"""
API 에러 로깅 유틸리티 (JSONL 기록 + 로테이션 + 클라이언트 IP 추출)
"""
from __future__ import annotations

import os
import time
import json
import re
from typing import Dict, Any
from fastapi import Request


LOG_DIR = "logs"
os.makedirs(LOG_DIR, exist_ok=True)

API_ERROR_LOG_PATH = os.path.join(LOG_DIR, "api_errors.jsonl")
API_ERROR_MAX_BYTES = 10 * 1024 * 1024  # 10MB
API_ERROR_BACKUP_COUNT = 5


def _rotate_if_needed() -> None:
    try:
        if os.path.exists(API_ERROR_LOG_PATH) and os.path.getsize(API_ERROR_LOG_PATH) >= API_ERROR_MAX_BYTES:
            ts = time.strftime("%Y%m%d-%H%M%S")
            rotated_path = os.path.join(LOG_DIR, f"api_errors_{ts}.jsonl")
            os.replace(API_ERROR_LOG_PATH, rotated_path)

            rotated = [
                os.path.join(LOG_DIR, f) for f in os.listdir(LOG_DIR)
                if f.startswith("api_errors_") and f.endswith(".jsonl")
            ]
            rotated.sort(key=lambda p: os.path.getmtime(p), reverse=True)
            for old in rotated[API_ERROR_BACKUP_COUNT:]:
                try:
                    os.remove(old)
                except Exception:
                    pass
    except Exception:
        # 로테이션 실패는 치명적이지 않으므로 무시
        pass


def append_api_error_log(record: Dict[str, Any]) -> None:
    try:
        _rotate_if_needed()
        with open(API_ERROR_LOG_PATH, "a", encoding="utf-8") as f:
            f.write(json.dumps(record, ensure_ascii=False) + "\n")
    except Exception:
        pass


def extract_client_ip(request: Request) -> str:
    try:
        xff = request.headers.get("x-forwarded-for") or request.headers.get("X-Forwarded-For")
        if xff:
            first_ip = xff.split(",")[0].strip()
            if first_ip:
                return first_ip
        xri = request.headers.get("x-real-ip") or request.headers.get("X-Real-IP")
        if xri:
            return xri.strip()
        fwd = request.headers.get("forwarded") or request.headers.get("Forwarded")
        if fwd:
            m = re.search(r"for=([^;,\s]+)", fwd)
            if m:
                return m.group(1).strip('"')
        if request.client and request.client.host:
            return request.client.host
    except Exception:
        pass
    return ""


def get_content_length(request: Request) -> int:
    try:
        v = request.headers.get("content-length") or request.headers.get("Content-Length")
        if v is None:
            return 0
        return int(v)
    except Exception:
        return 0