from libc.string cimport memcpy, memset

from cymem.cymem cimport Pool

from ..structs cimport TokenC, Entity

from ..vocab cimport EMPTY_LEXEME


cdef class StateClass:
    cdef Pool mem
    cdef int* _stack
    cdef int* _buffer
    cdef bint* shifted
    cdef TokenC* _sent
    cdef Entity* _ents
    cdef TokenC _empty_token
    cdef int length
    cdef int _s_i
    cdef int _b_i
    cdef int _e_i
    cdef int _break

    @staticmethod
    cdef inline StateClass init(const TokenC* sent, int length):
        cdef StateClass self = StateClass(length)
        cdef int i
        for i in range(length):
            self._sent[i] = sent[i]
            self._buffer[i] = i
        for i in range(length, length + 5):
            self._sent[i].lex = &EMPTY_LEXEME
        return self

    cdef inline int S(self, int i) nogil:
        if i >= self._s_i:
            return -1
        return self._stack[self._s_i - (i+1)]

    cdef inline int B(self, int i) nogil:
        if (i + self._b_i) >= self.length:
            return -1
        return self._buffer[self._b_i + i]
    
    cdef int H(self, int i) nogil
    cdef int E(self, int i) nogil
    
    cdef int L(self, int i, int idx) nogil
    cdef int R(self, int i, int idx) nogil

    cdef const TokenC* S_(self, int i) nogil
    cdef const TokenC* B_(self, int i) nogil

    cdef const TokenC* H_(self, int i) nogil
    cdef const TokenC* E_(self, int i) nogil

    cdef const TokenC* L_(self, int i, int idx) nogil
    cdef const TokenC* R_(self, int i, int idx) nogil

    cdef const TokenC* safe_get(self, int i) nogil

    cdef bint empty(self) nogil
    
    cdef bint entity_is_open(self) nogil

    cdef bint eol(self) nogil
    
    cdef bint at_break(self) nogil

    cdef bint is_final(self) nogil

    cdef bint has_head(self, int i) nogil

    cdef int n_L(self, int i) nogil

    cdef int n_R(self, int i) nogil

    cdef bint stack_is_connected(self) nogil

    cdef int stack_depth(self) nogil
    
    cdef int buffer_length(self) nogil

    cdef void push(self) nogil

    cdef void pop(self) nogil
    
    cdef void unshift(self) nogil

    cdef void add_arc(self, int head, int child, int label) nogil
    
    cdef void del_arc(self, int head, int child) nogil
    
    cdef void open_ent(self, int label) nogil
    
    cdef void close_ent(self) nogil
    
    cdef void set_ent_tag(self, int i, int ent_iob, int ent_type) nogil

    cdef void set_break(self, int i) nogil

    cdef void clone(self, StateClass src) nogil

    cdef void fast_forward(self) nogil