"""
These managers handles the 
"""

from django.db import models
from django.contrib.contenttypes.models import ContentType
from src.utils.utils import is_iter

class CommError(Exception):
    "Raise by comm system, to allow feedback to player when caught."
    pass

# helper function

def to_object(inp, objtype='player'):
    """
    Locates the object related to the given
    playername or channel key. If input was already
    the correct object, return it.
    inp - the input object/string 
    objtype - 'player' or 'channel'
    """
    from src.players.models import PlayerDB
    if objtype == 'player':
        if type(inp) == PlayerDB:
            return inp
        if hasattr(inp, 'player'):
            return inp.player
        else:
            umatch = PlayerDB.objects.filter(user__username__iexact=inp)
            if umatch:
                return umatch[0]    
    else:
        # have to import this way to avoid circular imports
        from src.comms.models import Channel 
        #= ContentType.objects.get(app_label="comms", 
        #                                  model="channel").model_class()
        if type(inp) == Channel:
            return inp
        cmatch = Channel.objects.filter(db_key__iexact=inp)
        if cmatch:
            return cmatch[0]
    return None 
    
#
# Msg manager
#

class MsgManager(models.Manager):
    """
    Handle msg database
    """
    
    def get_message_by_id(self, idnum):
        "Retrieve message by its id."        
        try:
            idnum = int(idnum)
            return self.get(id=id)
        except:
            return None
        
    def get_messages_by_sender(self, player):
        """
        Get all messages sent by one player
        """
        player = to_object(player, objtype='player')        
        if not player:
            return None 
        return self.filter(db_sender=player).exclude(db_hide_from_sender=True)

    def get_messages_by_receiver(self, receiver):
        """
        Get all messages sent to one player
        """
        receiver = to_object(receiver)
        if not receiver:
            return None 
        return [msg for msg in self.all()
                if receiver in msg.receivers
                and receiver not in msg.hide_from_receivers]

    def get_messages_by_channel(self, channel):
        """
        Get all messages sent to one channel
        """
        channel = to_object(channel, objtype='channel')
        if not channel:
            return None 
        return [msg for msg in self.all()
                if channel in msg.channels 
                and channel not in msg.hide_from_channels]

    #TODO add search limited by send_times 
    def text_search(self, searchstring, filterdict=None):
        """
        Returns all messages that contain the matching
        search string. To avoid too many results, and also
        since this can be a very computing-
        heavy operation, it's recommended to be filtered
        by at least channel or sender/receiver. 
        searchstring - string to search for
        filterdict -
            {'channels':[list],
             'senders':[list],
             'receivers':[list]}
            lists can contain either the name/keys of the
            objects or the actual objects to filter by. 
        """        

        if filterdict:
            # obtain valid objects for all filters 
            channels = [chan for chan in
                        [to_object(chan, objtype='channel')
                         for chan in filterdict.get('channels',[])]
                        if chan]
            senders = [sender for sender in
                       [to_object(sender)
                        for sender in filterdict.get('senders',[])]
                        if sender]                       
            receivers = [receiver for receiver in
                         [to_object(receiver)
                          for receiver in filterdict.get('receivers',[])]
                         if receiver]
            # filter the messages lazily using the filter objects        
            msgs = []
            for sender in senders:
                msgs = list(sender.message_set.filter(
                        db_message__icontains=searchstring))                
            for receiver in receivers:
                rec_msgs = receiver.message_set.filter(
                        db_message__icontains=searchstring)
                if msgs:
                    msgs = [msg for msg in rec_msgs if msg in msgs]
                else:
                    msgs = rec_msgs 
            for channel in channels:
                chan_msgs = list(channel.message_set.filter(
                        db_message__icontains=searchstring))
                if msgs:
                    msgs = [msg for msg in chan_msgs if msg in msgs]
                else:
                    msgs = chan_msgs
            return list(set(msgs))
        return list(self.all().filter(db_message__icontains=searchstring))

    def message_search(self, sender=None, receiver=None, channel=None, freetext=None, dbref=None):    
        """
        Search the message database for particular messages. At least one 
        of the arguments must be given to do a search. 

        sender - get messages sent by a particular player
        receiver - get messages received by a certain player or players
        channel - get messages sent to a particular channel or channels
        freetext - Search for a text string in a message. 
                   NOTE: This can potentially be slow, so make sure to supply
                   one of the other arguments to limit the search.                     
        dbref - (int) the exact database id of the message. This will override 
                all other search crieteria since it's unique and
                always gives a list with only one match.
        """        
        if dbref:
            return self.filter(id=dbref)
        if freetext:
            if sender:
                sender = [sender]
            if receiver and not is_iter(receiver):
                receiver = [receiver]
            if channel and not is_iter(channel):
                channel = [channel]
            filterdict = {"senders":sender,
                          "receivers":receiver,
                          "channels":channel}
            return self.textsearch(freetext, filterdict)
        msgs = []
        if sender:
            msgs = self.get_messages_by_sender(sender)
        if receiver:           
            rec_msgs = self.get_messages_by_receiver(receiver)
            if msgs:
                msgs = [msg for msg in rec_msgs if msg in msgs]
            else:
                msgs = rec_msgs        
        if channel:
            chan_msgs = self.get_messaqge_by_channel(channel)
            if msgs:
                msgs = [msg for msg in chan_msgs if msg in msgs]
            else:
                msgs = chan_msgs
        return msgs
            
#
# Channel manager
#

class ChannelManager(models.Manager):
    """
    Handle channel database
    """

    def get_all_channels(self):
        """
        Returns all channels in game.
        """
        return self.all()

    def get_channel(self, channelkey):
        """
        Return the channel object if given its key.
        Also searches its aliases. 
        """
        # first check the channel key 
        channels = self.filter(db_key__iexact=channelkey)
        if not channels:
            # also check aliases
            channels = [channel for channel in self.all()
                        if channelkey in channel.aliases]
        if channels:
            return channels[0]
        return None 

    def del_channel(self, channelkey):
        """
        Delete channel matching channelkey.
        Also cleans up channelhandler. 
        """
        channels = self.filter(db_key__iexact=channelkey)
        if not channels:
            # no aliases allowed for deletion.
            return False        
        for channel in channels:
            channel.delete() 
        from src.comms.channelhandler import CHANNELHANDLER
        CHANNELHANDLER.update()
        return None 
                
    def has_connection(self, player, channel):
        "Check so the player is really listening to this channel."
        ChannelConnection = ContentType.objects.get(app_label="comms", 
                                 model="channelconnection").model_class()
        return ChannelConnection.objects.has_connection(player, channel)

    def get_all_connections(self, channel):
        """
        Return the connections of all players listening
        to this channel
        """
        # import here to avoid circular imports
        from src.comms.models import ChannelConnection
        #= ContentType.objects.get(app_label="comms", 
        #                        model="channelconnection").model_class()
        return ChannelConnection.objects.get_all_connections(channel)

    def channel_search(self, ostring):
        """
        Search the channel database for a particular channel.

        ostring - the key or database id of the channel.
        """
        channels = []
        try:
            # try an id match first        
            dbref = int(ostring.strip('#'))
            channels = self.filter(id=dbref)
        except Exception:       
            pass
        if not channels:
            # no id match. Search on the key.
            channels = self.filter(db_key=ostring)
        return channels 

#
# ChannelConnection manager
#
class ChannelConnectionManager(models.Manager):
    """
    This handles all connections between a player and
    a channel. 
    """
    
    def get_all_player_connections(self, player):
        "Get all connections that the given player has."
        player = to_object(player)
        return self.filter(db_player=player)

    def has_connection(self, player, channel):
        "Checks so a connection exists player<->channel"
        player = to_object(player)
        channel = to_object(channel, objtype="channel")
        if player and channel:
            return self.filter(db_player=player).filter(db_channel=channel).count() > 0
        return False
    
    def get_all_connections(self, channel):
        """
        Get all connections for a channel
        """
        channel = to_object(channel, objtype='channel')
        return self.filter(db_channel=channel)
    
    def create_connection(self, player, channel):
        """
        Connect a player to a channel. player and channel
        can be actual objects or keystrings. 
        """
        player = to_object(player)
        channel = to_object(channel, objtype='channel')
        if not player or not channel:
            raise CommError("NOTFOUND")
        new_connection = self.model(db_player=player, db_channel=channel)
        new_connection.save()
        return new_connection

    def break_connection(self, player, channel):
        "Remove link between player and channel"
        player = to_object(player)
        channel = to_object(channel, objtype='channel')
        if not player or not channel:
            raise CommError("NOTFOUND")
        conns = self.filter(db_player=player).filter(db_channel=channel)
        for conn in conns:
            conn.delete()