// To get required headers, run
// sudo apt-get install libcups2-dev libcupsimage2-dev
#include <cups/cups.h>
#include <cups/ppd.h>
#include <cups/raster.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>

#ifndef DEBUGFILE
#define DEBUGFILE "/tmp/debugraster.txt"
#endif

struct settings_ {
  int cashDrawer1;
  int cashDrawer2;
  int blankSpace;
  int feedDist;
};
struct settings_ settings;

struct command {
  int length;
  char *command;
};

/*
 * zj uses kind of epson ESC/P dialect code. Here is subset of commands
 *
 * initialize - esc @
 * cash drawer 1 - esc p 0 @ P
 * cash drawer 2 - esc p 1 @ P
 * start raster - esc v 0
 * skip lines - esc j
 * cut - esc i
 */
// define printer initialize command
static const struct command printerInitializeCommand = {2,
                                                        (char[2]){0x1b, 0x40}}; // esc @

// define cashDrawerEjector command
static const struct command cashDrawerEject[2] = {
    {5, (char[5]){0x1b, 0x70, 0, 0x40, 0x50}}, // esc p N @ P
    {5, (char[5]){0x1b, 0x70, 1, 0x40, 0x50}}};

// define raster mode start command
static const struct command rasterModeStartCommand = {
    4, (char[4]){0x1d, 0x76, 0x30, 0}}; // esc v 0

#ifndef DEBUGP

static inline void mputchar(char c) { putchar(c); }

#else

FILE *lfd = 0;
// putchar with debug wrapper
static inline void mputchar(char c) {
  unsigned char m = c;
  if (lfd)
    fprintf(lfd, "%02x ", m);
  putchar(m);
}
#endif

// procedure to output an array
static inline void outputarray(const char *array, int length) {
  int i = 0;
  for (; i < length; ++i)
    mputchar(array[i]);
}

// output a command
static inline void outputCommand(struct command output) {
  outputarray(output.command, output.length);
}

static inline int lo(int val) { return val & 0xFF; }

static inline int hi(int val) { return lo(val >> 8); }

// enter raster mode and set up x and y dimensions
static inline void rasterheader(int xsize, int ysize) {
  outputCommand(rasterModeStartCommand);
  mputchar(lo(xsize));
  mputchar(hi(xsize));
  mputchar(lo(ysize));
  mputchar(hi(ysize));
}

// print all unprinted (i.e. flush the buffer)
// then feed given number of lines
static inline void skiplines(int size) {
  mputchar(0x1b);
  mputchar(0x4a); // esc j
  mputchar(size);
}

// get an option
static inline int getOptionChoiceIndex(const char *choiceName,
                                       ppd_file_t *ppd) {
  ppd_choice_t *choice;
  ppd_option_t *option;

  choice = ppdFindMarkedChoice(ppd, choiceName);

  if (choice == NULL) {
    if ((option = ppdFindOption(ppd, choiceName)) == NULL)
      return -1;
    if ((choice = ppdFindChoice(option, option->defchoice)) == NULL)
      return -1;
  }

  return atoi(choice->choice);
}

static void initializeSettings(char *commandLineOptionSettings) {
  ppd_file_t *ppd = NULL;
  cups_option_t *options = NULL;
  int numOptions = 0;

  ppd = ppdOpenFile(getenv("PPD"));

  ppdMarkDefaults(ppd);

  numOptions = cupsParseOptions(commandLineOptionSettings, 0, &options);
  if ((numOptions != 0) && (options != NULL)) {
    cupsMarkOptions(ppd, numOptions, options);
    cupsFreeOptions(numOptions, options);
  }

  memset(&settings, 0x00, sizeof(struct settings_));

  settings.cashDrawer1 = getOptionChoiceIndex("CashDrawer1Setting", ppd);
  settings.cashDrawer2 = getOptionChoiceIndex("CashDrawer2Setting", ppd);
  settings.blankSpace = getOptionChoiceIndex("BlankSpace", ppd);
  settings.feedDist = getOptionChoiceIndex("FeedDist", ppd);

  ppdClose(ppd);
}

// sent on the beginning of print job
void jobSetup() {
  if (settings.cashDrawer1 == 1)
    outputCommand(cashDrawerEject[0]);
  if (settings.cashDrawer2 == 1)
    outputCommand(cashDrawerEject[1]);
  outputCommand(printerInitializeCommand);
}

// sent at the very end of print job
void ShutDown() {
  if (settings.cashDrawer1 == 2)
    outputCommand(cashDrawerEject[0]);
  if (settings.cashDrawer2 == 2)
    outputCommand(cashDrawerEject[1]);
  outputCommand(printerInitializeCommand);
}

// sent at the end of every page
#ifndef __sighandler_t
typedef void (*__sighandler_t)(int);
#endif

__sighandler_t old_signal;
void EndPage() {
  int i;
  for (i = 0; i < settings.feedDist; ++i)
    skiplines(0x18);
  signal(15, old_signal);
}

// sent on job canceling
void cancelJob() {
  int i = 0;
  for (; i < 0x258; ++i)
    mputchar(0);
  EndPage();
  ShutDown();
}

// invoked before starting to print a page
void pageSetup() { old_signal = signal(15, cancelJob); }

//////////////////////////////////////////////
//////////////////////////////////////////////
int main(int argc, char *argv[]) {
  int fd = 0;                 // File descriptor providing CUPS raster data
  cups_raster_t *ras = NULL;  // Raster stream for printing
  cups_page_header2_t header; // CUPS Page header
  int page = 0;               // Current page
  int y = 0; // Vertical position in page 0 <= y <= header.cupsHeight

  unsigned char *rasterData = NULL; // Pointer to raster data from CUPS
  unsigned char *originalRasterDataPtr =
      NULL; // Copy of original pointer for freeing buffer

  if (argc < 6 || argc > 7) {
    fputs("ERROR: rastertozj job-id user title copies options [file]\n",
          stderr);
    return EXIT_FAILURE;
  }

  if (argc == 7) {
    if ((fd = open(argv[6], O_RDONLY)) == -1) {
      perror("ERROR: Unable to open raster file - ");
      sleep(1);
      return EXIT_FAILURE;
    }
  } else
    fd = 0;

#ifdef DEBUGP
  lfd = fopen(DEBUGFILE, "w");
#endif

  initializeSettings(argv[5]);
  jobSetup();
  ras = cupsRasterOpen(fd, CUPS_RASTER_READ);
  page = 0;

  while (cupsRasterReadHeader2(ras, &header)) {
    if ((header.cupsHeight == 0) || (header.cupsBytesPerLine == 0))
      break;

#ifdef DEBUGP
    if (lfd)
      fprintf(lfd, "\nheader.cupsHeight=%d, header.cupsBytesPerLine=%d\n",
              header.cupsHeight, header.cupsBytesPerLine);
#endif

    if (rasterData == NULL) {
      rasterData = malloc(header.cupsBytesPerLine * 24);
      if (rasterData == NULL) {
        if (originalRasterDataPtr != NULL)
          free(originalRasterDataPtr);
        cupsRasterClose(ras);
        if (fd != 0)
          close(fd);
        return EXIT_FAILURE;
      }
      originalRasterDataPtr = rasterData; // used to later free the memory
    }

    fprintf(stderr, "PAGE: %d %d\n", ++page, header.NumCopies);
    pageSetup();

    int foo = (header.cupsWidth > 0x180) ? 0x180 : header.cupsWidth;
    foo = (foo + 7) & 0xFFFFFFF8;
    int width_size = foo >> 3;

#ifdef DEBUGP
    if (lfd)
      fprintf(lfd, "\nheader.cupsWidth=%d, foo=%d, width_size=%d\n",
              header.cupsWidth, foo, width_size);
#endif
    y = 0;
    int zeroy = 0;

    while (y < header.cupsHeight) {
      if ((y & 127) != 0)
        fprintf(stderr, "INFO: Printing page %d, %d%% complete...\n", page,
                (100 * y / header.cupsHeight));

      int rest = header.cupsHeight - y;
      if (rest > 24)
        rest = 24;

#ifdef DEBUGP
      if (lfd)
        fprintf(lfd, "\nProcessing block of %d, starting from %d lines\n", rest,
                y);
#endif
      y += rest;

      if (y) {
        unsigned char *buf = rasterData;
        int j;
        for (j = 0; j < rest; ++j) {
          if (!cupsRasterReadPixels(ras, buf, header.cupsBytesPerLine))
            break;
          buf += width_size;
        }
#ifdef DEBUGP
        if (lfd)
          fprintf(lfd, "\nRead %d lines\n", j);
#endif
        if (j < rest)
          continue;
      }
      int rest_bytes = rest * width_size;
      int j;
      for (j = 0; j < rest_bytes; ++j)
        if (rasterData[j] != 0)
          break;

#ifdef DEBUGP
      if (lfd)
        fprintf(lfd, "\nChecked %d bytes of %d for zero\n", j, rest_bytes);
#endif

      if (j >= rest_bytes) {
        ++zeroy;
        continue;
      }

      for (; zeroy > 0; --zeroy)
        skiplines(24);

      rasterheader(width_size, rest);
      outputarray((char *)rasterData, width_size * 24);
      skiplines(0);
    }

    if (!settings.blankSpace)
      for (; zeroy > 0; --zeroy)
        skiplines(24);

    EndPage();
  }

  ShutDown();

  if (originalRasterDataPtr)
    free(originalRasterDataPtr);
  cupsRasterClose(ras);
  if (fd)
    close(fd);

  fputs(page ? "INFO: Ready to print.\n" : "ERROR: No pages found!\n", stderr);

#ifdef DEBUGP
  if (lfd)
    fclose(lfd);
#endif

  return page ? EXIT_SUCCESS : EXIT_FAILURE;
}

// end of rastertozj.c