import os
import subprocess as sp
import tempfile
from pathlib import Path
from fastapi import FastAPI
from fastapi import FastAPI, File, UploadFile
from fastapi.middleware.cors import CORSMiddleware
import shutil


app = FastAPI()

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["POST"],
    allow_headers=["*"],
)


def extract_text(pdf_file):
    """
    Generate a text rendering of a PDF file in the form of a list of lines.
    """
    args = ['pdftotext', '-layout', pdf_file, '-']
    cp = sp.run(
      args, stdout=sp.PIPE, stderr=sp.DEVNULL,
      check=True, text=True
    )
    return cp.stdout


def save_and_export(pdf_file: UploadFile):
    with tempfile.NamedTemporaryFile() as tmp_file:
        shutil.copyfileobj(pdf_file.file, tmp_file)
        resulting_text = extract_text(tmp_file.name)
    return resulting_text


@app.post('/extract_text')
async def app_extract_text(pdf_file: UploadFile) -> str:
    return save_and_export(pdf_file)


@app.get("/")
def read_root():
    return {"Hello": "World"}