import os
from pypdf import PdfReader, PdfWriter

import datetime as dt
import logging
import sys

# Setup Logging
logging.basicConfig(
    # level=logging.ERROR,
    # level=logging.INFO,
    level=logging.DEBUG,
    format=str(dt.datetime.now()).replace(" ", "_") + " | %(asctime)s [%(levelname)s] %(message)s",
    handlers=[
        logging.FileHandler("/var/log/" + str(dt.datetime.today().strftime('%Y-%m-%d')) + "_-_pdf_util.log"),
        logging.StreamHandler(sys.stdout)
    ]
)


class pdf_util:
    def __init__(self, file_path):
        self.file_path = file_path
        self.file_name = os.path.basename(file_path)
        self.file_name_wo_extension = os.path.splitext(os.path.basename(file_path))[0]

    def split_pdf_with_location(self, output_filepath, no_names=False, int_padding=False):
        out_filenames = []
        os.makedirs(os.path.dirname(output_filepath), exist_ok=True)
        with open(self.file_path, 'rb') as pdf_file:
            pdf_reader = PdfReader(pdf_file)
            num_pages = len(pdf_reader.pages)
            for page_num in range(num_pages):
                writer = PdfWriter()
                writer.add_page(pdf_reader.pages[page_num])

                str_page_num = str(page_num + 1)
                if int_padding:
                    str_page_num = str_page_num.zfill(4)

                if no_names:
                    out_filename = os.path.dirname(output_filepath) + '/' + str_page_num + '.pdf'
                else:
                    out_filename = os.path.dirname(output_filepath) + '/' + self.file_name_wo_extension + '_' + str_page_num + '.pdf'

                with open(out_filename, 'wb') as outfile:
                    writer.write(outfile)
                    out_filenames.append(out_filename)

        return out_filenames

    # Deprecate when pdf_project_manager takes effect
    def split_pdf(self, int_padding=False):
        os.makedirs(os.path.dirname(self.file_path) + "/split_pdf", exist_ok=True)
        return self.split_pdf_with_location(os.path.dirname(self.file_path) + "/split_pdf/", False, int_padding)

    def merge_pdf_with_and_location(self, merge_file_path, output_filepath):
        os.makedirs(os.path.dirname(output_filepath), exist_ok=True)
        pdf_reader_1 = PdfReader(self.file_path)
        pdf_reader_2 = PdfReader(merge_file_path)
        writer = PdfWriter()

        for page_num in range(len(pdf_reader_1.pages)):
            writer.add_page(pdf_reader_1.pages[page_num])

        for page_num in range(len(pdf_reader_2.pages)):
            writer.add_page(pdf_reader_2.pages[page_num])

        with open(output_filepath, 'wb') as outfile:
            writer.write(outfile)

        return output_filepath

    # Deprecate when pdf_project_manager takes effect
    def merge_pdf_with(self, merge_file_path, merged_name="merged"):
        os.makedirs(os.path.dirname(self.file_path) + "/merge_pdf", exist_ok=True)
        return self.merge_pdf_with_and_location(merge_file_path, os.path.dirname(self.file_path) + "/merge_pdf" + '/merger.pdf')