#include <assert.h>

#include "dle.h"

size_t dle_decode(const uint8_t* s, size_t ls, uint8_t* d, size_t *ld, int (*dle_func) (uint8_t c, void *user), void *user, int *dle_flag) {
    size_t ns, nd;
    assert(s && ls && d && ld && *ld && dle_flag);

    for (ns = nd = 0; ns < ls && nd < *ld; ns++) {
        
        if (*dle_flag) {
            if (s[ns] == DLE)
                d[nd++] = DLE;
            else {
                if (dle_func) 
                    if (dle_func(s[ns], user) < 0) {
                        ns++;
                        break;
                    }
            }
            
            *dle_flag = 0;
        } else {
            if (s[ns] == DLE)
                *dle_flag = 1;
            else
                d[nd++] = s[ns];
        }
    }

    *ld = nd;
    return ns;
}

size_t dle_encode(const uint8_t* s, size_t ls, uint8_t* d, size_t *ld) {
    size_t ns, nd;

    for (ns = nd = 0; ns < ls && nd < *ld; ns++) {
        if (s[ns] == DLE) {
            if (nd+1 >= *ld)
                break;
            d[nd++] = DLE;
        }

        d[nd++] = s[ns];
    }

    *ld = nd;
    return ns;
}