#include "grid.h"

extern "C" {
#include "pgm.h"
#include "ppm.h"
#undef min
#undef max
}

#include <algorithm>

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

void resize(int xsize, int ysize, grid* out, depth def) {
  out->resize(xsize);
  for (int x = 0; x < xsize; ++x) (*out)[x].resize(ysize, def);
}

static void init() {
  static int is_init = 0;
  if (is_init++) return;
  pm_init("boring", 0);
}

void read_pgm(char const* filename, grid* out, depth* zsize) {
  init();

  FILE* fp = filename ? fopen(filename, "rb") : stdin;
  if (fp == NULL) {
    perror(filename);
    exit(1);
  }

  int cols, rows;
  gray maxval, **data = pgm_readpgm(fp, &cols, &rows, &maxval);
  if (filename) fclose(fp);

  resize(cols, rows, out);
  for (int x = 0; x < cols; ++x)
    for (int y = 0; y < rows; ++y)
      (*out)[x][rows - 1 - y] = data[y][x] ? maxval - data[y][x] : BOTTOM;

  pgm_freearray(data, rows);
  if (zsize) *zsize = maxval;
}

void write_pgm(grid const& in, char const* filename, depth zsize) {
  init();

  FILE* fp = filename ? fopen(filename, "wb") : stdout;
  if (fp == NULL) {
    perror(filename);
    exit(1);
  }

  if (zsize == 0) {
    for (int x = 0; x < xsize(in); ++x)
      for (int y = 0; y < ysize(in); ++y)
        if (in[x][y] < BOTTOM && in[x][y] >= zsize) zsize = in[x][y] + 1;
  }

  gray** out = pgm_allocarray(xsize(in), ysize(in));
  for (int x = 0; x < xsize(in); ++x)
    for (int y = 0; y < ysize(in); ++y)
      out[ysize(in) - 1 - y][x] = std::max(0, zsize - in[x][y]);
  pgm_writepgm(fp, out, xsize(in), ysize(in), zsize, 0);
  pgm_freearray(out, ysize(in));
  if (filename) fclose(fp);
}

void write_ppm(grid const& in, char const* filename) {
  init();

  FILE* fp = filename ? fopen(filename, "wb") : stdout;
  if (fp == NULL) {
    perror(filename);
    exit(1);
  }

  pixel** out = ppm_allocarray(xsize(in), ysize(in));
  for (int x = 0; x < xsize(in); ++x) {
    for (int y = 0; y < ysize(in); ++y) {
      int outy = ysize(in) - 1 - y;
      PPM_PUTR(out[outy][x], 0xFF & in[x][y] >> 11 << 3);
      PPM_PUTG(out[outy][x], 0xFF & in[x][y] >> 5 << 2);
      PPM_PUTB(out[outy][x], 0xFF & in[x][y] << 3);
    }
  }

  ppm_writeppm(fp, out, xsize(in), ysize(in), 0xFF, 0);
  ppm_freearray(out, ysize(in));
  if (filename) fclose(fp);
}