'''Serve pointers to Lexeme structs, given strings. Maintain a reverse index,
so that strings can be retrieved from hashes.  Use 64-bit hash values and
boldly assume no collisions.
'''
from __future__ import unicode_literals


from libc.stdlib cimport malloc, calloc, free
from libc.stdint cimport uint64_t
from libcpp.vector cimport vector

from spacy.string_tools cimport substr
from spacy.spacy cimport Language
from . import util

cimport spacy


cdef class EnglishPTB(Language):
    cdef int find_split(self, unicode word):
        length = len(word)
        cdef int i = 0
        # Contractions
        if word.endswith("'s"):
            return length - 2
        # Leading punctuation
        if is_punct(word, 0, length):
            return 1
        elif length >= 1:
            # Split off all trailing punctuation characters
            i = 0
            while i < length and not is_punct(word, i, length):
                i += 1
        return i


cdef bint is_punct(unicode word, size_t i, size_t length):
    is_final = i == (length - 1)
    if word[i] == '.':
        return False
    if not is_final and word[i] == '-' and word[i+1] == '-':
        return True
    # Don't count appostrophes as punct if the next char is a letter
    if word[i] == "'" and i < (length - 1) and word[i+1].isalpha():
        return False
    punct_chars = set(',;:' + '@#$%&' + '!?' + '[({' + '})]')
    return word[i] in punct_chars


cdef EnglishPTB EN_PTB = EnglishPTB('en_ptb')

cpdef Tokens tokenize(unicode string):
    return EN_PTB.tokenize(string)


cpdef Lexeme_addr lookup(unicode string) except 0:
    return <Lexeme_addr>EN_PTB.lookup(string)


cpdef unicode unhash(StringHash hash_value):
    return EN_PTB.unhash(hash_value)