from __future__ import unicode_literals, division, absolute_import

from flexget import plugin
from flexget.event import event
from flexget.plugins.filter.seen import FilterSeen


class FilterSeenInfoHash(FilterSeen):
    """Prevents the same torrent from being downloaded twice by remembering the infohash of all downloaded torrents."""
    schema = {
        'oneOf': [
            {'type': 'boolean'},
            {'type': 'string', 'enum': ['global', 'local']}
        ]
    }

    def __init__(self):
        # remember and filter by these fields
        self.fields = ['torrent_info_hash']
        self.keyword = 'seen_info_hash'

    @plugin.priority(180)
    def on_task_filter(self, task, config):
        # Return if we are disabled.
        if config is False:
            return
        # First make sure all the torrent_info_hash fields are in upper case
        for entry in task.entries:
            if isinstance(entry.get('torrent_info_hash'), basestring):
                entry['torrent_info_hash'] = entry['torrent_info_hash'].upper()
        FilterSeen.on_task_filter(self, task, config, remember_rejected=True)

    def on_task_modify(self, task, config):
        # Return if we are disabled.
        if config is False:
            return
        # Run the filter again after the torrent plugin has populated the infohash
        self.on_task_filter(task, config)
        # Make sure no duplicates were accepted this run
        accepted_infohashes = set()
        for entry in task.accepted:
            if 'torrent_info_hash' in entry:
                infohash = entry['torrent_info_hash']
                if infohash in accepted_infohashes:
                    entry.reject('Already accepted torrent with this infohash once for this task')
                else:
                    accepted_infohashes.add(infohash)


@event('plugin.register')
def register_plugin():
    plugin.register(FilterSeenInfoHash, 'seen_info_hash', builtin=True, api_ver=2)
