/*
winnie - an experimental window system

Copyright (C) 2013 Eleni Maria Stea

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Author: Eleni Maria Stea <elene.mst@gmail.com>
*/

#include "pixmap.h"
#include <errno.h>
#include <stdio.h>
#include <string.h>

Pixmap::Pixmap()
{
  width = height = 0;
  pixels = 0;
}

Pixmap::Pixmap(const Pixmap &pixmap)
{
  width = height = 0;
  pixels = 0;
  set_image(pixmap.width, pixmap.height, pixmap.pixels);
}

Pixmap &
Pixmap::operator=(const Pixmap &pixmap)
{
  if (this != &pixmap) {
    set_image(pixmap.width, pixmap.height, pixmap.pixels);
  }

  return *this;
}

Pixmap::~Pixmap()
{
  if (pixels) {
    delete[] pixels;
  }
}

int
Pixmap::get_width() const
{
  return width;
}

int
Pixmap::get_height() const
{
  return height;
}

Rect
Pixmap::get_rect() const
{
  Rect rect(0, 0, width, height);
  return rect;
}

bool
Pixmap::set_image(int x, int y, unsigned char *pix)
{
  delete[] pixels;

  pixels = new unsigned char[x * y * 4];
  width = x;
  height = y;

  if (pix) {
    memcpy(pixels, pix, x * y * 4);
  }
  return true;
}

const unsigned char *
Pixmap::get_image() const
{
  return pixels;
}

unsigned char *
Pixmap::get_image()
{
  return pixels;
}

bool
Pixmap::load(const char *fname)
{
  FILE *fp;
  int hdrline = 0;

  if (!(fp = fopen(fname, "rb"))) {
    fprintf(stderr, "failed to open pixmap: %s: %s\n", fname, strerror(errno));
    return false;
  }

  /* read ppm header */
  while (hdrline < 3) {
    char buf[64];

    if (!fgets(buf, sizeof buf, fp))
      goto err;

    /* skip comments */
    if (buf[0] == '#')
      continue;

    switch (hdrline++) {
    case 0:
      /* first header line should be P6 */
      if (strcmp(buf, "P6\n") != 0)
        goto err;
      break;

    case 1:
      /* second header line contains the pixmap dimensions */
      if (sscanf(buf, "%d %d", &width, &height) != 2)
        goto err;
      break;
    }
  }

  set_image(width, height, 0);

  for (int i = 0; i < width * height * 4; i++) {
    int c;
    if (i % 4 != 3) {
      c = fgetc(fp);
      if (c < 0)
        goto err;
    } else {
      c = 255;
    }
    pixels[i] = c;
  }
  fclose(fp);
  return true;

err:
  fprintf(stderr, "failed to load pixmap: %s\n", fname);
  fclose(fp);
  return false;
}

bool
Pixmap::save(const char *fname) const
{
  if (!pixels) {
    return false;
  }

  FILE *fp = fopen(fname, "wb");
  if (!fp) {
    fprintf(stderr, "failed to save pixmap: %s: %s\n", fname, strerror(errno));
    return false;
  }

  fprintf(fp, "P6\n%d %d\n255\n", width, height);

  for (int i = 0; i < width * height; i++) {
    fputc(pixels[i * 4], fp);
    fputc(pixels[i * 4 + 1], fp);
    fputc(pixels[i * 4 + 2], fp);
  }

  fclose(fp);
  return true;
}