import re
import sys
import gzip
import urllib.request as request
import urllib.parse as parse
import urllib.error
import os.path

from bs4 import BeautifulSoup

import pirate.data

from io import BytesIO


parser_regex = r'"(magnet\:\?xt=[^"]*)|<td align="right">([^<]+)</td>'


def parse_category(printer, category):
    try:
        category = int(category)
    except ValueError:
        pass
    if category in pirate.data.categories.values():
        return category
    elif category in pirate.data.categories.keys():
        return pirate.data.categories[category]
    else:
        printer.print('Invalid category ignored', color='WARN')
        return 0


def parse_sort(printer, sort):
    try:
        sort = int(sort)
    except ValueError:
        pass
    if sort in pirate.data.sorts.values():
        return sort
    elif sort in pirate.data.sorts.keys():
        return pirate.data.sorts[sort]
    else:
        printer.print('Invalid sort ignored', color='WARN')
        return 99


# TODO: warn users when using a sort in a mode that doesn't accept sorts
# TODO: warn users when using search terms in a mode that doesn't accept search terms
# TODO: same with page parameter for top and top48h
# TODO: warn the user if trying to use a minor category with top48h
def build_request_path(page, category, sort, mode, terms):
    if mode == 'browse':
        if(category == 0):
            category = 100
        return '/browse/{}/{}/{}'.format(category, page, sort)
    elif mode == 'recent':
        # This is not a typo. There is no / between 48h and the category.
        path = '/top/48h'
        # only major categories can be used with this mode
        if(category == 0):
            return path + 'all'
        else:
            return path + str(category)
    elif mode == 'top':
        path = '/top/'
        if(category == 0):
            return path + 'all'
        else:
            return path + str(category)
    elif mode == 'search':
        query = urllib.parse.quote_plus(' '.join(terms))
        return '/search/{}/{}/{}/{}'.format(query, page, sort, category)
    else:
        raise Exception('Unknown mode.')


# this returns a list of dictionaries
def parse_page(html):
    soup = BeautifulSoup(html, 'html.parser')
    table = soup.find('table', id='searchResult')

    results = []
    no_results = re.search(r'No hits\. Try adding an asterisk in '
                           r'you search phrase\.', html)

    # check for a blocked mirror
    if not table and not no_results:
        # Contradiction - we found no results,
        # but the page didn't say there were no results.
        # The page is probably not actually the pirate bay,
        # so let's try another mirror
        raise IOError('Blocked mirror detected.')

    if no_results:
        return results

    # parse the rows one by one (skipping headings)
    for row in table('tr')[1:]:
        # grab info about the row
        id_ = row.find('a', class_='detLink')['href'].split('/')[2]
        seeds, leechers = [i.text for i in row('td')[-2:]]
        magnet = row.find(lambda tag:
                          tag.name == 'a' and
                          tag['href'].startswith('magnet'))['href']

        # parse descriptions separately
        description = row.find('font', class_='detDesc').text
        size = re.findall(r'(?<=Size )[0-9.]+\s[KMGT]*[i ]*B', description)[0].split()
        uploaded = re.findall(r'(?<=Uploaded ).+(?=\, Size)', description)[0]

        results.append({
            'magnet': magnet,
            'seeds': seeds,
            'leechers': leechers,
            'size': size,
            'uploaded': uploaded,
            'id': id_
        })

    return results


def remote(printer, pages, category, sort, mode, terms, mirror):
    res_l = []

    if pages < 1:
        raise ValueError('Please provide an integer greater than 0 '
                         'for the number of pages to fetch.')

    # Catch the Ctrl-C exception and exit cleanly
    try:
        for page in range(pages):
            path = build_request_path(page, category, sort, mode, terms)

            req = request.Request(mirror + path,
                                  headers=pirate.data.default_headers)
            req.add_header('Accept-encoding', 'gzip')
            f = request.urlopen(req, timeout=pirate.data.default_timeout)
            if f.info().get('Content-Encoding') == 'gzip':
                f = gzip.GzipFile(fileobj=BytesIO(f.read()))
            res = f.read().decode('utf-8')

            res_l += parse_page(res)

    except KeyboardInterrupt:
        printer.print('\nCancelled.')
        sys.exit(0)

    return res_l


def get_torrent(info_hash):
    url = 'http://torcache.net/torrent/{:X}.torrent'
    req = request.Request(url.format(info_hash),
                          headers=pirate.data.default_headers)
    req.add_header('Accept-encoding', 'gzip')

    torrent = request.urlopen(req, timeout=pirate.data.default_timeout)
    if torrent.info().get('Content-Encoding') == 'gzip':
        torrent = gzip.GzipFile(fileobj=BytesIO(torrent.read()))

    return torrent.read()


def save_torrents(printer, chosen_links, results, folder):
    for link in chosen_links:
        magnet = results[link]['magnet']
        name = re.search(r'dn=([^\&]*)', magnet)
        torrent_name = parse.unquote(name.group(1)).replace('+', ' ')
        info_hash = int(re.search(r'btih:([a-f0-9]{40})', magnet).group(1), 16)
        torrent_name = torrent_name.replace('/', '_').replace('\\', '_')
        file = os.path.join(folder, torrent_name + '.torrent')

        try:
            torrent = get_torrent(info_hash)
        except urllib.error.HTTPError:
            printer.print('There is no cached file for this torrent :(', color='ERROR')
        else:
            open(file, 'wb').write(torrent)
            printer.print('Saved {:X} in {}'.format(info_hash, file))


def save_magnets(printer, chosen_links, results, folder):
    for link in chosen_links:
        magnet = results[link]['magnet']
        name = re.search(r'dn=([^\&]*)', magnet)
        torrent_name = parse.unquote(name.group(1)).replace('+', ' ')
        info_hash = int(re.search(r'btih:([a-f0-9]{40})', magnet).group(1), 16)
        torrent_name = torrent_name.replace('/', '_').replace('\\', '_')
        file = os.path.join(folder,  torrent_name + '.magnet')

        printer.print('Saved {:X} in {}'.format(info_hash, file))
        with open(file, 'w') as f:
            f.write(magnet + '\n')