#!/bin/env python3

# Copyright (c) 2016, Daniel Miranda <danielkza2@gmail.com>
# All rights reserved.

# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:

# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.

# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import os.path
import sys
import json
import argparse
import praw

def read_filters(fname):
    fp = None
    try:
        if fname == '-':
            fp = sys.stdin
        else:
            fp = open(fname, 'r')

        return set(line.rstrip('\n').lower() for line in fp.readlines())
    finally:
        if fp and fp != sys.stdin:
            fp.close()

def sync_filters(reddit, username, filters):
    response = reddit.request('GET',
                              '/api/filter/user/{}/f/all'.format(username))
    cur_filters = set(map(lambda sr: sr['name'].lower(),
                   response['data']['subreddits']))

    to_add = filters.difference(cur_filters)
    to_remove = cur_filters.difference(filters)

    for sub in sorted(to_add):
        print('+ ' + sub)
        reddit.request('PUT',
                       '/api/filter/user/{}/f/all/r/{}'.format(username, sub),
                       data={'model': json.dumps({'name': sub})})

    for sub in sorted(to_remove):
        print('- ' + sub)
        reddit.request('DELETE',
                       '/api/filter/user/{}/f/all/r/{}'.format(username, sub))

if __name__ == '__main__':
    args = argparse.ArgumentParser(description="Manage Reddit's /r/all filter")
    args.add_argument('--username', metavar='NAME', help='Reddit username')
    args.add_argument('--password', metavar='PASS', help='Reddit password')
    args.add_argument('--client-id', metavar='ID',
                      help='Reddit application client ID')
    args.add_argument('--client-secret', metavar='SECRET',
                      help='Reddit application client secret')
    args.add_argument('filter_file', metavar='FILE', nargs='?',
                      default='./reddit-filters.txt',
                      help=('File containing subreddits names, one per line, '
                            'to replace the list of filters with. Text case is '
                            'irrelevant'))
    args = args.parse_args()

    reddit = praw.Reddit(client_id=args.client_id,
                         client_secret=args.client_secret,
                         user_agent='filter manager by /u/danielkza',
                         username=args.username,
                         password=args.password)
    filters = read_filters(args.filter_file)

    sync_filters(reddit, args.username, filters)