/// @file

#include "jets/q.h"
#include "jets/w.h"

#include "noun.h"
#include "murmur3.h"

u3_noun
u3qc_muk(u3_atom sed,
         u3_atom len,
         u3_atom key)
{
  if ( c3n == u3a_is_cat(len) ) {
    return u3m_bail(c3__fail);
  }
  else {
    c3_w len_w = (c3_w)len;
    c3_w key_w = u3r_met(3, key);

    //  NB: this condition is implicit in the pad subtraction
    //
    if ( key_w > len_w ) {
      return u3m_bail(c3__exit);
    }
    else {
      c3_w  sed_w = u3r_word(0, sed);
      c3_o  loc_o = c3n;
      c3_y* key_y = 0;
      c3_w  out_w;

      //  if we're hashing more bytes than we have, allocate and copy
      //  to ensure trailing null bytes
      //
      if ( len_w > key_w ) {
        loc_o = c3y;
        key_y = u3a_calloc(sizeof(c3_y), len_w);
        u3r_bytes(0, len_w, key_y, key);
      }
      else if ( len_w > 0 ) {
        //  XX assumes little-endian
        //
        key_y = ( c3y == u3a_is_cat(key) )
                ? (c3_y*)&key
                : (c3_y*)((u3a_atom*)u3a_to_ptr(key))->buf_w;
      }

      MurmurHash3_x86_32(key_y, len_w, sed_w, &out_w);

      if ( c3y == loc_o ) {
        u3a_free(key_y);
      }

      return u3i_words(1, &out_w);
    }
  }
}

u3_noun
u3wc_muk(u3_noun cor)
{
  u3_noun sed, len, key;
  u3x_mean(cor, u3x_sam_2, &sed,
                u3x_sam_6, &len,
                u3x_sam_7, &key, 0);

  if (  (c3n == u3ud(sed))
     || (c3n == u3ud(len))
     || (c3n == u3ud(key)) )
  {
    return u3m_bail(c3__exit);
  }
  else {
    return u3qc_muk(sed, len, key);
  }
}