#### PATTERN | DE | INFLECT ########################################################################
# -*- coding: utf-8 -*-
# Copyright (c) 2012 University of Antwerp, Belgium
# Author: Tom De Smedt <tom@organisms.be>
# License: BSD (see LICENSE.txt for details).

####################################################################################################
# Regular expressions-based rules for German word inflection:
# - pluralization and singularization of nouns and adjectives,
# - conjugation of verbs,
# - attributive and predicative of adjectives,
# - comparative and superlative of adjectives.

# Accuracy (measured on CELEX German morphology word forms):
# 75% for gender()
# 72% for pluralize()
# 84% for singularize() (for nominative)
# 87% for Verbs.find_lemma()
# 87% for Verbs.find_lexeme()
# 98% for predicative

import os
import sys
import re

try:
    MODULE = os.path.dirname(os.path.realpath(__file__))
except:
    MODULE = ""
    
sys.path.insert(0, os.path.join(MODULE, "..", "..", "..", ".."))

from pattern.text import Verbs as _Verbs
from pattern.text import (
    INFINITIVE, PRESENT, PAST, FUTURE,
    FIRST, SECOND, THIRD,
    SINGULAR, PLURAL, SG, PL,
    INDICATIVE, IMPERATIVE, SUBJUNCTIVE,
    PROGRESSIVE,
    PARTICIPLE, GERUND
)

sys.path.pop(0)

VERB, NOUN, ADJECTIVE, ADVERB = "VB", "NN", "JJ", "RB"

VOWELS = "aeiouy"
re_vowel = re.compile(r"a|e|i|o|u|y", re.I)
is_vowel = lambda ch: ch in VOWELS

#### ARTICLE #######################################################################################
# German inflection of depends on gender, role and number + the determiner (if any).

# Inflection gender.
# Masculine is the most common, so it is the default for all functions.
MASCULINE, FEMININE, NEUTER, PLURAL = \
    MALE, FEMALE, NEUTRAL, PLURAL = \
        M, F, N, PL = "m", "f", "n", "p"

# Inflection role.
# - nom = subject, "Der Hund bellt" (the dog barks).
# - acc = object, "Das Mädchen küsst den Hund" (the girl kisses the dog).
# - dat = object (indirect), "Der Mann gibt einen Knochen zum Hund" (the man gives the dog a bone).
# - gen = property, "die Knochen des Hundes" (the dog's bone).
NOMINATIVE, ACCUSATIVE, DATIVE, GENITIVE = SUBJECT, OBJECT, INDIRECT, PROPERTY = \
    "nominative", "accusative", "dative", "genitive"

article_definite = {
    ("m", "nom"): "der", ("f", "nom"): "die", ("n", "nom"): "das", ("p", "nom"): "die",
    ("m", "acc"): "den", ("f", "acc"): "die", ("n", "acc"): "das", ("p", "acc"): "die",
    ("m", "dat"): "dem", ("f", "dat"): "der", ("n", "dat"): "dem", ("p", "dat"): "den",
    ("m", "gen"): "des", ("f", "gen"): "der", ("n", "gen"): "des", ("p", "gen"): "der",
}

article_indefinite = {
    ("m", "nom"): "ein"  , ("f", "nom"): "eine" , ("n", "nom"): "ein"  , ("p", "nom"): "eine",
    ("m", "acc"): "einen", ("f", "acc"): "eine" , ("n", "acc"): "ein"  , ("p", "acc"): "eine",
    ("m", "dat"): "einem", ("f", "dat"): "einer", ("n", "dat"): "einem", ("p", "dat"): "einen",
    ("m", "gen"): "eines", ("f", "gen"): "einer", ("n", "gen"): "eines", ("p", "gen"): "einer",
}

def definite_article(word, gender=MALE, role=SUBJECT):
    """ Returns the definite article (der/die/das/die) for a given word.
    """
    return article_definite.get((gender[:1].lower(), role[:3].lower()))

def indefinite_article(word, gender=MALE, role=SUBJECT):
    """ Returns the indefinite article (ein) for a given word.
    """
    return article_indefinite.get((gender[:1].lower(), role[:3].lower()))

DEFINITE   = "definite"
INDEFINITE = "indefinite"

def article(word, function=INDEFINITE, gender=MALE, role=SUBJECT):
    """ Returns the indefinite (ein) or definite (der/die/das/die) article for the given word.
    """
    return function == DEFINITE \
       and definite_article(word, gender, role) \
        or indefinite_article(word, gender, role)
_article = article

def referenced(word, article=INDEFINITE, gender=MALE, role=SUBJECT):
    """ Returns a string with the article + the word.
    """
    return "%s %s" % (_article(word, article, gender, role), word)

#### GENDER #########################################################################################

gender_masculine = (
    "ant", "ast", "ich", "ig", "ismus", "ling", "or", "us"
)
gender_feminine = (
    "a", "anz", "ei", "enz", "heit", "ie", "ik", "in", "keit", "schaf", "sion", "sis", 
    u"tät", "tion", "ung", "ur"
)
gender_neuter = (
    "chen", "icht", "il", "it", "lein", "ma", "ment", "tel", "tum", "um","al", "an", "ar", 
    u"ät", "ent", "ett", "ier", "iv", "o", "on", "nis", "sal"
)
gender_majority_vote = {
    MASCULINE: (
        "ab", "af", "ag", "ak", "am", "an", "ar", "at", "au", "ch", "ck", "eb", "ef", "eg", 
        "el", "er", "es", "ex", "ff", "go", "hn", "hs", "ib", "if", "ig", "ir", "kt", "lf", 
        "li", "ll", "lm", "ls", "lt", "mi", "nd", "nk", "nn", "nt", "od", "of", "og", "or", 
        "pf", "ph", "pp", "ps", "rb", "rd", "rf", "rg", "ri", "rl", "rm", "rr", "rs", "rt", 
        "rz", "ss", "st", "tz", "ub", "uf", "ug", "uh", "un", "us", "ut", "xt", "zt"
    ), 
    FEMININE: (
        "be", "ce", "da", "de", "dt", "ee", "ei", "et", "eu", "fe", "ft", "ge", "he", "hr", 
        "ht", "ia", "ie", "ik", "in", "it", "iz", "ka", "ke", "la", "le", "me", "na", "ne", 
        "ng", "nz", "on", "pe", "ra", "re", "se", "ta", "te", "ue", "ur", "ve", "ze"
    ), 

    NEUTER: (
        "ad", "al", "as", "do", "ed", "eh", "em", "en", "hl", "id", "il", "im", "io", "is", 
        "iv", "ix", "ld", "lk", "lo", "lz", "ma", "md", "mm", "mt", "no", "ns", "ol", "om", 
        "op", "os", "ot", "pt", "rk", "rn", "ro", "to", "tt", "ul", "um", "uz"
    )
}

def gender(word, pos=NOUN):
    """ Returns the gender (MALE, FEMALE or NEUTRAL) for nouns (majority vote).
        Returns None for words that are not nouns.
    """
    w = word.lower()
    if pos == NOUN:
        # Default rules (baseline = 32%).
        if w.endswith(gender_masculine):
            return MASCULINE
        if w.endswith(gender_feminine):
            return FEMININE
        if w.endswith(gender_neuter):
            return NEUTER
        # Majority vote.
        for g in gender_majority_vote:
            if w.endswith(gender_majority_vote[g]):
                return g

#### PLURALIZE ######################################################################################

plural_inflections = [
    ("aal", u"äle"   ), ("aat",  "aaten"), ( "abe",  "aben" ), ("ach", u"ächer"), ("ade",  "aden"  ),
    ("age",  "agen"  ), ("ahn",  "ahnen"), ( "ahr",  "ahre" ), ("akt",  "akte" ), ("ale",  "alen"  ),
    ("ame",  "amen"  ), ("amt", u"ämter"), ( "ane",  "anen" ), ("ang", u"änge" ), ("ank", u"änke"  ),
    ("ann", u"änner" ), ("ant",  "anten"), ( "aph",  "aphen"), ("are",  "aren" ), ("arn",  "arne"  ),
    ("ase",  "asen"  ), ("ate",  "aten" ), ( "att", u"ätter"), ("atz", u"ätze" ), ("aum",  "äume"  ),
    ("aus", u"äuser" ), ("bad", u"bäder"), ( "bel",  "bel"  ), ("ben",  "ben"  ), ("ber",  "ber"   ),
    ("bot",  "bote"  ), ("che",  "chen" ), ( "chs",  "chse" ), ("cke",  "cken" ), ("del",  "del"   ),
    ("den",  "den"   ), ("der",  "der"  ), ( "ebe",  "ebe"  ), ("ede",  "eden" ), ("ehl",  "ehle"  ),
    ("ehr",  "ehr"   ), ("eil",  "eile" ), ( "eim",  "eime" ), ("eis",  "eise" ), ("eit",  "eit"   ),
    ("ekt",  "ekte"  ), ("eld",  "elder"), ( "ell",  "elle" ), ("ene",  "enen" ), ("enz",  "enzen" ),
    ("erd",  "erde"  ), ("ere",  "eren" ), ( "erk",  "erke" ), ("ern",  "erne" ), ("ert",  "erte"  ),
    ("ese",  "esen"  ), ("ess",  "esse" ), ( "est",  "este" ), ("etz",  "etze" ), ("eug",  "euge"  ),
    ("eur",  "eure"  ), ("fel",  "fel"  ), ( "fen",  "fen"  ), ("fer",  "fer"  ), ("ffe",  "ffen"  ),
    ("gel",  "gel"   ), ("gen",  "gen"  ), ( "ger",  "ger"  ), ("gie",  "gie"  ), ("hen",  "hen"   ),
    ("her",  "her"   ), ("hie",  "hien" ), ( "hle",  "hlen" ), ("hme",  "hmen" ), ("hne",  "hnen"  ),
    ("hof", u"höfe"  ), ("hre",  "hren" ), ( "hrt",  "hrten"), ("hse",  "hsen" ), ("hte",  "hten"  ),
    ("ich",  "iche"  ), ("ick",  "icke" ), ( "ide",  "iden" ), ("ieb",  "iebe" ), ("ief",  "iefe"  ),
    ("ieg",  "iege"  ), ("iel",  "iele" ), ( "ien",  "ium"  ), ("iet",  "iete" ), ("ife",  "ifen"  ),
    ("iff",  "iffe"  ), ("ift",  "iften"), ( "ige",  "igen" ), ("ika",  "ikum" ), ("ild",  "ilder" ),
    ("ilm",  "ilme"  ), ("ine",  "inen" ), ( "ing",  "inge" ), ("ion",  "ionen"), ("ise",  "isen"  ),
    ("iss",  "isse"  ), ("ist",  "isten"), ( "ite",  "iten" ), ("itt",  "itte" ), ("itz",  "itze"  ),
    ("ium",  "ium"   ), ("kel",  "kel"  ), ( "ken",  "ken"  ), ("ker",  "ker"  ), ("lag", u"läge"  ),
    ("lan", u"läne"  ), ("lar",  "lare" ), ( "lei",  "leien"), ("len",  "len"  ), ("ler",  "ler"   ),
    ("lge",  "lgen"  ), ("lie",  "lien" ), ( "lle",  "llen" ), ("mel",  "mel"  ), ("mer",  "mer"   ),
    ("mme",  "mmen"  ), ("mpe",  "mpen" ), ( "mpf",  "mpfe" ), ("mus",  "mus"  ), ("mut",  "mut"   ),
    ("nat",  "nate"  ), ("nde",  "nden" ), ( "nen",  "nen"  ), ("ner",  "ner"  ), ("nge",  "ngen"  ),
    ("nie",  "nien"  ), ("nis",  "nisse"), ( "nke",  "nken" ), ("nkt",  "nkte" ), ("nne",  "nnen"  ),
    ("nst",  "nste"  ), ("nte",  "nten" ), ( "nze",  "nzen" ), ("ock", u"öcke" ), ("ode",  "oden"  ),
    ("off",  "offe"  ), ("oge",  "ogen" ), ( "ohn", u"öhne" ), ("ohr",  "ohre" ), ("olz", u"ölzer" ),
    ("one",  "onen"  ), ("oot",  "oote" ), ( "opf", u"öpfe" ), ("ord",  "orde" ), ("orm",  "ormen" ),
    ("orn", u"örner" ), ("ose",  "osen" ), ( "ote",  "oten" ), ("pel",  "pel"  ), ("pen",  "pen"   ),
    ("per",  "per"   ), ("pie",  "pien" ), ( "ppe",  "ppen" ), ("rag", u"räge" ), ("rau", u"raün"  ),
    ("rbe",  "rben"  ), ("rde",  "rden" ), ( "rei",  "reien"), ("rer",  "rer"  ), ("rie",  "rien"  ),
    ("rin",  "rinnen"), ("rke",  "rken" ), ( "rot",  "rote" ), ("rre",  "rren" ), ("rte",  "rten"  ),
    ("ruf",  "rufe"  ), ("rzt",  "rzte" ), ( "sel",  "sel"  ), ("sen",  "sen"  ), ("ser",  "ser"   ),
    ("sie",  "sien"  ), ("sik",  "sik"  ), ( "sse",  "ssen" ), ("ste",  "sten" ), ("tag",  "tage"  ),
    ("tel",  "tel"   ), ("ten",  "ten"  ), ( "ter",  "ter"  ), ("tie",  "tien" ), ("tin",  "tinnen"),
    ("tiv",  "tive"  ), ("tor",  "toren"), ( "tte",  "tten" ), ("tum",  "tum"  ), ("tur",  "turen" ),
    ("tze",  "tzen"  ), ("ube",  "uben" ), ( "ude",  "uden" ), ("ufe",  "ufen" ), ("uge",  "ugen"  ),
    ("uhr",  "uhren" ), ("ule",  "ulen" ), ( "ume",  "umen" ), ("ung",  "ungen"), ("use",  "usen"  ),
    ("uss", u"üsse"  ), ("ute",  "uten" ), ( "utz",  "utz"  ), ("ver",  "ver"  ), ("weg",  "wege"  ),
    ("zer",  "zer"   ), ("zug", u"züge" ), (u"ück", u"ücke" )
]

def pluralize(word, pos=NOUN, gender=MALE, role=SUBJECT, custom={}):
    """ Returns the plural of a given word.
        The inflection is based on probability rather than gender and role.
    """
    w = word.lower().capitalize()
    if word in custom:
        return custom[word]
    if pos == NOUN:
        for a, b in plural_inflections:
            if w.endswith(a):
                return w[:-len(a)] + b
        # Default rules (baseline = 69%).
        if w.startswith("ge"):
            return w
        if w.endswith("gie"):
            return w
        if w.endswith("e"):
            return w + "n"
        if w.endswith("ien"):
            return w[:-2] + "um"
        if w.endswith(("au", "ein", "eit", "er", "en", "el", "chen", "mus", u"tät", "tik", "tum", "u")):
            return w
        if w.endswith(("ant", "ei", "enz", "ion", "ist", "or", "schaft", "tur", "ung")):
            return w + "en"
        if w.endswith("in"):
            return w + "nen"
        if w.endswith("nis"):
            return w + "se"
        if w.endswith(("eld", "ild", "ind")):
            return w + "er"
        if w.endswith("o"):
            return w + "s"
        if w.endswith("a"):
            return w[:-1] + "en"
        # Inflect common umlaut vowels: Kopf => Köpfe.
        if w.endswith(("all", "and", "ang", "ank", "atz", "auf", "ock", "opf", "uch", "uss")):
            umlaut = w[-3]
            umlaut = umlaut.replace("a", u"ä")
            umlaut = umlaut.replace("o", u"ö")
            umlaut = umlaut.replace("u", u"ü")
            return w[:-3] + umlaut + w[-2:] + "e"
        for a, b in (
          ("ag",  u"äge"), 
          ("ann", u"änner"), 
          ("aum", u"äume"), 
          ("aus", u"äuser"), 
          ("zug", u"züge")):
            if w.endswith(a):
                return w[:-len(a)] + b
        return w + "e"
    return w

#### SINGULARIZE ###################################################################################

singular_inflections = [
    ( "innen", "in" ), (u"täten", u"tät"), ( "ahnen",  "ahn"), ( "enten", "ent"), (u"räser",  "ras"),
    ( "hrten", "hrt"), (u"ücher",  "uch"), (u"örner",  "orn"), (u"änder", "and"), (u"ürmer",  "urm"),
    ( "ahlen", "ahl"), ( "uhren",  "uhr"), (u"ätter",  "att"), ( "suren", "sur"), ( "chten",  "cht"),
    ( "kuren", "kur"), ( "erzen",  "erz"), (u"güter",  "gut"), ( "soren", "sor"), (u"änner",  "ann"),
    (u"äuser", "aus"), ( "taten",  "tat"), ( "isten",  "ist"), (u"bäder", "bad"), (u"ämter",  "amt"),
    ( "eiten", "eit"), ( "raten",  "rat"), ( "ormen",  "orm"), ( "ionen", "ion"), ( "nisse",  "nis"),
    (u"ölzer", "olz"), ( "ungen",  "ung"), (u"läser",  "las"), (u"ächer", "ach"), ( "urten",  "urt"),
    ( "enzen", "enz"), ( "aaten",  "aat"), ( "aphen",  "aph"), (u"öcher", "och"), (u"türen", u"tür"),
    ( "sonen", "son"), (u"ühren", u"ühr"), (u"ühner",  "uhn"), ( "toren", "tor"), (u"örter",  "ort"),
    ( "anten", "ant"), (u"räder",  "rad"), ( "turen",  "tur"), (u"äuler", "aul"), ( u"änze",  "anz"),
    (  "tten", "tte"), (  "mben",  "mbe"), ( u"ädte",  "adt"), (  "llen", "lle"), (  "ysen",  "yse"),
    (  "rben", "rbe"), (  "hsen",  "hse"), ( u"raün",  "rau"), (  "rven", "rve"), (  "rken",  "rke"),
    ( u"ünge", "ung"), ( u"üten", u"üte"), (  "usen",  "use"), (  "tien", "tie"), ( u"läne",  "lan"),
    (  "iben", "ibe"), (  "ifen",  "ife"), (  "ssen",  "sse"), (  "gien", "gie"), (  "eten",  "ete"),
    (  "rden", "rde"), ( u"öhne",  "ohn"), ( u"ärte",  "art"), (  "ncen", "nce"), ( u"ünde",  "und"),
    (  "uben", "ube"), (  "lben",  "lbe"), ( u"üsse",  "uss"), (  "agen", "age"), ( u"räge",  "rag"),
    (  "ogen", "oge"), (  "anen",  "ane"), (  "sken",  "ske"), (  "eden", "ede"), ( u"össe",  "oss"),
    ( u"ürme", "urm"), (  "ggen",  "gge"), ( u"üren", u"üre"), (  "nten", "nte"), ( u"ühle", u"ühl"),
    ( u"änge", "ang"), (  "mmen",  "mme"), (  "igen",  "ige"), (  "nken", "nke"), ( u"äcke",  "ack"),
    (  "oden", "ode"), (  "oben",  "obe"), ( u"ähne",  "ahn"), ( u"änke", "ank"), (  "inen",  "ine"),
    (  "seen", "see"), ( u"äfte",  "aft"), (  "ulen",  "ule"), ( u"äste", "ast"), (  "hren",  "hre"),
    ( u"öcke", "ock"), (  "aben",  "abe"), ( u"öpfe",  "opf"), (  "ugen", "uge"), (  "lien",  "lie"),
    ( u"ände", "and"), ( u"ücke", u"ück"), (  "asen",  "ase"), (  "aden", "ade"), (  "dien",  "die"),
    (  "aren", "are"), (  "tzen",  "tze"), ( u"züge",  "zug"), ( u"üfte", "uft"), (  "hien",  "hie"),
    (  "nden", "nde"), ( u"älle",  "all"), (  "hmen",  "hme"), (  "ffen", "ffe"), (  "rmen",  "rma"),
    (  "olen", "ole"), (  "sten",  "ste"), (  "amen",  "ame"), ( u"höfe", "hof"), ( u"üste",  "ust"),
    (  "hnen", "hne"), ( u"ähte",  "aht"), (  "umen",  "ume"), (  "nnen", "nne"), (  "alen",  "ale"),
    (  "mpen", "mpe"), (  "mien",  "mie"), (  "rten",  "rte"), (  "rien", "rie"), ( u"äute",  "aut"),
    (  "uden", "ude"), (  "lgen",  "lge"), (  "ngen",  "nge"), (  "iden", "ide"), ( u"ässe",  "ass"),
    (  "osen", "ose"), (  "lken",  "lke"), (  "eren",  "ere"), ( u"üche", "uch"), ( u"lüge",  "lug"),
    (  "hlen", "hle"), (  "isen",  "ise"), ( u"ären", u"äre"), ( u"töne", "ton"), (  "onen",  "one"),
    (  "rnen", "rne"), ( u"üsen", u"üse"), ( u"haün",  "hau"), (  "pien", "pie"), (  "ihen",  "ihe"),
    ( u"ürfe", "urf"), (  "esen",  "ese"), ( u"ätze",  "atz"), (  "sien", "sie"), ( u"läge",  "lag"),
    (  "iven", "ive"), ( u"ämme",  "amm"), ( u"äufe",  "auf"), (  "ppen", "ppe"), (  "enen",  "ene"),
    (  "lfen", "lfe"), ( u"äume",  "aum"), (  "nien",  "nie"), (  "unen", "une"), (  "cken",  "cke"),
    (  "oten", "ote"), (   "mie",  "mie"), (   "rie",  "rie"), (   "sis", "sen"), (   "rin",  "rin"),
    (   "ein", "ein"), (   "age",  "age"), (   "ern",  "ern"), (   "ber", "ber"), (   "ion",  "ion"),
    (   "inn", "inn"), (   "ben",  "ben"), (  u"äse", u"äse"), (   "eis", "eis"), (   "hme",  "hme"),
    (   "iss", "iss"), (   "hen",  "hen"), (   "fer",  "fer"), (   "gie", "gie"), (   "fen",  "fen"),
    (   "her", "her"), (   "ker",  "ker"), (   "nie",  "nie"), (   "mer", "mer"), (   "ler",  "ler"),
    (   "men", "men"), (   "ass",  "ass"), (   "ner",  "ner"), (   "per", "per"), (   "rer",  "rer"),
    (   "mus", "mus"), (   "abe",  "abe"), (   "ter",  "ter"), (   "ser", "ser"), (  u"äle",  "aal"),
    (   "hie", "hie"), (   "ger",  "ger"), (   "tus",  "tus"), (   "gen", "gen"), (   "ier",  "ier"),
    (   "ver", "ver"), (   "zer",  "zer"),
]

singular = {
    u"Löwen": u"Löwe",
}

def singularize(word, pos=NOUN, gender=MALE, role=SUBJECT, custom={}):
    """ Returns the singular of a given word.
        The inflection is based on probability rather than gender and role.
    """
    w = word.lower().capitalize()
    if word in custom:
        return custom[word]
    if word in singular:
        return singular[word]
    if pos == NOUN:
        for a, b in singular_inflections:
            if w.endswith(a):
                return w[:-len(a)] + b
        # Default rule: strip known plural suffixes (baseline = 51%).
        for suffix in ("nen", "en", "n", "e", "er", "s"):
            if w.endswith(suffix):
                w = w[:-len(suffix)]
                break
        # Corrections (these add about 1% accuracy):
        if w.endswith(("rr", "rv", "nz")):
            return w + "e"
        return w
    return w

#### VERB CONJUGATION ##############################################################################
# The verb table was trained on CELEX and contains the top 2000 most frequent verbs.

prefix_inseparable = (
    "be", "emp", "ent", "er", "ge", "miss", u"über", "unter", "ver", "voll", "wider", "zer"
)
prefix_separable = (
    "ab", "an", "auf", "aus", "bei", "durch", "ein", "fort", "mit", "nach", "vor", "weg", 
    u"zurück", "zusammen", "zu", "dabei", "daran", "da", "empor", "entgegen", "entlang", 
    "fehl", "fest", u"gegenüber", "gleich", "herab", "heran", "herauf", "heraus", "herum", 
    "her", "hinweg", "hinzu", "hin", "los", "nieder", "statt", "umher", "um", "weg", 
    "weiter", "wieder", "zwischen"
) + ( # There are many more...
     "dort", "fertig", "frei", "gut", "heim", "hoch", "klein", "klar", "nahe", "offen", "richtig"
)
prefixes = prefix_inseparable + prefix_separable

def encode_sz(s):
    return s.replace(u"ß", "ss")
def decode_sz(s):
    return s.replace("ss", u"ß")

class Verbs(_Verbs):
    
    def __init__(self):
        _Verbs.__init__(self, os.path.join(MODULE, "de-verbs.txt"),
            language = "de",
              format = [0, 1, 2, 3, 4, 5, 8, 17, 18, 19, 20, 21, 24, 52, 54, 53, 55, 56, 58, 59, 67, 68, 70, 71],
             default = {6: 4, 22: 20, 57: 55, 60: 58, 69: 67, 72: 70}
            )
    
    def find_lemma(self, verb):
        """ Returns the base form of the given inflected verb, using a rule-based approach.
        """
        v = verb.lower()
        # Common prefixes: be-finden and emp-finden probably inflect like finden.
        if not (v.startswith("ge") and v.endswith("t")): # Probably gerund.
            for prefix in prefixes:
                if v.startswith(prefix) and v[len(prefix):] in self.inflections:
                    return prefix + self.inflections[v[len(prefix):]]
        # Common sufixes: setze nieder => niedersetzen.
        b, suffix = " " in v and v.split()[:2] or  (v, "")
        # Infinitive -ln: trommeln.
        if b.endswith(("ln", "rn")):
            return b
        # Lemmatize regular inflections.
        for x in ("test", "est", "end", "ten", "tet", "en", "et", "te", "st", "e", "t"):
            if b.endswith(x): b = b[:-len(x)]; break
        # Subjunctive: hielte => halten, schnitte => schneiden.
        for x, y in (
          ("ieb",  "eib"), ( "ied", "eid"), ( "ief",  "auf" ), ( "ieg", "eig" ), ("iel", "alt"), 
          ("ien",  "ein"), ("iess", "ass"), (u"ieß", u"aß"  ), ( "iff", "eif" ), ("iss", "eiss"), 
          (u"iß", u"eiß"), (  "it", "eid"), ( "oss",  "iess"), (u"öss", "iess")):
            if b.endswith(x): b = b[:-len(x)] + y; break
        b = b.replace("eeiss", "eiss")
        b = b.replace("eeid", "eit")
        # Subjunctive: wechselte => wechseln
        if not b.endswith(("e", "l")) and not (b.endswith("er") and len(b) >= 3 and not b[-3] in VOWELS):
            b = b + "e"
        # abknallst != abknalln => abknallen
        if b.endswith(("hl", "ll", "ul", "eil")):
            b = b + "e"
        # Strip ge- from (likely) gerund:
        if b.startswith("ge") and v.endswith("t"):
            b = b[2:]
        # Corrections (these add about 1.5% accuracy):
        if b.endswith(("lnde", "rnde")):
            b = b[:-3]
        if b.endswith(("ae", "al", u"öe", u"üe")):
            b = b.rstrip("e") + "te"
        if b.endswith(u"äl"):
            b = b + "e"
        return suffix + b + "n"

    def find_lexeme(self, verb):
        """ For a regular verb (base form), returns the forms using a rule-based approach.
        """
        v = verb.lower()
        # Stem = infinitive minus -en, -ln, -rn.
        b = b0 = re.sub("en$", "", re.sub("ln$", "l", re.sub("rn$", "r", v)))
        # Split common prefixes.
        x, x1, x2 = "", "", ""
        for prefix in prefix_separable:
            if v.startswith(prefix):
                b, x = b[len(prefix):], prefix
                x1 = (" " + x).rstrip()
                x2 = x + "ge"
                break
        # Present tense 1sg and subjunctive -el: handeln => ich handle, du handlest.
        pl = b.endswith("el") and b[:-2]+"l" or b
        # Present tense 1pl -el: handeln => wir handeln
        pw = v.endswith(("ln", "rn")) and v or b+"en"
        # Present tense ending in -d or -t gets -e:
        pr = b.endswith(("d", "t")) and b+"e" or b
        # Present tense 2sg gets -st, unless stem ends with -s or -z.
        p2 = pr.endswith(("s","z")) and pr+"t" or pr+"st"
        # Present participle: spiel + -end, arbeiten + -d:
        pp = v.endswith(("en", "ln", "rn")) and v+"d" or v+"end"
        # Past tense regular:
        pt = encode_sz(pr) + "t"
        # Past participle: haushalten => hausgehalten
        ge = (v.startswith(prefix_inseparable) or b.endswith(("r","t"))) and pt or "ge"+pt
        ge = x and x+"ge"+pt or ge
        # Present subjunctive: stem + -e, -est, -en, -et:
        s1 = encode_sz(pl)
        # Past subjunctive: past (usually with Umlaut) + -e, -est, -en, -et:
        s2 = encode_sz(pt)
        # Construct the lexeme:
        lexeme = a = [
            v, 
            pl+"e"+x1, p2+x1, pr+"t"+x1, pw+x1, pr+"t"+x1, pp,             # present
            pt+"e"+x1, pt+"est"+x1, pt+"e"+x1, pt+"en"+x1, pt+"et"+x1, ge, # past
            b+"e"+x1, pr+"t"+x1, x+pw,                                     # imperative
            s1+"e"+x1, s1+"est"+x1, s1+"en"+x1, s1+"et"+x1,                # subjunctive I
            s2+"e"+x1, s2+"est"+x1, s2+"en"+x1, s2+"et"+x1                 # subjunctive II
        ]
        # Encode Eszett (ß) and attempt to retrieve from the lexicon.
        # Decode Eszett for present and imperative.
        if encode_sz(v) in self:
            a = self[encode_sz(v)]
            a = [decode_sz(v) for v in a[:7]] + a[7:13] + [decode_sz(v) for v in a[13:20]] + a[20:]
        # Since the lexicon does not contain imperative for all verbs, don't simply return it.
        # Instead, update the rule-based lexeme with inflections from the lexicon.
        return [a[i] or lexeme[i] for i in range(len(a))]

    def tenses(self, verb, parse=True):
        """ Returns a list of possible tenses for the given inflected verb.
        """
        tenses = _Verbs.tenses(self, verb, parse)
        if len(tenses) == 0:
            # auswirkte => wirkte aus
            for prefix in prefix_separable:
                if verb.startswith(prefix):
                    tenses = _Verbs.tenses(self, verb[len(prefix):] + " " + prefix, parse)
                    break
        return tenses

verbs = Verbs()

conjugate, lemma, lexeme, tenses = \
    verbs.conjugate, verbs.lemma, verbs.lexeme, verbs.tenses

#### ATTRIBUTIVE & PREDICATIVE #####################################################################

# Strong inflection: no article.
adjectives_strong = {
    ("m", "nom"): "er", ("f", "nom"): "e" , ("n", "nom"): "es", ("p", "nom"): "e",
    ("m", "acc"): "en", ("f", "acc"): "e" , ("n", "acc"): "es", ("p", "acc"): "e",
    ("m", "dat"): "em", ("f", "dat"): "er", ("n", "dat"): "em", ("p", "dat"): "en",
    ("m", "gen"): "en", ("f", "gen"): "er", ("n", "gen"): "en", ("p", "gen"): "er",
}

# Mixed inflection: after indefinite article ein & kein and possessive determiners.
adjectives_mixed = {
    ("m", "nom"): "er", ("f", "nom"): "e" , ("n", "nom"): "es", ("p", "nom"): "en",
    ("m", "acc"): "en", ("f", "acc"): "e" , ("n", "acc"): "es", ("p", "acc"): "en",
    ("m", "dat"): "en", ("f", "dat"): "en", ("n", "dat"): "en", ("p", "dat"): "en",
    ("m", "gen"): "en", ("f", "gen"): "en", ("n", "gen"): "en", ("p", "gen"): "en",
}

# Weak inflection: after definite article.
adjectives_weak = {
    ("m", "nom"): "e",  ("f", "nom"): "e" , ("n", "nom"): "e",  ("p", "nom"): "en",
    ("m", "acc"): "en", ("f", "acc"): "e" , ("n", "acc"): "e",  ("p", "acc"): "en",
    ("m", "dat"): "en", ("f", "dat"): "en", ("n", "dat"): "en", ("p", "dat"): "en",
    ("m", "gen"): "en", ("f", "gen"): "en", ("n", "gen"): "en", ("p", "gen"): "en",
}

# Uninflected + exceptions.
adjective_attributive = {
    "etwas" : "etwas",
    "genug" : "genug",
    "viel"  : "viel",
    "wenig" : "wenig"
}

def attributive(adjective, gender=MALE, role=SUBJECT, article=None):
    """ For a predicative adjective, returns the attributive form (lowercase).
        In German, the attributive is formed with -e, -em, -en, -er or -es,
        depending on gender (masculine, feminine, neuter or plural) and role
        (nominative, accusative, dative, genitive).
    """
    w, g, c, a = \
        adjective.lower(), gender[:1].lower(), role[:3].lower(), article and article.lower() or None
    if w in adjective_attributive:
        return adjective_attributive[w]
    if a is None \
    or a in ("mir", "dir", "ihm") \
    or a in ("ein", "etwas", "mehr") \
    or a.startswith(("all", "mehrer", "wenig", "viel")):
        return w + adjectives_strong.get((g, c), "")
    if a.startswith(("ein", "kein")) \
    or a.startswith(("mein", "dein", "sein", "ihr", "Ihr", "unser", "euer")):
        return w + adjectives_mixed.get((g, c), "")
    if a in ("arm", "alt", "all", "der", "die", "das", "den", "dem", "des") \
    or a.startswith((
      "derselb", "derjenig", "jed", "jeglich", "jen", "manch", 
      "dies", "solch", "welch")):
        return w + adjectives_weak.get((g, c), "")
    # Default to strong inflection.
    return w + adjectives_strong.get((g, c), "")

def predicative(adjective):
    """ Returns the predicative adjective (lowercase).
        In German, the attributive form preceding a noun is always used:
        "ein kleiner Junge" => strong, masculine, nominative,
        "eine schöne Frau" => mixed, feminine, nominative,
        "der kleine Prinz" => weak, masculine, nominative, etc.
        The predicative is useful for lemmatization.
    """
    w = adjective.lower()
    if len(w) > 3:
        for suffix in ("em", "en", "er", "es", "e"):
            if w.endswith(suffix):
                b = w[:max(-len(suffix), -(len(w)-3))]
                if b.endswith("bl"): # plausibles => plausibel
                    b = b[:-1] + "el"
                if b.endswith("pr"): # propres => proper
                    b = b[:-1] + "er"
                return b
    return w

#### COMPARATIVE & SUPERLATIVE #####################################################################

COMPARATIVE = "er"
SUPERLATIVE = "st"

def grade(adjective, suffix=COMPARATIVE):
    """ Returns the comparative or superlative form of the given (inflected) adjective.
    """
    b = predicative(adjective)
    # groß => großt, schön => schönst
    if suffix == SUPERLATIVE and b.endswith(("s", u"ß")):
        suffix = suffix[1:]
    # große => großere, schönes => schöneres
    return adjective[:len(b)] + suffix + adjective[len(b):]

def comparative(adjective):
    return grade(adjective, COMPARATIVE)

def superlative(adjective):
    return grade(adjective, SUPERLATIVE)

#print(comparative(u"schönes"))
#print(superlative(u"schönes"))
#print(superlative(u"große"))