#include "core.h"

#include <string.h>

int ecp_rbuf_init(ECPRBuffer *rbuf, ECPRBMessage *msg, unsigned int msg_size) {
    rbuf->msg = msg;
    if (msg_size) {
        rbuf->msg_size = msg_size;
    } else {
        rbuf->msg_size = ECP_RBUF_SEQ_HALF;
    }
    
    return ECP_OK;
}

int ecp_rbuf_msg_idx(ECPRBuffer *rbuf, ecp_seq_t seq) {
    ecp_seq_t seq_offset = seq - rbuf->seq_start;

    // This also checks for seq_start <= seq if seq type range >> rbuf->msg_size
    if (seq_offset < rbuf->msg_size) return ECP_RBUF_IDX_MASK(rbuf->msg_start + seq_offset, rbuf->msg_size);
    return ECP_ERR_RBUF_IDX;
}

ssize_t ecp_rbuf_msg_store(ECPRBuffer *rbuf, ecp_seq_t seq, unsigned char *msg, size_t msg_size, unsigned char test_flags, unsigned char set_flags) {
    int idx = ecp_rbuf_msg_idx(rbuf, seq);
    if (idx < 0) return idx;

    if (rbuf->msg == NULL) return 0;
    if (test_flags && (test_flags & rbuf->msg[idx].flags)) return ECP_ERR_RBUF_FLAG;
    
    memcpy(rbuf->msg[idx].msg, msg, msg_size);
    rbuf->msg[idx].size = msg_size;
    rbuf->msg[idx].flags = set_flags;

    return msg_size;
}