#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include "fileutils.h"
#include "generic.h"

#define THRESHOLD 2000

int main(int argc, char ** argv) {
    int h, n, o, i, p, c, pp, b;
    
    verbosity = M_INFO;
    
    if (argc != 2) {
	printm(M_BARE, "Usage: search-script <file>\n");
	exit(-1);
    }
    
    if ((h = open(argv[1], O_RDONLY)) < 0) {
	printm(M_ERROR, "Error opening file %s\n", argv[1]);
	exit(-1);
    }
    
    printm(M_STATUS, "Reading informations from %s...\n", argv[1]);
    
    read(h, &n, 4);
    
    o = n;
    
    n -= 4;
    n /= 8;
    
    printm(M_INFO, "Script claims to have %i texts.\n", n);
    
    if (n > THRESHOLD) {
	printm(M_ERROR, "Too much texts to make sense.\n");
	exit(-1);
    }
    
    printm(M_STATUS, "Reading index.\n");
    
    pp = -1;
    for (i = 0; i < n; i++) {
	lseek(h, i * 8 + 4, SEEK_SET);
	read(h, &c, 4);
	read(h, &p, 4);
	printm(M_INFO, "Index #%i has pointer %i and counter %i\n", i, p, c);
	if (pp > p) {
	    printm(M_ERROR, "Script's text overlapping.\n");
	    exit(-1);
	}
	
	if (((unsigned int)(p + o)) > filesize(h)) {
	    printm(M_ERROR, "Text bigger than script.\n");
	    exit(-1);
	}
	
	lseek(h, p + o - 1, SEEK_SET);
	b = 0;
	read(h, &b, 1);
	
	if (b) {
	    printm(M_ERROR, "Byte before the pointer is not 0 (%i = 0x%02x)\n", b, b);
	    exit(-1);
	}
	
	pp = p;
    }
    
    printm(M_STATUS, "Script seems ok to me.\n");
    
    exit(0);
}