#!/usr/bin/env python

###
# Copyright (c) 2002, Jeremiah Fincher
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###

"""
Handles "factoids," little tidbits of information held in a database and
available on demand via several commands.
"""

import plugins

import time
import getopt
import string
import os.path
from itertools import imap

import sqlite

import conf
import utils
import ircdb
import ircutils
import privmsgs
import callbacks

class Factoids(plugins.ChannelDBHandler, callbacks.Privmsg):
    def __init__(self):
        plugins.ChannelDBHandler.__init__(self)
        callbacks.Privmsg.__init__(self)

    def makeDb(self, filename):
        if os.path.exists(filename):
            return sqlite.connect(filename)
        db = sqlite.connect(filename)
        cursor = db.cursor()
        cursor.execute("""CREATE TABLE keys (
                          id INTEGER PRIMARY KEY,
                          key TEXT UNIQUE ON CONFLICT IGNORE,
                          locked BOOLEAN
                          )""")
        cursor.execute("""CREATE TABLE factoids (
                          id INTEGER PRIMARY KEY,
                          key_id INTEGER,
                          added_by TEXT,
                          added_at TIMESTAMP,
                          fact TEXT
                          )""")
        cursor.execute("""CREATE TRIGGER remove_factoids
                          BEFORE DELETE ON keys
                          BEGIN
                            DELETE FROM factoids WHERE key_id = old.id;
                          END
                       """)
        db.commit()
        return db

    def learn(self, irc, msg, args):
        """[<channel>] <key> as <value>

        Associates <key> with <value>.  <channel> is only necessary if the
        message isn't sent on the channel itself.
        """
        channel = privmsgs.getChannel(msg, args)
        try:
            i = args.index('as')
        except ValueError:
            raise callbacks.ArgumentError
        args.pop(i)
        key = ' '.join(args[:i])
        factoid = ' '.join(args[i:])
        db = self.getDb(channel)
        cursor = db.cursor()
        cursor.execute("SELECT id, locked FROM keys WHERE key LIKE %s", key)
        if cursor.rowcount == 0:
            cursor.execute("""INSERT INTO keys VALUES (NULL, %s, 0)""", key)
            db.commit()
            cursor.execute("SELECT id, locked FROM keys WHERE key LIKE %s",key)
        (id, locked) = imap(int, cursor.fetchone())
        capability = ircdb.makeChannelCapability(channel, 'factoids')
        if not locked:
            if not ircdb.checkCapability(msg.prefix, capability):
                irc.error(msg, conf.replyNoCapability % capability)
                return
            if ircdb.users.hasUser(msg.prefix):
                name = ircdb.users.getUser(msg.prefix).name
            else:
                name = msg.nick
            cursor.execute("""INSERT INTO factoids VALUES
                              (NULL, %s, %s, %s, %s)""",
                           id, name, int(time.time()), factoid)
            db.commit()
            irc.reply(msg, conf.replySuccess)
        else:
            irc.error(msg, 'That factoid is locked.')

    def whatis(self, irc, msg, args):
        """[<channel>] <key> [<number>]

        Looks up the value of <key> in the factoid database.  If given a
        number, will return only that exact factoid.  <channel> is only
        necessary if the message isn't sent in the channel itself.
        """
        channel = privmsgs.getChannel(msg, args)
        if args[-1].isdigit():
            number = args.pop()
        else:
            number = ''
        key = privmsgs.getArgs(args)
        if number:
            try:
                number = int(number)
            except ValueError:
                irc.error(msg, '%s is not a valid number.' % number)
                return
        else:
            number = 0
        db = self.getDb(channel)
        cursor = db.cursor()
        cursor.execute("""SELECT factoids.fact FROM factoids, keys WHERE
                          keys.key LIKE %s AND factoids.key_id=keys.id
                          ORDER BY factoids.id
                          LIMIT 20""", key)
        if cursor.rowcount == 0:
            irc.error(msg, 'No factoid matches that key.')
        else:
            if not number:
                factoids = []
                counter = 1
                for result in cursor.fetchall():
                    factoids.append('(#%s) %s' % (counter, result[0]))
                    counter += 1
                irc.reply(msg,'%r could be %s' % (key, ', or '.join(factoids)))
            else:
                try:
                    irc.reply(msg, cursor.fetchall()[number-1][0])
                except IndexError:
                    irc.error(msg, 'That\'s not a valid number for this key.')
                    return

    def lock(self, irc, msg, args):
        """[<channel>] <key>

        Locks the factoid(s) associated with <key> so that they cannot be
        removed or added to.  <channel> is only necessary if the message isn't
        sent in the channel itself.
        """
        channel = privmsgs.getChannel(msg, args)
        key = privmsgs.getArgs(args)
        db = self.getDb(channel)
        capability = ircdb.makeChannelCapability(channel, 'factoids')
        if ircdb.checkCapability(msg.prefix, capability):
            cursor = db.cursor()
            cursor.execute("UPDATE keys SET locked=1 WHERE key LIKE %s", key)
            db.commit()
            irc.reply(msg, conf.replySuccess)
        else:
            irc.error(msg, conf.replyNoCapability % capability)

    def unlock(self, irc, msg, args):
        """[<channel>] <key>

        Unlocks the factoid(s) associated with <key> so that they can be
        removed or added to.  <channel> is only necessary if the message isn't
        sent in the channel itself.
        """
        channel = privmsgs.getChannel(msg, args)
        key = privmsgs.getArgs(args)
        db = self.getDb(channel)
        capability = ircdb.makeChannelCapability(channel, 'factoids')
        if ircdb.checkCapability(msg.prefix, capability):
            cursor = db.cursor()
            cursor.execute("UPDATE keys SET locked=0 WHERE key LIKE %s", key)
            db.commit()
            irc.reply(msg, conf.replySuccess)
        else:
            irc.error(msg, conf.replyNoCapability % capability)

    def forget(self, irc, msg, args):
        """[<channel>] <key> [<number>|*]

        Removes the factoid <key> from the factoids database.  If there are
        more than one factoid with such a key, a number is necessary to
        determine which one should be removed.  A * can be used to remove all
        factoids associated with a key.  <channel> is only necessary if
        the message isn't sent in the channel itself.
        """
        channel = privmsgs.getChannel(msg, args)
        if args[-1].isdigit():
            number = int(args.pop())
            number -= 1
            if number < 0:
                irc.error(msg, 'Negative numbers aren\'t valid.')
                return
        elif args[-1] == '*':
            del args[-1]
            number = True
        else:
            number = None
        key = privmsgs.getArgs(args)
        db = self.getDb(channel)
        capability = ircdb.makeChannelCapability(channel, 'factoids')
        if ircdb.checkCapability(msg.prefix, capability):
            cursor = db.cursor()
            cursor.execute("""SELECT keys.id, factoids.id
                              FROM keys, factoids
                              WHERE key LIKE %s AND
                                    factoids.key_id=keys.id""", key)
            if cursor.rowcount == 0:
                irc.error(msg, 'There is no such factoid.')
            elif cursor.rowcount == 1 or number is True:
                (id, _) = cursor.fetchone()
                cursor.execute("""DELETE FROM factoids WHERE key_id=%s""", id)
                cursor.execute("""DELETE FROM keys WHERE key LIKE %s""", key)
                db.commit()
                irc.reply(msg, conf.replySuccess)
            else:
                if number is not None:
                    results = cursor.fetchall()
                    try:
                        (_, id) = results[number]
                    except IndexError:
                        irc.error(msg, 'Invalid factoid number.')
                        return
                    cursor.execute("DELETE FROM factoids WHERE id=%s", id)
                    db.commit()
                    irc.reply(msg, conf.replySuccess)
                else:
                    irc.error(msg, '%s factoids have that key.  ' \
                                   'Please specify which one to remove, ' \
                                   'or use * to designate all of them.' % \
                                   cursor.rowcount)
        else:
            irc.error(msg, conf.replyNoCapability % capability)

    def random(self, irc, msg, args):
        """[<channel>]

        Returns a random factoid from the database for <channel>.  <channel>
        is only necessary if the message isn't sent in the channel itself.
        """
        channel = privmsgs.getChannel(msg, args)
        db = self.getDb(channel)
        cursor = db.cursor()
        cursor.execute("""SELECT fact, key_id FROM factoids
                          ORDER BY random()
                          LIMIT 3""")
        if cursor.rowcount != 0:
            L = []
            for (factoid, id) in cursor.fetchall():
                cursor.execute("""SELECT key FROM keys WHERE id=%s""", id)
                (key,) = cursor.fetchone()
                L.append('"%s": %s' % (ircutils.bold(key), factoid))
            irc.reply(msg, '; '.join(L))
        else:
            irc.error(msg, 'I couldn\'t find a factoid.')

    def info(self, irc, msg, args):
        """[<channel>] <key>

        Gives information about the factoid(s) associated with <key>.
        <channel> is only necessary if the message isn't sent in the channel
        itself.
        """
        channel = privmsgs.getChannel(msg, args)
        key = privmsgs.getArgs(args)
        db = self.getDb(channel)
        cursor = db.cursor()
        cursor.execute("SELECT id, locked FROM keys WHERE key LIKE %s", key)
        if cursor.rowcount == 0:
            irc.error(msg, 'No factoid matches that key.')
            return
        (id, locked) = imap(int, cursor.fetchone())
        cursor.execute("""SELECT  added_by, added_at FROM factoids
                          WHERE key_id=%s
                          ORDER BY id""", id)
        factoids = cursor.fetchall()
        L = []
        counter = 0
        for (added_by, added_at) in factoids:
            counter += 1
            added_at = time.strftime(conf.humanTimestampFormat,
                                     time.localtime(int(added_at)))
            L.append('#%s was added by %s at %s' % (counter,added_by,added_at))
        factoids = '; '.join(L)
        s = 'Key %r is %s and has %s associated with it: %s' % \
            (key, locked and 'locked' or 'not locked',
             utils.nItems(counter, 'factoid'), factoids)
        irc.reply(msg, s)

    def change(self, irc, msg, args):
        """[<channel>] <key> <number> <regexp>

        Changes the factoid #<number> associated with <key> according to
        <regexp>.
        """
        channel = privmsgs.getChannel(msg, args)
        (key, number, regexp) = privmsgs.getArgs(args, required=3)
        try:
            replacer = utils.perlReToReplacer(regexp)
        except ValueError, e:
            irc.error(msg, 'Invalid regexp: %s' % e)
            return
        try:
            number = int(number)
            if number <= 0:
                raise ValueError
        except ValueError:
            irc.error(msg, 'Invalid key id.')
            return
        db = self.getDb(channel)
        cursor = db.cursor()
        cursor.execute("""SELECT factoids.id, factoids.fact
                          FROM keys, factoids
                          WHERE keys.key LIKE %s AND
                                keys.id=factoids.key_id""", key)
        if cursor.rowcount == 0:
            irc.error(msg, 'I couldn\'t find any key %r' % key)
            return
        elif cursor.rowcount < number:
            irc.error(msg, 'That\'s not a valid key id.')
            return
        (id, fact) = cursor.fetchall()[number-1]
        newfact = replacer(fact)
        cursor.execute("UPDATE factoids SET fact=%s WHERE id=%s", newfact, id)
        db.commit()
        irc.reply(msg, conf.replySuccess)

    _sqlTrans = string.maketrans('*?', '%_')
    def search(self, irc, msg, args):
        """[<channel>] [--{regexp,exact}=<value>] [<glob>]

        Searches the keyspace for keys matching <glob>.  If --regexp is given,
        it associated value is taken as a regexp and matched against the keys;
        if --exact is given, its associated value is taken as an exact string
        to match against the key.
        """
        channel = privmsgs.getChannel(msg, args)
        (optlist, rest) = getopt.getopt(args, '', ['regexp=', 'exact='])
        if not optlist and not rest:
            raise callbacks.ArgumentError
        criteria = []
        formats = []
        predicateName = 'p'
        db = self.getDb(channel)
        for (option, arg) in optlist:
            if option == '--exact':
                ### FIXME: no way to escape LIKE metacharacters in SQLite.
                criteria.append('key LIKE %s')
                formats.append('%' + arg + '%')
            elif option == '--regexp':
                criteria.append('%s(key)' % predicateName)
                try:
                    r = utils.perlReToPythonRe(arg)
                except ValueError, e:
                    irc.error(msg, 'Invalid regexp: %s' % e)
                    return
                def p(s, r=r):
                    return int(bool(r.search(s)))
                db.create_function(predicateName, 1, p)
                predicateName += 'p'
        for glob in rest:
            if '*' not in glob and '?' not in glob:
                glob = '*%s*' % glob
            criteria.append('key LIKE %s')
            formats.append(glob.translate(self._sqlTrans))
        cursor = db.cursor()
        sql = """SELECT key FROM keys WHERE %s""" % ' AND '.join(criteria)
        cursor.execute(sql, formats)
        if cursor.rowcount == 0:
            irc.reply(msg, 'No keys matched that query.')
        elif cursor.rowcount == 1:
            self.whatis(irc, msg, [cursor.fetchone()[0]])
        elif cursor.rowcount > 100:
            irc.reply(msg, 'More than 100 keys matched that query; '
                           'please narrow your query.')
        else:
            keys = [repr(t[0]) for t in cursor.fetchall()]
            s = utils.commaAndify(keys)
            irc.reply(msg, s)

        
Class = Factoids
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