#include "convolutional_layer.h"
#include "utils.h"
#include "im2col.h"
#include "col2im.h"
#include "blas.h"
#include "gemm.h"
#include <stdio.h>
#include <time.h>

int convolutional_out_height(convolutional_layer l)
{
    int h = l.h;
    if (!l.pad) h -= l.size;
    else h -= 1;
    return h/l.stride + 1;
}

int convolutional_out_width(convolutional_layer l)
{
    int w = l.w;
    if (!l.pad) w -= l.size;
    else w -= 1;
    return w/l.stride + 1;
}

image get_convolutional_image(convolutional_layer l)
{
    int h,w,c;
    h = convolutional_out_height(l);
    w = convolutional_out_width(l);
    c = l.n;
    return float_to_image(w,h,c,l.output);
}

image get_convolutional_delta(convolutional_layer l)
{
    int h,w,c;
    h = convolutional_out_height(l);
    w = convolutional_out_width(l);
    c = l.n;
    return float_to_image(w,h,c,l.delta);
}

convolutional_layer make_convolutional_layer(int batch, int h, int w, int c, int n, int size, int stride, int pad, ACTIVATION activation)
{
    int i;
    convolutional_layer l = {0};
    l.type = CONVOLUTIONAL;

    l.h = h;
    l.w = w;
    l.c = c;
    l.n = n;
    l.batch = batch;
    l.stride = stride;
    l.size = size;
    l.pad = pad;

    l.filters = calloc(c*n*size*size, sizeof(float));
    l.filter_updates = calloc(c*n*size*size, sizeof(float));

    l.biases = calloc(n, sizeof(float));
    l.bias_updates = calloc(n, sizeof(float));
    //float scale = 1./sqrt(size*size*c);
    float scale = sqrt(2./(size*size*c));
    for(i = 0; i < c*n*size*size; ++i) l.filters[i] = 2*scale*rand_uniform() - scale;
    for(i = 0; i < n; ++i){
        l.biases[i] = scale;
    }
    int out_h = convolutional_out_height(l);
    int out_w = convolutional_out_width(l);
    l.out_h = out_h;
    l.out_w = out_w;
    l.out_c = n;
    l.outputs = l.out_h * l.out_w * l.out_c;
    l.inputs = l.w * l.h * l.c;

    l.col_image = calloc(out_h*out_w*size*size*c, sizeof(float));
    l.output = calloc(l.batch*out_h * out_w * n, sizeof(float));
    l.delta  = calloc(l.batch*out_h * out_w * n, sizeof(float));

    #ifdef GPU
    l.filters_gpu = cuda_make_array(l.filters, c*n*size*size);
    l.filter_updates_gpu = cuda_make_array(l.filter_updates, c*n*size*size);

    l.biases_gpu = cuda_make_array(l.biases, n);
    l.bias_updates_gpu = cuda_make_array(l.bias_updates, n);

    l.col_image_gpu = cuda_make_array(l.col_image, out_h*out_w*size*size*c);
    l.delta_gpu = cuda_make_array(l.delta, l.batch*out_h*out_w*n);
    l.output_gpu = cuda_make_array(l.output, l.batch*out_h*out_w*n);
    #endif
    l.activation = activation;

    fprintf(stderr, "Convolutional Layer: %d x %d x %d image, %d filters -> %d x %d x %d image\n", h,w,c,n, out_h, out_w, n);

    return l;
}

void resize_convolutional_layer(convolutional_layer *l, int w, int h)
{
    l->w = w;
    l->h = h;
    int out_w = convolutional_out_width(*l);
    int out_h = convolutional_out_height(*l);

    l->out_w = out_w;
    l->out_h = out_h;

    l->outputs = l->out_h * l->out_w * l->out_c;
    l->inputs = l->w * l->h * l->c;

    l->col_image = realloc(l->col_image,
                                out_h*out_w*l->size*l->size*l->c*sizeof(float));
    l->output = realloc(l->output,
                                l->batch*out_h * out_w * l->n*sizeof(float));
    l->delta  = realloc(l->delta,
                                l->batch*out_h * out_w * l->n*sizeof(float));

    #ifdef GPU
    cuda_free(l->col_image_gpu);
    cuda_free(l->delta_gpu);
    cuda_free(l->output_gpu);

    l->col_image_gpu = cuda_make_array(l->col_image, out_h*out_w*l->size*l->size*l->c);
    l->delta_gpu =     cuda_make_array(l->delta, l->batch*out_h*out_w*l->n);
    l->output_gpu =    cuda_make_array(l->output, l->batch*out_h*out_w*l->n);
    #endif
}

void bias_output(float *output, float *biases, int batch, int n, int size)
{
    int i,j,b;
    for(b = 0; b < batch; ++b){
        for(i = 0; i < n; ++i){
            for(j = 0; j < size; ++j){
                output[(b*n + i)*size + j] = biases[i];
            }
        }
    }
}

void backward_bias(float *bias_updates, float *delta, int batch, int n, int size)
{
    int i,b;
    for(b = 0; b < batch; ++b){
        for(i = 0; i < n; ++i){
            bias_updates[i] += sum_array(delta+size*(i+b*n), size);
        }
    }
}


void forward_convolutional_layer(const convolutional_layer l, network_state state)
{
    int out_h = convolutional_out_height(l);
    int out_w = convolutional_out_width(l);
    int i;

    bias_output(l.output, l.biases, l.batch, l.n, out_h*out_w);

    int m = l.n;
    int k = l.size*l.size*l.c;
    int n = out_h*out_w;

    float *a = l.filters;
    float *b = l.col_image;
    float *c = l.output;

    for(i = 0; i < l.batch; ++i){
        im2col_cpu(state.input, l.c, l.h, l.w, 
            l.size, l.stride, l.pad, b);
        gemm(0,0,m,n,k,1,a,k,b,n,1,c,n);
        c += n*m;
        state.input += l.c*l.h*l.w;
    }
    activate_array(l.output, m*n*l.batch, l.activation);
}

void backward_convolutional_layer(convolutional_layer l, network_state state)
{
    int i;
    int m = l.n;
    int n = l.size*l.size*l.c;
    int k = convolutional_out_height(l)*
        convolutional_out_width(l);

    gradient_array(l.output, m*k*l.batch, l.activation, l.delta);
    backward_bias(l.bias_updates, l.delta, l.batch, l.n, k);

    for(i = 0; i < l.batch; ++i){
        float *a = l.delta + i*m*k;
        float *b = l.col_image;
        float *c = l.filter_updates;

        float *im = state.input+i*l.c*l.h*l.w;

        im2col_cpu(im, l.c, l.h, l.w, 
                l.size, l.stride, l.pad, b);
        gemm(0,1,m,n,k,1,a,k,b,k,1,c,n);

        if(state.delta){
            a = l.filters;
            b = l.delta + i*m*k;
            c = l.col_image;

            gemm(1,0,n,k,m,1,a,n,b,k,0,c,k);

            col2im_cpu(l.col_image, l.c,  l.h,  l.w,  l.size,  l.stride, l.pad, state.delta+i*l.c*l.h*l.w);
        }
    }
}

void update_convolutional_layer(convolutional_layer l, int batch, float learning_rate, float momentum, float decay)
{
    int size = l.size*l.size*l.c*l.n;
    axpy_cpu(l.n, learning_rate/batch, l.bias_updates, 1, l.biases, 1);
    scal_cpu(l.n, momentum, l.bias_updates, 1);

    axpy_cpu(size, -decay*batch, l.filters, 1, l.filter_updates, 1);
    axpy_cpu(size, learning_rate/batch, l.filter_updates, 1, l.filters, 1);
    scal_cpu(size, momentum, l.filter_updates, 1);
}


image get_convolutional_filter(convolutional_layer l, int i)
{
    int h = l.size;
    int w = l.size;
    int c = l.c;
    return float_to_image(w,h,c,l.filters+i*h*w*c);
}

void rgbgr_filters(convolutional_layer l)
{
    int i;
    for(i = 0; i < l.n; ++i){
        image im = get_convolutional_filter(l, i);
        if (im.c == 3) {
            rgbgr_image(im);
        }
    }
}

void rescale_filters(convolutional_layer l, float scale, float trans)
{
    int i;
    for(i = 0; i < l.n; ++i){
        image im = get_convolutional_filter(l, i);
        if (im.c == 3) {
            scale_image(im, scale);
            float sum = sum_array(im.data, im.w*im.h*im.c);
            l.biases[i] += sum*trans;
        }
    }
}

image *get_filters(convolutional_layer l)
{
    image *filters = calloc(l.n, sizeof(image));
    int i;
    for(i = 0; i < l.n; ++i){
        filters[i] = copy_image(get_convolutional_filter(l, i));
        //normalize_image(filters[i]);
    }
    return filters;
}

image *visualize_convolutional_layer(convolutional_layer l, char *window, image *prev_filters)
{
    image *single_filters = get_filters(l);
    show_images(single_filters, l.n, window);

    image delta = get_convolutional_image(l);
    image dc = collapse_image_layers(delta, 1);
    char buff[256];
    sprintf(buff, "%s: Output", window);
    //show_image(dc, buff);
    //save_image(dc, buff);
    free_image(dc);
    return single_filters;
}

