#ifndef ESCAPE_ENCODING_H_
#define ESCAPE_ENCODING_H_

#include <stddef.h>
#include <stdint.h>

#ifndef ESCAPE_ERROR_ENCODING
#define ESCAPE_ERROR_ENCODING 1
#endif /* ESCAPE_ERROR_ENCODING */

size_t ee_maximum_encoding_length(size_t length) { return length * 2; }

int ee_decode(uint8_t *dst, size_t *dst_length, const uint8_t *src, size_t *src_length) {
    size_t ds = 0;
    size_t dl = *dst_length;
    size_t ss = 0;
    size_t sl = *src_length;

    while ((ss < sl) && (ds < dl)) {
        if (src[ss] == 0xFE) {
            if (ss + 1 >= sl) {
                return ESCAPE_ERROR_ENCODING;
            }
            dst[ds++] = src[ss + 1] + 1;
            ss += 2;
        } else {
            dst[ds++] = src[ss++];
        }
    }

    *dst_length = ds;
    *src_length = ss;
    return 0;
}

int ee_decode_char_string_in_place(char *buf, size_t *length) {
    size_t ss = 0;
    size_t ds = 0;

    while (buf[ss] != '\0') {
        if (((uint8_t)buf[ss]) == 0xFE) {
            if (buf[ss + 1] == '\0') {
                return ESCAPE_ERROR_ENCODING;
            }
            buf[ds++] = buf[ss + 1] + 1;
            ss += 2;
        } else {
            buf[ds++] = buf[ss++];
        }
    }

    *length = ds;
    return 0;
}

int ee_encode(uint8_t *dst, size_t *dst_length, const uint8_t *src, size_t *src_length) {
    size_t ds = 0;
    size_t dl = *dst_length;
    size_t ss = 0;
    size_t sl = *src_length;

    while ((ss < sl) && (ds < dl)) {
        if ((src[ss] == 0x0) || (src[ss] == 0xFE)) {
            if (ds + 1 >= dl) {
                break;
            }
            dst[ds] = 0xFE;
            dst[ds + 1] = src[ss++] - 1;
            ds += 2;
        } else {
            dst[ds++] = src[ss++];
        }
    }

    *dst_length = ds;
    *src_length = ss;
    return 0;
}

#endif /* ESCAPE_ENCODING_H_ */