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

#if __EMSCRIPTEN__
#include <emscripten/emscripten.h>
#include <SDL/SDL.h>
#include <SDL/SDL_ttf.h>
#include <GLES2/gl2.h>
#else
#include <SDL2/SDL.h>
#include <SDL2/SDL_ttf.h>
#include <GLES2/gl2.h>
#endif

#include "koh.h"

#define SCREEN_WIDTH   320
#define SCREEN_WIDTH2  (SCREEN_WIDTH/2)
#define SCREEN_HEIGHT  320
#define SCREEN_HEIGHT2 (SCREEN_HEIGHT/2)

static int quit=0;
static SDL_Window *window = NULL;
static SDL_Renderer *renderer = NULL;

typedef struct rgba32_t
{
    double r,g,b,a;
} rgba32_t;

#define MAX_LEVEL 7
#define QUEUE_SIZE (1+MAX_LEVEL*MAX_LEVEL*MAX_LEVEL*MAX_LEVEL*3)

int queue_index=0;
koh_node koh_queue[QUEUE_SIZE];
koh_config koh_set_config;
int first_run=1;



void queue_init()
{
    int i;
    queue_index = 0;
    for (i=0;i<QUEUE_SIZE;i++)
    {
        koh_queue[i].generaton = 0;
        koh_queue[i].size      = 0;
        koh_queue[i].x         = 0;
        koh_queue[i].y         = 0;
    }
}


void queue_add(koh_node kn)
{
    if (queue_index >= QUEUE_SIZE)
    {
        printf("Cannot add to queue\n");
        return ;
    }
    koh_queue[queue_index] = kn;
    queue_index += 1;
    return;
}


koh_node queue_get(int idx)
{
    koh_node kn = {-1,-1,-1,-1};

    if ((idx<0) || (idx>=QUEUE_SIZE))
    {
        return kn;
    }

    kn = koh_queue[idx];

    return kn;
}

rgba32_t color_gen_shade(rgba32_t original, int gen, int max_gen)
{
    rgba32_t c = {0,0,0,0};
    
    c.r = (1.0*original.r/max_gen)*gen;
    c.g = (1.0*original.g/max_gen)*gen;
    c.b = (1.0*original.b/max_gen)*gen;
    c.a = original.a;    
    
    return c;
}
rgba32_t color_gen_shade_inv(rgba32_t original, int gen, int max_gen)
{
    rgba32_t c = {0,0,0,0};
    
    c.r = original.r-(1.0*original.r/max_gen)*gen;
    c.g = original.g-(1.0*original.g/max_gen)*gen;
    c.b = original.b-(1.0*original.b/max_gen)*gen;
    c.a = original.a;
    
    return c;
}

rgba32_t color_gen_mainlv(rgba32_t original, int gen, int max_gen)
{
    double color_r = 10.0/255;
    double color_g = 20.0/255;
    double color_b = 14.0/255;
    rgba32_t c = {color_r, color_g, color_b,0};

    c.r = 1.0*180/255 - (max_gen-gen)*color_r;
    c.g = 1.0*100/255 - (max_gen-gen)*color_g;
    c.b = 1.0*50/255  - (max_gen-gen)*color_b;
    c.a = original.a;

    return c;
}

rgba32_t color_gen_redish(rgba32_t original, int gen, int max_gen)
{
    double color_r = 20.0/255;
    double color_g = 10.0/255;
    double color_b = 14.0/255;
    rgba32_t c = {color_r, color_g, color_b,0};

    c.r = 1.0*180/255 - (max_gen-gen)*color_r;
    c.g = 1.0*30/255 - (max_gen-gen)*color_g;
    c.b = 1.0*10/255  - (max_gen-gen)*color_b;
    c.a = original.a;

    return c;
}

rgba32_t color_gen_yellowish(rgba32_t original, int gen, int max_gen)
{
    double color_r = 10.0/255;
    double color_g = 20.0/255;
    double color_b = 14.0/255;
    rgba32_t c = {color_r, color_g, color_b,0};

    c.r = 1.0*180/255 - (max_gen-gen)*color_r;
    c.g = 1.0*160/255 - (max_gen-gen)*color_g;
    c.b = 1.0*40/255  - (max_gen-gen)*color_b;
    c.a = original.a;

    return c;
}

rgba32_t color_switch(int pattern_id, rgba32_t original, int gen, int max_gen)
{
    switch(pattern_id)
    {
        case 0:
            return color_gen_shade(original, gen, max_gen);
        case 1:
            return color_gen_shade_inv(original, gen, max_gen);
        case 2:
            return color_gen_mainlv(original, gen, max_gen);
        case 3:
            return color_gen_yellowish(original, gen, max_gen);
        case 4:
            return color_gen_redish(original, gen, max_gen);
        default:
            return color_gen_mainlv(original, gen, max_gen);
    }

    return color_gen_mainlv(original, gen, max_gen);
}

void generate_koh(int gener, double size, int posx, int posy, double k)
{
    int i;
    koh_node kn = {-1,-1,-1,-1};

    double t_size = size*k;

    if (gener<0)
    {
        return;
    }

    kn.generaton = gener;
    kn.size      = size;
    kn.x         = posx;
    kn.y         = posy;

    
    //printf("Gener %d posx %d posy %d size %f=>%f\n",gener,posx,posy,size,t_size);
    queue_add(kn);

    generate_koh(gener-1, t_size, posx-t_size/2,      posy-t_size/2,      k);
    generate_koh(gener-1, t_size, posx-t_size/2,      posy+size-t_size/2, k);
    generate_koh(gener-1, t_size, posx+size-t_size/2, posy+size-t_size/2, k);
    generate_koh(gener-1, t_size, posx+size-t_size/2, posy-t_size/2,      k);
}

void Triangle( int x, int y, int w, int h)
{
    // An array of 3 vectors which represents 3 vertices
    static const GLfloat g_vertex_buffer_data[] = {
    -1.0f, -1.0f, 0.0f,
    1.0f, -1.0f, 0.0f,
    0.0f,  1.0f, 0.0f,
    };

    // This will identify our vertex buffer
    GLuint vertexbuffer;
    // Generate 1 buffer, put the resulting identifier in vertexbuffer
    glGenBuffers(1, &vertexbuffer);
    // The following commands will talk about our 'vertexbuffer' buffer
    glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
    // Give our vertices to OpenGL.
    glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);

    // 1st attribute buffer : vertices
    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
    glVertexAttribPointer(
    0,                  // attribute 0. No particular reason for 0, but must match the layout in the shader.
    3,                  // size
    GL_FLOAT,           // type
    GL_FALSE,           // normalized?
    0,                  // stride
    (void*)0            // array buffer offset
    );
    // Draw the triangle !
    glDrawArrays(GL_TRIANGLES, 0, 3); // Starting from vertex 0; 3 vertices total -> 1 triangle
    glDisableVertexAttribArray(0);

}

// Shader sources
#if 1
const GLchar* vertexSource =
    "#version 100 \n"
    "attribute vec4 position;    \n"
    "attribute vec4 colour;      \n"
    "varying vec4 interpolated_colour;\n"
    "void main()                  \n"
    "{                            \n"
    "   interpolated_colour = colour;\n"
    "   gl_Position = position;  \n"
    "   \n"
    "}                            \n";
#else
const GLchar* vertexSource = 
"layout(location = 0) in vec3 vertexPosition;\n"
"layout(location = 1) in vec3 vertexColor;\n"
"out vec3 fragmentColor;\n"
"uniform mat4 MVP;\n"
"void main(){	\n"
"	gl_Position =  vec4(vertexPosition,1);\n"
"	fragmentColor = vertexColor;\n"
"}\n";
#endif

#if 1
const GLchar* fragmentSource =
    "#version 100 \n"
    "precision mediump float;\n"
    "varying vec4 interpolated_colour;\n"
    "void main()                                  \n"
    "{                                            \n"
    "  gl_FragColor = interpolated_colour;\n"
    "}                                            \n";
#else
const GLchar* fragmentSource =
"in vec3 fragmentColor;\n"
"out vec3 color;\n"
"void main(){\n"
"	color = vec3(0.0,0.0,0.0);\n"
"}\n";
#endif

GLuint vertexShader;
GLuint fragmentShader;
GLuint shaderProgram;
GLint posAttrib;


void RectPX( int x, int y,int w, int h )
{
    GLfloat x1 = (1.0f*x-SCREEN_WIDTH2)/SCREEN_WIDTH2;
    GLfloat y1 = (1.0f*y-SCREEN_HEIGHT2)/SCREEN_HEIGHT2;
    GLfloat x2 = (1.0f*(x+w)-SCREEN_WIDTH2)/SCREEN_WIDTH2;
    GLfloat y2 = (1.0f*(y+h)-SCREEN_HEIGHT2)/SCREEN_HEIGHT2;
    GLfloat vVertices[] = { x1, y2, 0.0f, 
                            x2, y2, 0.0f,
                            x2, y1, 0.0f,
                            x1, y1, 0.0f };
    GLuint vertexPosObject;

    //printf("x1 %f y1 %f x2 %f y2 %f\n",x1,y1,x2,y2);

    glGenBuffers(1, &vertexPosObject);
    glBindBuffer(GL_ARRAY_BUFFER, vertexPosObject);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vVertices), vVertices, GL_STATIC_DRAW);

    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, vertexPosObject);
    glVertexAttribPointer(0 /* ? */, 3, GL_FLOAT, GL_FALSE, 0, 0);
    
    glDrawArrays (  GL_TRIANGLE_FAN, 0, 4 );

}


void RectPXcolor( int x, int y,int w, int h, rgba32_t c )
{
    GLfloat x1 = (1.0f*x-SCREEN_WIDTH2)/SCREEN_WIDTH2;
    GLfloat y1 = (1.0f*y-SCREEN_HEIGHT2)/SCREEN_HEIGHT2;
    GLfloat x2 = (1.0f*(x+w)-SCREEN_WIDTH2)/SCREEN_WIDTH2;
    GLfloat y2 = (1.0f*(y+h)-SCREEN_HEIGHT2)/SCREEN_HEIGHT2;
    GLfloat vVertices[] = { x1, y2, 0.0f, 
                            x2, y2, 0.0f,
                            x2, y1, 0.0f,
                            x1, y1, 0.0f };
    GLfloat cVertices[] = { c.r, c.g, c.b,
                            c.r, c.g, c.b,
                            c.r, c.g, c.b,
                            c.r, c.g, c.b};
    GLuint vertexPosObject;
    GLuint colorBuffer;

    glGenBuffers(1, &vertexPosObject);
    glBindBuffer(GL_ARRAY_BUFFER, vertexPosObject);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vVertices), vVertices, GL_STATIC_DRAW);

    //printf("!!!x1 %f y1 %f x2 %f y2 %f\n",x1,y1,x2,y2);
    glGenBuffers(1, &colorBuffer);
    glBindBuffer(GL_ARRAY_BUFFER, colorBuffer);
    glBufferData(GL_ARRAY_BUFFER, sizeof(cVertices), cVertices, GL_STATIC_DRAW);
    
    
    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, vertexPosObject);
    glVertexAttribPointer(0 /* ? */, 3, GL_FLOAT, GL_FALSE, 0, 0);


    glEnableVertexAttribArray(1);
    glBindBuffer(GL_ARRAY_BUFFER, colorBuffer);
    glVertexAttribPointer(1 /* ? */, 3, GL_FLOAT, GL_FALSE, 0, 0);
    
    glDrawArrays (  GL_TRIANGLE_FAN, 0, 4 );

    glDeleteBuffers( 1, &vertexPosObject );
    glDeleteBuffers( 1, &colorBuffer );

}

void koh_generation_inc()
{
    koh_set_config.max_generations += 1;
    if (koh_set_config.max_generations > MAX_LEVEL-1)
    {
        koh_set_config.max_generations = MAX_LEVEL-1;
    }
}

void koh_generation_dec()
{
    koh_set_config.max_generations -= 1;
    if (koh_set_config.max_generations < 0)
    {
        koh_set_config.max_generations = 0;
    }
}

void koh_pos_x_add(int x)
{
    koh_set_config.x += 10;
}

void koh_pos_x_sub(int x)
{
    koh_set_config.x -= 10;
}

void koh_pos_y_add(int y)
{
    koh_set_config.y += 10;
}

void koh_pos_y_sub(int y)
{
    koh_set_config.y -= 10;
}

void koh_pattern_next()
{
    koh_set_config.color_pattern += 1;
    if (koh_set_config.color_pattern>4)
    {
        koh_set_config.color_pattern=4;
    }
}

void koh_pattern_prev()
{
    koh_set_config.color_pattern -= 1;
    if (koh_set_config.color_pattern<0)
        koh_set_config.color_pattern=0;
}

void koh_size_dec()
{
    koh_set_config.size -= 25;
    if (koh_set_config.size<50)
        koh_set_config.size = 50;
}

void koh_size_inc()
{
    koh_set_config.size += 25;
    if (koh_set_config.size>400)
        koh_set_config.size = 400;
}

rgba32_t start_col = {0.0,1.0,0.0,0.0};

#if __EMSCRIPTEN__
void main_tick() {
#else
int main_tick() {
#endif
	int i,j;
    int update_fractal=0;
    SDL_Event event;
	SDL_StartTextInput();
        while (SDL_PollEvent(&event) != 0)
        {
                    
            switch (event.type)
            {
                case SDL_QUIT:
                {
                    quit = 1;
                    break;
                }
                case SDL_KEYDOWN:
                {
                    switch (event.key.keysym.sym)
                    {
                    case 81:
                    case SDLK_DOWN:
                        update_fractal = 1;
                        koh_pos_y_sub(10);
                        break;

                    case 82:
                    case SDLK_UP:
                        update_fractal = 1;
                        koh_pos_y_add(10);
                        break;
                    case 80:
                    case SDLK_LEFT:
                        koh_pos_x_sub(10);
                        update_fractal = 1;
                        printf("sub 10\n");
                        break;
                    case 79:
                    case SDLK_RIGHT:
                        update_fractal = 1;
                        printf("add 10\n");
                        koh_pos_x_add(10);
                        break;

                    case 61:
                    case 46:
                    case SDLK_KP_PLUS:
                    case SDLK_PLUS:
                        update_fractal=1;
                        koh_generation_inc();
                        printf("plus\n");
                        break;

                    case SDLK_MINUS:
                        update_fractal = 1;
                        koh_generation_dec();
                        break;

                    case 21:
                    case SDLK_r:
                        update_fractal = 1;
                        koh_set_config.size = 100.0;
                        koh_set_config.x = SCREEN_WIDTH2-100/2;
                        koh_set_config.y = SCREEN_WIDTH2-100/2;
                        koh_set_config.k = 0.5f;
                        koh_set_config.max_generations = MAX_LEVEL-1;
                        koh_set_config.color_pattern = 0;
                        break;
                    
                    case 20:
                    case SDLK_q:
                        koh_pattern_prev();
                        break;
                    
                    case 26:
                    case SDLK_w:
                        koh_pattern_next();
                        break;
                    
                    case 4:
                    case SDLK_a:
                        update_fractal = 1;
                        koh_size_dec();
                        break;
                    
                    case 22:
                    case SDLK_s:
                        update_fractal = 1;
                        koh_size_inc();
                        break;

                    default:
                        printf("Unknown key %d\n",event.key.keysym.sym);
                        update_fractal = 1;
                    }
                    break;
                }
            }
            //printf("Poll event\n");
        }

        //check for first ever run
        if (first_run == 1)
        {
            first_run = 0;
            update_fractal = 1;
        }

        if (update_fractal == 1)
        {
            queue_init();
            printf("k=%f",koh_set_config.k);
            generate_koh(
                koh_set_config.max_generations, 
                koh_set_config.size, 
                koh_set_config.x, 
                koh_set_config.y, 
                koh_set_config.k
            );
            printf("Regenerated fractal\n");
        }
        
        
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glUseProgram(shaderProgram);

        for (i=0;i<=koh_set_config.max_generations;i++)
        {
            rgba32_t c = color_switch(koh_set_config.color_pattern, start_col, i, MAX_LEVEL);
            for (j=0;j<queue_index;j++)
            {
                
                
                if (koh_queue[j].generaton == i)
                {
                    koh_node kn = queue_get(j);
                    #ifndef __EMSCRIPTEN__
                    if (update_fractal == 1)
                    #endif
                        RectPXcolor(kn.x, kn.y, kn.size, kn.size, c);
                }
            }
        }
        #ifndef __EMSCRIPTEN__
        if (update_fractal == 1)
        #endif
        {
            SDL_GL_SwapWindow( window );
        }
        update_fractal=0;

#if !__EMSCRIPTEN__
	return 0;
#endif
}

void main_loop()
{

#if __EMSCRIPTEN__
    emscripten_set_main_loop(main_tick, 25, 1);
#else
	while (0 == quit)
	{
		main_tick();
	}
#endif
}

int main()
{
    int i,j;
    SDL_Event event;
    GLenum error = GL_NO_ERROR;
    GLint Result = GL_FALSE;
	int InfoLogLength;
    
    printf("Max queue size %d\n", QUEUE_SIZE);
    SDL_Init(SDL_INIT_VIDEO);
    //Use OpenGL 2.1
    SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 2 );
    SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 1 );
    window = SDL_CreateWindow("KOH", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_OPENGL|SDL_WINDOW_SHOWN);
    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    SDL_SetRenderDrawColor(renderer, 0xff, 0xaa, 0xaa, 0xaa);
    SDL_GLContext gl_context = SDL_GL_CreateContext(window);
    SDL_GL_SetSwapInterval( 0 );

    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);


    //init OpenGL

    error = glGetError();
	if( error != GL_NO_ERROR )
	{
		printf( "Error initializing OpenGL! \n");
	}
    error = glGetError();
	if( error != GL_NO_ERROR )
	{
		printf( "Error initializing OpenGL! \n");
	}
    glClearColor( 0.f, 0.f, 0.f, 1.f );
    error = glGetError();
	if( error != GL_NO_ERROR )
	{
		printf( "Error initializing OpenGL!\n" );
	}

    //set initial values
    const int frac_size=100;
    koh_set_config.size = 100;
    koh_set_config.x = SCREEN_WIDTH2-frac_size/2;
    koh_set_config.y = SCREEN_WIDTH2-frac_size/2;
    koh_set_config.k = 0.5f;
    koh_set_config.max_generations = MAX_LEVEL-1;

    generate_koh(
        koh_set_config.max_generations, 
        koh_set_config.size, 
        koh_set_config.x, 
        koh_set_config.y, 
        koh_set_config.k
    );

    //prepare shaders
    vertexShader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShader, 1, &vertexSource, NULL);
    glCompileShader(vertexShader);
    {
        char buf[1024];
        glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &Result);
        glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &InfoLogLength);
        glGetShaderInfoLog(vertexShader, InfoLogLength, NULL, &buf[0]);
        printf("shader %s\n",buf);
        if (Result == GL_FALSE)
        {
            exit(1);
        }
    }

    // Create and compile the fragment shader
    fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader, 1, &fragmentSource, NULL);
    glCompileShader(fragmentShader);
    {
        char buf[1024];
        glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &Result);
        glGetShaderiv(fragmentShader, GL_INFO_LOG_LENGTH, &InfoLogLength);
        glGetShaderInfoLog(fragmentShader, InfoLogLength, NULL, &buf[0]);
        printf("fragment %s\n",buf);
        if (Result == GL_FALSE)
        {
            exit(1);
        }
    }

    // Link the vertex and fragment shader into a shader program
    shaderProgram = glCreateProgram();
    glAttachShader(shaderProgram, vertexShader);
    glAttachShader(shaderProgram, fragmentShader);
    glLinkProgram(shaderProgram);
    glUseProgram(shaderProgram);

    posAttrib = glGetAttribLocation(shaderProgram, "position");
    glEnableVertexAttribArray(posAttrib);
    //changed from 2 to 3
    glVertexAttribPointer(posAttrib, 3, GL_FLOAT, GL_FALSE, 0, 0);
    glVertexAttribPointer(posAttrib, 3, GL_FLOAT, GL_FALSE, 0, 0);

    main_loop();

    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}