#!/usr/bin/env python3

import sys
import os
import os.path
import glob
from hashlib import sha1
from io import BytesIO
from torrentool.api import Torrent

"""
'announce_urls', 'comment', 'create_from', 'created_by', 'creation_date', 'files', 'from_file', 'from_string',
'get_magnet', 'httpseeds', 'info_hash', 'magnet_link', 'name', 'private', 'to_file', 'to_string', 'total_size',
'webseeds']

"""

ARG_OPTIONS = {'short': False, 'files': False, 'existing': False, 'non-existing': False, 'validate': False}


def make_blob(buffer, fileinfo):
    if os.path.exists(fileinfo[0]):
        with open(fileinfo[0], 'rb') as datafd:
            num_written = buffer.write(datafd.read())
    else:
        num_written = buffer.write(b'\x00' * fileinfo[1])
    return num_written


def parse_torrent_file(torrentfile):
    buffer = BytesIO()

    torrent = Torrent.from_file(torrentfile)
    print('+- Torrent  : {}'.format(os.path.basename(torrentfile)))
    print('|  Title    : {}'.format(torrent.name))
    info_struct = torrent._struct.get('info')
    print('|  Piece Len: {:,} Bytes'.format(info_struct['piece length']))
    try:
        print('|  Size     : {:,} Bytes'.format(torrent.total_size))
    except:
        print('|  Size     : {}'.format('n/a'))
    if not ARG_OPTIONS['short']:
        print('|  Comment  : {}'.format(torrent.comment or 'n/a'))
        print('|  Created  : {}'.format(torrent.creation_date or 'n/a'))
        print('|  Hash     : {}'.format(torrent.info_hash))
        if torrent.comment:
            print('|  Comment  : {}'.format(torrent.comment))
        if len(torrent.httpseeds) > 0:
            print('|  httpseeds: {}'.format(torrent.httpseeds))
        if len(torrent.webseeds) > 0:
            print('|  webseeds : {}'.format(torrent.webseeds))
        if ARG_OPTIONS['files']:
            # TODO: move to separate print file detail method
            num_written = 0
            for index, fileinfo in enumerate(torrent.files):
                if ARG_OPTIONS['validate']:
                    num_written += make_blob(buffer, fileinfo)
                if ARG_OPTIONS['existing']:
                    if os.path.exists(fileinfo[0]):
                        print('|  FOUND   [{:4}] name = {} (size = {:,} Bytes)'.format(index, fileinfo[0], fileinfo[1]))
                elif ARG_OPTIONS['non-existing']:
                    print('|  MISSING [{:4}] name = {} (size = {:,} Bytes)'.format(index, fileinfo[0], fileinfo[1]))

            if ARG_OPTIONS['validate']:
                pieceshash = info_struct['pieces']
                buffer.seek(0)
                print('|  Validation:')
                chunk_size = info_struct['piece length']
                chunk = buffer.read(chunk_size)
                chunk_hashes = []
                while len(chunk) > 0:
                    hashcalc = sha1()
                    hashcalc.update(chunk)
                    chunk_hashes.append(hashcalc.digest())
                    chunk = buffer.read(chunk_size)

                out_wrap = 0
                completed = True
                sys.stdout.write('|  ')
                for digest in chunk_hashes:
                    out_wrap += 1
                    if digest in pieceshash:
                        sys.stdout.write('▒')
                    else:
                        completed = False
                        sys.stdout.write('░')
                    if not(out_wrap % 64):
                        sys.stdout.write('\n|  ')
                sys.stdout.write('\n')
                print('|  Completed: {}'.format(completed))


if __name__ == '__main__':
    try:
        for option in ARG_OPTIONS.keys():
            if '--' + option in sys.argv:
                ARG_OPTIONS[option] = not ARG_OPTIONS[option]
                sys.argv.remove('--' + option)
        if len(sys.argv) <= 1 or len(sys.argv) > 2:
            raise IndexError
        scan_path = sys.argv[-1]
        if os.name == 'nt':
            if not scan_path[-1] == '\\' and os.path.isdir(scan_path):
                scan_path += '\\'
                scan_path = scan_path.replace('\\', '\\')
        else:
            if not scan_path[-1] == '/' and os.path.isdir(scan_path):
                scan_path += '/'
    except IndexError:
        print('Not enough parameters.\n  Usage: {} [--short|--files] <directory|filename>'.format(sys.argv[0]))
        sys.exit(1)

    if os.path.isdir(scan_path):
        for index, torrentfile in enumerate(glob.glob(scan_path + '*.torrent')):
            parse_torrent_file(torrentfile)
        try:
            print('Found {} .torrent files.'.format(index+1))
        except NameError:
            print('No valid files found.')
            sys.exit(1)
    else:
        parse_torrent_file(scan_path)