/* Copyright (c) 2018 Mozilla
                 2008-2011 Octasic Inc.
                 2012-2017 Jean-Marc Valin */
/*
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   - Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

   - Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <math.h>
#include "opus_types.h"
#include "arch.h"
#include "common.h"
#include "tansig_table.h"
#include "nnet.h"
#include "nnet_data.h"

#define SOFTMAX_HACK

#ifdef __AVX__
#include "vec_avx.h"
#elif __ARM_NEON__
#include "vec_neon.h"
#else
#warning Compiling without any vectorization. This code will be very slow
#include "vec.h"
#endif

static OPUS_INLINE float relu(float x)
{
   return x < 0 ? 0 : x;
}


static void sgemv_accum(float *out, const float *weights, int rows, int cols, int col_stride, const float *x)
{
   int i, j;
   if (rows % 16 == 0)
   {
      sgemv_accum16(out, weights, rows, cols, col_stride, x);
   } else {
      for (i=0;i<rows;i++)
      {
         for (j=0;j<cols;j++)
            out[i] += weights[j*col_stride + i]*x[j];
      }
   }
}

void compute_activation(float *output, float *input, int N, int activation)
{
   int i;
   if (activation == ACTIVATION_SIGMOID) {
      vec_sigmoid(output, input, N);
   } else if (activation == ACTIVATION_TANH) {
      vec_tanh(output, input, N);
   } else if (activation == ACTIVATION_RELU) {
      for (i=0;i<N;i++)
         output[i] = relu(input[i]);
   } else if (activation == ACTIVATION_SOFTMAX) {
#ifdef SOFTMAX_HACK
      for (i=0;i<N;i++)
         output[i] = input[i];
#else
      float sum = 0;
      softmax(output, input, N);
      for (i=0;i<N;i++) {
         sum += output[i];
      }
      sum = 1.f/(sum+1e-30);
      for (i=0;i<N;i++)
         output[i] = sum*output[i];
#endif
   } else {
      celt_assert(activation == ACTIVATION_LINEAR);
      for (i=0;i<N;i++)
         output[i] = input[i];
   }
}

void compute_dense(const DenseLayer *layer, float *output, const float *input)
{
   int i;
   int N, M;
   int stride;
   M = layer->nb_inputs;
   N = layer->nb_neurons;
   stride = N;
   celt_assert(input != output);
   for (i=0;i<N;i++)
      output[i] = layer->bias[i];
   sgemv_accum(output, layer->input_weights, N, M, stride, input);
   compute_activation(output, output, N, layer->activation);
}

void compute_mdense(const MDenseLayer *layer, float *output, const float *input)
{
   int i, c;
   int N, M, C;
   int stride;
   float tmp[MAX_MDENSE_TMP];
   celt_assert(input != output);
   M = layer->nb_inputs;
   N = layer->nb_neurons;
   C = layer->nb_channels;
   celt_assert(N*C <= MAX_MDENSE_TMP);
   stride = N*C;
   for (i=0;i<N*C;i++)
      tmp[i] = layer->bias[i];
   sgemv_accum(tmp, layer->input_weights, N*C, M, stride, input);
   compute_activation(tmp, tmp, N*C, ACTIVATION_TANH);
   for (i=0;i<N;i++)
      output[i] = 0;
   for (c=0;c<C;c++)
   {
      for (i=0;i<N;i++)
         output[i] += tmp[c*N + i]*layer->factor[c*N + i];
   }
   compute_activation(output, output, N, layer->activation);
}

void compute_gru(const GRULayer *gru, float *state, const float *input)
{
   int i;
   int N, M;
   int stride;
   float tmp[MAX_RNN_NEURONS];
   float z[MAX_RNN_NEURONS];
   float r[MAX_RNN_NEURONS];
   float h[MAX_RNN_NEURONS];
   celt_assert(gru->nb_neurons <= MAX_RNN_NEURONS);
   celt_assert(input != state);
   M = gru->nb_inputs;
   N = gru->nb_neurons;
   stride = 3*N;
   /* Compute update gate. */
   for (i=0;i<N;i++)
      z[i] = gru->bias[i];
   if (gru->reset_after)
   {
      for (i=0;i<N;i++)
         z[i] += gru->bias[3*N + i];
   }
   sgemv_accum(z, gru->input_weights, N, M, stride, input);
   sgemv_accum(z, gru->recurrent_weights, N, N, stride, state);
   compute_activation(z, z, N, ACTIVATION_SIGMOID);

   /* Compute reset gate. */
   for (i=0;i<N;i++)
      r[i] = gru->bias[N + i];
   if (gru->reset_after)
   {
      for (i=0;i<N;i++)
         r[i] += gru->bias[4*N + i];
   }
   sgemv_accum(r, &gru->input_weights[N], N, M, stride, input);
   sgemv_accum(r, &gru->recurrent_weights[N], N, N, stride, state);
   compute_activation(r, r, N, ACTIVATION_SIGMOID);

   /* Compute output. */
   for (i=0;i<N;i++)
      h[i] = gru->bias[2*N + i];
   if (gru->reset_after)
   {
      for (i=0;i<N;i++)
         tmp[i] = gru->bias[5*N + i];
      sgemv_accum(tmp, &gru->recurrent_weights[2*N], N, N, stride, state);
      for (i=0;i<N;i++)
         h[i] += tmp[i] * r[i];
      sgemv_accum(h, &gru->input_weights[2*N], N, M, stride, input);
   } else {
      for (i=0;i<N;i++)
         tmp[i] = state[i] * r[i];
      sgemv_accum(h, &gru->input_weights[2*N], N, M, stride, input);
      sgemv_accum(h, &gru->recurrent_weights[2*N], N, N, stride, tmp);
   }
   compute_activation(h, h, N, gru->activation);
   for (i=0;i<N;i++)
      h[i] = z[i]*state[i] + (1-z[i])*h[i];
   for (i=0;i<N;i++)
      state[i] = h[i];
}

void compute_gru2(const GRULayer *gru, float *state, const float *input)
{
   int i;
   int N, M;
   int stride;
   float zrh[3*MAX_RNN_NEURONS];
   float recur[3*MAX_RNN_NEURONS];
   float *z;
   float *r;
   float *h;
   M = gru->nb_inputs;
   N = gru->nb_neurons;
   z = zrh;
   r = &zrh[N];
   h = &zrh[2*N];
   celt_assert(gru->nb_neurons <= MAX_RNN_NEURONS);
   celt_assert(input != state);
   celt_assert(gru->reset_after);
   stride = 3*N;
   /* Compute update gate. */
   for (i=0;i<3*N;i++)
      zrh[i] = gru->bias[i];
   sgemv_accum(zrh, gru->input_weights, 3*N, M, stride, input);
   for (i=0;i<3*N;i++)
      recur[i] = gru->bias[3*N + i];
   sgemv_accum(recur, gru->recurrent_weights, 3*N, N, stride, state);
   for (i=0;i<2*N;i++)
      zrh[i] += recur[i];
   compute_activation(zrh, zrh, 2*N, ACTIVATION_SIGMOID);
   for (i=0;i<N;i++)
      h[i] += recur[2*N+i]*r[i];
   compute_activation(h, h, N, gru->activation);
   for (i=0;i<N;i++)
      h[i] = z[i]*state[i] + (1-z[i])*h[i];
   for (i=0;i<N;i++)
      state[i] = h[i];
}

void compute_gru3(const GRULayer *gru, float *state, const float *input)
{
   int i;
   int N;
   int stride;
   float zrh[3*MAX_RNN_NEURONS];
   float recur[3*MAX_RNN_NEURONS];
   float *z;
   float *r;
   float *h;
   N = gru->nb_neurons;
   z = zrh;
   r = &zrh[N];
   h = &zrh[2*N];
   celt_assert(gru->nb_neurons <= MAX_RNN_NEURONS);
   celt_assert(input != state);
   celt_assert(gru->reset_after);
   stride = 3*N;
   RNN_COPY(zrh, input, 3*N);
   for (i=0;i<3*N;i++)
      recur[i] = gru->bias[3*N + i];
   sgemv_accum(recur, gru->recurrent_weights, 3*N, N, stride, state);
   for (i=0;i<2*N;i++)
      zrh[i] += recur[i];
   compute_activation(zrh, zrh, 2*N, ACTIVATION_SIGMOID);
   for (i=0;i<N;i++)
      h[i] += recur[2*N+i]*r[i];
   compute_activation(h, h, N, gru->activation);
   for (i=0;i<N;i++)
      h[i] = z[i]*state[i] + (1-z[i])*h[i];
   for (i=0;i<N;i++)
      state[i] = h[i];
}

void compute_sparse_gru(const SparseGRULayer *gru, float *state, const float *input)
{
   int i, k;
   int N;
   float zrh[3*MAX_RNN_NEURONS];
   float recur[3*MAX_RNN_NEURONS];
   float *z;
   float *r;
   float *h;
   N = gru->nb_neurons;
   z = zrh;
   r = &zrh[N];
   h = &zrh[2*N];
   celt_assert(gru->nb_neurons <= MAX_RNN_NEURONS);
   celt_assert(input != state);
   celt_assert(gru->reset_after);
   RNN_COPY(zrh, input, 3*N);
   for (i=0;i<3*N;i++)
      recur[i] = gru->bias[3*N + i];
   for (k=0;k<3;k++)
   {
      for (i=0;i<N;i++)
         recur[k*N + i] += gru->diag_weights[k*N + i]*state[i];
   }
   sparse_sgemv_accum16(recur, gru->recurrent_weights, 3*N, gru->idx, state);
   for (i=0;i<2*N;i++)
      zrh[i] += recur[i];
   compute_activation(zrh, zrh, 2*N, ACTIVATION_SIGMOID);
   for (i=0;i<N;i++)
      h[i] += recur[2*N+i]*r[i];
   compute_activation(h, h, N, gru->activation);
   for (i=0;i<N;i++)
      h[i] = z[i]*state[i] + (1-z[i])*h[i];
   for (i=0;i<N;i++)
      state[i] = h[i];
}

void compute_conv1d(const Conv1DLayer *layer, float *output, float *mem, const float *input)
{
   int i;
   int N, M;
   int stride;
   float tmp[MAX_CONV_INPUTS];
   celt_assert(input != output);
   celt_assert(layer->nb_inputs*layer->kernel_size <= MAX_CONV_INPUTS);
   RNN_COPY(tmp, mem, layer->nb_inputs*(layer->kernel_size-1));
   RNN_COPY(&tmp[layer->nb_inputs*(layer->kernel_size-1)], input, layer->nb_inputs);
   M = layer->nb_inputs*layer->kernel_size;
   N = layer->nb_neurons;
   stride = N;
   for (i=0;i<N;i++)
      output[i] = layer->bias[i];
   sgemv_accum(output, layer->input_weights, N, M, stride, tmp);
   compute_activation(output, output, N, layer->activation);
   RNN_COPY(mem, &tmp[layer->nb_inputs], layer->nb_inputs*(layer->kernel_size-1));
}

void compute_embedding(const EmbeddingLayer *layer, float *output, int input)
{
   int i;
   celt_assert(input >= 0);
   celt_assert(input < layer->nb_inputs);
   /*if (layer->dim == 64) printf("%d\n", input);*/
   for (i=0;i<layer->dim;i++)
   {
      output[i] = layer->embedding_weights[input*layer->dim + i];
   }    
}

void accum_embedding(const EmbeddingLayer *layer, float *output, int input)
{
   int i;
   celt_assert(input >= 0);
   celt_assert(input < layer->nb_inputs);
   /*if (layer->dim == 64) printf("%d\n", input);*/
   for (i=0;i<layer->dim;i++)
   {
      output[i] += layer->embedding_weights[input*layer->dim + i];
   }    
}

/* needed to replace Windows/gcc rand() with our own rand() function
   to get click free synthesised audio - not sure why */
#define NNET_RAND_MAX 32768
static uint32_t next = 1;
uint16_t nnet_rand(void) {
    next = next * 1103515245 + 12345;
    uint32_t r = (next/65536) % 32768;
    return((uint16_t)r);
}

int sample_from_pdf(const float *pdf, int N, float exp_boost, float pdf_floor)
{
    int i;
    float sum, norm;
    float r;
    float tmp[DUAL_FC_OUT_SIZE];
    celt_assert(N <= DUAL_FC_OUT_SIZE);
    sum = 0;
#ifdef SOFTMAX_HACK
    for (i=0;i<N;i++)
    {
        tmp[i] = pdf[i] * (1.f+exp_boost);
    }
    softmax(tmp, tmp, N);
    for (i=0;i<N;i++)
    {
        sum += tmp[i];
    }
#else
    /* Decrease the temperature of the sampling. */
    for (i=0;i<N;i++)
    {
        tmp[i] = pow(pdf[i], 1.f+exp_boost);
        sum += tmp[i];
    }
#endif
    norm = 1.f/sum;
    /* Convert tmp to a CDF while subtracting the floor */
    tmp[0] = MAX16(0, norm*tmp[0] - pdf_floor);
    for (i=1;i<N;i++)
    {
        tmp[i] = tmp[i-1] + MAX16(0, norm*tmp[i] - pdf_floor);
    }
    /* Do the sampling (from the cdf). */
    float annr = (float)nnet_rand();
    float arand = (annr/NNET_RAND_MAX);
    r = tmp[N-1] * arand;
    
    for (i=0;i<N-1;i++)
    {
        if (r < tmp[i]) return i;
    }
    //fprintf(stderr, "DUAL_FC_OUT_SIZE: %d annr: %f arand: %f\n", DUAL_FC_OUT_SIZE, annr, arand);
    return N-1;
}
