"""
Twitter - access to Twitter through bot commands
Copyright (C) 2010  Brian S. Stephan

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

import oauth2 as oauth
import re
import thread
import time
import urlparse

import MySQLdb as mdb

from extlib import twitter

from Module import Module

class Twitter(Module):

    """Access Twitter via the bot as an authenticated client."""

    def __init__(self, irc, config):
        """Prepare for oauth stuff (but don't execute it yet)."""

        Module.__init__(self, irc, config)

        # setup regexes
        getstatuspattern = "^!twitter\s+getstatus(\s+nosource)?(\s+noid)?\s+(\S+)$"
        getuserstatuspattern = "^!twitter\s+getuserstatus(\s+nosource)?(\s+noid)?\s+(\S+)(\s+.*|$)"
        tweetpattern = "^!twitter\s+tweet\s+(.*)"
        gettokenpattern = "^!twitter\s+gettoken$"
        authpattern = "^!twitter\s+auth\s+(\S+)$"
        replytopattern = "^!twitter\s+replyto\s+(\S+)\s+(.*)"

        self.getstatusre = re.compile(getstatuspattern)
        self.getuserstatusre = re.compile(getuserstatuspattern)
        self.tweetre = re.compile(tweetpattern)
        self.gettokenre = re.compile(gettokenpattern)
        self.authre = re.compile(authpattern)
        self.replytore = re.compile(replytopattern)

        # prep oauth magic
        self.consumer_key = 'N2aSGxBP8t3cCgWyF1B2Aw'
        self.consumer_secret = '0aQPEV4K3MMpicfi2lDtCP5pvjsKaqIpfuWtsPzx8'

        self.request_token_url = "https://api.twitter.com/oauth/request_token"
        self.access_token_url = "https://api.twitter.com/oauth/access_token"
        self.authorize_url = "https://api.twitter.com/oauth/authorize"

        self.consumer = oauth.Consumer(self.consumer_key, self.consumer_secret)
        self.client = oauth.Client(self.consumer)

        # settings
        # force timeline check to wait 5 minutes (for channel joins and antispam)
        self.next_timeline_check = time.time() + 300

        # try getting the stored auth tokens and logging in
        (oauth_token, oauth_token_secret) = self._retrieve_stored_auth_tokens()
        if oauth_token is not None and oauth_token_secret is not None:
            self._log_in_to_twitter(oauth_token, oauth_token_secret)
            if self._verify_credentials():
                # self.twit is set

                # ugly, but the best place to track it. store the connection for later use
                self.connection = irc.server

                # print timeline stuff. this will set up the appropriate timer
                self._check_self_timeline()

                self.log.debug("Logged in to Twitter with saved token.")
            else:
                self.log.error("Could not log in to Twitter with saved token.")
                self.twit = twitter.Api()
        else:
            # create a default twitter API account, in case we never auth
            self.twit = twitter.Api()
        thread.start_new_thread(self.thread_do, ())

    def db_init(self):
        """Set up the settings table."""

        # init the table if it doesn't exist
        version = self.db_module_registered(self.__class__.__name__)
        if version == None or version < 1:
            db = self.get_db()
            # create tables
            try:
                version = 1
                cur = db.cursor(mdb.cursors.DictCursor)
                cur.execute("""
                    CREATE TABLE twitter_settings (
                        since_id BIGINT(20) UNSIGNED NOT NULL,
                        output_channel VARCHAR(64) NOT NULL,
                        oauth_token VARCHAR(256) DEFAULT NULL,
                        oauth_token_secret VARCHAR(256) DEFAULT NULL
                    ) ENGINE=InnoDB CHARACTER SET utf8 COLLATE utf8_bin
                    """)
                cur.execute("""INSERT INTO twitter_settings (since_id, output_channel) VALUES (0, '#dr.botzo')""")
                db.commit()
                self.db_register_module_version(self.__class__.__name__, version)
            except mdb.Error as e:
                db.rollback()
                self.log.error("database error trying to create tables")
                self.log.exception(e)
                raise
            finally: cur.close()

    def shutdown(self):
        """Deauth, and make the twitter API item inoperable."""

        Module.shutdown(self)
        self.twit.ClearCredentials()

    def do(self, connection, event, nick, userhost, what, admin_unlocked):
        """Attempt to do twitter things."""

        if self.getstatusre.search(what):
            return self.irc.reply(event, self.twitter_getstatus(connection, event, nick,
                                                                        userhost, what, admin_unlocked))
        elif self.getuserstatusre.search(what):
            return self.irc.reply(event, self.twitter_getuserstatus(connection, event, nick,
                                                                            userhost, what, admin_unlocked))
        elif self.tweetre.search(what):
            return self.irc.reply(event, self.twitter_tweet(connection, event, nick,
                                                                    userhost, what, admin_unlocked))
        elif self.replytore.search(what):
            return self.irc.reply(event, self.twitter_replyto(connection, event, nick,
                                                                      userhost, what, admin_unlocked))
        elif self.gettokenre.search(what):
            return self.irc.reply(event, self.twitter_gettoken(connection, event, nick,
                                                                       userhost, what, admin_unlocked))
        elif self.authre.search(what):
            return self.irc.reply(event, self.twitter_auth(connection, event, nick,
                                                                   userhost, what, admin_unlocked))

    def twitter_getstatus(self, connection, event, nick, userhost, what, admin_unlocked):
        """Get a status by tweet ID."""

        match = self.getstatusre.search(what)
        if match:
            print_source = True
            print_id = True
            if match.group(1):
                print_source = False
            if match.group(2):
                print_id = False
            status = match.group(3)
            try:
                tweet = self.twit.GetStatus(status)
                return self._return_tweet_or_retweet_text(tweet=tweet, print_source=print_source, print_id=print_id)
            except twitter.TwitterError as e:
                return "Couldn't obtain status: " + str(e)

    def twitter_getuserstatus(self, connection, event, nick, userhost, what, admin_unlocked):
        """Get a status for a user. Allows for getting one other than the most recent."""

        match = self.getuserstatusre.search(what)
        if match:
            print_source = True
            print_id = True
            if match.group(1):
                print_source = False
            if match.group(2):
                print_id = False
            user = match.group(3)
            index = match.group(4)

            try:
                if index:
                    index = int(index)
                    if index > 0:
                        index = 0
                else:
                    index = 0
            except ValueError as e:
                self.log.error("Couldn't convert index: " + str(e))
                index = 0

            count = (-1*index) + 1

            try:
                tweets = self.twit.GetUserTimeline(screen_name=user, count=count, include_rts=True)
                if tweets:
                    tweet = tweets[-1*index]
                    return self._return_tweet_or_retweet_text(tweet=tweet, print_source=print_source, print_id=print_id)
            except twitter.TwitterError as e:
                return "Couldn't obtain status: " + str(e)
            except ValueError as e:
                return "Couldn't obtain status: " + str(e)

    def twitter_tweet(self, connection, event, nick, userhost, what, admin_unlocked):
        """Tweet. Needs authentication."""

        match = self.tweetre.search(what)
        if match:
            tweet = match.group(1)
            if self._verify_credentials() is None:
                return "You must be authenticated to tweet."
            if admin_unlocked is False:
                return "Only admins can tweet."

            try:
                if self.twit.PostUpdates(tweet, continuation='\xe2\x80\xa6') is not None:
                    return "'{0:s}' tweeted.".format(tweet)
                else:
                    return "Unknown error sending tweet(s)."
            except twitter.TwitterError as e:
                return "Couldn't tweet: " + str(e)

    def twitter_replyto(self, connection, event, nick, userhost, what, admin_unlocked):
        """Reply to a tweet, in the twitter in_reply_to_status_id sense. Needs authentication."""

        match = self.replytore.search(what)
        if match:
            status_id = match.group(1)
            tweet = match.group(2)

            if self._verify_credentials() is None:
                return "You must be authenticated to tweet."
            if admin_unlocked is False:
                return "Only admins can tweet."

            replyee_tweet = self.twit.GetStatus(status_id)
            target = replyee_tweet.user.screen_name.encode('utf-8', 'ignore')

            try:
                reptweet = "@{0:s}: {1:s}".format(target, tweet)
                if self.twit.PostUpdate(reptweet, in_reply_to_status_id=status_id) is not None:
                    return "'{0:s}' tweeted.".format(tweet)
                else:
                    return "Unknown error sending tweet."
            except twitter.TwitterError as e:
                return "Couldn't tweet: " + str(e)

    def twitter_gettoken(self, connection, event, nick, userhost, what, admin_unlocked):
        """Get an oauth token, so that the user may authenticate the bot."""

        match = self.gettokenre.search(what)
        if match:
            # get request token
            resp, content = self.client.request(self.request_token_url, "GET")
            if resp['status'] != '200':
                raise Exception("Invalid response %s." % resp['status'])

            self.request_token = dict(urlparse.parse_qsl(content))

            # have the user auth
            return "Go to the following link in your browser: %s?oauth_token=%s and then send me the pin." % (self.authorize_url, self.request_token['oauth_token'])

    def twitter_auth(self, connection, event, nick, userhost, what, admin_unlocked):
        """Authenticate, given a PIN (following gettoken)."""

        match = self.authre.search(what)
        if match:
            if self._verify_credentials() is not None:
                return "The bot is already logged in!"

            authtoken = match.group(1)
            oauth_verifier = authtoken

            # request access token
            token = oauth.Token(self.request_token['oauth_token'], self.request_token['oauth_token_secret'])
            token.set_verifier(oauth_verifier)
            client = oauth.Client(self.consumer, token)

            resp, content = client.request(self.access_token_url, "POST")
            access_token = dict(urlparse.parse_qsl(content))
            self._log_in_to_twitter(access_token['oauth_token'], access_token['oauth_token_secret'])

            if self._verify_credentials() is not None:
                # ugly, but the best place to track it. store the connection for later use
                self.connection = connection

                # print timeline stuff. this will set up the appropriate timer
                self._check_self_timeline()

                return "The bot is now logged in."
            else:
                return "Could not log in with supplied credentials."

    def _verify_credentials(self):
        """Wrap the exceptions in the twitter client VerifyExceptions()."""

        try:
            return self.twit.VerifyCredentials()
        except Exception:
            return None

    def _log_in_to_twitter(self, oauth_token, oauth_token_secret):
        """Do the actual authentication against Twitter."""

        # create the twitter API object
        self.twit = twitter.Api(self.consumer_key, self.consumer_secret, oauth_token, oauth_token_secret)

        if self._verify_credentials() is not None:
            # save the auth token for later reuse
            self._persist_auth_tokens(oauth_token, oauth_token_secret)

    def thread_do(self):
        """Check the timeline."""

        while not self.is_shutdown:
            self._check_self_timeline()
            time.sleep(1)

    def _check_self_timeline(self):
        """Check my timeline, and if there are entries, print them to the channel."""

        if self.next_timeline_check < time.time():
            self.next_timeline_check = time.time() + 300

            if self._verify_credentials() is not None:
                # get the id of the last check we made
                since_id = self._get_last_since_id()
                output_channel = self._get_output_channel()

                if since_id is not None and output_channel != '':
                    # TODO: make this an option in the settings, just
                    # disabled in code for now
                    #tweets = self.twit.GetFriendsTimeline(since_id=since_id)
                    #tweets.reverse()
                    #for tweet in tweets:
                    #    tweet_text = self._return_tweet_or_retweet_text(tweet=tweet, print_source=True)
                    #    self.sendmsg(self.connection, output_channel.encode('utf-8', 'ignore'), tweet_text)
                    #
                    ## friends timeline printed, find the latest id
                    #new_since_id = self._get_latest_tweet_id(tweets, since_id)

                    tweets = self.twit.GetMentions(since_id=since_id)
                    tweets.reverse()
                    for tweet in tweets:
                        tweet_text = self._return_tweet_or_retweet_text(tweet=tweet, print_source=True)
                        self.sendmsg(self.connection, output_channel.encode('utf-8', 'ignore'), tweet_text)

                    # mentions printed, find the latest id
                    new_since_id = self._get_latest_tweet_id(tweets, new_since_id)

                    # set since_id
                    self._set_last_since_id(new_since_id)

    def _return_tweet_or_retweet_text(self, tweet, print_source=False, print_id=True):
        """
        Return a string of the author and text body of a status,
        accounting for whether or not the fetched status is a
        retweet.
        """

        reply = ""
        if tweet.retweeted_status:
            retweet = tweet.retweeted_status
            if print_source:
                reply = "@%s (RT @%s): %s" % (tweet.user.screen_name.encode('utf-8', 'ignore'),
                                              retweet.user.screen_name.encode('utf-8', 'ignore'),
                                              super(Twitter, self)._unencode_xml(retweet.text.encode('utf-8', 'ignore')))
            else:
                reply = "(RT @%s): %s" % (retweet.user.screen_name.encode('utf-8', 'ignore'),
                                          super(Twitter, self)._unencode_xml(retweet.text.encode('utf-8', 'ignore')))
        else:
            if print_source:
                reply = "@%s: %s" % (tweet.user.screen_name.encode('utf-8', 'ignore'),
                                     super(Twitter, self)._unencode_xml(tweet.text.encode('utf-8', 'ignore')))
            else:
                reply = "%s" % (super(Twitter, self)._unencode_xml(tweet.text.encode('utf-8', 'ignore')))

        if print_id:
            reply = reply + " [{0:d}]".format(tweet.id)

        return reply

    def _get_last_since_id(self):
        """Get the since_id out of the database."""

        db = self.get_db()
        try:
            cur = db.cursor(mdb.cursors.DictCursor)
            query = "SELECT since_id FROM twitter_settings"
            cur.execute(query)
            result = cur.fetchone()
            if result:
                return result['since_id']
        except mdb.Error as e:
            self.log.error("database error getting last since ID")
            self.log.exception(e)
            raise
        finally: cur.close()

    def _get_output_channel(self):
        """Get the output_channel out of the database."""

        db = self.get_db()
        try:
            cur = db.cursor(mdb.cursors.DictCursor)
            query = "SELECT output_channel FROM twitter_settings"
            cur.execute(query)
            result = cur.fetchone()
            if result:
                return result['output_channel']
        except mdb.Error as e:
            self.log.error("database error getting output channel")
            self.log.exception(e)
            raise
        finally: cur.close()

    def _set_last_since_id(self, since_id):
        """Set the since_id."""

        db = self.get_db()
        try:
            cur = db.cursor(mdb.cursors.DictCursor)
            statement = "UPDATE twitter_settings SET since_id = %s"
            cur.execute(statement, (since_id,))
            db.commit()
        except mdb.Error as e:
            self.log.error("database error saving last since ID")
            self.log.exception(e)
            raise
        finally: cur.close()

    def _get_latest_tweet_id(self, tweets, since_id):
        """Find the latest tweet id in the provided list, or the given since_id."""

        latest = since_id
        for tweet in tweets:
            if tweet.id > latest:
                latest = tweet.id

        return latest

    def _persist_auth_tokens(self, oauth_token, oauth_token_secret):
        """Save the auth tokens to the database, with the intent of reusing them."""

        db = self.get_db()
        try:
            cur = db.cursor(mdb.cursors.DictCursor)
            statement = "UPDATE twitter_settings SET oauth_token = %s, oauth_token_secret = %s"
            cur.execute(statement, (oauth_token, oauth_token_secret))
            db.commit()
        except mdb.Error as e:
            self.log.error("database error saving auth tokens")
            self.log.exception(e)
            raise
        finally: cur.close()

    def _retrieve_stored_auth_tokens(self):
        """Check the database for existing auth tokens, try reusing them."""

        db = self.get_db()
        try:
            cur = db.cursor(mdb.cursors.DictCursor)
            query = "SELECT oauth_token, oauth_token_secret FROM twitter_settings"
            cur.execute(query)
            result = cur.fetchone()
            if result:
                return (result['oauth_token'], result['oauth_token_secret'])
        except mdb.Error as e:
            self.log.error("database error retrieving auth tokens")
            self.log.exception(e)
            raise
        finally: cur.close()

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