#!/usr/bin/env python

import getopt
import re
import simplejson
import sys
import time
import twitter
import urllib2
from getpass import getpass
from urllib import urlencode

def compile_filter(query):
    good = []
    bad = []
    words = query.split()
    for word in words:
        if word[0] == '-':
            bad.append(re.compile(word, re.IGNORECASE))
        else:
            good.append(re.compile(word, re.IGNORECASE))
    return (good, bad)

def filter_user_by_bio(user, filter, api=None):
    if api is None:
        api = twitter.Api()
    bio = api.GetUser(user).GetDescription()
    if bio is None:
        return False # We only follow those with bios
    good, bad = filter
    goodmatches = []
    for word in bad:
        if not word.search(bio) is None:
            return False
    for word in good:
        if not word.search(bio) is None:
            goodmatches.append(word)
    if good == goodmatches:
        return True
    return False

def follow_by_query(username, password, q, rpp=None, lang=None):
    filter = compile_filter(q)
    api = twitter.Api(username=username, password=password)
    friends = []
    for user in api.GetFriends():
        friends.append(user.GetScreenName())
    goodusers = []
    for user in get_users_from_search(q, rpp, lang):
        if filter_user_by_bio(user, filter, api):
            goodusers.append(user)
    newusers = []
    for user in goodusers:
        if not user in friends:
            api.CreateFriendship(user)
            friends.append(user)
            newusers.append(user)
    return newusers

def get_users_from_search(query, resultnum=None, lang=None):
    q = []
    rpp = 10
    q.append(urlencode({'q': query}))
    if not lang is None:
        q.append(urlencode({'lang': lang}))
    if not resultnum is None:
        rpp = resultnum
    q.append(urlencode({'rpp': rpp}))
    response = urllib2.urlopen(
        'http://search.twitter.com/search.json?',
        '&'.join(q)
    )
    data = simplejson.load(response)
    for result in data['results']:
        yield result['from_user'] 

def print_usage():
    sys.stderr.write("""
    Usage: %s -u username [-p password] [-r search_result_number] [-l language]
        terms ...

    -l language = Filter search by language.
    -p password = Optional.  If not supplied, you will be asked for it.
    -r search_result_number = Number of results to pull from twitter searches.
    -u username = twitter username.
""" % sys.argv[0])

if __name__ == '__main__':
    optlist, args = getopt.getopt(sys.argv[1:], 'l:p:r:u:')
    if not args:
        sys.stderr.write("You must specify search terms\n")
        print_usage()
        raise SystemExit, 1
    optd = dict(optlist)
    if not '-u' in optd:
        sys.stderr.write("You must specify a user\n")
        print_usage()
        raise SystemExit, 1
    username = optd['-u']
    query = " ".join(args)

    if not '-p' in optd:
        sys.stderr.write("Password:")
        password = getpass("")
    else:
        password = optd['-p']

    rpp = None
    if '-r' in optd:
        rpp = optd['-r']

    lang = None
    if '-l' in optd:
        lang = optd['-l']


    try:
        newusers = follow_by_query(username, password, query, rpp, lang)
    except urllib2.HTTPError, e:
        sys.stderr.write("Cannot connect to Twitter\n")
        sys.stderr.write(str(e))
        sys.stderr.write("\n")
    else:
        if newusers:
            print ", ".join(newusers), 'Added!'