#!/usr/bin/env python

import os
import sys
import logging
import argparse
import json

from re import sub
from random import shuffle, randint
from simpleconfigparser import simpleconfigparser
from datetime import datetime, timedelta

import praw
from praw.errors import InvalidUser, InvalidUserPass, RateLimitExceeded, \
                        HTTPException, OAuthAppRequired
from praw.objects import Comment, Submission

logging.basicConfig(stream=sys.stdout)
log = logging.getLogger(__name__)
log.setLevel(level=logging.WARNING)

try:
    from loremipsum import get_sentence  # This only works on Python 2
except ImportError:
    def get_sentence():
        return '''I have been Shreddited for privacy!'''
    os_wordlist = '/usr/share/dict/words'
    if os.name == 'posix' and os.path.isfile(os_wordlist):
        # Generate a random string of words from our system's dictionary
        fh = open(os_wordlist)
        words = fh.read().splitlines()
        fh.close()
        shuffle(words)

        def get_sentence():
            return ' '.join(words[:randint(50, 150)])

assert get_sentence

parser = argparse.ArgumentParser()
parser.add_argument(
    '-c',
    '--config',
    help="config file to use instead of the default shreddit.cfg"
)
args = parser.parse_args()

config = simpleconfigparser()
if args.config:
    config.read(args.config)
else:
    config.read('shreddit.cfg')

hours = config.getint('main', 'hours')
whitelist = config.get('main', 'whitelist')
whitelist_ids = config.get('main', 'whitelist_ids')
sort = config.get('main', 'sort')
verbose = config.getboolean('main', 'verbose')
clear_vote = config.getboolean('main', 'clear_vote')
trial_run = config.getboolean('main', 'trial_run')
edit_only = config.getboolean('main', 'edit_only')
item = config.get('main', 'item')
whitelist_distinguished = config.getboolean('main', 'whitelist_distinguished')
whitelist_gilded = config.getboolean('main', 'whitelist_gilded')
nuke_hours = config.getint('main', 'nuke_hours')
try:
    max_score = config.getint('main', 'max_score')
except ValueError:
    max_score = None
except TypeError:
    max_score = None
save_directory = config.get('main', 'save_directory')

_user = config.get('main', 'username')
_pass = config.get('main', 'password')

r = praw.Reddit(user_agent="shreddit/4.1")
if save_directory:
    r.config.store_json_result = True

if verbose:
    log.setLevel(level=logging.INFO)

try:
    # Try to login with OAuth2
    r.refresh_access_information()
    log.debug("Logged in with OAuth.")
except (HTTPException, OAuthAppRequired) as e:
    log.warning("You should migrate to OAuth2 using get_secret.py before \
            Reddit disables this login method.")
    try:
        try:
            r.login(_user, _pass)
        except InvalidUserPass:
            r.login()  # Supply details on the command line
    except InvalidUser as e:
        raise InvalidUser("User does not exist.", e)
    except InvalidUserPass as e:
        raise InvalidUserPass("Specified an incorrect password.", e)
    except RateLimitExceeded as e:
        raise RateLimitExceeded("You're doing that too much.", e)

log.info("Logged in as {user}.".format(user=r.user))
log.debug("Deleting messages before {time}.".format(
    time=datetime.now() - timedelta(hours=hours)))

whitelist = [y.strip().lower() for y in whitelist.split(',')]
whitelist_ids = [y.strip().lower() for y in whitelist_ids.split(',')]

if whitelist:
    log.debug("Keeping messages from subreddits {subs}".format(
        subs=', '.join(whitelist))
    )


def get_things(after=None):
    limit = None
    if item == "comments":
        return r.user.get_comments(limit=limit, sort=sort)
    elif item == "submitted":
        return r.user.get_submitted(limit=limit, sort=sort)
    elif item == "overview":
        return r.user.get_overview(limit=limit, sort=sort)
    else:
        raise Exception("Your deletion section is wrong")


def remove_things(things):
    for thing in things:
        # Seems to be in users's timezone. Unclear.
        thing_time = datetime.fromtimestamp(thing.created_utc)
        # Exclude items from being deleted unless past X hours.
        after_time = datetime.now() - timedelta(hours=hours)
        if thing_time > after_time:
            if thing_time + timedelta(hours=nuke_hours) < datetime.utcnow():
                pass
            continue
        # For edit_only we're assuming that the hours aren't altered.
        # This saves time when deleting (you don't edit already edited posts).
        if edit_only:
            end_time = after_time - timedelta(hours=hours)
            if thing_time < end_time:
                    continue

        if str(thing.subreddit).lower() in whitelist or \
           thing.id in whitelist_ids:
            continue

        if whitelist_distinguished and thing.distinguished:
            continue
        if whitelist_gilded and thing.gilded:
            continue
        if max_score is not None and thing.score > max_score:
            continue

        if trial_run:  # Don't do anything, trial mode!
            log.debug("Would have deleted {thing}: '{content}'".format(
                thing=thing.id, content=thing))
            continue

        if save_directory:
            if not os.path.exists(save_directory):
                os.makedirs(save_directory)
            with open("%s/%s.json" % (save_directory, thing.id), "w") as fh:
                json.dump(thing.json_dict, fh)

        if clear_vote:
            thing.clear_vote()

        if isinstance(thing, Submission):
            log.info('Deleting submission: #{id} {url}'.format(
                id=thing.id,
                url=thing.url.encode('utf-8'))
            )
        elif isinstance(thing, Comment):
            replacement_text = get_sentence()
            msg = '/r/{3}/ #{0} with:\n\t"{1}" to\n\t"{2}"'.format(
                thing.id,
                sub(b'\n\r\t', ' ', thing.body[:78].encode('utf-8')),
                replacement_text[:78],
                thing.subreddit
            )
            if edit_only:
                log.info('Editing (not removing) {msg}'.format(msg=msg))
            else:
                log.info('Editing and deleting {msg}'.format(msg=msg))

            thing.edit(replacement_text)
        if not edit_only:
            thing.delete()

remove_things(get_things())