hanabi-league/database.py

import json
from typing import Optional

import psycopg2
import psycopg2.extensions
import psycopg2.extras
import psycopg2.errors
import requests
import unidecode

import constants
from config import config_manager
from log_setup import logger


class DBConnectionManager:
    def __init__(self):
        self._conn = None

    def connect(self):
        config = config_manager.get_db_config()
        logger.debug("Establishing database connection with dbname={}, user={}, password={}".format(
            config.db_name, config.db_user, config.db_pass
        ))
        self._conn = psycopg2.connect("dbname='{}' user='{}' password='{}' host='localhost'".format(
            config.db_name, config.db_user, config.db_pass
        ))
        logger.debug("Established database connection.")

    def get_connection(self) -> psycopg2.extensions.connection:
        """
        Get the database connection.
        If not already connected, this reads the database config file and connects to the DB.
        Otherwise, the already active connection is returned.
        """
        if self._conn is None:
            self.connect()
        return self._conn

    def get_new_cursor(self) -> psycopg2.extensions.cursor:
        if self._conn is None:
            self.connect()
        return self._conn.cursor()


# Global instance that will hold our DB connection
conn_manager = DBConnectionManager()


def get_existing_tables():
    conn = conn_manager.get_connection()
    cur = conn.cursor()
    table_names = ", ".join("'{}'".format(tablename) for tablename in constants.DB_TABLE_NAMES)
    cur.execute(
        "SELECT tablename FROM pg_tables WHERE"
        "  schemaname = 'public' AND"
        "  tablename IN ({})".format(
            table_names
        )
    )
    return [table for (table,) in cur.fetchall()]


def init_database():
    """
    Warning: This drops all existing tables from the database
    """
    conn = conn_manager.get_connection()
    cur = conn.cursor()

    with open(constants.DATABASE_SCHEMA_PATH, "r") as f:
        cur.execute(f.read())
        conn.commit()
    logger.verbose("Initialized DB tables.")


def fetch_and_initialize_variants():
    response = requests.get(constants.VARIANTS_JSON_URL)
    if not response.status_code == 200:
        logger.error(
            "Could not download variants.json file from github (tried url {})".format(constants.VARIANTS_JSON_URL))
        return
    variants = json.loads(response.text)

    config = config_manager.get_config()

    for variant in variants:
        variant_id = variant['id']
        name = variant['name']
        clue_starved = variant.get('clueStarved', False)
        num_suits = len(variant['suits'])

        if config.min_suit_count <= num_suits <= config.max_suit_count:
            if any(var_name in name.lower() for var_name in config.excluded_variants):
                continue
            cur = conn_manager.get_new_cursor()
            cur.execute(
                "INSERT INTO variants (id, name, num_suits, clue_starved) VALUES (%s, %s, %s, %s)",
                (variant_id, name, num_suits, clue_starved)
            )
    conn_manager.get_connection().commit()


def initialize_variant_base_ratings():
    config = config_manager.get_config()
    conn = conn_manager.get_connection()
    cur = conn.cursor()
    cur.execute("SELECT id, name from variants")
    ratings = []
    for variant_id, variant_name in cur.fetchall():
        for num_players in range(config.min_player_count, config.max_player_count + 1):
            rating = config.variant_base_rating(variant_name, num_players)
            ratings.append((variant_id, num_players, rating))

    psycopg2.extras.execute_values(
        cur,
        "INSERT INTO variant_base_ratings (variant_id, player_count, rating)"
        "VALUES %s "
        "ON CONFLICT (variant_id, player_count) "
        "DO UPDATE SET rating = EXCLUDED.rating",
        ratings
    )
    conn.commit()


def normalize_username(username: str) -> str:
    decoded = unidecode.unidecode(username)
    return decoded.lower()


def get_user_id(player_name: str) -> Optional[id]:
    cur = conn_manager.get_new_cursor()
    cur.execute("SELECT id FROM users WHERE player_name = (%s)", (player_name,))
    return cur.fetchone()


def add_player_name(player_name: str):
    conn = conn_manager.get_connection()
    cur = conn.cursor()
    try:
        cur.execute("INSERT INTO users (player_name) VALUES (%s)", (player_name,))
        conn.commit()
    except psycopg2.errors.UniqueViolation:
        logger.warn("Player name {} already exists in the database, aborting insertion.".format(player_name))
        conn.rollback()


def add_user_name_to_player(hanabi_username: str, player_name: str):
    normalized_username = normalize_username(hanabi_username)
    user_id = get_user_id(player_name)
    if user_id is None:
        logger.error("Player {} not found in database, cannot add username to it.".format(player_name))
        return
    else:
        cur = conn_manager.get_new_cursor()
        cur.execute("SELECT username, player_name from user_accounts "
                    "INNER JOIN users"
                    "  ON user_accounts.user_id = users.id "
                    "WHERE "
                    "  normalized_username = (%s)",
                    (normalized_username,)
                    )
        res = cur.fetchone()
        if res is not None:
            existing_username, existing_player_name = res
            if existing_player_name == player_name:
                logger.warn(
                    "Hanabi username {} is already registered to player {}, attempted to re-register it.".format(
                        existing_username, existing_player_name
                    ))
            else:
                logger.error(
                    "Hanabi username {} is already associated to player {}, cannot register it to player {}.".format(
                        res[0], res[1], player_name
                    ))
            return
        cur.execute(
            "INSERT INTO user_accounts (username, normalized_username, user_id) VALUES (%s, %s, %s)",
            (hanabi_username, normalized_username, user_id)
        )
        conn_manager.get_connection().commit()


def init_player_base_rating(player_name: str, base_rating: Optional[int] = None):
    config = config_manager.get_config()
    if base_rating is None:
        base_rating = config.player_base_rating
    cur = conn_manager.get_new_cursor()
    vals = []
    user_id = get_user_id(player_name)
    if user_id is None:
        err_msg = "Cannot initialise base rating for player {}: No such registered player.".format(player_name)
        logger.error(err_msg)
        raise ValueError(err_msg)
    for rating_type in range(0, 2):
        vals.append((user_id, rating_type, base_rating))
    try:
        psycopg2.extras.execute_values(
            cur,
            "INSERT INTO user_base_ratings (user_id, type, rating) VALUES %s",
            vals
        )
        conn_manager.get_connection().commit()
    except psycopg2.errors.UniqueViolation as e:
        err_msg = "Failed to initialize base ratings for player {}: Ratings already exist".format(player_name)
        logger.error("{}:\n{}".format(err_msg, e))
        raise ValueError(err_msg) from e


def add_player(user_name: str, player_name: str, base_rating: Optional[int] = None):
    """
    Convenience function: Adds a player to the database, along with associated username and
    initializes the rating for this player.
    """
    add_player_name(player_name)
    add_user_name_to_player(user_name, player_name)
    init_player_base_rating(player_name, base_rating)


def get_variant_ids():
    cur = conn_manager.get_new_cursor()
    cur.execute("SELECT id FROM variants")
    return [var_id for (var_id,) in cur.fetchall()]