from typing import cast
import time

from server.metrics import MetricsCollector
from server.GameBoard import GameBoard

from storage import StorageLoader
from snakes import SnakeBuilder

class GameRuntimeService:
  def __init__(self, game_state_store:StorageLoader, snake_type:str, game_state_local_cache:bool, stale_game_timeout_sec:int):
    self.game_state_store = game_state_store
    self.snake_type = snake_type
    self.game_state_local_cache = game_state_local_cache
    self.stale_game_timeout_sec = stale_game_timeout_sec
    self.metrics_collector = None

    self.running_games: dict[str, GameBoard] = {}
    self.game_move_counts: dict[str, int] = {}
    self.game_last_seen_unix: dict[str, int] = {}

  def attach_metrics_collector(self, metrics_collector:MetricsCollector) -> None:
    self.metrics_collector = metrics_collector

  async def create_game_board(self, game_state:dict, snake_builder:SnakeBuilder) -> GameBoard:
    game_id = game_state['game']['id']
    new_game_board = GameBoard(
      game_id=game_id,
      width=game_state['board']['width'],
      height=game_state['board']['height'],
      ruleset=game_state['game']['ruleset'],
      source=game_state['game']['source'],
      map=game_state['game']['map'],
      snake_class=snake_builder.build(self.snake_type),
    )
    await new_game_board.start_game(game_state)

    if self.game_state_local_cache:
      self.running_games[game_id] = new_game_board

    await self.game_state_store.save(game_id, new_game_board)
    self.game_move_counts[game_id] = 0
    self.game_last_seen_unix[game_id] = int(time.time())
    if self.metrics_collector is not None:
      await self.metrics_collector.record_game_started(len(self.game_last_seen_unix))
    return new_game_board

  async def persist_game_board(self, game_id:str, game_board:GameBoard) -> None:
    if self.game_state_local_cache:
      self.running_games[game_id] = game_board
    await self.game_state_store.save(game_id, game_board)

  async def delete_game_board(self, game_state:dict) -> None:
    game_id = game_state['game']['id']
    self.running_games.pop(game_id, None)
    self.game_move_counts.pop(game_id, None)
    self.game_last_seen_unix.pop(game_id, None)
    await self.game_state_store.delete(game_id)

  async def get_game_board(self, game_state:dict, snake_builder:SnakeBuilder, end:bool=False) -> GameBoard:
    game_id = game_state['game']['id']
    game_board: GameBoard
    if self.game_state_local_cache and game_id in self.running_games:
      game_board = self.running_games[game_id]
    else:
      persisted_board = await self.game_state_store.load(game_id)
      if persisted_board is not None:
        game_board = cast(GameBoard, persisted_board)
        if self.game_state_local_cache:
          self.running_games[game_id] = game_board
      else:
        game_board = await self.create_game_board(game_state, snake_builder)
        if self.metrics_collector is not None:
          await self.metrics_collector.record_game_autocreated()

    if not end:
      self.game_move_counts[game_id] = self.game_move_counts.get(game_id, 0) + 1

    self.game_last_seen_unix[game_id] = int(time.time())

    game_board.read_game_data(game_state)
    if end:
      game_board.end_game(game_state)
      await self.persist_game_board(game_id, game_board)

    return game_board

  async def prune_stale_games(self) -> None:
    if not self.game_last_seen_unix:
      return

    now = int(time.time())
    stale_ids = [
      game_id
      for game_id, last_seen in self.game_last_seen_unix.items()
      if now - last_seen >= self.stale_game_timeout_sec
    ]
    for game_id in stale_ids:
      self.running_games.pop(game_id, None)
      self.game_move_counts.pop(game_id, None)
      self.game_last_seen_unix.pop(game_id, None)
      if self.metrics_collector is not None:
        await self.metrics_collector.record_stuck_removed()