import json
import logging
import logging.config
import os
from pathlib import Path


def _as_bool(val: str | None, default: bool = False) -> bool:
    if val is None:
        return default
    return val.strip().lower() in ("1", "true", "yes", "on")


def _level_from_env() -> int:
    level_name = os.getenv("LOG_LEVEL", "INFO").upper()
    return getattr(logging, level_name, logging.INFO)


def setup_logging() -> None:
    level = _level_from_env()
    to_file = _as_bool(os.getenv("LOG_TO_FILE"), True)
    log_file = os.getenv("LOG_FILE", "logs/mathema.log")
    as_json = _as_bool(os.getenv("LOG_JSON"), False)

    if to_file:
        Path(log_file).parent.mkdir(parents=True, exist_ok=True)

    if as_json:
        fmt = '%(message)s'
    else:
        fmt = ("%(asctime)s | %(levelname)-8s | %(name)s | "
               "task=%(taskName)s | %(message)s")

    console_handler = {
        "class": "logging.StreamHandler",
        "level": level,
        "formatter": "json" if as_json else "default",
    }

    file_handler = {
        "class": "logging.FileHandler",
        "level": level,
        "filename": log_file,
        "encoding": "utf-8",
        "formatter": "json" if as_json else "default",
    }

    handlers = {"console": console_handler}
    if to_file:
        handlers["file"] = file_handler

    formatters = {
        "default": {
            "format": fmt,
            "datefmt": "%Y-%m-%d %H:%M:%S",
        },
        "json": {
            "()": "logging.Formatter",
            "format": "%(message)s",
        },
    }

    config = {
        "version": 1,
        "disable_existing_loggers": False,  
        "formatters": formatters,
        "handlers": handlers,
        "root": {
            "level": level,
            "handlers": list(handlers.keys()),
        },
        "loggers": {
            "mathema": {"level": level, "propagate": True},
            "asyncio": {"level": "WARNING"},
            "gymnasium": {"level": "WARNING"},
            "pygame": {"level": "WARNING"},
            "neo4j": {"level": "WARNING"},
        },
    }

    logging.config.dictConfig(config)

    if as_json:
        class JsonFilter(logging.Filter):
            def filter(self, record: logging.LogRecord) -> bool:
                payload = {
                    "ts": record.created,
                    "level": record.levelname,
                    "logger": record.name,
                    "task": getattr(record, "taskName", None),
                    "msg": record.getMessage(),
                }
                record.msg = json.dumps(payload, ensure_ascii=False)
                return True

        for h in logging.getLogger().handlers:
            h.addFilter(JsonFilter())