#include <math.h>

#include <stdlib.h>

#include <string.h>

#include <helianthus.h>

#define TILESIZE     512

#define ROWS           8

#define COLS          12

const double cellRatio = 1.0;

const double genRatio  = 0.5;

Animation tiles[1024];

int tilesCount = 0;

Framebuffer framebuffer;

Animation fbAnim;

void groundLine(double len) {

  double ky = 0.02;

  double x = 0;

  double y = 0;

  moveTo(x, y);

  while(x < len) {

    double ny;

    do { ny = (randomFloat()*2 - 1)*ky; } while(fabs(y + ny) > ky);

    y += ny;

    x += (1 + (randomFloat()*2 - 1)*0.5)*ky;

    if (x >= len) { x = len; y = 0; }

    lineTo(x, y);

  }

  strokePath();

}

void generate() {

  saveState();

  target(framebuffer);

  background(COLOR_TRANSPARENT);

  clear();

  zoom(TILESIZE*cellRatio*genRatio);

  fill(colorByRGBA(1, 1, 1, 1));

  noStroke();

  double thikness  = 0.02/cellRatio*genRatio;

  strokeWidth(thikness);

  saveState();

  translate(0.5, 0.5);

  if (tilesCount > 0)

    for(int y = 0; y < ROWS; ++y)

      for(int x = 0; x < COLS; ++x) {

        saveState();

        translate(x, y);

        zoom(1/cellRatio);

        rectTextured(tiles[rand()%tilesCount], -0.5, -0.5, 1, 1);

        restoreState();

      }

  restoreState();

  saveState();

  stroke(COLOR_BLACK);

  double k = 1/3.0;

  saveState();

    translate(0.5 - k, 0.5);

    for(int i = 0; i < ROWS; ++i) {

      saveState();

      translate(0, i - k);

      groundLine(COLS + 2*k - 1);

      restoreState();

      saveState();

      translate(0, i + k);

      groundLine(COLS + 2*k - 1);

      restoreState();

    }

  restoreState();

  saveState();

    rotate(90);

    scale(1, -1);

    translate(0.5 - k, 0.5);

    for(int i = 0; i < COLS; ++i) {

      saveState();

      translate(0, i - k);

      groundLine(ROWS + 2*k - 1);

      restoreState();

      saveState();

      translate(0, i + k);

      groundLine(ROWS + 2*k -  1);

      restoreState();

    }

  restoreState();

  restoreState();

  viewportSave("data/output/generated-dungeon.png");

  restoreState();

}

Animation subImage(int width, int height, unsigned char *pixels, int x, int y, int w, int h) {

  if (x < 0 || y < 0 || x + w > width || y + h > height || !pixels)

    return NULL;

  unsigned char *px = calloc(4, w*h);

  for(int i = 0; i < h; ++i)

    memcpy(px + i*w*4, pixels + ((y+i)*width + x)*4, w*4);

  Animation anim = createAnimationFromImage(w, h, px, FALSE);

  free(px);

  return anim;

}

void init() {

  int w = 0;

  int h = 0;

  unsigned char *px = NULL;

  imageLoad("data/dungeon.png", &w, &h, &px);

  int s = TILESIZE + TILESIZE/2;

  for(int y = 0; y < 2; ++y)

    for(int x = 0; x < 6; ++x)

      if ((tiles[tilesCount] = subImage(w, h, px, x*TILESIZE + TILESIZE/4, y*TILESIZE + TILESIZE/4, TILESIZE, TILESIZE)))

        ++tilesCount;

  free(px);

  w = ceil(TILESIZE*COLS*cellRatio*genRatio - 0.001);

  h = ceil(TILESIZE*ROWS*cellRatio*genRatio - 0.001);

  framebuffer = createFramebuffer(w, h);

  fbAnim = createAnimationFromFramebuffer(framebuffer);

  generate();

}

void draw() {

  background(COLOR_WHITE);

  double w = windowGetWidth();

  double h = windowGetHeight();

  if (keyWentDown("space")) generate();

  saveState();

  translate(w/2, h/2);

  zoom(w/COLS);

  fill(COLOR_WHITE);

  noStroke();

  rectTextured(fbAnim, -COLS/2.0, -ROWS/2.0, COLS, ROWS);

  restoreState();

}

int main() {

  windowSetVariableFrameRate();

  windowSetResizable(TRUE);

  windowSetInit(&init);

  windowSetDraw(&draw);

  windowRun();

}