from fastapi import APIRouter, File, UploadFile, Form, HTTPException
from fastapi.responses import FileResponse
from typing import Optional
import os
import shutil
import tempfile
import traceback
from ..services.pdf_generator import generate_school_pdf

router = APIRouter()

@router.post("/generate-list")
async def generate_list(
    institution: str = Form(...),
    date_info: str = Form(...),
    list_type: str = Form("k"),
    students_file: UploadFile = File(...),
    families_file: Optional[UploadFile] = File(None)
):
    try:
        with tempfile.TemporaryDirectory() as temp_dir:
            students_path = os.path.join(temp_dir, "students.csv")
            with open(students_path, "wb") as buffer:
                shutil.copyfileobj(students_file.file, buffer)
            families_path = None
            if families_file:
                families_path = os.path.join(temp_dir, "families.csv")
                with open(families_path, "wb") as buffer:
                    shutil.copyfileobj(families_file.file, buffer)
            print(f"Generating PDF for: {institution}, Type: {list_type}")
            pdf_path = generate_school_pdf(
                institution=institution,
                date_info=date_info,
                list_type=list_type,
                students_csv_path=students_path,
                families_csv_path=families_path,
                output_dir=temp_dir
            )
            if not pdf_path or not os.path.exists(pdf_path):
                raise HTTPException(status_code=500, detail="PDF generation failed - file not created.")
            with open(pdf_path, "rb") as f:
                pdf_bytes = f.read()
            final_output_path = os.path.join("/tmp", os.path.basename(pdf_path))
            with open(final_output_path, "wb") as f:
                f.write(pdf_bytes)
            return FileResponse(path=final_output_path, filename=os.path.basename(pdf_path), media_type="application/pdf")
    except Exception as e:
        print("ERROR IN GENERATE LIST:")
        traceback.print_exc()
        raise HTTPException(status_code=500, detail=f"Internal Server Error: {str(e)}")