical = name
            elif name.endswith('.zetaweb.com'):
                canonical = name
            else:
                canonical = basename(realpath(join(WWW, name)))

            if name != canonical:
                domain_map[name] = canonical

                # Automatically handle www for aliases.
                # =====================================

                if name.startswith('www.'):
                    www_alt = name[4:]
                else:
                    www_alt = 'www.' + name
                if not islink(join(WWW, www_alt)):
                    domain_map[www_alt] = canonical


            # Automatically handle www for canonical as well.
            # ===============================================

            if canonical.startswith('www.'):
                www_alt = canonical[4:]
            else:
                www_alt = 'www.' + canonical
            domain_map[www_alt] = canonical

        return domain_map


    def _porter(self):
        """Build a port map from conf files.
        """
        port_map = dict()

        for hostname in os.listdir(WWW):
            home = realpath(join(WWW, hostname))
            if hostname.endswith('.flanderous.com'):
                canonical = hostname
            else:
                canonical = basename(home)

            if canonical != hostname:
                continue

            port = None
            zope_conf = join(home, 'etc', 'zope.conf')
            aspen_conf = join(home, '__', 'etc', 'aspen.conf')
            if isfile(zope_conf):
                try:
                    out = getoutput("grep -E 'address [0-9]{4,5}' %s" % zope_conf)
                    port = out.strip().split()[1]
                    port = int(port)
                    assert 1024 < port < 65535
                except:
                    traceback.print_exc()
            elif isfile(aspen_conf):
                try:
                    out = getoutput("grep -E 'address.*?[0-9]{4,5}' %s" % aspen_conf)
                    port = out.split(':')[1]
                    port = int(port)
                    assert 1024 < port < 65535
                except:
                    traceback.print_exc()

            if port is not None:
                port_map[hostname] = port

        return port_map



if __name__ == '__main__':

    try:
        command = sys.argv[1]
    except IndexError:
        command = basename(sys.argv[0])[:-3]
    assert command in ('porter', 'canonizer', 'dump'), command

    base = Base()
    base.dump() if (command == 'dump') else base.main(command)