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

struct NoiseLevel;

struct NoiseGenerator
{
    int size1;
    int size2;
    int size3;
    double* noise;
    double height_offset;
    int level_count;
    struct NoiseLevel* levels;
};

#include "shared/types.h"
#include "shared/functions.h"

static inline double _cubicInterpolate(double* p, double x)
{
    return p[1] + 0.5 * x * (p[2] - p[0] + x * (2.0 * p[0] - 5.0 * p[1] + 4.0 * p[2] - p[3] + x * (3.0 * (p[1] - p[2]) + p[3] - p[0])));
}


NoiseGenerator* noiseCreateGenerator()
{
    NoiseGenerator* result;

    /* initialize */
    result = malloc(sizeof(NoiseGenerator));
    result->size1 = 1;
    result->size2 = 1;
    result->size3 = 1;
    result->noise = malloc(sizeof(double));
    result->noise[0] = 0.0;
    result->level_count = 0;
    result->levels = malloc(sizeof(NoiseLevel));
    result->height_offset = 0.0;

    return result;
}

void noiseDeleteGenerator(NoiseGenerator* generator)
{
    free(generator->noise);
    free(generator->levels);
    free(generator);
}

void noiseSave(NoiseGenerator* perlin, FILE* f)
{
    int x;
    double* it_noise;

    toolsSaveInt(f, perlin->size1);
    toolsSaveInt(f, perlin->size2);
    toolsSaveInt(f, perlin->size3);
    toolsSaveDouble(f, perlin->height_offset);
    toolsSaveInt(f, perlin->level_count);

    it_noise = perlin->noise;
    for (x = 0; x < perlin->size1; x++)
    {
        toolsSaveDouble(f, *(it_noise++));
    }

    for (x = 0; x < perlin->level_count; x++)
    {
        NoiseLevel level = perlin->levels[x];
        toolsSaveDouble(f, level.scaling);
        toolsSaveDouble(f, level.height);
        toolsSaveDouble(f, level.xoffset);
        toolsSaveDouble(f, level.yoffset);
        toolsSaveDouble(f, level.zoffset);
    }
}

void noiseLoad(NoiseGenerator* perlin, FILE* f)
{
    int x;
    double* it_noise;

    perlin->size1 = toolsLoadInt(f);
    perlin->size2 = toolsLoadInt(f);
    perlin->size3 = toolsLoadInt(f);
    perlin->height_offset = toolsLoadDouble(f);
    perlin->level_count = toolsLoadInt(f);

    perlin->noise = realloc(perlin->noise, sizeof(double) * perlin->size1);
    it_noise = perlin->noise;
    for (x = 0; x < perlin->size1; x++)
    {
        *(it_noise++) = toolsLoadDouble(f);
    }

    perlin->levels = realloc(perlin->levels, sizeof(NoiseLevel) * perlin->level_count);
    for (x = 0; x < perlin->level_count; x++)
    {
        NoiseLevel* level = perlin->levels + x;
        level->scaling = toolsLoadDouble(f);
        level->height = toolsLoadDouble(f);
        level->xoffset = toolsLoadDouble(f);
        level->yoffset = toolsLoadDouble(f);
        level->zoffset = toolsLoadDouble(f);
    }
}

void noiseCopy(NoiseGenerator* source, NoiseGenerator* destination)
{
    destination->size1 = source->size1;
    destination->size2 = source->size2;
    destination->size3 = source->size3;
    destination->height_offset = source->height_offset;
    destination->level_count = source->level_count;

    destination->noise = realloc(destination->noise, sizeof(double) * destination->size1);
    memcpy(destination->noise, source->noise, sizeof(double) * destination->size1);

    destination->levels = realloc(destination->levels, sizeof(NoiseLevel) * destination->level_count);
    memcpy(destination->levels, source->levels, sizeof(NoiseLevel) * destination->level_count);
}

void noiseGenerateBaseNoise(NoiseGenerator* generator, int size)
{
    int x;
    double* it_noise;

    size = (size < 1) ? 1 : size;
    size = (size > 4000000) ? 4000000 : size;

    generator->size1 = size;
    generator->size2 = (int)floor(sqrt((float)size));
    generator->size3 = (int)floor(cbrt((float)size));
    generator->noise = realloc(generator->noise, sizeof(double) * size);

    it_noise = generator->noise;
    for (x = 0; x < size; x++)
    {
        *(it_noise++) = toolsRandom() - 0.5;
    }
}

int noiseGetBaseSize(NoiseGenerator* generator)
{
    return generator->size1;
}

double noiseGetMaxValue(NoiseGenerator* generator)
{
    int x;
    double result = generator->height_offset;

    for (x = 0; x < generator->level_count; x++)
    {
        result += generator->levels[x].height / 2.0;
    }

    return result;
}

int noiseGetLevelCount(NoiseGenerator* generator)
{
    return generator->level_count;
}

void noiseClearLevels(NoiseGenerator* generator)
{
    generator->level_count = 0;
}

void noiseAddLevel(NoiseGenerator* generator, NoiseLevel level)
{
    if (level.scaling < 0.0000001 || level.height < 0.0000001)
    {
        return;
    }

    generator->levels = realloc(generator->levels, sizeof(NoiseLevel) * (generator->level_count + 1));
    generator->levels[generator->level_count] = level;
    generator->level_count++;
}

void noiseAddLevelSimple(NoiseGenerator* generator, double scaling, double height)
{
    NoiseLevel level;
    
    level.scaling = scaling;
    level.height = height;
    level.xoffset = toolsRandom();
    level.yoffset = toolsRandom();
    level.zoffset = toolsRandom();
    
    noiseAddLevel(generator, level);
}

void noiseAddLevels(NoiseGenerator* generator, int level_count, NoiseLevel start_level, double scaling_factor, double height_factor, int randomize_offset)
{
    int i;

    for (i = 0; i < level_count; i++)
    {
        if (randomize_offset)
        {
            start_level.xoffset = toolsRandom();
            start_level.yoffset = toolsRandom();
            start_level.zoffset = toolsRandom();
        }
        noiseAddLevel(generator, start_level);
        start_level.scaling *= scaling_factor;
        start_level.height *= height_factor;
    }
}

void noiseAddLevelsSimple(NoiseGenerator* generator, int level_count, double scaling, double height)
{
    NoiseLevel level;
    
    level.scaling = scaling;
    level.height = height;
    noiseAddLevels(generator, level_count, level, 0.5, 0.5, 1);
}

int noiseGetLevel(NoiseGenerator* generator, int level, NoiseLevel* params)
{
    if (level >= 0 && level < generator->level_count)
    {
        *params = generator->levels[level];
        return 1;
    }
    else
    {
        return 0;
    }
}

void noiseSetLevel(NoiseGenerator* generator, int level, NoiseLevel params)
{
    if (level >= 0 && level < generator->level_count)
    {
        generator->levels[level] = params;
    }
}

void noiseSetLevelSimple(NoiseGenerator* generator, int level, double scaling, double height)
{
    NoiseLevel params;
    
    params.scaling = scaling;
    params.height = height;
    params.xoffset = toolsRandom();
    params.yoffset = toolsRandom();
    params.zoffset = toolsRandom();
    
    noiseSetLevel(generator, level, params);
}

void noiseNormalizeHeight(NoiseGenerator* generator, double min_height, double max_height, int adjust_scaling)
{
    int level;
    double height = 0.0;
    double target_height = max_height - min_height;

    if (generator->level_count == 0)
    {
        return;
    }

    for (level = 0; level < generator->level_count; level++)
    {
        height += generator->levels[level].height;
    }
    for (level = 0; level < generator->level_count; level++)
    {
        generator->levels[level].height *= target_height / height;
        if (adjust_scaling)
        {
            generator->levels[level].scaling *= target_height / height;
        }
    }
    generator->height_offset = min_height + target_height / 2.0;
}




static inline double _get1DRawNoiseValue(NoiseGenerator* generator, double x)
{
    double* noise = generator->noise;
    int size = generator->size1;

    int xbase = (int)floor(x);

    double xinternal = x - (double)xbase;

    int x0 = (xbase - 1) % size;
    if (x0 < 0)
    {
        x0 += size;
    }
    int x1 = xbase % size;
    if (x1 < 0)
    {
        x1 += size;
    }
    int x2 = (xbase + 1) % size;
    if (x2 < 0)
    {
        x2 += size;
    }
    int x3 = (xbase + 2) % size;
    if (x3 < 0)
    {
        x3 += size;
    }

    double buf_cubic_x[4];

    buf_cubic_x[0] = noise[x0];
    buf_cubic_x[1] = noise[x1];
    buf_cubic_x[2] = noise[x2];
    buf_cubic_x[3] = noise[x3];

    return _cubicInterpolate(buf_cubic_x, xinternal);
}

static inline double _get1DLevelValue(NoiseGenerator* generator, NoiseLevel* level, double x)
{
    return _get1DRawNoiseValue(generator, x / level->scaling + level->xoffset * generator->size1) * level->height;
}

double noiseGet1DLevel(NoiseGenerator* generator, int level, double x)
{
    if (level >= 0 && level < generator->level_count)
    {
        return _get1DLevelValue(generator, generator->levels + level, x);
    }
    else
    {
        return 0.0;
    }
}

double noiseGet1DTotal(NoiseGenerator* generator, double x)
{
    int level;
    double result;

    result = 0.0;
    for (level = 0; level < generator->level_count; level++)
    {
        result += _get1DLevelValue(generator, generator->levels + level, x);
    }
    return result + generator->height_offset;
}

double noiseGet1DDetail(NoiseGenerator* generator, double x, double detail)
{
    int level;
    double result, height, factor;

    result = 0.0;
    for (level = 0; level < generator->level_count; level++)
    {
        height = generator->levels[level].height;
        factor = 1.0;
        if (height < detail * 0.25)
        {
            break;
        }
        else if (height < detail * 0.5)
        {
            factor = (detail * 0.5 - height) / 0.25;
        }

        result += _get1DLevelValue(generator, generator->levels + level, x) * factor;
    }
    return result + generator->height_offset;
}




static inline double _get2DRawNoiseValue(NoiseGenerator* generator, double x, double y)
{
    double* noise = generator->noise;
    int size = generator->size2;

    int xbase = (int)floor(x);
    int ybase = (int)floor(y);

    double xinternal = x - (double)xbase;
    double yinternal = y - (double)ybase;

    int x0 = (xbase - 1) % size;
    if (x0 < 0)
    {
        x0 += size;
    }
    int x1 = xbase % size;
    if (x1 < 0)
    {
        x1 += size;
    }
    int x2 = (xbase + 1) % size;
    if (x2 < 0)
    {
        x2 += size;
    }
    int x3 = (xbase + 2) % size;
    if (x3 < 0)
    {
        x3 += size;
    }

    int y0 = (ybase - 1) % size;
    if (y0 < 0)
    {
        y0 += size;
    }
    int y1 = ybase % size;
    if (y1 < 0)
    {
        y1 += size;
    }
    int y2 = (ybase + 1) % size;
    if (y2 < 0)
    {
        y2 += size;
    }
    int y3 = (ybase + 2) % size;
    if (y3 < 0)
    {
        y3 += size;
    }

    double buf_cubic_x[4];
    double buf_cubic_y[4];

    buf_cubic_x[0] = noise[y0 * size + x0];
    buf_cubic_x[1] = noise[y0 * size + x1];
    buf_cubic_x[2] = noise[y0 * size + x2];
    buf_cubic_x[3] = noise[y0 * size + x3];
    buf_cubic_y[0] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y1 * size + x0];
    buf_cubic_x[1] = noise[y1 * size + x1];
    buf_cubic_x[2] = noise[y1 * size + x2];
    buf_cubic_x[3] = noise[y1 * size + x3];
    buf_cubic_y[1] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y2 * size + x0];
    buf_cubic_x[1] = noise[y2 * size + x1];
    buf_cubic_x[2] = noise[y2 * size + x2];
    buf_cubic_x[3] = noise[y2 * size + x3];
    buf_cubic_y[2] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y3 * size + x0];
    buf_cubic_x[1] = noise[y3 * size + x1];
    buf_cubic_x[2] = noise[y3 * size + x2];
    buf_cubic_x[3] = noise[y3 * size + x3];
    buf_cubic_y[3] = _cubicInterpolate(buf_cubic_x, xinternal);

    return _cubicInterpolate(buf_cubic_y, yinternal);
}

static inline double _get2DLevelValue(NoiseGenerator* generator, NoiseLevel* level, double x, double y)
{
    return _get2DRawNoiseValue(generator, x / level->scaling + level->xoffset * generator->size2, y / level->scaling + level->yoffset * generator->size2) * level->height;
}

double noiseGet2DLevel(NoiseGenerator* generator, int level, double x, double y)
{
    if (level >= 0 && level < generator->level_count)
    {
        return _get2DLevelValue(generator, generator->levels + level, x, y);
    }
    else
    {
        return 0.0;
    }
}

double noiseGet2DTotal(NoiseGenerator* generator, double x, double y)
{
    int level;
    double result;

    result = 0.0;
    for (level = 0; level < generator->level_count; level++)
    {
        result += _get2DLevelValue(generator, generator->levels + level, x, y);
    }
    return result + generator->height_offset;
}

double noiseGet2DDetail(NoiseGenerator* generator, double x, double y, double detail)
{
    int level;
    double result, height, factor;

    result = 0.0;
    for (level = 0; level < generator->level_count; level++)
    {
        height = generator->levels[level].height;
        factor = 1.0;
        if (height < detail * 0.25)
        {
            break;
        }
        else if (height < detail * 0.5)
        {
            factor = (detail * 0.5 - height) / 0.25;
        }

        result += _get2DLevelValue(generator, generator->levels + level, x, y) * factor;
    }
    return result + generator->height_offset;
}




static inline double _get3DRawNoiseValue(NoiseGenerator* generator, double x, double y, double z)
{
    double* noise = generator->noise;
    int size = generator->size3;

    int xbase = (int)floor(x);
    int ybase = (int)floor(y);
    int zbase = (int)floor(z);

    double xinternal = x - (double)xbase;
    double yinternal = y - (double)ybase;
    double zinternal = z - (double)zbase;

    int x0 = (xbase - 1) % size;
    if (x0 < 0)
    {
        x0 += size;
    }
    int x1 = xbase % size;
    if (x1 < 0)
    {
        x1 += size;
    }
    int x2 = (xbase + 1) % size;
    if (x2 < 0)
    {
        x2 += size;
    }
    int x3 = (xbase + 2) % size;
    if (x3 < 0)
    {
        x3 += size;
    }

    int y0 = (ybase - 1) % size;
    if (y0 < 0)
    {
        y0 += size;
    }
    int y1 = ybase % size;
    if (y1 < 0)
    {
        y1 += size;
    }
    int y2 = (ybase + 1) % size;
    if (y2 < 0)
    {
        y2 += size;
    }
    int y3 = (ybase + 2) % size;
    if (y3 < 0)
    {
        y3 += size;
    }

    int z0 = (zbase - 1) % size;
    if (z0 < 0)
    {
        z0 += size;
    }
    int z1 = zbase % size;
    if (z1 < 0)
    {
        z1 += size;
    }
    int z2 = (zbase + 1) % size;
    if (z2 < 0)
    {
        z2 += size;
    }
    int z3 = (zbase + 2) % size;
    if (z3 < 0)
    {
        z3 += size;
    }

    double buf_cubic_x[4];
    double buf_cubic_y[4];
    double buf_cubic_z[4];

    buf_cubic_x[0] = noise[y0 * size * size + x0 * size + z0];
    buf_cubic_x[1] = noise[y0 * size * size + x1 * size + z0];
    buf_cubic_x[2] = noise[y0 * size * size + x2 * size + z0];
    buf_cubic_x[3] = noise[y0 * size * size + x3 * size + z0];
    buf_cubic_y[0] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y1 * size * size + x0 * size + z0];
    buf_cubic_x[1] = noise[y1 * size * size + x1 * size + z0];
    buf_cubic_x[2] = noise[y1 * size * size + x2 * size + z0];
    buf_cubic_x[3] = noise[y1 * size * size + x3 * size + z0];
    buf_cubic_y[1] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y2 * size * size + x0 * size + z0];
    buf_cubic_x[1] = noise[y2 * size * size + x1 * size + z0];
    buf_cubic_x[2] = noise[y2 * size * size + x2 * size + z0];
    buf_cubic_x[3] = noise[y2 * size * size + x3 * size + z0];
    buf_cubic_y[2] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y3 * size * size + x0 * size + z0];
    buf_cubic_x[1] = noise[y3 * size * size + x1 * size + z0];
    buf_cubic_x[2] = noise[y3 * size * size + x2 * size + z0];
    buf_cubic_x[3] = noise[y3 * size * size + x3 * size + z0];
    buf_cubic_y[3] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_z[0] =  _cubicInterpolate(buf_cubic_y, yinternal);

    buf_cubic_x[0] = noise[y0 * size * size + x0 * size + z1];
    buf_cubic_x[1] = noise[y0 * size * size + x1 * size + z1];
    buf_cubic_x[2] = noise[y0 * size * size + x2 * size + z1];
    buf_cubic_x[3] = noise[y0 * size * size + x3 * size + z1];
    buf_cubic_y[0] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y1 * size * size + x0 * size + z1];
    buf_cubic_x[1] = noise[y1 * size * size + x1 * size + z1];
    buf_cubic_x[2] = noise[y1 * size * size + x2 * size + z1];
    buf_cubic_x[3] = noise[y1 * size * size + x3 * size + z1];
    buf_cubic_y[1] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y2 * size * size + x0 * size + z1];
    buf_cubic_x[1] = noise[y2 * size * size + x1 * size + z1];
    buf_cubic_x[2] = noise[y2 * size * size + x2 * size + z1];
    buf_cubic_x[3] = noise[y2 * size * size + x3 * size + z1];
    buf_cubic_y[2] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y3 * size * size + x0 * size + z1];
    buf_cubic_x[1] = noise[y3 * size * size + x1 * size + z1];
    buf_cubic_x[2] = noise[y3 * size * size + x2 * size + z1];
    buf_cubic_x[3] = noise[y3 * size * size + x3 * size + z1];
    buf_cubic_y[3] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_z[1] =  _cubicInterpolate(buf_cubic_y, yinternal);

    buf_cubic_x[0] = noise[y0 * size * size + x0 * size + z2];
    buf_cubic_x[1] = noise[y0 * size * size + x1 * size + z2];
    buf_cubic_x[2] = noise[y0 * size * size + x2 * size + z2];
    buf_cubic_x[3] = noise[y0 * size * size + x3 * size + z2];
    buf_cubic_y[0] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y1 * size * size + x0 * size + z2];
    buf_cubic_x[1] = noise[y1 * size * size + x1 * size + z2];
    buf_cubic_x[2] = noise[y1 * size * size + x2 * size + z2];
    buf_cubic_x[3] = noise[y1 * size * size + x3 * size + z2];
    buf_cubic_y[1] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y2 * size * size + x0 * size + z2];
    buf_cubic_x[1] = noise[y2 * size * size + x1 * size + z2];
    buf_cubic_x[2] = noise[y2 * size * size + x2 * size + z2];
    buf_cubic_x[3] = noise[y2 * size * size + x3 * size + z2];
    buf_cubic_y[2] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y3 * size * size + x0 * size + z2];
    buf_cubic_x[1] = noise[y3 * size * size + x1 * size + z2];
    buf_cubic_x[2] = noise[y3 * size * size + x2 * size + z2];
    buf_cubic_x[3] = noise[y3 * size * size + x3 * size + z2];
    buf_cubic_y[3] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_z[2] =  _cubicInterpolate(buf_cubic_y, yinternal);

    buf_cubic_x[0] = noise[y0 * size * size + x0 * size + z3];
    buf_cubic_x[1] = noise[y0 * size * size + x1 * size + z3];
    buf_cubic_x[2] = noise[y0 * size * size + x2 * size + z3];
    buf_cubic_x[3] = noise[y0 * size * size + x3 * size + z3];
    buf_cubic_y[0] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y1 * size * size + x0 * size + z3];
    buf_cubic_x[1] = noise[y1 * size * size + x1 * size + z3];
    buf_cubic_x[2] = noise[y1 * size * size + x2 * size + z3];
    buf_cubic_x[3] = noise[y1 * size * size + x3 * size + z3];
    buf_cubic_y[1] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y2 * size * size + x0 * size + z3];
    buf_cubic_x[1] = noise[y2 * size * size + x1 * size + z3];
    buf_cubic_x[2] = noise[y2 * size * size + x2 * size + z3];
    buf_cubic_x[3] = noise[y2 * size * size + x3 * size + z3];
    buf_cubic_y[2] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_x[0] = noise[y3 * size * size + x0 * size + z3];
    buf_cubic_x[1] = noise[y3 * size * size + x1 * size + z3];
    buf_cubic_x[2] = noise[y3 * size * size + x2 * size + z3];
    buf_cubic_x[3] = noise[y3 * size * size + x3 * size + z3];
    buf_cubic_y[3] = _cubicInterpolate(buf_cubic_x, xinternal);

    buf_cubic_z[3] =  _cubicInterpolate(buf_cubic_y, yinternal);

    return _cubicInterpolate(buf_cubic_z, zinternal);
}

static inline double _get3DLevelValue(NoiseGenerator* generator, NoiseLevel* level, double x, double y, double z)
{
    return _get3DRawNoiseValue(generator, x / level->scaling + level->xoffset * generator->size3, y / level->scaling + level->yoffset * generator->size3, z / level->scaling + level->zoffset * generator->size3) * level->height;
}

double noiseGet3DLevel(NoiseGenerator* generator, int level, double x, double y, double z)
{
    if (level >= 0 && level < generator->level_count)
    {
        return _get3DLevelValue(generator, generator->levels + level, x, y, z);
    }
    else
    {
        return 0.0;
    }
}

double noiseGet3DTotal(NoiseGenerator* generator, double x, double y, double z)
{
    int level;
    double result;

    result = 0.0;
    for (level = 0; level < generator->level_count; level++)
    {
        result += _get3DLevelValue(generator, generator->levels + level, x, y, z);
    }
    return result + generator->height_offset;
}

double noiseGet3DDetail(NoiseGenerator* generator, double x, double y, double z, double detail)
{
    int level;
    double result, height, factor;

    result = 0.0;
    for (level = 0; level < generator->level_count; level++)
    {
        height = generator->levels[level].height;
        factor = 1.0;
        if (height < detail * 0.25)
        {
            break;
        }
        else if (height < detail * 0.5)
        {
            factor = (detail * 0.5 - height) / 0.25;
        }

        result += _get3DLevelValue(generator, generator->levels + level, x, y, z) * factor;
    }
    return result + generator->height_offset;
}