"""Structured JSON logging configuration."""

import logging
import json
from datetime import datetime, timezone


class JSONFormatter(logging.Formatter):
    """Format log records as single-line JSON for structured log ingestion."""

    def format(self, record):
        log_data = {
            "timestamp": datetime.now(timezone.utc).isoformat(),
            "level": record.levelname,
            "logger": record.name,
            "message": record.getMessage(),
        }
        if hasattr(record, "project_id"):
            log_data["project_id"] = record.project_id
        if hasattr(record, "episode_id"):
            log_data["episode_id"] = record.episode_id
        if record.exc_info:
            log_data["exception"] = self.formatException(record.exc_info)
        return json.dumps(log_data, ensure_ascii=False)


def setup_logging():
    """Configure root logger with JSON formatter.

    Call once at application startup, before any other initialization.
    """
    handler = logging.StreamHandler()
    handler.setFormatter(JSONFormatter())
    logging.root.handlers = [handler]
    logging.root.setLevel(logging.INFO)