import sys
import os
from datetime import datetime, timedelta
import pytz
import logging
import shutil
import pandas as pd
from models import TazDownloader, TazConfiguration
from exceptions import TazConfigurationError, TazDownloadError, TazDownloadFormatException

# Get directory
dir_path = os.path.dirname(os.path.realpath(__file__))


def main(config: dict):
    # Get german date for tomorrow
    tomorrow = (datetime.now(pytz.timezone('Europe/Berlin')) + timedelta(1)).strftime('%Y_%m_%d')

    # Define tmp/ folder
    tmp_folder = os.path.join(dir_path, 'tmp')

    # Set log level
    try:
        logging.getLogger().setLevel(config['log_level'].upper())
    except ValueError as e:
        logging.error(f"Could not set log level.\n    {e}")

    # Read download history from csv file
    try:
        df = pd.read_csv(os.path.join(dir_path, 'download_history.csv'), header=0)
    except FileNotFoundError:
        # In case, there isn't yet a csv file, create data frame with headers
        df = pd.DataFrame(
            columns=[
                'file',
                'download_timestamp',
            ]
        )

    # If the 'limit_requests' argument is specified, check whether tomorrow's newspaper has already been downloaded
    if config['limit_requests']:
        try:
            if any(df.file.str.contains(pat=tomorrow)):
                logging.info('Tomorrow\'s newspaper was already downloaded. Execution canceled.')
                sys.exit(0)
        except Exception as e:
            logging.error(f"Could not check whether tomorrow's newspaper has already been downloaded.\n    {e}")

    # Instantiate downloader object
    try:
        taz_dl = TazDownloader(config['id'], config['password'], config['download_format'])
    except TazDownloadFormatException as e:
        logging.error(e)
        sys.exit(1)

    try:
        # Get newspaper available for download
        newspaper_available = taz_dl.scrape_newspaper()

        # Remove outdated newspaper from download_history.csv
        df.drop([index for index, row in df.iterrows() if row.file not in newspaper_available], inplace=True)

        # Find newspaper which are not already downloaded
        newspaper_to_download = [n for n in newspaper_available if n not in df.file.values]
    except TazDownloadError as e:
        logging.error(e)
        sys.exit(1)

    # Download newspaper
    newspaper_downloaded = []
    for n in newspaper_to_download:
        try:
            if taz_dl.download_newspaper(n, tmp_folder):
                newspaper_downloaded.append(n)
        except Exception as e:
            logging.error(f"Could not download {n}\n    {e}")

    # Add downloaded newspaper to download_history.csv
    try:
        for n in newspaper_downloaded:
            df_tmp = pd.DataFrame(
                {
                    'file': [n],
                    'download_timestamp': [datetime.strftime(datetime.now(), '%Y-%m-%d %H:%M:%S')],
                }
            )
            df = df.append(df_tmp, ignore_index=True)
        df.sort_values(by='file', ascending=False, inplace=True)
        df.to_csv(os.path.join(dir_path, 'download_history.csv'), index=False)
    except Exception as e:
        logging.error(f"Could not update download_history.csv\n    {e}")

    # Move downloaded file to download folder
    newspaper_downloaded_string = "\n    ".join(newspaper_downloaded)
    if os.path.isdir(config['download_folder']):
        download_folder = \
            config['download_folder'] \
            if config['download_folder'].endswith(os.path.sep) \
            else config['download_folder'] + os.path.sep
        for n in newspaper_downloaded:
            try:
                shutil.move(os.path.join(tmp_folder, n), download_folder)
            except Exception as e:
                logging.error(f"Could not move {n} to download folder \"{download_folder}\"\n    {e}")
        if newspaper_downloaded:
            logging.info(f"Downloaded\n    {newspaper_downloaded_string}\n    to {config['download_folder']}")
    else:
        logging.error(f"{config['download_folder']} does not exists.\n    {newspaper_downloaded_string}"
                      f"\n    downloaded to {tmp_folder}")


if __name__ == '__main__':

    # Set up logging
    logging.basicConfig(
        filename=os.path.join(dir_path, 'tazPlease.log'),
        level=logging.ERROR,
        format='%(asctime)s - %(message)s'
    )

    # Load configuration
    try:
        configuration = TazConfiguration().get_config()
    except TazConfigurationError as tce:
        print(tce)
        sys.exit(1)
    except Exception as exception:
        print(exception)
        sys.exit(1)

    # Execute main function
    if configuration:
        main(configuration)