import logging
import json
import sys
from contextvars import ContextVar
from datetime import datetime, timezone

request_id_var: ContextVar[str] = ContextVar("request_id", default="-")


class JSONFormatter(logging.Formatter):
    def format(self, record: logging.LogRecord) -> str:
        log_data = {
            "timestamp": datetime.now(timezone.utc).isoformat(),
            "level": record.levelname,
            "module": record.module,
            "function": record.funcName,
            "line": record.lineno,
            "message": record.getMessage(),
            "request_id": request_id_var.get("-"),
        }
        if record.exc_info and record.exc_info[0] is not None:
            log_data["exception"] = self.formatException(record.exc_info)
        if hasattr(record, "extra_data"):
            log_data["extra"] = record.extra_data
        return json.dumps(log_data, ensure_ascii=False)


def get_logger(name: str) -> logging.Logger:
    from core.config import settings

    logger = logging.getLogger(name)
    if not logger.handlers:
        handler = logging.StreamHandler(sys.stdout)
        handler.setFormatter(JSONFormatter())
        logger.addHandler(handler)
        logger.setLevel(getattr(logging, settings.log_level, logging.INFO))
        logger.propagate = False
    return logger