#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Delaunay_triangulation_2.h>
#include <CGAL/natural_neighbor_coordinates_2.h>

#include <pipi.h>

#define TOTAL_POINTS 138
#define POINTS_PER_CELL 2

#define RANGE_X 16
#define RANGE_Y 16
#define RANGE_R 5
#define RANGE_G 5
#define RANGE_B 5
#define RANGE_S 1

#define RANGE_SY (RANGE_S*RANGE_Y)
#define RANGE_SYX (RANGE_S*RANGE_Y*RANGE_X)
#define RANGE_SYXR (RANGE_S*RANGE_Y*RANGE_X*RANGE_R)
#define RANGE_SYXRG (RANGE_S*RANGE_Y*RANGE_X*RANGE_R*RANGE_G)
#define RANGE_SYXRGB (RANGE_S*RANGE_Y*RANGE_X*RANGE_R*RANGE_G*RANGE_B)

struct K : CGAL::Exact_predicates_inexact_constructions_kernel {};
typedef CGAL::Delaunay_triangulation_2<K> Delaunay_triangulation;
typedef std::vector<std::pair<K::Point_2, K::FT> > Point_coordinate_vector;

/* Global aspect ratio */
static int dw, dh;

/* Global point encoding */
static uint32_t points[1024];
static int npoints = 0;

/* Global triangulation */
static Delaunay_triangulation dt;

static unsigned int det_rand(unsigned int mod)
{
    static unsigned long next = 1;
    next = next * 1103515245 + 12345;
    return ((unsigned)(next / 65536) % 32768) % mod;
}

static inline int float2int(float val, int range)
{
    int ret = (int)(val * ((float)range - 0.0001));
    return ret < 0 ? 0 : ret > range - 1? range - 1 : ret;
}

static inline float int2float(int val, int range)
{
    return (float)(1 + 2 * val) / (float)(2 * range);
}

static inline uint32_t set_point(int index, float x, float y, float r,
                                 float g, float b, float s)
{
    int dx = (index / POINTS_PER_CELL) % dw;
    int dy = (index / POINTS_PER_CELL) / dw;

    float fx = (x - dx * RANGE_X) / RANGE_X;
    float fy = (y - dy * RANGE_Y) / RANGE_Y;

    int is = float2int(s, RANGE_S);

    int ix = float2int(fx, RANGE_X);
    int iy = float2int(fy, RANGE_Y);

    int ir = float2int(r, RANGE_R);
    int ig = float2int(g, RANGE_G);
    int ib = float2int(b, RANGE_B);

    points[index] = is + RANGE_S * (iy + RANGE_Y * (ix + RANGE_X *
                               (ib + RANGE_B * (ig + (RANGE_R * ir)))));
}

static inline void get_point(int index, float *x, float *y, float *r,
                             float *g, float *b, float *s)
{
    uint32_t pt = points[index];

    unsigned int dx = (index / POINTS_PER_CELL) % dw;
    unsigned int dy = (index / POINTS_PER_CELL) / dw;

    float fs = int2float(pt % RANGE_S, RANGE_S); pt /= RANGE_S;

    *s = fs < 0.5 ? 0.0 : 1.0;

    float fy = int2float(pt % RANGE_Y, RANGE_Y); pt /= RANGE_Y;
    float fx = int2float(pt % RANGE_X, RANGE_X); pt /= RANGE_X;

    *x = (fx + dx) * RANGE_X;
    *y = (fy + dy) * RANGE_Y;

    *b = int2float(pt % RANGE_R, RANGE_R); pt /= RANGE_R;
    *g = int2float(pt % RANGE_G, RANGE_G); pt /= RANGE_G;
    *r = int2float(pt % RANGE_B, RANGE_B); pt /= RANGE_B;
}

static inline float clip(float x, int modulo)
{
    float mul = (float)modulo + 0.9999;
    int round = (int)(x * mul);
    return (float)round / (float)modulo;
}

static void add_point(float x, float y, float r, float g, float b, float s)
{
    set_point(npoints, x, y, r, g, b, s);
    get_point(npoints, &x, &y, &r, &g, &b, &s);
    npoints++;
}

#define MAX_OPS 15

static uint32_t apply_op(uint8_t op, uint32_t val)
{
    uint32_t rem, ext;

    switch(op)
    {
    case 0: /* Flip strength value */
        return val ^ 1;
    case 1: /* Move up; if impossible, down */
        rem = val % RANGE_S;
        ext = (val / RANGE_S) % RANGE_Y;
        ext = ext > 0 ? ext - 1 : ext + 1;
        return (val / RANGE_SY * RANGE_Y + ext) * RANGE_S + rem;
    case 2: /* Move down; if impossible, up */
        rem = val % RANGE_S;
        ext = (val / RANGE_S) % RANGE_Y;
        ext = ext < RANGE_Y - 1 ? ext + 1 : ext - 1;
        return (val / RANGE_SY * RANGE_Y + ext) * RANGE_S + rem;
    case 3: /* Move left; if impossible, right */
        rem = val % RANGE_SY;
        ext = (val / RANGE_SY) % RANGE_X;
        ext = ext > 0 ? ext - 1 : ext + 1;
        return (val / RANGE_SYX * RANGE_X + ext) * RANGE_SY + rem;
    case 4: /* Move left; if impossible, right */
        rem = val % RANGE_SY;
        ext = (val / RANGE_SY) % RANGE_X;
        ext = ext < RANGE_X - 1 ? ext + 1 : ext - 1;
        return (val / RANGE_SYX * RANGE_X + ext) * RANGE_SY + rem;
    case 5: /* Corner 1 */
        return apply_op(1, apply_op(3, val));
    case 6: /* Corner 2 */
        return apply_op(1, apply_op(4, val));
    case 7: /* Corner 3 */
        return apply_op(2, apply_op(4, val));
    case 8: /* Corner 4 */
        return apply_op(2, apply_op(3, val));
    case 9: /* R-- (or R++) */
        rem = val % RANGE_SYX;
        ext = (val / RANGE_SYX) % RANGE_R;
        ext = ext > 0 ? ext - 1 : ext + 1;
        return (val / RANGE_SYXR * RANGE_R + ext) * RANGE_SYX + rem;
    case 10: /* R++ (or R--) */
        rem = val % RANGE_SYX;
        ext = (val / RANGE_SYX) % RANGE_R;
        ext = ext < RANGE_R - 1 ? ext + 1 : ext - 1;
        return (val / RANGE_SYXR * RANGE_R + ext) * RANGE_SYX + rem;
    case 11: /* G-- (or G++) */
        rem = val % RANGE_SYXR;
        ext = (val / RANGE_SYXR) % RANGE_G;
        ext = ext > 0 ? ext - 1 : ext + 1;
        return (val / RANGE_SYXRG * RANGE_G + ext) * RANGE_SYXR + rem;
    case 12: /* G++ (or G--) */
        rem = val % RANGE_SYXR;
        ext = (val / RANGE_SYXR) % RANGE_G;
        ext = ext < RANGE_G - 1 ? ext + 1 : ext - 1;
        return (val / RANGE_SYXRG * RANGE_G + ext) * RANGE_SYXR + rem;
    case 13: /* B-- (or B++) */
        rem = val % RANGE_SYXRG;
        ext = (val / RANGE_SYXRG) % RANGE_B;
        ext = ext > 0 ? ext - 1 : ext + 1;
        return ext * RANGE_SYXRG + rem;
    case 14: /* B++ (or B--) */
        rem = val % RANGE_SYXRG;
        ext = (val / RANGE_SYXRG) % RANGE_B;
        ext = ext < RANGE_B - 1 ? ext + 1 : ext - 1;
        return ext * RANGE_SYXRG + rem;
#if 0
    case 15: /* Brightness-- */
        return apply_op(9, apply_op(11, apply_op(13, val)));
    case 16: /* Brightness++ */
        return apply_op(10, apply_op(12, apply_op(14, val)));
    case 17: /* RG-- */
        return apply_op(9, apply_op(11, val));
    case 18: /* RG++ */
        return apply_op(10, apply_op(12, val));
    case 19: /* GB-- */
        return apply_op(11, apply_op(13, val));
    case 20: /* GB++ */
        return apply_op(12, apply_op(14, val));
    case 21: /* RB-- */
        return apply_op(9, apply_op(13, val));
    case 22: /* RB++ */
        return apply_op(10, apply_op(14, val));
#endif
    default:
        return val;
    }
}

static void render(pipi_image_t *dst, int rx, int ry, int rw, int rh)
{
    uint8_t lookup[TOTAL_POINTS / POINTS_PER_CELL * RANGE_X * RANGE_Y];
    pipi_pixels_t *p = pipi_get_pixels(dst, PIPI_PIXELS_RGBA_F32);
    float *data = (float *)p->pixels;
    float fx, fy, fr, fg, fb, fs;
    int i, x, y;

    memset(lookup, 0, sizeof(lookup));
    dt.clear();
    for(i = 0; i < npoints; i++)
    {
        get_point(i, &fx, &fy, &fr, &fg, &fb, &fs);
        lookup[(int)fx + dw * RANGE_X * (int)fy] = i; /* Keep link to point */
        dt.insert(K::Point_2(fx, fy));
    }

    /* Add fake points to close the triangulation */
    dt.insert(K::Point_2(-p->w, -p->h));
    dt.insert(K::Point_2(2 * p->w, -p->h));
    dt.insert(K::Point_2(-p->w, 2 * p->h));
    dt.insert(K::Point_2(2 * p->w, 2 * p->h));

    for(y = ry; y < ry + rh; y++)
    {
        for(x = rx; x < rx + rw; x++)
        {
            int i1 = 0, i2 = 0, i3 = 0;
            float d1 = 1000000, d2 = 0, d3 = 0;

            K::Point_2 m(x, y);
            Point_coordinate_vector coords;
            CGAL::Triple<
              std::back_insert_iterator<Point_coordinate_vector>,
              K::FT, bool> result =
              CGAL::natural_neighbor_coordinates_2(dt, m,
                                                   std::back_inserter(coords));

            float r = 0.0f, g = 0.0f, b = 0.0f, norm = 0.0f;

            Point_coordinate_vector::iterator it;
            for(it = coords.begin(); it != coords.end(); ++it)
            {
                float fx = (*it).first.x();
                float fy = (*it).first.y();

                if(fx < 0 || fy < 0 || fx > p->w - 1 || fy > p->h - 1)
                    continue;

                int index = lookup[(int)fx + dw * RANGE_X * (int)fy];

                get_point(index, &fx, &fy, &fr, &fg, &fb, &fs);

                float k = (*it).second;
                if(fs > 0.5) k = pow(k, 1.2);
                else k = pow(k, 0.8);
                //float k = (*it).second * (1.0f + fs);

                r += k * fr;
                g += k * fg;
                b += k * fb;
                norm += k;
            }

            data[4 * (x + y * p->w) + 0] = r / norm;
            data[4 * (x + y * p->w) + 1] = g / norm;
            data[4 * (x + y * p->w) + 2] = b / norm;
            data[4 * (x + y * p->w) + 3] = 0.0;
        }
    }

    pipi_release_pixels(dst, p);
}

static void analyse(pipi_image_t *src)
{
    pipi_pixels_t *p = pipi_get_pixels(src, PIPI_PIXELS_RGBA_F32);
    float *data = (float *)p->pixels;
    int i;

    for(int dy = 0; dy < dh; dy++)
        for(int dx = 0; dx < dw; dx++)
        {
            float min = 1.1f, max = -0.1f;
            float total = 0.0;
            int xmin = 0, xmax = 0, ymin = 0, ymax = 0;
            int npixels = 0;

            for(int iy = RANGE_Y * dy; iy < RANGE_Y * (dy + 1); iy++)
                for(int ix = RANGE_X * dx; ix < RANGE_X * (dx + 1); ix++)
                {
                    float lum = 0.0f;

                    lum += data[4 * (ix + iy * p->w) + 0];
                    lum += data[4 * (ix + iy * p->w) + 1];
                    lum += data[4 * (ix + iy * p->w) + 2];

                    if(lum < min)
                    {
                        min = lum;
                        xmin = ix;
                        ymin = iy;
                    }

                    if(lum > max)
                    {
                        max = lum;
                        xmax = ix;
                        ymax = iy;
                    }

                    total += lum;
                    npixels++;
                }

            total /= npixels;

            float wmin, wmax;

            if(total < min + (max - min) / 4)
                wmin = 1.0, wmax = 0.0;
            else if(total < min + (max - min) / 4 * 2)
                wmin = 0.0, wmax = 0.0;
            else if(total < min + (max - min) / 4 * 3)
                wmin = 0.0, wmax = 0.0;
            else
                wmin = 0.0, wmax = 1.0;

//wmin = wmax = 1.0;
//if(total < min + (max - min) /3 )
//if((dx + dy) & 1)
{
            add_point(xmin, ymin,
                      data[4 * (xmin + ymin * p->w) + 0],
                      data[4 * (xmin + ymin * p->w) + 1],
                      data[4 * (xmin + ymin * p->w) + 2],
                      wmin);
}
//else
{
            add_point(xmax, ymax,
                      data[4 * (xmax + ymax * p->w) + 0],
                      data[4 * (xmax + ymax * p->w) + 1],
                      data[4 * (xmax + ymax * p->w) + 2],
                      wmax);
}
        }
}

int main(int argc, char *argv[])
{
    int opstats[2 * MAX_OPS];
    pipi_image_t *src, *tmp, *dst;
    double error = 1.0;
    int width, height, ret = 0;

    /* Load image */
    pipi_set_gamma(1.0);
    src = pipi_load(argv[1]);
    width = pipi_get_image_width(src);
    height = pipi_get_image_height(src);

    /* Compute best w/h ratio */
    dw = 1;
    for(int i = 1; i <= TOTAL_POINTS / POINTS_PER_CELL; i++)
    {
        float r = (float)width / (float)height;
        float ir = (float)i / (float)(TOTAL_POINTS / POINTS_PER_CELL / i);
        float dwr = (float)dw / (float)(TOTAL_POINTS / POINTS_PER_CELL / dw);

        if(fabs(logf(r / ir)) < fabs(logf(r / dwr)))
            dw = i;
    }
    dh = TOTAL_POINTS / POINTS_PER_CELL / dw;
    fprintf(stderr, "Chosen image ratio: %i:%i\n", dw, dh);

    /* Resize and filter image to better state */
    tmp = pipi_resize(src, dw * RANGE_X, dh * RANGE_Y);
    pipi_free(src);
    src = pipi_median_ext(tmp, 2, 2);

    /* Analyse image */
    analyse(src);

    /* Render what we just computed */
    tmp = pipi_new(dw * RANGE_X, dh * RANGE_Y);
    render(tmp, 0, 0, dw * RANGE_X, dh * RANGE_Y);
    error = pipi_measure_rmsd(src, tmp);

    fprintf(stderr, "Distance: %2.10g\n", error);

    memset(opstats, 0, sizeof(opstats));
    for(int iter = 0, failures = 0; /*failures < 200 &&*/ iter < 3000; iter++)
    {
        uint32_t oldval;
        pipi_image_t *scrap = pipi_copy(tmp);

        /* Choose a point at random */
        int pt = det_rand(npoints);
        oldval = points[pt];

        /* Apply a random operation and measure its effect */
        uint8_t op = det_rand(MAX_OPS);
        points[pt] = apply_op(op, oldval);
        render(scrap, 0, 0, dw * RANGE_X, dh * RANGE_Y);

        opstats[op * 2]++;

        double newerr = pipi_measure_rmsd(src, scrap);
        if(newerr < error)
        {
            pipi_free(tmp);
            tmp = scrap;
            error = newerr;
            fprintf(stderr, "%06i %2.010g after op%i(%i)\n",
                    iter, error, op, pt);
            opstats[op * 2 + 1]++;
            failures = 0;
        }
        else
        {
            pipi_free(scrap);
            points[pt] = oldval;
            failures++;
        }
    }

    fprintf(stderr,   "operation: ");
    for(int i = 0; i < MAX_OPS; i++)
        fprintf(stderr, "%3i ", i);
    fprintf(stderr, "\nattempts:  ");
    for(int i = 0; i < MAX_OPS; i++)
        fprintf(stderr, "%3i ", opstats[i * 2]);
    fprintf(stderr, "\nsuccesses: ");
    for(int i = 0; i < MAX_OPS; i++)
        fprintf(stderr, "%3i ", opstats[i * 2 + 1]);
    fprintf(stderr, "\n");

    fprintf(stderr, "Distance: %2.10g\n", error);

    dst = pipi_resize(tmp, width, height);
    pipi_free(tmp);

    /* Save image and bail out */
    pipi_save(dst, "lol.bmp");
    pipi_free(dst);

    return ret;
}