//
// Copyright 2007-2009 Johannes Hofmann <Johannes.Hofmann@gmx.de>
//
// This software may be used and distributed according to the terms
// of the GNU General Public License, incorporated herein by reference.

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include "PostscriptDSC.H"

PostscriptDSC::PostscriptDSC() {
	bb_x = 0;
	bb_y = 0;
	bb_w = 594; // A4 
	bb_h = 841; //
	setup_len = 0;
	pages = 0;
	page_off = NULL;
	page_len = NULL;
}

PostscriptDSC::~PostscriptDSC() {
	if (page_off) {
		free(page_off);
	}
	if (page_len) {
		free(page_len);
	}
}

int 
PostscriptDSC::parse(int fd) {
	FILE *fp;
	char linebuf[1024];
	int x, y, w, h;
	int p1 = 0;
	int bb_read = 0;
	int max_pages = 128;

	bb_x = 0;
	bb_y = 0;
	bb_w = 594; // A4 
	bb_h = 841; //
	setup_len = 0;
	pages = 0;

	if (page_off) {
		free(page_off);
		page_off = NULL;
	}
	if(page_len) {
		free(page_len);
		page_len = NULL;
	}

	fp = fdopen(fd, "r");
	if (!fp) {
		perror("fdopen");
		return 1;
	}

	page_off = (size_t*) malloc(sizeof(size_t) * max_pages);
	memset(page_off, 0, sizeof(size_t) * max_pages);
	page_len = (size_t*) malloc(sizeof(size_t) * max_pages);
	memset(page_len, 0, sizeof(size_t) * max_pages);

	while (fgets(linebuf, sizeof(linebuf), fp) != NULL) {
		if (!bb_read &&
			sscanf(linebuf, "%%%%BoundingBox: %d %d %d %d", &x, &y, &w, &h) == 4) {
			bb_x = x; 
			bb_y = y; 
			bb_w = w; 
			bb_h = h; 
			bb_read++;
		} else if (setup_len == 0 &&
			strncmp(linebuf, "%%EndSetup", strlen("%%EndSetup")) == 0) {
			setup_len = ftell(fp);
		} else if (strncmp(linebuf, "%%Page: ", strlen("%%Page: ")) == 0) {
			char *p_str = &linebuf[strlen(linebuf)];

			// implicitely end setup section
			if (!setup_len) {
				setup_len = ftell(fp);
			}

			// move p_str back to beginning of last number in linebuf
			while (p_str > linebuf && !isdigit(*p_str)) {
				p_str--;
			}
			while (p_str > linebuf && isdigit(*p_str)) {
				p_str--;
			}

			p1 = atoi(p_str);

			if (p1 < 1) {
				fprintf(stderr, "Page %d out of range\n", p1);
				return 1;
			} 

			if (p1 > max_pages) {
				page_off = (size_t*) realloc(page_off, 2 * max_pages * sizeof(size_t));
				memset(page_off + max_pages, 0, sizeof(size_t) * max_pages);
				page_len = (size_t*) realloc(page_len, 2 * max_pages * sizeof(size_t));
				memset(page_len + max_pages, 0, sizeof(size_t) * max_pages);
				max_pages = max_pages * 2;
			}

			if (page_off[p1 - 1] != 0) {
				fprintf(stderr, "Page %d already defined\n", p1);
				return 1;
			}
			if (p1 > 1 && page_off[p1 - 2] == 0) {
				fprintf(stderr, "Page %d not yet defined\n", p1 - 1);
				return 1;
			}

			page_off[p1 - 1] = ftell(fp);
			if (p1 > 1) {
				page_len[p1 - 2] = page_off[p1 - 1] - page_off[p1 - 2];
			}

			if (p1 > pages) {
				pages = p1;
			}
		}      
	}

	// Now do some checks 
	if (!setup_len) {
		fprintf(stderr, "PageSetup end not found\n");
		return 1;
	}
	if (page_len && page_off && p1 > 0 && p1 <= pages) {
		page_len[p1 - 1] = ftell(fp) - page_off[p1 - 1];

		for (int i=0; i<pages; i++) {
			if (page_off[i] == 0 || page_len[i] == 0) {
				fprintf(stderr, "Page %d not defined\n", i);
				return 1;
			}
		}
	} else {
		return 1;
	}

	return 0;
}

void
PostscriptDSC::get_bounding_box(int *x, int *y, int *w, int *h) {
	*x = bb_x;
	*y = bb_y;
	*w = bb_w;
	*h = bb_h;
}

int
PostscriptDSC::get_pages() {
	return pages;
}

size_t
PostscriptDSC::get_setup_len() {
	return setup_len;
}

size_t
PostscriptDSC::get_page_off(int p) {
	if (p < 1 || p > pages) {
		return 0;
	} else {
		return page_off[p - 1];
	}
}

size_t
PostscriptDSC::get_page_len(int p) {
	if (p < 1 || p > pages) {
		return 0;
	} else {
		return page_len[p - 1];
	}
}

void
PostscriptDSC::print() {
	int i;

	printf("x %d, y %d, w %d, h %d\n", bb_x, bb_y, bb_w, bb_h);
	printf("setup_len %zu\n", setup_len);
	for (i=0; i<pages; i++) {
		printf("p %d, off %zu, len %zu\n", i, page_off[i], page_len[i]);
	}
}