import json
from typing import Dict, List, Optional

import platformdirs
import requests_cache
import psycopg2.extras

import hanabi.live.hanab_live
import hanabi.hanab_game

import constants
import games_db_interface
import database
import utils
from database import conn_manager
from log_setup import logger
from config import config_manager

# This ensures that we do not pose too many requests to the website, especially while in development where we
# might frequently re-initialize the database.
session = requests_cache.CachedSession(
    platformdirs.user_cache_dir(constants.APP_NAME) + 'hanab.live.requests-cache',
    urls_expire_after={
        # Game exports will never change, so cache them forever
        'hanab.live/export/*': requests_cache.NEVER_EXPIRE
    }
)


class GameInfo:
    def __init__(self, game_id: int, num_players: int, variant_id: int, seed: str, score: int, num_turns: int,
                 user_ids: List[int], normalized_usernames: List[str]):
        self.game_id = game_id
        self.num_players = num_players
        self.variant_id = variant_id
        self.seed = seed
        self.score = score
        self.num_turns = num_turns
        self.user_ids = user_ids
        self.normalized_usernames = normalized_usernames


def fetch_games_for_player(username: str, latest_game_id: int):
    logger.verbose("Fetching games for username {} more recent than id {}".format(username, latest_game_id))
    url = "https://hanab.live/api/v1/history-full/{}?start={}".format(username, latest_game_id + 1)
    response = session.get(url)
    if not response.status_code == 200:
        err_msg = "Failed to fetch games for username {}, requested URL {}".format(username, url)
        logger.error(err_msg)
        raise ConnectionError(err_msg)
    return json.loads(response.text)


def process_game_entry(game_json: Dict, username_dict: Dict, variant_ids: List[int]) -> Optional[GameInfo]:
    logger.debug("Processing entry {}".format(game_json))
    config = config_manager.get_config()

    # Parse game properties
    game_id = game_json["id"]
    players = game_json["playerNames"]
    num_players = len(players)
    seed = game_json["seed"]
    score = game_json["score"]
    num_turns = game_json["numTurns"]

    game_options = game_json["options"]
    var_id = game_options["variantID"]

    normalized_usernames = [utils.normalize_username(username) for username in players]

    # Now, check if the game is one that we accept for league

    if not utils.are_game_options_allowed(game_id, game_options):
        return

    if not utils.is_player_count_allowed(game_id, num_players):
        return

    if var_id not in variant_ids:
        logger.debug("Rejected game {} due to invalid variant id {}".format(game_id, var_id))
        return

    # Everything matches, so we can parse the participants now
    user_ids = []  # This will be a list of the (league specific) user_id's that played this game.
    for normalized_username in normalized_usernames:
        user_id = username_dict.get(normalized_username, None)
        if user_id is None:
            logger.debug("Rejected game {} due to unregistered participant {}".format(game_id, normalized_username))
            return
        user_ids.append(user_id)

    return GameInfo(game_id, num_players, 0, seed, score, num_turns, user_ids, normalized_usernames)


def fetch_games_for_all_players():
    logger.info("Fetching new games.")
    cur = conn_manager.get_new_cursor()
    cur.execute("SELECT user_accounts.normalized_username, user_accounts.user_id, downloads.latest_game_id "
                "FROM user_accounts "
                "LEFT OUTER JOIN downloads "
                "  ON user_accounts.normalized_username = downloads.normalized_username"
                )
    # This will be a mapping of normalized username -> user ID that we built from the DB data
    username_dict = {}

    # This will be a mapping of game id -> JSON data that we get from hanab.live, where we will collect all the
    # possibly relevant games now
    games: Dict[int, Dict] = {}
    for username, user_id, latest_game_id in cur.fetchall():
        username_dict[username] = user_id
        # Use the starting id as fallback if we have not downloaded any games for this player yet.
        if latest_game_id is None:
            latest_game_id = config_manager.get_config().starting_game_id

        player_games = fetch_games_for_player(username, latest_game_id)
        for game in player_games:
            games[game['id']] = game

    logger.info("Found {} potential league game(s) to process.".format(len(games)))

    allowed_variants = database.get_variant_ids()

    # This will hold the processed games that we will add to the database.
    good_games: Dict[int, GameInfo] = {}

    for game_id, game in games.items():
        game_info = process_game_entry(game, username_dict, allowed_variants)
        if game_info is not None:
            good_games[game_id] = game_info

    logger.verbose("Found {} valid league game(s).".format(len(good_games)))
    return good_games


def store_new_games(games: Dict[int, GameInfo]):
    conn = conn_manager.get_connection()
    cur = conn.cursor()
    games_vals = []
    game_participants_vals = []
    latest_game_ids: Dict[str, int] = {}

    # Now, iterate over all games and convert to tuples for insertion
    for game in sorted(games.values(), key=lambda game_info: game_info.game_id):
        tup = (game.game_id, game.num_players, game.variant_id, game.seed, game.score, game.num_turns)
        games_vals.append(tup)
        for player_id in game.user_ids:
            tup = (game.game_id, player_id)
            game_participants_vals.append(tup)

        # Note that this gives the maximum in the end since we process the games in order
        for normalized_username in game.normalized_usernames:
            latest_game_ids[normalized_username] = game.game_id

    # Do the insertions
    # Notice that on conflict we can just do nothing: In that case, we already have the game in the DB for some reason
    # (for example, because we forced a download refresh)
    psycopg2.extras.execute_values(
        cur,
        "INSERT INTO games (id, num_players, variant_id, seed, score, num_turns) "
        "VALUES %s "
        "ON CONFLICT (id) DO NOTHING",
        games_vals
    )
    psycopg2.extras.execute_values(
        cur,
        "INSERT INTO game_participants (game_id, user_id) "
        "VALUES %s "
        "ON CONFLICT (game_id, user_id) DO NOTHING",
        game_participants_vals
    )
    # Here, we want to update on insertion conflict
    psycopg2.extras.execute_values(
        cur,
        "INSERT INTO downloads (normalized_username, latest_game_id) "
        "VALUES %s "
        "ON CONFLICT (normalized_username) "
        "DO UPDATE SET (normalized_username, latest_game_id) = (EXCLUDED.normalized_username, EXCLUDED.latest_game_id)",
        latest_game_ids.items()
    )
    logger.info("Added {} game(s) to database.".format(len(games)))
    # We only commit after performing all insertions. This guarantees that the download table is always in sync
    # with the actual games stored in the database.
    conn.commit()


def detailed_fetch_game(game_id: int) -> bool:
    """
    Fetches full game details from the server and stores it in local DB if this game is a league game.
    @param game_id: Game ID from hanab.live
    @return: Whether the processed game was accepted as a league game, i.e. inserted into the DB
    """
    logger.verbose("Fetching details on game {}.".format(game_id))
    url = "https://hanab.live/export/{}".format(game_id)
    response = session.get(url)
    if not response.status_code == 200:
        err_msg = "Failed to fetch game {}, requested URL {}".format(game_id, url)
        logger.error(err_msg)
        raise ConnectionError(err_msg)
    game_json = json.loads(response.text)

    instance, actions = hanabi.live.hanab_live.parse_json_game(game_json, False)

    game_id = game_json["id"]
    players = game_json["players"]
    num_players = len(players)
    seed = game_json["seed"]
    game_options = game_json.get("options", {})
    var_name = game_options.get("variant", "No Variant")

    if not utils.are_game_options_allowed(game_id, game_options):
        return False

    if not utils.is_player_count_allowed(game_id, num_players):
        return False

    var_id = database.get_variant_id(var_name)
    if var_id is None:
        logger.debug("Rejected game {} due to invalid variant id {}".format(game_id, var_id))
        return False

    # All game options are ok, now check if the number of players is okay.
    normalized_usernames = [utils.normalize_username(username) for username in players]
    user_ids = database.get_user_ids_from_normalized_usernames(normalized_usernames)
    # The return value here is a str if there was an unregistered participant
    if type(user_ids) is str:
        logger.debug("Rejected game {} due to unregistered participant {}".format(game_id, user_ids))
        return False

    # Now, we can start to actually process the game details
    instance, actions = hanabi.live.hanab_live.parse_json_game(game_json, False)
    game = hanabi.hanab_game.GameState(instance)
    # In order to figure out the score, we will need to play the game once
    for action in actions:
        game.make_action(action)

    conn = conn_manager.get_connection()
    cur = conn_manager.get_new_cursor()
    # Insert the game into the database if not present
    cur.execute("INSERT INTO games "
                "(id, num_players, variant_id, seed, score, num_turns) "
                "VALUES "
                "(%s, %s, %s, %s, %s, %s) "
                "ON CONFLICT (id) DO NOTHING",
                (game_id, num_players, var_id, seed, game.score, len(actions)))
    # TODO Max: Check if len(actions) is the correct number here, in case there was a VTK action, we might want to subtract one

    game_participants_vals = []
    for seat, user_id in enumerate(user_ids):
        tup = (game_id, user_id, seat)
        game_participants_vals.append(tup)

    # This inserts the game participants now.
    # Note that the participants might already be stored, but not their seat (since we do not know the seat when only
    # getting a game list from the server on fetching the games played by some player)
    psycopg2.extras.execute_values(
        cur,
        "INSERT INTO game_participants "
        "(game_id, user_id, seat) "
        "VALUES %s "
        "ON CONFLICT (game_id, user_id) DO UPDATE "
        "SET seat = EXCLUDED.seat",
        game_participants_vals
    )
    # DB is now in a consistent state again: We made sure the game and its participants are added.
    conn.commit()

    # It remains to store the seed and action data for this game
    # Note that we store the seed first. This ensures that whenever we have actions stored, we also have the seed stored.
    games_db_interface.store_deck_for_seed(seed, instance.deck)
    games_db_interface.store_actions(game_id, actions)
    logger.debug("Fetched all game details of game {}.".format(game_id))

    # Do some sanity checks that loading the stored data did not change it
    assert actions == games_db_interface.load_actions(game_id)
    assert instance.deck == games_db_interface.load_deck(seed)
    return True


def fetch_all_game_details():
    logger.info("Fetching detailed game data for all games.")
    cur = conn_manager.get_new_cursor()

    # Get all games with no actions
    cur.execute("SELECT id FROM games "
                "LEFT OUTER JOIN game_actions"
                "  ON games.id = game_actions.game_id "
                "WHERE game_actions.game_id IS NULL"
                )
    for (game_id,) in cur.fetchall():
        detailed_fetch_game(game_id)

    # Just to make sure, check that we have data on all seeds
    cur.execute("SELECT id FROM games "
                "LEFT OUTER JOIN seeds"
                "  ON seeds.seed = games.seed "
                "WHERE seeds.seed IS NULL"
                )
    games_without_seeds = [game_id for (game_id,) in cur.fetchall()]
    if len(games_without_seeds) != 0:
        logger.warn("Detected the following games without seed data, but with actions already stored: {}."
                    "Fetching them now".format(", ".join(games_without_seeds))
                    )
        for game_id in games_without_seeds:
            detailed_fetch_game(game_id)