from starlette.applications import Starlette
from starlette.responses import JSONResponse, PlainTextResponse
from starlette.routing import Route
from starlette.requests import Request
from starlette.middleware import Middleware
from starlette.middleware.cors import CORSMiddleware
import tempfile
import shutil
import os

import pymupdf4llm
from unstructured.partition.auto import partition
from unstructured.cleaners.core import clean
from chonkie import RecursiveChunker, RecursiveRules

recipe = RecursiveRules.from_dict({   
    "name": "default",
    "schema": "v1",
    "description": "Default recipe for plaintext documents in Korean",
    "language": "kr",
    "metadata": {
        "version": "0.1.0",
        "author": "Chonkie Team"
    },
    "recipe": {
        "delimiters": [".", "。", "!", "！", "?", "？", "\n"],
        "include_delim": "prev",
        "recursive_rules": {
            "levels": 
            [
            {
                "delimiters": [
                    "\n\n", 
                    "\n\r"
                ],
                "whitespace": False,
                "include_delim": "next"
            },
            {
                "delimiters": [
                    "\n",
                    "\r"
                ],
                "whitespace": False,
                "include_delim": "prev"
            },
            {
                "delimiters": [
                    ".",
                    "。",
                    "!",
                    "！",
                    "?",
                    "？"
                ],
                "whitespace": False,
                "include_delim": "prev"
            },
            {
                "delimiters": None,
                "whitespace": True,
                "include_delim": "prev"
            },
            {
                "delimiters": None,
                "whitespace": False,
                "include_delim": "prev"
            }
        ]
    }
    }
})
chunker = RecursiveChunker(rules=recipe)

# 문서 처리 함수
async def handle_file_upload(request: Request):
    form = await request.form()
    upload = form.get("file")

    if not upload or not upload.filename:
        return JSONResponse({"error": "파일을 업로드해주세요."}, status_code=400)

    filename = upload.filename
    ext = os.path.splitext(filename)[1].lower()

    # 임시 파일로 저장
    with tempfile.NamedTemporaryFile(delete=False, suffix=ext) as tmp:
        shutil.copyfileobj(upload.file, tmp)
        tmp_path = tmp.name

    try:
        if ext == ".pdf":
            # PDF 처리
            markdown_text = pymupdf4llm.to_markdown(tmp_path)
            chunks = chunker(markdown_text)
            return JSONResponse([chunk.text for chunk in chunks])
        else:
            # 비-PDF 문서 처리
            elements = partition(tmp_path)
            cleaned_text = clean(
                "\n".join([str(el) for el in elements]),
                dashes=True,
                trailing_punctuation=True,
            )
            chunks =chunker(cleaned_text)
            return JSONResponse([chunk.text for chunk in chunks])
    except Exception as e:
        return JSONResponse({"error": f"문서 처리 실패: {str(e)}"}, status_code=500)
    finally:
        os.unlink(tmp_path)

# 라우팅 설정
routes = [
    Route("/upload", handle_file_upload, methods=["POST"]),
]

# CORS 허용 (옵션)
middleware = [
    Middleware(CORSMiddleware, allow_origins=["*"], allow_methods=["*"], allow_headers=["*"]),
]

app = Starlette(debug=True, routes=routes, middleware=middleware)