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

#include "awindow.h"

/* TODO: stdio to dos.library */
/* TODO: malloc to AllocVecPooled */

#ifndef SEEK_SET
#define SEEK_SET 0
#endif

/******************************************************************************/

typedef struct _rawImageRec {
  unsigned short imagic;
  unsigned short type;
  unsigned short dim;
  unsigned short sizeX, sizeY, sizeZ;
  unsigned long min, max;
  unsigned long wasteBytes;
  char name[80];
  unsigned long colorMap;
  FILE *file;
  unsigned char *tmp, *tmpR, *tmpG, *tmpB;
  unsigned long rleEnd;
  GLuint *rowStart;
  GLint *rowSize;
} rawImageRec;

/******************************************************************************/

static void ConvertShort(unsigned short *array, long length)
{
  unsigned long b1, b2;
  unsigned char *ptr;

  ptr = (unsigned char *)array;
  while (length--) {
    b1 = *ptr++;
    b2 = *ptr++;
    *array++ = (b1 << 8) | (b2);
  }
}

static void ConvertLong(GLuint * array, long length)
{
  unsigned long b1, b2, b3, b4;
  unsigned char *ptr;

  ptr = (unsigned char *)array;
  while (length--) {
    b1 = *ptr++;
    b2 = *ptr++;
    b3 = *ptr++;
    b4 = *ptr++;
    *array++ = (b1 << 24) | (b2 << 16) | (b3 << 8) | (b4);
  }
}

static rawImageRec *RawImageOpen(char *fileName)
{
  union {
    int testWord;
    char testByte[4];
  } endianTest;
  rawImageRec *raw;
  GLenum swapFlag;
  int x;

  endianTest.testWord = 1;
  if (endianTest.testByte[0] == 1)
    swapFlag = GL_TRUE;
  else
    swapFlag = GL_FALSE;

  if (!(raw = (rawImageRec *) malloc(sizeof(rawImageRec)))) {
    printf("Out of memory!\n");
    tkQuit();
  }
  if ((raw->file = fopen(fileName, "rb")) == NULL) {
    perror(fileName);
    tkQuit();
  }

  fread(raw, 1, 12, raw->file);

  if (swapFlag)
    ConvertShort(&raw->imagic, 6);

  raw->tmp = (unsigned char *)malloc(raw->sizeX * 256);
  raw->tmpR = (unsigned char *)malloc(raw->sizeX * 256);
  raw->tmpG = (unsigned char *)malloc(raw->sizeX * 256);
  raw->tmpB = (unsigned char *)malloc(raw->sizeX * 256);
  if (raw->tmp == NULL || raw->tmpR == NULL || raw->tmpG == NULL ||
      raw->tmpB == NULL) {
    printf("Out of memory!\n");
    tkQuit();
  }

  if ((raw->type & 0xFF00) == 0x0100) {
    x = raw->sizeY * raw->sizeZ * sizeof(GLuint);
    raw->rowStart = (GLuint *) malloc(x);
    raw->rowSize = (GLint *) malloc(x);
    if (raw->rowStart == NULL || raw->rowSize == NULL) {
      fprintf(stderr, "Out of memory!\n");
      tkQuit();
    }
    raw->rleEnd = 512 + (2 * x);
    fseek(raw->file, 512, SEEK_SET);
    fread(raw->rowStart, 1, x, raw->file);
    fread(raw->rowSize, 1, x, raw->file);
    if (swapFlag) {
      ConvertLong(raw->rowStart, x / sizeof(GLuint));
      ConvertLong((GLuint *) raw->rowSize, x / sizeof(GLint));
    }
  }

  return raw;
}

static void RawImageClose(rawImageRec * raw)
{
  fclose(raw->file);
  free(raw->tmp);
  free(raw->tmpR);
  free(raw->tmpG);
  free(raw->tmpB);
  free(raw);
}

static void RawImageGetRow(rawImageRec * raw, unsigned char *buf, int y, int z)
{
  unsigned char *iPtr, *oPtr, pixel;
  int count;

  if ((raw->type & 0xFF00) == 0x0100) {
    fseek(raw->file, raw->rowStart[y + z * raw->sizeY], SEEK_SET);
    fread(raw->tmp, 1, (unsigned int)raw->rowSize[y + z * raw->sizeY],
	  raw->file);

    iPtr = raw->tmp;
    oPtr = buf;
    while (1) {
      pixel = *iPtr++;
      count = (int)(pixel & 0x7F);
      if (!count) {
	return;
      }
      if (pixel & 0x80) {
	while (count--) {
	  *oPtr++ = *iPtr++;
	}
      }
      else {
	pixel = *iPtr++;
	while (count--) {
	  *oPtr++ = pixel;
	}
      }
    }
  }
  else {
    fseek(raw->file, 512 + (y * raw->sizeX) + (z * raw->sizeX * raw->sizeY), SEEK_SET);
    fread(buf, 1, raw->sizeX, raw->file);
  }
}

static void RawImageGetData(rawImageRec * raw, TK_RGBImageRec * final)
{
  unsigned char *ptr;
  int i, j;

  final->data = (unsigned char *)malloc((raw->sizeX + 1) * (raw->sizeY + 1) * 4);
  if (final->data == NULL) {
    fprintf(stderr, "Out of memory!\n");
    tkQuit();
  }

  ptr = final->data;
  for (i = 0; i < (int)(raw->sizeY); i++) {
    RawImageGetRow(raw, raw->tmpR, i, 0);
    RawImageGetRow(raw, raw->tmpG, i, 1);
    RawImageGetRow(raw, raw->tmpB, i, 2);
    for (j = 0; j < (int)(raw->sizeX); j++) {
      *ptr++ = *(raw->tmpR + j);
      *ptr++ = *(raw->tmpG + j);
      *ptr++ = *(raw->tmpB + j);
    }
  }
}

TK_RGBImageRec *tkRGBImageLoad(char *fileName)
{
  rawImageRec *raw;
  TK_RGBImageRec *final;

  raw = RawImageOpen(fileName);
  final = (TK_RGBImageRec *) malloc(sizeof(TK_RGBImageRec));
  if (final == NULL) {
    fprintf(stderr, "Out of memory!\n");
    tkQuit();
  }
  final->sizeX = raw->sizeX;
  final->sizeY = raw->sizeY;
  RawImageGetData(raw, final);
  RawImageClose(raw);
  return final;
}

/******************************************************************************/