import json
import logging
from datetime import datetime, timezone

_FIELDS = ("event", "monitor_id", "url", "outcome", "latency_ms", "http_status", "error")


class JsonFormatter(logging.Formatter):
    def format(self, record: logging.LogRecord) -> str:
        payload: dict[str, object] = {
            "timestamp": datetime.now(timezone.utc).isoformat(),
            "level": record.levelname,
            "logger": record.name,
            "message": record.getMessage(),
        }
        for field in _FIELDS:
            value = getattr(record, field, None)
            if value is not None:
                payload[field] = value
        if record.exc_info:
            payload["exception"] = self.formatException(record.exc_info)
        return json.dumps(payload, separators=(",", ":"), default=str)


def configure_logging(level: str) -> None:
    handler = logging.StreamHandler()
    handler.setFormatter(JsonFormatter())
    root = logging.getLogger()
    root.handlers.clear()
    root.addHandler(handler)
    root.setLevel(level)