/*
//
//                  INTEL CORPORATION PROPRIETARY INFORMATION
//     This software is supplied under the terms of a license agreement or
//     nondisclosure agreement with Intel Corporation and may not be copied
//     or disclosed except in accordance with the terms of that agreement.
//          Copyright(c) 1999-2006 Intel Corporation. All Rights Reserved.
//
//     Intel(R) Integrated Performance Primitives Gaussian Mixture Sample for Windows*
//
//  By downloading and installing this sample, you hereby agree that the
//  accompanying Materials are being provided to you under the terms and
//  conditions of the End User License Agreement for the Intel(R) Integrated
//  Performance Primitives product previously accepted by you. Please refer
//  to the file ippEULA.rtf located in the root directory of your Intel(R) IPP
//  product installation for more information.
//
//
//
//     Decoder Imitation Class
//
*/

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <ipps.h>
#include <ippsr.h>

#include "fake_decoder.h"
#include "prob_cache.h"

#define MAX_RAND (0x7fff)

Fake_Decoder::Fake_Decoder(int N, int L) {
   state_number = N;
   avr_active   = N/5;
   max_live     = L;
   live_len     = 256;
   frame_num    = 256+max_live;
   shift        = 0;
   all_prob     = 0;
   rept_prob    = 0;
   t            = 0;
   sum          = 0.0;
   sumsq        = 0.0;
   cache        = NULL;
   last_act     = NULL;
   state_weight = NULL;
   last_len     = NULL;
   act_num      = NULL;
   sum_inact    = NULL;
   sumsq_inact  = NULL;
   live_stat    = NULL;
   if_calc      = NULL;
   flog         = NULL;
   ready        = -2;
}

int Fake_Decoder::Init_LogFile(char *prob_log) {

   if (ready!=0)                return -10;

   if (!prob_log) {
      flog=NULL;
   } else if (!prob_log[0]) {
      flog=NULL;
   } else {
      if (!(flog=fopen(prob_log, "wb")))                          return -3;
   }
   return 0;
}

int Fake_Decoder::Init_Decoder(void) {

   if (ready!=-2)               return -10;

   if (state_number<=0)         return -1;
   if (avr_active<=0)           return -1;
   if (max_live<=0)             return -1;
   if (frame_num<=0)            return -1;
   if (avr_active>state_number)
      avr_active=state_number;

   if (!(last_act     = ippsMalloc_32s(state_number)))            return -2;
   if (!(state_weight = ippsMalloc_32f(state_number)))            return -2;
   if (!(last_len     = ippsMalloc_32s(state_number)))            return -2;
   if (!(if_calc      = ippsMalloc_8u(state_number)))             return -2;
   if (!(act_num      = ippsMalloc_32s(frame_num+max_live)))      return -2;
   if (!(sum_inact    = ippsMalloc_64f(frame_num+max_live)))      return -2;
   if (!(sumsq_inact  = ippsMalloc_64f(frame_num+max_live)))      return -2;
   if (!(live_stat    = ippsMalloc_32s(live_len)))                return -2;

   int i;
   int *q=(int*)state_weight;

   sum=0.0;
   for (i=0; i<state_number; i++) {
      q[i]=rand()&MAX_RAND;
      sum+=(double)q[i];
   }
   sum=1.0/sum;
   for (i=0; i<state_number; i++) {
      state_weight[i]=(float)(q[i]*sum);
   }
   sum=0.0;
   sumsq=0.0;
   for (i=0; i<state_number; i++) {
      sum+=state_weight[i];
      sumsq+=state_weight[i]*state_weight[i];
   }
   ippsSet_32s(-1,last_act,state_number);
   ippsZero_32f((float*)last_len,state_number);
   ippsSet_64f(sum,sum_inact,frame_num);
   ippsSet_64f(sumsq,sumsq_inact,frame_num);
   ippsZero_32f((float*)act_num,frame_num);
   ippsZero_32f((float*)live_stat,live_len);
   ippsZero_8u(if_calc,state_number);

   rept_prob=0;
   all_prob=0;
   t=0;

   ready=-1;
   return 0;
}

Fake_Decoder::~Fake_Decoder(void) {
   state_number = 0;
   avr_active   = 0;
   max_live     = 0;
   live_len     = 0;
   frame_num    = 0;
   shift        = 0;
   all_prob     = 0;
   rept_prob    = 0;
   t            = 0;
   sum          = 0.0;
   sumsq        = 0.0;
   if (live_stat)    ippsFree(live_stat);
   if (sumsq_inact)  ippsFree(sumsq_inact);
   if (sum_inact)    ippsFree(sum_inact);
   if (act_num)      ippsFree(act_num);
   if (last_len)     ippsFree(last_len);
   if (state_weight) ippsFree(state_weight);
   if (last_act)     ippsFree(last_act);
   if (flog)         fclose(flog);
   cache        = NULL;
   last_act     = NULL;
   state_weight = NULL;
   last_len     = NULL;
   act_num      = NULL;
   sum_inact    = NULL;
   sumsq_inact  = NULL;
   live_stat    = NULL;
   if_calc      = NULL;
   flog         = NULL;
   ready        = -2;

}

void Fake_Decoder::Get_Statistics(Len_Stat *stat) {
// all     -  all probabilities calculated
// lost    -  repeated probabilities
// nums[i] -  number of intervals of length i+1
   ippsCopy_32f((float*)live_stat,(float*)(stat->nums),stat->len);
   stat->lost=rept_prob;
   stat->all=all_prob;
}

bool Fake_Decoder::Attach_Cache(Prob_Cache *c) {
   if (ready!=-1)                          return false;
   cache=c;
   if (!cache)                             return false;
   if (!cache->Ready())                    return false;
   if (cache->State_Number()<state_number) return false;

   ready=0;
   return true;
}

int Fake_Decoder::Activity_Interval(int max_len) {
   int l;
   float p=(float)(rand()&MAX_RAND)/(float)MAX_RAND;
   l=(int)(p*max_len+1.0);
//   l=(int)(exp(-8*(p-0.5)*(p-0.5))*max_len+0.5);
   if (l<1) l=1;
   return l;
}

int Fake_Decoder::Get_Probability(int state, float *prob) {
   rept_prob+=if_calc[state];
   if_calc[state]=1;
   return cache->Get_Probability(state,prob);
}

int Fake_Decoder::Use_Probability(int state, float *prob) {
   if (flog)
      fwrite((void*)prob, sizeof(float), 1, flog);
   *prob=(float)exp(log(*prob+1.0));
   return 0;
}

void Fake_Decoder::Close_Decoder(void) {
   int i;
      for (i=0; i<state_number; i++) {
         if (last_len[i]>=live_len) last_len[i]=live_len;
         if (last_len[i])           live_stat[last_len[i]-1]++;
         last_len[i]=0;
      }
}

bool Fake_Decoder::Decode_Frame(int M) {

   // tends to M different states calculated once

   int i,j,MM,live;
   float prand,plim,prob,act_prob;
   float pp=(float)(1.0/sum_inact[t-shift]);
   bool all=false;

   if (ready!=0)                           return false;

   if (M>0) avr_active=M;
   if (avr_active>state_number) avr_active=state_number;

   if (avr_active<=act_num[t-shift]) {

      for (i=0; i<state_number; i++) {
         if (last_act[i]>=t) {
            if (Get_Probability(i,&prob))
               Use_Probability(i,&prob);
         }
      }

   } else {

      if ((sum_inact[t-shift]<=0)||(avr_active>=state_number)) {
         MM=avr_active-act_num[t-shift];
         all=true;
      } else {
         MM=(int)((double)(avr_active-act_num[t-shift])/
            (1.0-(avr_active-act_num[t-shift])*sumsq_inact[t-shift]*pp*pp*0.5));
         MM=(int)((double)(avr_active-act_num[t-shift])/(1.0-MM*sumsq_inact[t-shift]*pp*pp*0.5));
         all=false;
      }

      for (i=0; i<state_number; i++) {
         if (last_act[i]>=t) {
            if (Get_Probability(i,&prob))
               Use_Probability(i,&prob);
         } else {
            if (all)    act_prob=1.0f;
            else        act_prob=(float)(1.0-exp(MM*log(1.0-state_weight[i]*pp)));
            prand=(float)(rand()&MAX_RAND);
            plim=(float)(act_prob*MAX_RAND);
            if (prand<=plim) {
               if (Get_Probability(i,&prob))
                  Use_Probability(i,&prob);
               live=Activity_Interval(max_live);
               last_act[i]=t+live;
               last_len[i]+=live;
               for (j=t; j<=last_act[i]; j++) {
                  act_num[j-shift]++;
                  sum_inact[j-shift]-=state_weight[i];
                  sumsq_inact[j-shift]-=state_weight[i]*state_weight[i];
               }
            } else {
               if (last_len[i]) {
                  if (last_len[i]>=live_len) last_len[i]=live_len;
                  live_stat[last_len[i]-1]++;
               }
               last_len[i]=0;
            }
         }
      }
   }

   ippsZero_8u(if_calc,state_number);
   all_prob+=act_num[t-shift];
   if (++t>=frame_num-max_live+shift) {
      shift+=frame_num-max_live;
      ippsCopy_32f((float*)act_num+frame_num-max_live,(float*)act_num,max_live);
      ippsZero_32f((float*)act_num+max_live,frame_num-max_live);
      ippsCopy_64f(sum_inact+frame_num-max_live,sum_inact,max_live);
      ippsSet_64f(sum,sum_inact+max_live,frame_num-max_live);
      ippsCopy_64f(sumsq_inact+frame_num-max_live,sumsq_inact,max_live);
      ippsSet_64f(sumsq,sumsq_inact+max_live,frame_num-max_live);
   }

   return cache->Step_Forward();
}