from datetime import UTC, datetime
from pathlib import Path
from typing import Any

import gzip, json, os

class RLBootstrapDataset:
  def __init__(self):
    self.enabled = self._env_bool("RL_BOOTSTRAP_ENABLED", default=False)
    self.min_base_rows = self._env_int("RL_MIN_BASE_ROWS", default=5000)
    self.base_dataset_path = Path(os.getenv("RL_BASE_DATASET", "data/dataset/best_moves.jsonl"))
    self.output_path = Path(os.getenv("RL_BOOTSTRAP_OUTPUT", "data/dataset/rl_bootstrap.jsonl"))
    self.max_bytes = int(float(os.getenv("RL_BOOTSTRAP_MAX_MB", "50")) * 1024 * 1024)
    self.needs_more_data = False

  @staticmethod
  def _env_bool(name:str, default:bool=False) -> bool:
    value = os.getenv(name)
    if value is None:
      return default
    return value.lower() in {"1", "true", "yes", "on"}

  @staticmethod
  def _env_int(name:str, default:int) -> int:
    value = os.getenv(name)
    if value is None:
      return default
    try:
      return int(value)
    except ValueError:
      return default

  @staticmethod
  def count_jsonl_rows(path:Path) -> int:
    count = 0

    candidates = [path]
    if path.suffix == ".gz":
      candidates.append(path.with_suffix(""))
    else:
      candidates.append(Path(f"{path}.gz"))

    seen = set()
    for candidate in candidates:
      if candidate in seen:
        continue
      seen.add(candidate)

      if not candidate.exists() or not candidate.is_file():
        continue

      open_fn = gzip.open if candidate.suffix == ".gz" else open
      try:
        with open_fn(candidate, "rt", encoding="utf-8") as handle:
          for line in handle:
            if line.strip():
              count += 1
      except (OSError, UnicodeError):
        continue

    return count

  @staticmethod
  def rotate_and_gzip_if_size_reached(path:Path, max_bytes:int) -> bool:
    if max_bytes <= 0:
      return False
    if not path.exists() or not path.is_file():
      return False
    if path.stat().st_size < max_bytes:
      return False

    timestamp = datetime.now(UTC).strftime("%Y%m%d-%H%M%S")
    if path.suffix == ".jsonl":
      rotated_name = f"{path.stem}.{timestamp}.jsonl"
    else:
      rotated_name = f"{path.name}.{timestamp}"

    rotated_path = path.with_name(rotated_name)
    suffix = 1
    while rotated_path.exists():
      suffix += 1
      if path.suffix == ".jsonl":
        rotated_name = f"{path.stem}.{timestamp}.{suffix}.jsonl"
      else:
        rotated_name = f"{path.name}.{timestamp}.{suffix}"
      rotated_path = path.with_name(rotated_name)

    path.rename(rotated_path)
    with rotated_path.open("rb") as src:
      with gzip.open(f"{rotated_path}.gz", "wb") as dst:
        dst.writelines(src)
    rotated_path.unlink()
    return True

  def refresh_state(self):
    if not self.enabled:
      self.needs_more_data = False
      return
    base_rows = self.count_jsonl_rows(self.base_dataset_path)
    self.needs_more_data = base_rows < self.min_base_rows

  def record_sample(self, game_data:Any, move:str, safe_moves:dict[str, dict[str, int]], reason:str, scores:dict[str, float]|None=None,):
    if not self.enabled or not self.needs_more_data:
      return

    try:
      self.output_path.parent.mkdir(parents=True, exist_ok=True)
      row = {
        "source": "best_battlesnake_bootstrap",
        "game_id": getattr(game_data, "id", None),
        "turn": game_data.get_turn(),
        "move": move,
        "safe_moves": list(safe_moves.keys()),
        "reason": reason,
        "game_board": game_data.get_game_board_as_dict(),
      }
      if scores:
        row["scores"] = {k: round(v, 5) for k, v in scores.items()}

      with self.output_path.open("a", encoding="utf-8") as handle:
        handle.write(json.dumps(row, ensure_ascii=False) + "\n")
      self.rotate_and_gzip_if_size_reached(self.output_path, self.max_bytes)
    except Exception:
      return