from io import StringIO
import core.pipelines as pipelines_functions
from inspect import getmembers, isfunction, signature
from newspaper import Article
from PyPDF2 import PdfFileReader
import streamlit as st
import pandas as pd
import pytesseract
from PIL import Image


def get_pipelines():
    pipeline_names, pipeline_funcs = list(
        zip(*getmembers(pipelines_functions, isfunction))
    )
    pipeline_names = [
        " ".join([n.capitalize() for n in name.split("_")]) for name in pipeline_names
    ]
    pipeline_func_parameters = [
        {key: value.default for key, value in signature(pipe_func).parameters.items()}
        for pipe_func in pipeline_funcs
    ]
    return pipeline_names, pipeline_funcs, pipeline_func_parameters


@st.experimental_memo
def extract_text_from_url(url: str):
    article = Article(url)
    article.download()
    article.parse()

    return article.text


@st.experimental_memo
def extract_text_from_file(file):
    # read text file
    if file.type == "text/plain":
        # To convert to a string based IO:
        stringio = StringIO(file.getvalue().decode("utf-8"))

        # To read file as string:
        file_text = stringio.read()

        return file_text

    # read pdf file
    elif file.type == "application/pdf":
        pdfReader = PdfFileReader(file)
        count = pdfReader.numPages
        all_text = ""

        for i in range(count):
            try:
                page = pdfReader.getPage(i)
                all_text += page.extractText()
            except:
                continue
        file_text = all_text

        return file_text

    # read csv file
    elif file.type == "text/csv":
        csv = pd.read_csv(file)
        # get columns of type string
        string_columns = csv.select_dtypes(include=["object"]).columns
        # get data from columns and join it together
        file_text = ""
        for row in csv[string_columns].values.tolist():
            # remove NaNs
            row = [x for x in row if str(x) != "nan"]
            for column in row:
                txt = ""
                if isinstance(column, list):
                    try:
                        txt = " ".join(column)
                    except:
                        continue
                elif isinstance(column, str):
                    txt = column
                else:
                    continue
                file_text += " " + txt
        return file_text

    # read image file (OCR)
    elif file.type == "image/jpeg":
        return pytesseract.image_to_string(Image.open(file))

    else:
        st.warning(f"File type {file.type} not supported")
        return None