from secrets import token_hex
from datetime import datetime

from flask_login import UserMixin
from sqlalchemy.ext.associationproxy import association_proxy
from werkzeug.security import generate_password_hash, check_password_hash

from app import db, login
from app.models import GamePlayer, Role

class User(UserMixin, db.Model):
    """ !Always call set_auth_hash() after creating new instance! """
    __tablename__ = 'user'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), unique=True, nullable=False)
    auth_hash = db.Column(db.String(32), unique=True, nullable=True)
    password_hash = db.Column(db.String(128))

    user_games = db.relationship(
        'GamePlayer',
        back_populates='user',
        cascade='save-update, merge, delete, delete-orphan')
    games = association_proxy('user_games', 'game',
        creator=lambda game: GamePlayer(game=game))


    locations = db.relationship(
        'Location',
        lazy='select',
        backref=db.backref('player', lazy='joined'))

    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

    def set_auth_hash(self):
        self.auth_hash = token_hex(16)

    def check_password(self, password):
        if not password or not self.password_hash:
            return False
        return check_password_hash(self.password_hash, password)

    def locations_during_game(self, game):
        # pylint: disable=not-an-iterable
        if not self.locations:
            return None
        if game is None:
            return self.locations
        game_start = game.start_time or datetime.min
        game_end = game.end_time or datetime.max
        return (location for location in self.locations if location.timestamp > game_start and location.timestamp < game_end)

    def last_location(self, game=None):
        # pylint: disable=not-an-iterable
        if not self.locations:
            return None
        if game is None:
            return max(self.locations, key=lambda location: location.timestamp)
        return max(self.locations_during_game(game), key=lambda location: location.timestamp)

    def role_in_game(self, game):
        '''returns the role as Role enum of player in given game. Returns None if player does not participate in game'''
        # pylint: disable=not-an-iterable
        gameplayers = [gameplayer for gameplayer in self.user_games if gameplayer.game == game]
        if not gameplayers:
            return None
        return gameplayers[0].role

    def owns_game_played_by(self, player):
        '''self is an owner of a game the player participates in'''
        return self in [gameplayer.player for gameplayers in
                        [game.game_players for game in player.games]
                        for gameplayer in gameplayers if gameplayer.role == Role.owner]

    @staticmethod
    def delete_orphans():
        User.query.filter(~User.user_games.any()).delete()
        db.session.commit()


@login.user_loader
def load_user(id):
    return User.query.get(int(id))