#include<stdio.h>
#include<obliv.oh>

#include"editdist.h"

void readString(obliv unsigned char* dest, int n, const char* src,int party)
{
  OblivInputs specs[MAXN];
  int i;
  for(i=0;i<n;++i) setupOblivChar(specs+i,dest+i,src[i]);
  feedOblivInputs(specs,n,party);
}

typedef obliv int oint;
// This is where the obliv keyword is just an overhead that can be left out
oint omin(obliv int a, obliv int b) obliv
{
  obliv int res = b;
  obliv if(a<b) res=a;  // cannot return directly from obliv-if
  return res;
}

obliv int dp[MAXN+1][MAXN+1];

void editDistance(void* args)
{
  protocolIO *io = args;
  int n1,n2;
  int i,j;
  double lap2;
  obliv unsigned char s1[MAXN], s2[MAXN];

  n1 = ocBroadcastInt(io->n,1);
  n2 = ocBroadcastInt(io->n,2);
  feedOblivCharArray(s1,io->s,n1,1);
  feedOblivCharArray(s2,io->s,n2,2);
  
  // These really only work with single threaded protocols
  //   namely, YaoProtocol and DebugProtocol
  lap2 = wallClock();
  fprintf(stderr,"%s OT time: %lf s\n",mySide(),lap2-lap);

  for(i=0;i<=n1;++i) dp[i][0]=i;
  for(j=0;j<=n2;++j) dp[0][j]=j;
  for(i=1;i<=n1;++i) for(j=1;j<=n2;++j)
  {
    /*
    obliv int temp = dp[i-1][j-1] + (s1[i-1]!=s2[j-1]);
    obliv int temp2 = omin (dp[i][j-1], dp[i-1][j]) + 1;
    dp[i][j] = omin(temp,temp2);
    */
    obliv int temp = omin (dp[i][j-1], dp[i-1][j]);
    obliv int d = 1;
    obliv if (temp>=dp[i-1][j-1])
    { temp = dp[i-1][j-1];
      d = (s1[i-1]!=s2[j-1]); // FIXME sign extend to 32 bit on compare
    }
    dp[i][j] = temp + d;
  }
  revealOblivInt(&io->res,dp[n1][n2],0);
  fprintf(stderr,"%u\n",yaoGateCount());
}