# api.py

import asyncio
import json  # JSON 파싱을 위해 추가

from fastapi import APIRouter, FastAPI, HTTPException, UploadFile
from fastapi.middleware.cors import CORSMiddleware
from routers import google_docai
from utils.config import (
    CORS_ALLOW_CREDENTIALS,
    CORS_ALLOW_HEADERS,
    CORS_ALLOW_METHODS,
    CORS_ALLOW_ORIGINS,
    DOCAI_LOCATION,
    DOCAI_PROJECT_ID,
    UPLOAD_DOCS_DIR,
)

# 유틸리티 함수 임포트 (기존 코드 유지)
from utils.file_utils import (
    create_essential_directories,
    create_key,
    save_uploaded_file,
)

app = FastAPI()

# CORS 설정 (기존 코드 유지)
app.add_middleware(
    CORSMiddleware,
    allow_origins=CORS_ALLOW_ORIGINS,
    allow_credentials=CORS_ALLOW_CREDENTIALS,
    allow_methods=CORS_ALLOW_METHODS,
    allow_headers=CORS_ALLOW_HEADERS,
)


# 애플리케이션 시작 시 실행될 함수 (기존 코드 유지)
@app.on_event("startup")
async def startup_event():
    print("Starting up...")
    create_essential_directories()
    print("Essential directories created.")


# --- Document AI 라우터 ---
doc_ai_router = APIRouter(
    prefix="/docai",
    tags=["DocumentAI"],
)


# Document AI 관련 설정값 (프로덕션에서는 환경 변수나 설정 파일에서 로드 권장)
# DOCAI_PROCESSOR_ID = "b838676d4e3b4758"  # 실제 사용자의 프로세서 ID
# KEC_DOCAI_PROCESSOR_ID = "94de4322c20d276f"


async def run_sync_in_threadpool(func, *args, **kwargs):
    """동기 함수를 별도의 스레드에서 실행하고 await 가능하게 만듭니다."""
    loop = asyncio.get_event_loop()
    if hasattr(asyncio, "to_thread"):  # Python 3.9+
        return await asyncio.to_thread(func, *args, **kwargs)
    else:  # Python < 3.9
        return await loop.run_in_executor(None, lambda: func(*args, **kwargs))


@doc_ai_router.post("/available-processors", summary="도면 OCR API")
async def handle_docai_upload(file: UploadFile, processor_id: str):
    """
    국토교통부 = "b838676d4e3b4758"\n
    도로공사 = "94de4322c20d276f"

    """
    if not file.content_type:
        raise HTTPException(status_code=400, detail="File content type is missing.")

    allowed_mime_types = ["application/pdf", "image/jpeg", "image/png", "image/tiff"]
    if file.content_type not in allowed_mime_types:
        raise HTTPException(
            status_code=400,
            detail=f"Unsupported file type: '{file.content_type}'. Supported: {', '.join(allowed_mime_types)}",
        )

    print(f"Received file: {file.filename}")
    file_id = str(create_key())

    try:
        file_path, file_content = save_uploaded_file(file, UPLOAD_DOCS_DIR, file_id)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"파일 저장 실패: {str(e)}")

    try:
        document_result = await run_sync_in_threadpool(
            google_docai.process_document_from_content,
            project_id=DOCAI_PROJECT_ID,
            location=DOCAI_LOCATION,
            processor_id=processor_id,
            file_content=file_content,
            mime_type=file.content_type,
            field_mask="text,entities",
        )

        if not document_result:
            raise HTTPException(status_code=500, detail="Document AI 처리 결과 없음.")

        json_output_string = google_docai.extract_and_convert_to_json(document_result)
        return json.loads(json_output_string)

    except HTTPException as http_exc:
        raise http_exc
    except Exception as e:
        raise HTTPException(
            status_code=500,
            detail=f"Document AI 처리 중 오류 발생: {str(e)}",
        )
    finally:
        await file.close()


# app에 라우터 등록
app.include_router(doc_ai_router)


@app.get("/health/API")
async def health_check():
    """애플리케이션 상태 확인"""
    return {"status": "API ok"}