import json
import logging
import math
import sqlalchemy
import sqlalchemy.sql.functions as sfunc
from datetime import timedelta
from sqlalchemy.orm import mapper
from sqlalchemy.orm import scoped_session
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from xonstat.elo import KREDUCTION, ELOPARMS
from xonstat.util import strip_colors, html_colors, pretty_date

log = logging.getLogger(__name__)

DBSession = scoped_session(sessionmaker())
Base = declarative_base()

# define objects for all tables
class Player(object):
    def nick_html_colors(self):
        if self.nick is None:
            return "Anonymous Player"
        else:
            return html_colors(self.nick)

    def nick_strip_colors(self):
        if self.nick is None:
            return "Anonymous Player"
        else:
            return strip_colors(self.nick)

    def joined_pretty_date(self):
        return pretty_date(self.create_dt)

    def __repr__(self):
        return "<Player(%s, %s)>" % (self.player_id, self.nick.encode('utf-8'))

    def to_dict(self):
        return {'player_id':self.player_id, 'name':self.nick.encode('utf-8')}


class GameType(object):
    def __repr__(self):
        return "<GameType(%s, %s, %s)>" % (self.game_type_cd, self.descr, self.active_ind)

    def to_dict(self):
        return {'game_type_cd':self.game_type_cd, 'name':self.descr, 'active':self.active_ind}


class Weapon(object):
    def __repr__(self):
        return "<Weapon(%s, %s, %s)>" % (self.weapon_cd, self.descr, self.active_ind)

    def to_dict(self):
        return {'weapon_cd':self.weapon_cd, 'name':self.descr, 'active':self.active_ind}


class Server(object):
    def __init__(self, name=None, hashkey=None, ip_addr=None):
        self.name = name
        self.hashkey = hashkey
        self.ip_addr = ip_addr

    def __repr__(self):
        return "<Server(%s, %s)>" % (self.server_id, self.name.encode('utf-8'))

    def to_dict(self):
        return {'server_id':self.server_id, 'name':self.name.encode('utf-8')}


class Map(object):
    def __init__(self, name=None):
        self.name = name

    def __repr__(self):
        return "<Map(%s, %s, %s)>" % (self.map_id, self.name, self.version)

    def to_dict(self):
        return {'map_id':self.map_id, 'name':self.name, 'version':self.version}


class Game(object):
    def __init__(self, game_id=None, start_dt=None, game_type_cd=None, 
            server_id=None, map_id=None, winner=None):
        self.game_id = game_id
        self.start_dt = start_dt
        self.game_type_cd = game_type_cd
        self.server_id = server_id
        self.map_id = map_id
        self.winner = winner

    def __repr__(self):
        return "<Game(%s, %s, %s, %s)>" % (self.game_id, self.start_dt, self.game_type_cd, self.server_id)

    def to_dict(self):
        return {'game_id':self.game_id, 'start':self.start_dt.strftime('%Y-%m-%dT%H:%M:%SZ'), 'game_type_cd':self.game_type_cd, 'server_id':self.server_id}

    def fuzzy_date(self):
        return pretty_date(self.start_dt)

    def process_elos(self, session, game_type_cd=None):
        if game_type_cd is None:
            game_type_cd = self.game_type_cd

        # we do not have the actual duration of the game, so use the 
        # maximum alivetime of the players instead
        duration = 0
        for d in session.query(sfunc.max(PlayerGameStat.alivetime)).\
                    filter(PlayerGameStat.game_id==self.game_id).\
                    one():
            duration = d.seconds

        scores = {}
        alivetimes = {}
        for (p,s,a) in session.query(PlayerGameStat.player_id, 
                PlayerGameStat.score, PlayerGameStat.alivetime).\
                filter(PlayerGameStat.game_id==self.game_id).\
                filter(PlayerGameStat.alivetime > timedelta(seconds=0)).\
                filter(PlayerGameStat.player_id > 2).\
                all():
                    # scores are per second
                    scores[p] = s/float(a.seconds)
                    alivetimes[p] = a.seconds

        player_ids = scores.keys()

        elos = {}
        for e in session.query(PlayerElo).\
                filter(PlayerElo.player_id.in_(player_ids)).\
                filter(PlayerElo.game_type_cd==game_type_cd).all():
                    elos[e.player_id] = e

        # ensure that all player_ids have an elo record
        for pid in player_ids:
            if pid not in elos.keys():
                elos[pid] = PlayerElo(pid, game_type_cd)

        for pid in player_ids:
            elos[pid].k = KREDUCTION.eval(elos[pid].games, alivetimes[pid],
                    duration)
            if elos[pid].k == 0:
                del(elos[pid])
                del(scores[pid])
                del(alivetimes[pid])

        elos = self.update_elos(session, elos, scores, ELOPARMS)

        # add the elos to the session for committing
        for e in elos:
            session.add(elos[e])

        if game_type_cd == 'duel':
            self.process_elos(session, "dm")


    def update_elos(self, session, elos, scores, ep):
        eloadjust = {}
        for pid in elos.keys():
            eloadjust[pid] = 0

        if len(elos) < 2:
            return elos

        pids = elos.keys()

        for i in xrange(0, len(pids)):
            ei = elos[pids[i]]
            for j in xrange(i+1, len(pids)):
                ej = elos[pids[j]]
                si = scores[ei.player_id]
                sj = scores[ej.player_id]

                # normalize scores
                ofs = min(0, si, sj)
                si -= ofs
                sj -= ofs
                if si + sj == 0:
                    si, sj = 1, 1 # a draw

                # real score factor
                scorefactor_real = si / float(si + sj)

                # estimated score factor by elo
                elodiff = min(ep.maxlogdistance, max(-ep.maxlogdistance,
                    (float(ei.elo) - float(ej.elo)) * ep.logdistancefactor))
                scorefactor_elo = 1 / (1 + math.exp(-elodiff))

                # how much adjustment is good?
                # scorefactor(elodiff) = 1 / (1 + e^(-elodiff * logdistancefactor))
                # elodiff(scorefactor) = -ln(1/scorefactor - 1) / logdistancefactor
                # elodiff'(scorefactor) = 1 / ((scorefactor) (1 - scorefactor) logdistancefactor)
                # elodiff'(scorefactor) >= 4 / logdistancefactor

                # adjust'(scorefactor) = K1 + K2

                # so we want:
                # K1 + K2 <= 4 / logdistancefactor <= elodiff'(scorefactor)
                # as we then don't overcompensate

                adjustment = scorefactor_real - scorefactor_elo
                eloadjust[ei.player_id] += adjustment
                eloadjust[ej.player_id] -= adjustment
        elo_deltas = {}
        for pid in pids:
            elo_delta = eloadjust[pid] * elos[pid].k * ep.global_K / float(len(elos) - 1)

            if float(elos[pid].elo) + elo_delta < ep.floor:
                elo_deltas[pid] = elos[pid].elo - ep.floor
            else:
                elo_deltas[pid] = elo_delta

            # can't go below the floor
            elos[pid].elo = max(float(elos[pid].elo) + elo_delta, ep.floor)
            elos[pid].games += 1

        self.save_elo_deltas(session, elo_deltas)

        return elos


    def save_elo_deltas(self, session, elo_deltas):
        """
        Saves the amount by which each player's Elo goes up or down
        in a given game in the PlayerGameStat row, allowing for scoreboard display.

        elo_deltas is a dictionary such that elo_deltas[player_id] is the elo_delta
        for that player_id.
        """
        pgstats = {}
        for pgstat in session.query(PlayerGameStat).\
                filter(PlayerGameStat.game_id == self.game_id).\
                all():
                    pgstats[pgstat.player_id] = pgstat

        for pid in elo_deltas.keys():
            try:
                pgstats[pid].elo_delta = elo_deltas[pid]
                session.add(pgstats[pid])
            except:
                log.debug("Unable to save Elo delta value for player_id {0}".format(pid))


class PlayerGameStat(object):
    def __init__(self, player_game_stat_id=None, create_dt=None):
        self.player_game_stat_id = player_game_stat_id
        self.create_dt = create_dt

    def __repr__(self):
        return "<PlayerGameStat(%s, %s, %s)>" % (self.player_id, self.game_id, self.create_dt)

    def to_dict(self):
        return {'player_id':self.player_id, 'game_id':self.game_id, 'create_dt':self.create_dt.strftime('%Y-%m-%dT%H:%M:%SZ')}

    def nick_stripped(self):
        if self.nick is None:
            return "Anonymous Player"
        else:
            return strip_colors(self.nick)

    def nick_html_colors(self):
        if self.nick is None:
            return "Anonymous Player"
        else:
            return html_colors(self.nick)

    def team_html_color(self):
        # blue
        if self.team == 5:
            return "red"
        # red
        if self.team == 14:
            return "blue"
        if self.team == 13:
            return "yellow"
        if self.team == 10:
            return "pink"


class Achievement(object):
    def __repr__(self):
        return "<Achievement(%s, %s, %s)>" % (self.achievement_cd, self.descr, self.limit)

    def to_dict(self):
        return {'achievement_cd':self.achievement_cd, 'name':self.descr, 'limit':self.limit}


class PlayerAchievement(object):
    def __repr__(self):
        return "<PlayerAchievement(%s, %s)>" % (self.player_id, self.achievement_cd)

    def to_dict(self):
        return {'player_id':self.player_id, 'achievement_cd':self.achievement_cd}


class PlayerWeaponStat(object):
    def __repr__(self):
        return "<PlayerWeaponStat(%s, %s, %s)>" % (self.player_weapon_stats_id, self.player_id, self.game_id)

    def to_dict(self):
        return {'player_weapon_stats_id':self.player_weapon_stats_id, 'player_id':self.player_id, 'game_id':self.game_id}


class Hashkey(object):
    def __init__(self, player_id=None, hashkey=None):
        self.player_id = player_id
        self.hashkey = hashkey

    def __repr__(self):
        return "<Hashkey(%s, %s)>" % (self.player_id, self.hashkey)

    def to_dict(self):
        return {'player_id':self.player_id, 'hashkey':self.hashkey}


class PlayerNick(object):
    def __repr__(self):
        return "<PlayerNick(%s, %s)>" % (self.player_id, self.stripped_nick)

    def to_dict(self):
        return {'player_id':self.player_id, 'name':self.stripped_nick}


class PlayerElo(object):
    def __init__(self, player_id=None, game_type_cd=None):

        self.player_id = player_id
        self.game_type_cd = game_type_cd
        self.score = 0
        self.games = 0
        self.elo = ELOPARMS.initial

    def __repr__(self):
        return "<PlayerElo(pid=%s, gametype=%s, elo=%s)>" % (self.player_id, self.game_type_cd, self.elo)

    def to_dict(self):
        return {'player_id':self.player_id, 'game_type_cd':self.game_type_cd, 'elo':self.elo}


class PlayerRank(object):

    def nick_html_colors(self):
        if self.nick is None:
            return "Anonymous Player"
        else:
            return html_colors(self.nick)

    def __repr__(self):
        return "<PlayerRank(pid=%s, gametype=%s, rank=%s)>" % (self.player_id, self.game_type_cd, self.rank)

    def to_dict(self):
        return {'player_id':self.player_id, 'game_type_cd':self.game_type_cd, 'rank':self.rank}


def initialize_db(engine=None):
    DBSession.configure(bind=engine)
    Base.metadata.bind = engine
    Base.metadata.create_all(engine)
    MetaData = sqlalchemy.MetaData(bind=engine, reflect=True)

    # assign all those tables to an object
    achievements_table = MetaData.tables['achievements']
    cd_achievement_table = MetaData.tables['cd_achievement']
    cd_game_type_table = MetaData.tables['cd_game_type']
    cd_weapon_table = MetaData.tables['cd_weapon']
    db_version_table = MetaData.tables['db_version']
    games_table = MetaData.tables['games']
    hashkeys_table = MetaData.tables['hashkeys']
    maps_table = MetaData.tables['maps']
    player_game_stats_table = MetaData.tables['player_game_stats']
    players_table = MetaData.tables['players']
    player_weapon_stats_table = MetaData.tables['player_weapon_stats']
    servers_table = MetaData.tables['servers']
    player_nicks_table = MetaData.tables['player_nicks']
    player_elos_table = MetaData.tables['player_elos']
    player_ranks_table = MetaData.tables['player_ranks']

    # now map the tables and the objects together
    mapper(PlayerAchievement, achievements_table)
    mapper(Achievement, cd_achievement_table)
    mapper(GameType, cd_game_type_table)
    mapper(Weapon, cd_weapon_table)
    mapper(Game, games_table)
    mapper(Hashkey, hashkeys_table)
    mapper(Map, maps_table)
    mapper(PlayerGameStat, player_game_stats_table)
    mapper(Player, players_table)
    mapper(PlayerWeaponStat, player_weapon_stats_table)
    mapper(Server, servers_table)
    mapper(PlayerNick, player_nicks_table)
    mapper(PlayerElo, player_elos_table)
    mapper(PlayerRank, player_ranks_table)