import os
import hashlib
from subprocess import call

from shiny import App, reactive, render, ui

from core.read_pdf import process_pdf, temp_dir

last_pdf_md5_preprocess_stage = None


def compute_hash(file_pth):
    with open(file_pth, 'rb') as file_to_check:
        # read contents of the file
        data = file_to_check.read()
        # pipe contents of the file through
        md5_returned = hashlib.md5(data).hexdigest()
    return md5_returned


def ui_card(title, *args):
    return (ui.div(
        {"class": "card mb-4"},
        ui.div(title, class_="card-header"),
        ui.div({"class": "card-body"}, *args),
    ), )


app_ui = ui.page_fluid(
    ui.h1("Document2Slide Demo"),
    ui_card(
        "Upload PDF",
        ui.input_file("input_pdf", "Choose a .pdf file to upload:", multiple=True),
        ui.output_text("upload_file_status", ),
    ),
    ui_card(
        "Preprocess",
        ui.p(
            ui.input_action_button("preprocess_action", "Preprocess file", class_="btn-primary"),
            ui.output_text("preprocess_result", ),
        ),
        ui.output_text("preprocess_status", ),
        ui.download_button("download_preprocessed", "Download preprocessed file"),
    ),
    ui_card(
        "Download the bullet points in Markdown format.",
        ui.download_button("download_bullet_point", "Download bullet point"),
    ),
    ui_card(
        "Download the beamer source code `.tex` of the slide",
        ui.download_button("download_beamer", "Download beamer source code"),
    ),
    ui_card(
        "Download the PDF of slide.",
        ui.download_button("download_slide", "Download slide generated"),
    ),
)


def server(input, output, session):

    @output
    @render.text
    def upload_file_status():
        file_infos = input.input_pdf()
        # print(file_infos) # [{'name': 'Poster.pdf', 'size': 598394, 'type': 'application/pdf', 'datapath': '/tmp/fileupload-2c21fv0a/tmpi91sy07h/0.pdf'}]
        if not file_infos:
            return "There is no file provided currently."
        elif file_infos[0]['type'] != 'application/pdf':
            return "the file you provide is not in PDF format, upload another one!"
        else:
            return "PDF file successfully uploaded!"

    @output
    @render.text
    def preprocess_status():
        global last_pdf_md5_preprocess_stage
        file_infos = input.input_pdf()

        file_md5 = compute_hash(file_infos[0]['datapath']) if file_infos else None

        if (file_infos is not None) and file_infos[0]['type'] == 'application/pdf' and (file_md5 != last_pdf_md5_preprocess_stage):
            return "Ready to preprocess the PDF!"
        elif file_md5 == last_pdf_md5_preprocess_stage:
            return "PDF already preprocessed! You can continue!"
        else:
            return "No PDF ready currently, please upload a PDF!"

    @output
    @render.text
    @reactive.event(input.preprocess_action)  # Take a dependency on the button
    async def preprocess_result():

        global last_pdf_md5_preprocess_stage

        file_infos = input.input_pdf()
        if (file_infos is not None) and file_infos[0]['type'] == 'application/pdf':

            file_name = file_infos[0]['name']
            original_pdf_pth = file_infos[0]['datapath']
            dir_name = os.path.dirname(original_pdf_pth)
            new_pdf_pth = os.path.join(dir_name, file_name)
            os.rename(original_pdf_pth, new_pdf_pth)
            file_infos[0]['datapath'] = new_pdf_pth

            file_md5 = compute_hash(file_infos[0]['datapath'])

            try:
                if file_md5 != last_pdf_md5_preprocess_stage:
                    process_pdf(pdf_pth=new_pdf_pth, file_name=file_name)
                    last_pdf_md5_preprocess_stage = file_md5
                    return "Process successfully!"
                else:
                    return "Already processed!!!"

            except:
                return "Something wrong happen, please switch to another file!"

        else:
            return "No PDF provided!"

    @session.download()
    def download_preprocessed():
        file_infos = input.input_pdf()
        file_name = file_infos[0]['name'][:-4]
        preprocessed_file_dir = os.path.join(temp_dir, file_name)
        if os.path.exists(preprocessed_file_dir):  # this dir exists
            args = ['zip', '-r', file_name + '.zip', './' + file_name]
            call(args, cwd=temp_dir)
            return str(os.path.join(temp_dir, file_name + '.zip'))


app = App(app_ui, server)