import logging

from rest_framework.views import exception_handler as drf_exception_handler

logger = logging.getLogger(__name__)


def _error_messages(details):
    messages = []

    def collect(value):
        if isinstance(value, dict):
            for item in value.values():
                collect(item)
        elif isinstance(value, (list, tuple)):
            for item in value:
                collect(item)
        elif value is not None:
            message = str(value).strip()
            if message and message not in messages:
                messages.append(message)

    collect(details)
    return messages


def _error_message(details):
    messages = _error_messages(details)
    if not messages:
        return "请求未能完成"
    return "；".join(messages)[:300]


def exception_handler(exc, context):
    response = drf_exception_handler(exc, context)
    request = context.get("request")
    if response is None:
        logger.exception(
            "api_unhandled_error method=%s path=%s",
            getattr(request, "method", "-"),
            getattr(request, "path", "-"),
        )
        return response

    details = response.data
    code = getattr(exc, "default_code", "request_error")
    message = _error_message(details)
    fields = ",".join(details.keys()) if isinstance(details, dict) else "-"
    logger.info(
        "api_request_error method=%s path=%s status=%s code=%s fields=%s message=%s",
        getattr(request, "method", "-"),
        getattr(request, "path", "-"),
        response.status_code,
        code,
        fields,
        message,
    )
    response.data = {
        "error": {
            "code": code,
            "message": message,
            "details": details,
            "request_id": getattr(request, "request_id", None),
        }
    }
    return response