#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/poll.h>
#include "../../defines.h"
#include "../../util/common.h"
#include "../../util/dbg.h"
#include "../clock.h"
#include "../socket.h"
#include "feedbackReceiver.h"

void handle_feedback(PrrtSocket *prrtSocket, const size_t length)
{
    char bufin[MAX_PAYLOAD_LENGTH];
    ssize_t n;
    struct sockaddr_in remote;
    socklen_t addrlen = sizeof(remote);

    struct pollfd fds;
    int timeout_msecs = 1000;
    fds.fd = prrtSocket->feedbackSocketFd;
    fds.events = POLLIN;

    n = poll(&fds, 1, timeout_msecs);
    check(n >= 0, "Select failed.")
    if(n == 0) {
        return;
    }
    prrtTimestamp_t receiveTime = PrrtClock_get_current_time_us();

    n = recvfrom(prrtSocket->feedbackSocketFd, bufin, length, 0, (struct sockaddr *) &remote, &addrlen);
    check(n >= 0, "Receiving feedback failed.");

    PrrtPacket *prrtPacket = calloc(1, sizeof(PrrtPacket));
    check_mem(prrtPacket);
    PrrtPacket_decode(bufin, (uint16_t) n, prrtPacket);

    //PrrtPacketFeedbackPayload* payload = prrtPacket->payload;
    //struct in_addr a;
    //a.s_addr = payload->receiverAddress;
    //debug("Receiver Address: %s", inet_ntoa(a));

    prrtTimestamp_t forwardTripTimestamp = ((PrrtPacketFeedbackPayload *) prrtPacket->payload)->forwardTripTimestamp_us;

    PrrtChannelStateInformation_update_rtt(prrtSocket->csi, (prrtTimedelta_t) (receiveTime - forwardTripTimestamp));
    PrrtChannelStateInformation_print(prrtSocket->csi);

    error:
    if(prrtPacket != NULL) { PrrtPacket_destroy(prrtPacket); }
}

void *receive_feedback_loop(void *ptr)
{
    PrrtSocket *sock_ptr = ptr;

    check(pthread_mutex_lock(&sock_ptr->closingMutex) == 0, "Lock failed.");
    while(sock_ptr->closing == false) {
        check(pthread_mutex_unlock(&sock_ptr->closingMutex) == 0, "Unlock failed.");
        handle_feedback(sock_ptr, MAX_PAYLOAD_LENGTH);
        usleep(1);
        check(pthread_mutex_lock(&sock_ptr->closingMutex) == 0, "Lock failed.");
    }
    check(pthread_mutex_unlock(&sock_ptr->closingMutex) == 0, "Unlock failed.");

    return NULL;

    error:
    PERROR("Feedback reception failed.");
    return NULL;
}