import json
import logging
import time
from typing import Callable

from starlette.middleware.base import BaseHTTPMiddleware
from starlette.requests import Request
from starlette.responses import Response


def get_logger(name: str) -> logging.Logger:
    logger = logging.getLogger(name)
    if not logger.handlers:
        handler = logging.StreamHandler()
        handler.setFormatter(_JsonFormatter())
        logger.addHandler(handler)
        logger.propagate = False
    return logger


class _JsonFormatter(logging.Formatter):
    def format(self, record: logging.LogRecord) -> str:
        payload = {
            "time": self.formatTime(record, datefmt="%Y-%m-%dT%H:%M:%S"),
            "level": record.levelname,
            "logger": record.name,
            "message": record.getMessage(),
        }
        if record.exc_info:
            payload["exc_info"] = self.formatException(record.exc_info)
        # Merge any extra fields passed via `extra=`
        for key, value in record.__dict__.items():
            if key not in (
                "name", "msg", "args", "levelname", "levelno", "pathname",
                "filename", "module", "exc_info", "exc_text", "stack_info",
                "lineno", "funcName", "created", "msecs", "relativeCreated",
                "thread", "threadName", "processName", "process", "message",
                "taskName",
            ):
                payload[key] = value
        return json.dumps(payload, ensure_ascii=False)


class RequestLoggingMiddleware(BaseHTTPMiddleware):
    def __init__(self, app, logger: logging.Logger | None = None) -> None:
        super().__init__(app)
        self._logger = logger or get_logger("request")

    async def dispatch(self, request: Request, call_next: Callable) -> Response:
        start = time.perf_counter()
        response = await call_next(request)
        duration_ms = round((time.perf_counter() - start) * 1000, 1)
        self._logger.info(
            "request",
            extra={
                "method": request.method,
                "path": request.url.path,
                "status": response.status_code,
                "duration_ms": duration_ms,
            },
        )
        return response