#include<stdio.h>
#include"abc.h"
#include <stdlib.h>


#define MAX_IMAGE_SIZE 512

int AllocateImage(ImageData *img, int _w, int _h, int _channels){
  img->data = (unsigned char *)malloc(sizeof(unsigned char)*MAX_IMAGE_SIZE*MAX_IMAGE_SIZE*_channels);
  if(img->data==NULL){
    return 0;
  }
  img->w = _w;
  img->h = _h;
  img->chan = _channels;
  return 1;
}

void ReleaseImage(ImageData *img){
  free(img->data);
}

void CopyImage(ImageData *imgIn, ImageData *imgOut){
  int j;
  j = AllocateImage(imgOut, imgIn->w, imgIn->h, imgIn->chan);
  if(j==0) {
    printf("Error\n\n");
  }
  imgOut = imgIn;
  ReleaseImage(imgOut);
}

int LoadImage(const char *filename, ImageData *img){
  FILE *fp;
  char header[32];
  int _w, _h, _dummy;
  int is_binary = 0;

  fp = fopen(filename, "rb");
  if (fp == NULL)
    {
      fprintf(stderr, "Error: cannot open file: %s\n", filename);
      return 0;
    }
  fscanf(fp, "%s", header);
  if (img->chan==1){

    is_binary = (header[1] == '5');
    fscanf(fp, "%d %d\n", &_w, &_h);
    fscanf(fp, "%d¥n", &_dummy);
    if (_w <= 0 || _w >= MAX_IMAGE_SIZE || _h <= 0 || _h >= MAX_IMAGE_SIZE)
      {
	fprintf(stderr, "Error: invalid image size: %dx%d\n", _w, _h);
	fclose(fp);
	return 0;
      }
    if (is_binary)
      {
	int nExpectedBytes = sizeof(unsigned char) * _w * _h;
	int nRead = fread(img->data, sizeof(unsigned char), _w*_h, fp);
	if (nRead != nExpectedBytes)
	  {
	    fprintf(stderr, "Error: read data too little: %d\n",
		    nRead);
	    fclose(fp);
	    return 0;
	  }
      }
    else
      {
	int xi, yi;
	for (yi=0; yi<_h; yi++)
	  {
	    for (xi=0; xi<_w; xi++)
	      {
		int gray;
		int idx = xi + _w * yi;
		fscanf(fp, "%d", &gray);
		img->data[idx] = gray;
	      }
	  }
      }
    fclose(fp);
    img->w = _w;
    img->h = _h;
    fprintf(stderr, "note: pgm image loaded: %s\n", filename);
    return 1;
  }else if (img->chan==3 ) {
    is_binary = (header[1] == '6');
    fscanf(fp, "%d %d¥n", &_w, &_h);
    fscanf(fp, "%d¥n", &_dummy);
    if (_w <= 0 || _w >= MAX_IMAGE_SIZE || _h <= 0 || _h >= MAX_IMAGE_SIZE)
      {
	fprintf(stderr, "Error: invalid image size: %dx%d\n", _w, _h);
	fclose(fp);
	return 0;
      }
    if (is_binary)
      {
	int nExpectedBytes = 3 * sizeof(unsigned char) * _w * _h;
	int nRead = fread(img->data, sizeof(unsigned char), 3*_w*_h, fp);
	if (nRead != nExpectedBytes)
	  {
	    fprintf(stderr, "Error: read data too little: %d\n",
		    nRead);
	    fclose(fp);
	    return 0;
	  }
      }
    else
      {
	int xi, yi;
	for (yi=0; yi<_h; yi++)
	  {
	    for (xi=0; xi<_w; xi++)
	      {
		int r, g, b;
		int idx = 3 * (xi + _w * yi);
		fscanf(fp, "%d %d %d", &r, &g, &b);
		img->data[idx ] = r;
		img->data[idx+1] = g;
		img->data[idx+2] = b;
	      }
	  }
      }
    fclose(fp);
    return 1;
  }
}



int SaveImage(const char *filename, ImageData *img){
  if(img->chan==1){
    FILE *fp;
    int nExpectedBytes, nWritten;
    if (img->w <= 0 || img->w >= MAX_IMAGE_SIZE || img->h <= 0 || img->h >= MAX_IMAGE_SIZE)
      {
	fprintf(stderr, "Error: invalid image size: %dx%d\n", img->w, img->h);
	return 0;
      }
    fp = fopen(filename, "wb");
    if ( fp == NULL )
      {
	fprintf(stderr, "Error: cannot open file: %s\n", filename);
	return 0;
      }
    /* ヘッダを書き込み */
    fprintf(fp, "P5\n%d %d\n255\n", img->w, img->h);
    nExpectedBytes = sizeof(unsigned char) * img->w * img->h;
    /* バイナリデータを書き込み */
    nWritten = fwrite(img->data, sizeof(unsigned char), img->w*img->h, fp);
    if (nWritten != nExpectedBytes)
      {
	fprintf(stderr, "Error: written data too little: %d\n", nWritten);
	fclose(fp);
	return 0;
      }
    fclose(fp);
    fprintf(stderr, "note: pgm image saved: %s\n", filename);
    return 1;
  }else if(img->chan==3) {
    FILE *fp;
    int nExpectedBytes, nWritten;
    if (img->w <= 0 || img->w >= MAX_IMAGE_SIZE || img->h <= 0 || img->h >= MAX_IMAGE_SIZE)
      {
	fprintf(stderr, "Error: invalid image size: %dx%d\n", img->w, img->h);
	return 0;
      }
    fp = fopen(filename, "wb");
    if ( fp == NULL )
      {
	fprintf(stderr, "Error: cannot open file: %s\n", filename);
	return 0;
      }
    /* ヘッダを書き込み */
    fprintf(fp, "P6\n%d %d\n255\n", img->w, img->h);
    nExpectedBytes = 3 * sizeof(unsigned char) * img->w * img->h;
    /* バイナリデータを書き込み */
    nWritten = fwrite(img->data, sizeof(unsigned char), 3*img->w*img->h, fp);
    if (nWritten != nExpectedBytes)
      {
	fprintf(stderr, "Error: written data too little: %d\n", nWritten);
	fclose(fp);
	return 0;
      }
    fclose(fp);
    fprintf(stderr, "note: ppm image saved: %s\n", filename);
    return 1;
  }
}