/*
 * pdf_make.c
 *
 * Version 1.1 -- September 21, 2005 -- Pius Fischer
 *
 * Version history:
 * 1.0  05 Aug 2005  First version
 * 1.1  21 Sep 2005  Added ability to specify the stream filename prefix
 */
#include <errno.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

static char             linebuffer[256];
static long             filepos;
static long             objpos[128];
static unsigned int     numobj;

void die(const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	vfprintf(stderr, fmt, args);
	va_end(args);
	exit(1);
}

void read_and_write_stream(const char *_stream_filename_prefix)
{
	size_t                  stream_len;
	static char             stream_buffer[16384];
	static char             stream_filename[128];
	FILE *                  stream_file;

	snprintf(stream_filename, sizeof(stream_filename), "%s.%u",
		_stream_filename_prefix, numobj);

	if ((stream_file = fopen(stream_filename, "r")) == NULL)
		die("Cannot open %s: %s\n", stream_filename, strerror(errno));

	if (fseek(stream_file, 0, SEEK_END) != 0)
		die("fseek to end of file failed: %s\n", strerror(errno));
	if ((stream_len = ftell(stream_file)) < 0)
		die("ftell at end of file failed: %s\n", strerror(errno));
	if (fseek(stream_file, 0, SEEK_SET) != 0)
		die("fseek failed: %s\n", strerror(errno));

	filepos += printf("<<\n\t/Length %u\n", stream_len);
	filepos += printf("\t/Filter /FlateDecode\n>>\n");
	filepos += printf("stream\n");

	while (stream_len)
	{
		size_t read_len = sizeof(stream_buffer);
		if (stream_len < read_len)
			read_len = stream_len;

		fread(stream_buffer, read_len, 1, stream_file);
		fwrite(stream_buffer, read_len, 1, stdout);

		stream_len -= read_len;
		filepos += read_len;
	}

	fclose(stream_file);

	filepos += printf("\n");
}

void write_trailer(void)
{
	int i;

	printf("xref\n0 %u\n", numobj + 1);
	printf("%010u 65535 f \n", 0);
	for (i = 1; i <= numobj; ++i)
		printf("%010u 00000 n \n", objpos[i]);
	printf("trailer\n");
	printf("<<\t/Size %u\n", numobj + 1);
	printf("\t/Root 1 0 R\n");
	printf(">>\n");
	printf("startxref\n%ld\n%%%%EOF\n", filepos);
}

int main(int argc, char **argv)
{
	FILE *file;
	char *stream_filename_prefix = "stream";

	if (argc < 2 || argc > 3)
		die("Usage: %s <template file> [<stream file prefix>]\n", argv[0]);
	if (argc == 3)
		stream_filename_prefix = argv[2];

	if ((file = fopen(argv[1], "r")) == NULL)
		die("Cannot open %s: %s\n", argv[1], strerror(errno));

	filepos += printf("%%PDF-1.4\n%% \xff\xf2\xf3\xf4\n");

	while (fgets(linebuffer, sizeof(linebuffer), file) != NULL)
	{
		if (strncmp(linebuffer, "obj", 3) == 0)
		{
			objpos[++numobj] = filepos;
			sprintf(linebuffer, "%u 0 obj\n", numobj);
		}
		else if (strncmp(linebuffer, "stream", 6) == 0)
		{
			read_and_write_stream(stream_filename_prefix);
			continue;
		}
		filepos += strlen(linebuffer);
		fputs(linebuffer, stdout);
	}

	write_trailer();

	fclose(file);
	return 0;
}