#### PATTERN | NL | INFLECT ########################################################################
# -*- coding: utf-8 -*-
# Copyright (c) 2010 University of Antwerp, Belgium
# Author: Tom De Smedt <tom@organisms.be>
# License: BSD (see LICENSE.txt for details).

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

# Accuracy (measured on CELEX Dutch morphology word forms):
# 79% for pluralize()
# 91% for singularize()
# 90% for Verbs.find_lemma()
# 88% for Verbs.find_lexeme()
# 99% for predicative()
# 99% for attributive()

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,
    PROGRESSIVE,
    PARTICIPLE
)

sys.path.pop(0)

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

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

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

plural_irregular_en = set(("dag", "dak", "dal", "pad", "vat", "weg"))
plural_irregular_een = set(("fee", "genie", "idee", "orgie", "ree"))
plural_irregular_eren = set(("blad", "ei", "gelid", "gemoed", "kalf", "kind", "lied", "rad", "rund"))
plural_irregular_deren = set(("hoen", "been"))

plural_irregular = {
     "centrum": "centra",
    "escargot": "escargots",
      "gedrag": "gedragingen",
       "gelid": "gelederen",
       "kaars": "kaarsen",
       "kleed": "kleren",
         "koe": "koeien",
         "lam": "lammeren",
      "museum": "museums",
        "stad": "steden",
       "stoel": "stoelen",
         "vlo": "vlooien"
}

def pluralize(word, pos=NOUN, custom={}):
    """ Returns the plural of a given word.
        For example: stad => steden.
        The custom dictionary is for user-defined replacements.
    """
    if word in custom.keys():
        return custom[word]
    w = word.lower()
    if pos == NOUN:
        if w in plural_irregular_en:    # dag => dagen
            return w + "en"
        if w in plural_irregular_een:   # fee => feeën
            return w + u"ën"
        if w in plural_irregular_eren:  # blad => bladeren
            return w + "eren"
        if w in plural_irregular_deren: # been => beenderen
            return w + "deren"
        if w in plural_irregular:
            return plural_irregular[w]
        # Words ending in -icus get -ici: academicus => academici
        if w.endswith("icus"):
            return w[:-2] + "i"
        # Words ending in -s usually get -sen: les => lessen.
        if w.endswith(("es", "as", "nis", "ris", "vis")):
            return w + "sen"
        # Words ending in -s usually get -zen: huis => huizen.
        if w.endswith("s") and not w.endswith(("us", "ts", "mens")):
            return w[:-1] + "zen"
        # Words ending in -f usually get -ven: brief => brieven.
        if w.endswith("f"):
            return w[:-1] + "ven"
        # Words ending in -um get -ums: museum => museums.
        if w.endswith("um"):
            return w + "s"
        # Words ending in unstressed -ee or -ie get -ën: bacterie => bacteriën
        if w.endswith("ie"):
            return w + "s"
        if w.endswith(("ee","ie")):
            return w[:-1] + u"ën"
        # Words ending in -heid get -heden: mogelijkheid => mogelijkheden
        if w.endswith("heid"):
            return w[:-4] + "heden"
        # Words ending in -e -el -em -en -er -ie get -s: broer => broers.
        if w.endswith((u"é", "e", "el", "em", "en", "er", "eu", "ie", "ue", "ui", "eau", "ah")):
            return w + "s"
        # Words ending in a vowel get 's: auto => auto's.
        if w.endswith(VOWELS) or w.endswith("y") and not w.endswith("e"):
            return w + "'s"
        # Words ending in -or always get -en: motor => motoren.
        if w.endswith("or"):
            return w + "en"
        # Words ending in -ij get -en: boerderij => boerderijen.
        if w.endswith("ij"):
            return w + "en"
        # Words ending in two consonants get -en: hand => handen.
        if len(w) > 1 and not is_vowel(w[-1]) and not is_vowel(w[-2]):
            return w + "en"
        # Words ending in one consonant with a short sound: fles => flessen.
        if len(w) > 2 and not is_vowel(w[-1]) and not is_vowel(w[-3]):
            return w + w[-1] + "en"
        # Words ending in one consonant with a long sound: raam => ramen.
        if len(w) > 2 and not is_vowel(w[-1]) and w[-2] == w[-3]:
            return w[:-2] + w[-1] + "en"
        return w + "en"
    return w

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

singular_irregular = dict((v,k) for k,v in plural_irregular.iteritems())

def singularize(word, pos=NOUN, custom={}):
    if word in custom.keys():
        return custom[word]
    w = word.lower()
    if pos == NOUN and w in singular_irregular:
        return singular_irregular[w]
    if pos == NOUN and w.endswith((u"ën", "en", "s", "i")):
        # auto's => auto
        if w.endswith("'s"):
            return w[:-2]
        # broers => broer
        if w.endswith("s"):
            return w[:-1]
        # academici => academicus
        if w.endswith("ici"):
            return w[:-1] + "us"
        # feeën => fee
        if w.endswith(u"ën") and w[:-2] in plural_irregular_een:
            return w[:-2]
        # bacteriën => bacterie
        if w.endswith(u"ën"):
            return w[:-2] + "e"
        # mogelijkheden => mogelijkheid
        if w.endswith("heden"):
            return w[:-5] + "heid"
        # artikelen => artikel
        if w.endswith("elen") and not w.endswith("delen"):
            return w[:-2]
        # chinezen => chinees
        if w.endswith("ezen"):
            return w[:-4] + "ees"
        # neven => neef
        if w.endswith("even") and len(w) > 4 and not is_vowel(w[-5]):
            return w[:-4] + "eef"
        if w.endswith("en"):
            w = w[:-2]
            # ogen => oog
            if w in ("og","om","ur"):
                return w[:-1] + w[-2] + w[-1]
            # hoenderen => hoen
            if w.endswith("der") and w[:-3] in plural_irregular_deren:
                return w[:-3]
            # eieren => ei
            if w.endswith("er") and w[:-2] in plural_irregular_eren:
                return w[:-2]
            # dagen => dag (not daag)
            if w in plural_irregular_en:
                return w
            # huizen => huis
            if w.endswith("z"):
                return w[:-1] + "s"
            # brieven => brief
            if w.endswith("v"):
                return w[:-1] + "f"
             # motoren => motor
            if w.endswith("or"):
                return w
            # flessen => fles
            if len(w) > 1 and not is_vowel(w[-1]) and w[-1] == w[-2]:
                return w[:-1]
            # baarden => baard
            if len(w) > 1 and not is_vowel(w[-1]) and not is_vowel(w[-2]):
                return w
            # boerderijen => boerderij
            if w.endswith("ij"):
                return w
            # idealen => ideaal
            if w.endswith(("eal", "ean", "eol", "ial", "ian", "iat", "iol")):
                return w[:-1] + w[-2] + w[-1]
            # ramen => raam
            if len(w) > 2 and not is_vowel(w[-1]) and is_vowel(w[-2]) and not is_vowel(w[-3]):
                return w[:-1] + w[-2] + w[-1]
            return w
    return w

#### VERB CONJUGATION ##############################################################################

class Verbs(_Verbs):
    
    def __init__(self):
        _Verbs.__init__(self, os.path.join(MODULE, "nl-verbs.txt"),
            language = "nl",
              format = [0, 1, 2, 3, 7, 8, 17, 18, 19, 23, 25, 24, 16, 9, 10, 11, 15, 33, 26, 27, 28, 32],
             default = {
                 1: 0,   2: 0,   3: 0,   7: 0,  # present singular
                 4: 7,   5: 7,   6: 7,          # present plural
                17: 25, 18: 25, 19: 25, 23: 25, # past singular
                20: 23, 21: 23, 22: 23,         # past plural
                 9: 16, 10: 16, 11: 16, 15: 16, # present singular negated
                12: 15, 13: 15, 14: 15,         # present plural negated
                26: 33, 27: 33, 28: 33,         # past singular negated
                29: 32, 30: 32, 31: 32, 32: 33  # past plural negated
            })
    
    def load(self):
        _Verbs.load(self)
        self._inverse["was"]   = "zijn" # Instead of "wassen".
        self._inverse["waren"] = "zijn"
        self._inverse["zagen"] = "zien"
        self._inverse["wist"]  = "weten"
    
    def find_lemma(self, verb):
        """ Returns the base form of the given inflected verb, using a rule-based approach.
            This is problematic if a verb ending in -e is given in the past tense or gerund.
        """
        v = verb.lower()
        # Common prefixes: op-bouwen and ver-bouwen inflect like bouwen.
        for prefix in ("aan", "be", "her", "in", "mee", "ont", "op", "over", "uit", "ver"):
            if v.startswith(prefix) and v[len(prefix):] in self.inflections:
                return prefix + self.inflections[v[len(prefix):]]
        # Present participle -end: hengelend, knippend.
        if v.endswith("end"):
            b = v[:-3]
        # Past singular -de or -te: hengelde, knipte.
        elif v.endswith(("de", "det", "te", "tet")):
            b = v[:-2]
        # Past plural -den or -ten: hengelden, knipten.
        elif v.endswith(("chten"),):
            b = v[:-2]
        elif v.endswith(("den", "ten")) and len(v) > 3 and is_vowel(v[-4]):
            b = v[:-2]
        elif v.endswith(("den", "ten")):
            b = v[:-3]
        # Past participle ge- and -d or -t: gehengeld, geknipt.
        elif v.endswith(("d","t")) and v.startswith("ge"):
            b = v[2:-1]    
        # Present 2nd or 3rd singular: wordt, denkt, snakt, wacht.
        elif v.endswith(("cht"),):
            b = v
        elif v.endswith(("dt", "bt", "gt", "kt", "mt", "pt", "wt", "xt", "aait", "ooit")):
            b = v[:-1]
        elif v.endswith("t") and len(v) > 2 and not is_vowel(v[-2]):
            b = v[:-1]
        elif v.endswith("en") and len(v) > 3:
            return v
        else:
            b = v
        # hengel => hengelen (and not hengellen)
        if len(b) > 2 and b.endswith(("el", "nder", "om", "tter")) and not is_vowel(b[-3]):
            pass
        # Long vowel followed by -f or -s: geef => geven.
        elif len(b) > 2 and not is_vowel(b[-1]) and is_vowel(b[-2]) and is_vowel(b[-3])\
          or b.endswith(("ijf", "erf"),):
            if b.endswith("f"): b = b[:-1] + "v"
            if b.endswith("s"): b = b[:-1] + "z"
            if b[-2] == b[-3]: 
                b = b[:-2] + b[-1]
        # Short vowel followed by consonant: snak => snakken.
        elif len(b) > 1 and not is_vowel(b[-1]) and is_vowel(b[-2]) and not b.endswith(("er","ig")):
            b = b + b[-1]
        b = b + "en"
        b = b.replace("vven", "ven") # omgevven => omgeven
        b = b.replace("zzen", "zen") # genezzen => genezen
        b = b.replace("aen", "aan")  # doorgaen => doorgaan
        return b
        
    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.
        b = b0 = re.sub("en$", "", v)
        # zweven => zweef, graven => graaf
        if b.endswith("v"): b = b[:-1] + "f"
        if b.endswith("z"): b = b[:-1] + "s"
        # Vowels with a long sound are doubled, we need to guess how it sounds:
        if len(b) > 2 and not is_vowel(b[-1]) and is_vowel(b[-2]) and not is_vowel(b[-3]):
            if not v.endswith(("elen", "deren", "keren", "nderen", "tteren")):
                b = b[:-1] + b[-2] + b[-1]
        # pakk => pak
        if len(b) > 1 and not is_vowel(b[-1]) and b[-1] == b[-2]:
            b = b[:-1]
        # Present tense gets -t:
        sg = not b.endswith("t") and b + "t" or b
        # Past tense ending in a consonant in "xtc-koffieshop" gets -t, otherwise -d:
        dt = b0 and b0[-1] in "xtckfshp" and "t" or (not b.endswith("d") and "d" or "")
        # Past tense -e and handle common irregular inflections:
        p = b + dt + "e"
        for suffix, irregular in (("erfde", "ierf"), ("ijfde", "eef"), ("ingde", "ong"), ("inkte", "onk")):
            if p.endswith(suffix):
                p = p[:-len(suffix)] + irregular; break
        # Past participle: ge-:
        pp = re.sub("tt$", "t", "ge" + b + dt)
        pp = pp.startswith(("geop", "gein", "geaf")) and pp[2:4]+"ge"+pp[4:] or pp # geopstart => opgestart
        pp = pp.startswith(("gever", "gebe", "gege")) and pp[2:] or pp
        return [v, b, sg, sg, v, b0+"end", p, p, p, b+dt+"en", p, pp]

verbs = Verbs()

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

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

adjective_attributive = {
     "civiel": "civiele",
    "complex": "complexe",
      "enkel": "enkele",
       "grof": "grove",
       "half": "halve",
     "luttel": "luttele",
     "mobiel": "mobiele",
     "parijs": "parijse",
        "ruw": "ruwe",
     "simpel": "simpele",
    "stabiel": "stabiele",
    "steriel": "steriele",
    "subtiel": "subtiele",
       "teer": "tere"
}

def attributive(adjective):
    """ For a predicative adjective, returns the attributive form (lowercase).
        In Dutch, the attributive is formed with -e: "fel" => "felle kritiek".
    """
    w = adjective.lower()
    if w in adjective_attributive:
        return adjective_attributive[w]
    if w.endswith("e"):
        return w
    if w.endswith(("er","st")) and len(w) > 4:
        return w + "e"
    if w.endswith("ees"):
        return w[:-2] + w[-1] + "e"
    if w.endswith("el") and len(w) > 2 and not is_vowel(w[-3]):
        return w + "e"
    if w.endswith("ig"):
        return w + "e"
    if len(w) > 2 and (not is_vowel(w[-1]) and is_vowel(w[-2]) and is_vowel(w[-3]) or w[:-1].endswith("ij")):
        if w.endswith("f"): w = w[:-1] + "v"
        if w.endswith("s"): w = w[:-1] + "z"
        if w[-2] == w[-3]:
            w = w[:-2] + w[-1]
    elif len(w) > 1 and is_vowel(w[-2]) and w.endswith(tuple("bdfgklmnprst")):
        w = w + w[-1]
    return w + "e"

adjective_predicative = dict((v,k) for k,v in adjective_attributive.iteritems())
adjective_predicative.update({
          "moe": "moe",
        "taboe": "taboe",
    "voldoende": "voldoende"
})

def predicative(adjective):
    """ Returns the predicative adjective (lowercase).
        In Dutch, the attributive form preceding a noun is common:
        "rake opmerking" => "raak", "straffe uitspraak" => "straf", "dwaze blik" => "dwaas".
    """
    w = adjective.lower()
    if w in adjective_predicative:
        return adjective_predicative[w]
    if w.endswith("ste"):
        return w[:-1]
    if w.endswith("ere"):
        return w[:-1]
    if w.endswith("bele"):
        return w[:-1]
    if w.endswith("le") and len(w) > 2 and is_vowel(w[-3]) and not w.endswith(("eule", "oele")):
        return w[:-2] + w[-3] + "l"
    if w.endswith("ve") and len(w) > 2 and is_vowel(w[-3]) and not w.endswith(("euve", "oeve", "ieve")):
        return w[:-2] + w[-3] + "f"
    if w.endswith("ze") and len(w) > 2 and is_vowel(w[-3]) and not w.endswith(("euze", "oeze", "ieze")):
        return w[:-2] + w[-3] + "s"
    if w.endswith("ve"):
        return w[:-2] + "f"
    if w.endswith("ze"):
        return w[:-2] + "s"
    if w.endswith("e") and len(w) > 2:
        if not is_vowel(w[-2]) and w[-2] == w[-3]:
            return w[:-2]
        if len(w) > 3 and not is_vowel(w[-2]) and is_vowel(w[-3]) and w[-3] != "i" and not is_vowel(w[-4]):
            return w[:-2] + w[-3] + w[-2]
        return w[:-1]
    return w
