import os
from io import BytesIO

import tiktoken
from config.setting import ALLOWED_EXTENSIONS
from fastapi import HTTPException, UploadFile


def validate_all_files(*upload_files: UploadFile):
    for upload_file in upload_files:
        if not upload_file:
            continue

        _, ext = os.path.splitext(upload_file.filename.lower())

        if ext not in ALLOWED_EXTENSIONS:
            raise HTTPException(
                status_code=400,
                detail=(
                    f"파일 '{upload_file.filename}'은(는) 지원하지 않는 확장자입니다. "
                    f"허용된 확장자는 {', '.join(ALLOWED_EXTENSIONS)} 입니다."
                ),
            )


def token_counter(prompt: str, text: str) -> int:
    try:
        enc = tiktoken.get_encoding("cl100k_base")  # OpenAI 기반 tokenizer
        token_count = len(enc.encode(prompt + text))
    except Exception:
        token_count = len(prompt + text) // 4  # fallback: 대략적 추정
    return token_count


# ✅ UploadFile을 대신할 수 있는 간단한 래퍼 클래스
class SimpleUploadFile:
    def __init__(
        self,
        filename: str,
        content: bytes,
        content_type: str = "application/octet-stream",
    ):
        self.filename = filename
        self.file = BytesIO(content)
        self.content_type = content_type


# ✅ UploadFile 객체 복사 → SimpleUploadFile로 변환
def clone_upload_file(upload_file: UploadFile) -> SimpleUploadFile:
    file_bytes = upload_file.file.read()
    upload_file.file.seek(0)

    return SimpleUploadFile(
        filename=upload_file.filename,
        content=file_bytes,
        content_type=upload_file.content_type,
    )