#!/usr/bin/python2.1
# Copyright (C) 2000-2001 The OpenRPG Project
#
# openrpg-dev@lists.sourceforge.net
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
# --
#
# File: meta_server_lib.py
# Author: Chris Davis
# Maintainer:
# Version:
#   $Id: meta_server_lib.py,v Traipse 'Ornery-Orc' prof.ebral Exp $
#
# Description: A collection of functions to communicate with the meta server.
#


#added debug flag for meta messages to cut console server spam --Snowdog
META_DEBUG = False

__version__ = "$Id: meta_server_lib.py,v 1.40 2007/04/04 01:18:42 digitalxero Exp $"

from orpg.orpg_version import PROTOCOL_VERSION
from orpg.orpgCore import component
from orpg.tools.validate import validate
from orpg.dirpath import dir_struct

import urllib, time, sys, traceback, re

from threading import *
from random import uniform
import urllib2
from urllib import urlopen, urlencode
#from orpg.tools.orpg_log import debug

from xml.etree.ElementTree import Element, fromstring, parse, tostring
metacache_lock = RLock()

def get_server_dom(data=None, path=None, string=False):
    if path[len(path)-1] != "/": path += '/'

    # POST the data
    if META_DEBUG:
        print
        print "Sending the following POST info to Meta at " + path + ":"
        print "=========================================="
        print data
        print
    #recvdata = urllib2.Request(path, data)
    response = urllib2.urlopen(path, data)
    data = response.read()

    # Remove any leading or trailing data.  This can happen on some satellite connections
    p = re.compile('(<servers>.*?</servers>)',re.DOTALL|re.IGNORECASE)
    mo = p.search(data)
    if mo: data = mo.group(0)

    if META_DEBUG:
        print
        print "Got this string from the Meta at " + path + ":"
        print "==============================================="
        print data
        print
    # build dom
    if string: return data
    else: return fromstring(data)

def post_server_data(name, realHostName=None):
    if realHostName: data = urlencode({"server_data[name]":name,
                                  "server_data[version]":PROTOCOL_VERSION,
                                  "act":"new",
                                  "REMOTE_ADDR": realHostName })
    # print "Letting meta server decide the hostname to list..."
    else: data = urlencode({"server_data[name]":name,
                                  "server_data[version]":PROTOCOL_VERSION,
                                  "act":"new"})
    path = component.get('settings').get('MetaServerBaseURL') #getMetaServerList()
    etreeEl = get_server_dom(data, path)
    return int(etreeEl.get('id'))

def post_failed_connection(id,meta=None,address=None,port=None):
    #  For now, turning this off.  This needs to be re-vamped for
    #  handling multiple Metas.
    return 0
    #data = urlencode({"id":id,"act":"failed"});
    #xml_dom = get_server_dom(data)
    #ret_val = int(xml_dom.getAttribute("return"))
    #return ret_val

def remove_server(id):
    data = urlencode({"id":id,"act":"del"});
    etreeEl = get_server_dom(data)
    return int(etreeEl.get("return"))

def byStartAttribute(first, second):
    #  This function is used to easily sort a list of nodes by their start time
    # Ensure there is something to sort with for each
    first_start = int(first.get('start')) or 0
    second_start = int(second.get('start')) or 0
    # Return the result of the cmp function on the two strings
    return cmp(first_start, second_start)

def byNameAttribute(first, second):
    #  This function is used to easily sort a list of nodes by their name attribute
    # Ensure there is something to sort with for each
    first_name = first.get('name') or ''
    second_name = second.get('name') or ''
    # Return the result of the cmp function on the two strings
    return cmp(first_name,second_name)


def get_server_list(versions=None, sort_by="start"):
    data = urlencode({"version":PROTOCOL_VERSION,"ports":"%"})
    #all_metas = getMetaServers(versions, False)  # get the list of metas
    meta_list = getMetaServerList()
    #all_metas.reverse()  # The last one checked will take precedence, so reverse the order
                          #  so that the top one on the actual list is checked last
    return_hash = {}      # this will end up with an amalgamated list of servers

    for meta in meta_list: # check all of the metas
        #get the server's xml from the current meta
        bad_meta = 0
        #print "Getting server list from " + meta + "..."
        try: meta_path = meta.get('url'); xml_dom = get_server_dom(data, meta_path)
        except:
            if meta_path == None: meta_path = 'No URL available'
            bad_meta = 1; print "Trouble getting servers from " +meta_path+ "..."
        if bad_meta: continue
        node_list = xml_dom.findall('server')
        if len(node_list): 
            for n in node_list:
                if not n.get('name'): n.set('name','NO_NAME_GIVEN')
                name = n.get('name')
                if not n.get('num_users'): n.set('num_users','N/A')
                num_users = n.get('num_users')
                if not n.get('address'): n.set('address','NO_ADDRESS_GIVEN')
                address = n.get('address')
                if not n.get('port'): n.set('port','6774')
                port = n.get('port')
                n.set('meta',meta)
                end_point = str(address) + ":" + str(port)
                if return_hash.has_key(end_point):
                    if META_DEBUG: print "Replacing duplicate server entry at " + end_point
                return_hash[end_point] = n
    server_list = Element('servers')
    sort_list = return_hash.values()
    if sort_by == "start": sort_list.sort(byStartAttribute)
    elif sort_by == "name": sort_list.sort(byNameAttribute)
    for n in sort_list: server_list.append(n)
    return server_list

## List Format:
## <servers>
## <server address=? id=? name=? failed_count=? >
## </servers>

def updateMetaCache(xml_dom):
    try:
        if META_DEBUG: print "Updating Meta Server Cache"
        metaservers = xml_dom.findall('metaservers')   # pull out the metaservers bit
        if len(metaservers) == 0:
            cmetalist = getRawMetaList()
            xml_dom = get_server_dom(cmetalist[0])
            metaservers = xml_dom.findall('metaservers')
        authoritative = metaservers[0].get('auth')
        if META_DEBUG: print "  Authoritive Meta: "+str(authoritative)
        metas = metaservers[0].findall("meta")                # get the list of metas
        if META_DEBUG: print "  Meta List ("+str(len(metas))+" servers)"
        try:
            metacache_lock.acquire()
            ini = open(dir_struct["user"]+"metaservers.cache","w")
            for meta in metas:
                if META_DEBUG: print "   Writing: "+str(meta.get('path'))
                ini.write(str(meta.get('path')) + " " + str(meta.get('versions')) + "\n")
            ini.close()
        finally:
            metacache_lock.release()
    except Exception, e:
        if META_DEBUG: traceback.print_exc()
        print "Meta Server Lib: UpdateMetaCache(): " + str(e)


def getMetaServerList():
    # get meta server URL
    meta_list = fromstring("""
        <metaservers>
            <meta url="http://orpgmeta.appspot.com" versions="1 2" />
            <meta url="http://traipsemeta.madmathlabs.info" versions="1 2" />
        </metaservers>"""
        )
    try:
        component.get('validate').config_file("metaservers.xml","default_metaservers.xml")
        component.get('validate').config_file("settings.xml","default_settings.xml")
        setting = parse(dir_struct["user"]+"settings.xml")
        tree = setting.getroot()
        node_list = tree.getiterator("MetaServers")
        if len(node_list) == 0:
            component.get('frame').add_setting('Meta Servers')
            setting = parse(dir_struct["user"]+"settings.xml")
            metas = parse(dir_struct["user"]+'metaservers.xml').getroot()
        else: 
            meta = node_list[0].get("value")
            metas = parse(dir_struct["user"]+meta).getroot()
        meta_list = metas.findall('meta')
        return meta_list
    except Exception,e: print e
    return meta_list

"""
  Beginning of Class registerThread

  A Class to Manage Registration with the Meta2
  Create an instance and call it's start() method
  if you want to be (and stay) registered.  This class
  will take care of registering and re-registering as
  often as necessary to stay in the Meta list.

  You may call register() yourself if you wish to change your
  server's name.  It will immediately update the Meta.  There
  is no need to unregister first.

  Call unregister() when you no longer want to be registered.
  This will result in the registerThread dying after
  attempting to immediately remove itself from the Meta.

  If you need to become registered again after that, you
  must create a new instance of class registerThread.  Don't
  just try to call register() on the old, dead thread class.
"""

class registerThread(Thread):
    """
      Originally, I wrote this as a sub-class of wxThread, but
           A)  I couldn't get it to import right
           B)  I realized that I want this to be used in a server,
               which I don't want needing wxWindows to run!
    
       Because of this fact, there are some methods from wxThread
       that I implemented to minimize changes to the code I had
       just written, i.e. TestDeleteStatus() and Delete()
    """

    def __init__(self, name=None, realHostName=None, num_users="0", 
                    MetaPath=None, port=6774, register_callback=None):
        Thread.__init__(self, name="registerThread")
        self.rlock = RLock()      #  Re-entrant lock used to make this class thread safe
        self.die_event = Event()  #  The main loop in run() will wait with timeout on this
        self.name = name or 'Unnamed Server'    #  Name that the server want's displayed on the Meta
                                                #  But use Unnamed Server if for some crazy reason 
                                                #  no name is passed to the constructor
        self.num_users = num_users              #  the number of users currently on this server
        self.realHostName = realHostName        #  Name to advertise for connection
        self.id = "0"                           #  id returned from Meta.  Defaults to "0", which
                                                #  indicates a new registration.
        self.cookie = "0"                       #  cookie returned from Meta.  Defaults to "0", which
                                                #  indicates a new registration.
        self.interval = 0                       #  interval returned from Meta.  Is how often to
                                                #  re-register, in minutes.
        self.destroy = 0                        #  Used to flag that this thread should die
        self.port = str(port)
        self.register_callback = register_callback  # set a method to call to report result of register
        self.IdAttempts = 0
        """
          This thread will communicate with one and only one
          Meta.  If the Meta in ini.xml is changed after
          instantiation, then this instance must be
          unregistered and a new instance instantiated.
        
          Also, if MetaPath is specified, then use that.  Makes
          it easier to have multiple registerThreads going to keep the server registered
          on multiple (compatible) Metas.
        """
        if MetaPath == None: self.path = getMetaServerList()  #  Do this if no Meta specified
        else: self.path = MetaPath

    def getIdAndCookie(self):
        return self.id, self.cookie

    def TestDeleteStatus(self):
        try:
            self.rlock.acquire()
            return self.die_event.isSet()
        finally: self.rlock.release()

    def Delete(self):
        try:
            self.rlock.acquire()
            self.die_event.set()
        finally: self.rlock.release()

    def run(self):
        """
          This method gets called by Thread implementation
          when self.start() is called to begin the thread's
          execution
        
          We will basically enter a loop that continually
          re-registers this server and sleeps Interval
          minutes until the thread is ordered to die in place
        """
        while(not self.TestDeleteStatus()): # Loop while until told to die
            #  Otherwise, call thread safe register().
            self.register(self.name, self.realHostName, self.num_users)
            if META_DEBUG: print "Sent Registration Data"
            #  register() will end up setting the state variables
            #  for us, including self.interval.
            try:
                self.rlock.acquire()    #  Serialize access to this state information

                if self.interval >= 3:  #  If the number of minutes is one or greater
                    self.interval -= 1  #  wake up with 30 seconds left to re-register
                else:
                    self.interval = .5  #  Otherwise, we probably experienced some kind
                                        #  of error from the Meta in register().  Sleep
                                        #  for 6 seconds and start from scratch.

            finally: self.rlock.release() # no matter what, release the lock
            #  Wait interval minutes for a command to die
            die_signal = self.die_event.wait(self.interval*60)

        #  If we get past the while loop, it's because we've been asked to die,
        #  so just let run() end.  Once this occurs, the thread is dead and
        #  calls to Thread.isAlive() return False.

    def unregister(self):
        """
          This method can (I hope) be called from both within the thread
          and from other threads.  It will attempt to unregister this
          server from the Meta database
          When this is either accomplished or has been tried hard enough
          (after which it just makes sense to let the Meta remove the
          entry itself when we don't re-register using this id),
          this method will either cause the thread to immediately die
          (if called from this thread's context) or set the Destroy flag
          (if called from the main thread), a positive test for which will cause
          the code in Entry() to exit() when the thread wakes up and
          checks TestDeleteStatus().
          lock the critical section.  The unlock will
          automatically occur at the end of the function in the finally clause
        """
        try:
            self.rlock.acquire()
            if not self.isAlive():      #  check to see if this thread is dead
                return 1                #  If so, return an error result
            #  Do the actual unregistering here
            data = urlencode( {         "server_data[id]":self.id,
                                        "server_data[cookie]":self.cookie,
                                        "server_data[version]":PROTOCOL_VERSION,
                                        "act":"unregister"} )
            for path in getMetaServerList():
                try: # this POSTS the request and returns the result
                    etreeEl = get_server_dom(data, self.path)
                    if etreeEl.get("errmsg") != None:
                        print "Error durring unregistration:  " +etreeEl.get("errmsg")
                except Exception, e:
                    if META_DEBUG: print "Problem talking to Meta.  Will go ahead and die, letting Meta remove us."
                    if META_DEBUG: print e
            #  If there's an error, echo it to the console

            #  No special handling is required.  If the de-registration worked we're done.  If
            #  not, then it's because we've already been removed or have a bad cookie.  Either
            #  way, we can't do anything else, so die.
            self.Delete()            #  This will cause the registerThread to die in register()
            #  prep xml_dom for garbage collection
            try: xml_dom.unlink()
            except: pass
            return 0
        finally: self.rlock.release()

    def register(self, name=None, realHostName=None, num_users=None):
        """
          Designed to handle the registration, both new and
          repeated.
        
          It is intended to be called once every interval
            (or interval - delta) minutes.

          lock the critical section.  The unlock will
          automatically occur at the end of the function in the finally clause
        """
        try:
            self.rlock.acquire()
            if not self.isAlive():      #  check to see if this thread is dead
                return 1                #  If so, return an error result

            #  Set the server's attibutes, if specified.
            if name: self.name = name
            if num_users != None: 
                try: self.num_users = len(num_users)
                except: self.num_users = num_users
            else: self.num_users = 0
            if realHostName: self.realHostName = realHostName
            # build POST data
            if self.realHostName:
                data = urlencode( {     "server_data[id]":self.id,
                                        "server_data[cookie]":self.cookie,
                                        "server_data[name]":self.name,
                                        "server_data[port]":self.port,
                                        "server_data[version]":PROTOCOL_VERSION,
                                        "server_data[num_users]":self.num_users,
                                        "act":"register",
                                        "server_data[address]": self.realHostName } )
            else:
                if META_DEBUG:  print "Letting meta server decide the hostname to list..."
                data = urlencode( {     "server_data[id]":self.id,
                                        "server_data[cookie]":self.cookie,
                                        "server_data[name]":self.name,
                                        "server_data[port]":self.port,
                                        "server_data[version]":PROTOCOL_VERSION,
                                        "server_data[num_users]":self.num_users,
                                        "act":"register"} )
            try: # this POSTS the request and returns the result
                etreeEl = get_server_dom(data, self.path)
            except Exception, e:
                if META_DEBUG: print "Problem talking to server.  Setting interval for retry ..."
                if META_DEBUG: print data
                if META_DEBUG: print e
                self.interval = 0
                """
                  If we are in the registerThread thread, then setting interval to 0
                  will end up causing a retry in about 6 seconds (see self.run())
                  If we are in the main thread, then setting interval to 0 will do one
                  of two things:
                  1)  Do the same as if we were in the registerThread
                  2)  Cause the next, normally scheduled register() call to use the values
                      provided in this call.
                
                  Which case occurs depends on where the registerThread thread is when
                  the main thread calls register().
                """
                return 0  # indicates that it was okay to call, not that no errors occurred

            #  If there is a DOM returned ....
            if etreeEl != None:
                #  If there's an error, echo it to the console
                if etreeEl.get("errmsg") != None:
                    print "Error durring registration at: " +self.path+ " Error: " +etreeEl.get("errmsg")
                    if META_DEBUG: print data
                    if META_DEBUG: print
                """
                  No special handling is required.  If the registration worked, id, cookie, and interval
                  can be stored and used for the next time.
                  If an error occurred, then the Meta will delete us and we need to re-register as
                  a new server.  The way to indicate this is with a "0" id and "0" cookie sent to
                  the server during the next registration.  Since that's what the server returns to
                  us on an error anyway, we just store them and the next registration will
                  automatically be set up as a new one.
                
                  Unless the server calls register() itself in the meantime.  Of course, that's okay
                  too, because a success on THAT register() call will set up the next one to use
                  the issued id and cookie.
                
                  The interval is stored unconditionally for similar reasons.  If there's an error,
                  the interval will be less than 1, and the main thread's while loop will reset it
                  to 6 seconds for the next retry.
                  Is it wrong to have a method where there's more comments than code?  :)
                """
                try:
                    self.interval = int(etreeEl.get("interval"))
                    self.id = etreeEl.get("id")
                    self.cookie = etreeEl.get("cookie")
                    #if etreeEl.get("errmsg") == None: updateMetaCache(xml_dom)
                except Exception, e:
                    if META_DEBUG: print
                    if META_DEBUG: print "OOPS!  Is the Meta okay?  It should be returning an id, cookie, and interval."
                    if META_DEBUG: print "Check to see what it really returned.\n"
                    if META_DEBUG: print e
                #  Let xml_dom get garbage collected
                try: xml_dom.unlink()
                except: pass
            else:  #  else if no DOM is returned from get_server_dom()
                print "Error - no DOM constructed from Meta message!"
            return 0  # Let caller know it was okay to call us
        finally: self.rlock.release()
    #  End of class registerThread
    ################################################################################