from typing import List, Dict

import utils
from database import conn_manager

from log_setup import logger


def next_game_to_rate():
    cur = conn_manager.get_new_cursor()
    cur.execute("SELECT games.id FROM games "
                "LEFT OUTER JOIN user_ratings"
                "  ON games.league_id = user_ratings.league_id "
                "WHERE user_ratings.league_id IS NULL "
                "ORDER BY games.league_id ASC "
                "LIMIT 1"
                )
    query_result = cur.fetchone()
    if query_result is None:
        return

    (game_id,) = query_result
    return game_id


def get_current_ratings(user_ids: List[int], rating_type: int) -> Dict[int, float]:
    """
    Fetches the current ratings for specified players and rating type from DB
    @return: Mapping user_id -> current rating
    """
    cur = conn_manager.get_new_cursor()
    cur.execute("SELECT user_id, rating FROM user_base_ratings "
                "WHERE user_id IN ({}) AND type = %s".format(", ".join("%s" for _ in user_ids)),
                user_ids + [rating_type]
                )
    base_ratings = cur.fetchall()
    cur.execute("SELECT user_ratings.user_id, value_after FROM user_ratings "
                "INNER JOIN ("
                "    SELECT user_id, type, MAX(league_id) AS max_league_id"
                "    FROM user_ratings "
                "    GROUP BY (user_id, type)"
                "  ) AS latest_user_ratings "
                "  ON user_ratings.league_id = latest_user_ratings.max_league_id "
                )
    current_ratings = cur.fetchall()

    ratings: Dict[int, float] = {}
    for user_id, base_rating in base_ratings:
        ratings[user_id] = base_rating
    for user_id, rating in current_ratings:
        ratings[user_id] = rating

    return ratings


def process_rating_of_next_game():
    game_id = next_game_to_rate()
    if game_id is None:
        logger.info("All games already processed for rating changes.")
        return
    logger.verbose("Processing rating for game {}".format)
    cur = conn_manager.get_new_cursor()
    cur.execute("SELECT games.league_id, games.num_players, games.score, variants.num_suits, variants.clue_starved "
                "FROM games "
                "INNER JOIN variants "
                "  ON games.variant_id = variants.id "
                "WHERE games.id = %s",
                (game_id,)
                )
    league_id, num_players, score, num_suits, clue_starved = cur.fetchone()

    cur.execute("SELECT game_participants.user_id FROM games "
                "INNER JOIN game_participants "
                "  ON games.id = game_participants.game_id "
                "WHERE games.id = %s",
                (game_id,)
                )
    user_ids = cur.fetchall()
    if len(user_ids) != num_players:
        err_msg = "Player number mismatch: Expected {} participants for game {}, but only found {} in DB: [{}]".format(
            num_players, game_id, len(user_ids), ", ".join(user_ids)
        )
        logger.error(err_msg)
        raise ValueError(err_msg)

    rating_type = utils.get_rating_type(clue_starved)
    ratings = get_current_ratings(user_ids, rating_type)