#include <stdlib.h>
#include <stdint.h>
#include <string.h>

#include "eos.h"
#include "event.h"
#include "dev/net.h"

#include "sock.h"

static eos_evt_handler_t evt_handler[EOS_SOCK_MAX_SOCK];

static void sock_handle_msg(unsigned char type, unsigned char *buffer, uint16_t buf_len) {
    unsigned char sock;
    int i;

    if ((buffer == NULL) || (buf_len < 2)) {
        eos_net_bad_handler(type, buffer, buf_len);
        return;
    }

    switch(buffer[0]) {
        case EOS_SOCK_MTYPE_PKT: {
            sock = buffer[1];
            if ((sock == 0) || (sock > EOS_SOCK_MAX_SOCK) || (evt_handler[sock - 1] == NULL)) {
                eos_net_bad_handler(type, buffer, buf_len);
                return;
            }
            evt_handler[sock - 1](type, buffer, buf_len);
            break;
        }

        case EOS_SOCK_MTYPE_CLOSE: {
            for (i=1; i<buf_len; i++) {
                sock = buffer[i];
                if ((sock == 0) || (sock > EOS_SOCK_MAX_SOCK) || (evt_handler[sock - 1] == NULL)) {
                    eos_net_bad_handler(type, buffer, buf_len);
                    return;
                }
                evt_handler[sock - 1](type, buffer, buf_len);
            }
            break;
        }

        default:
            eos_net_bad_handler(type, buffer, buf_len);
            break;
    }
}

void eos_sock_init(void) {
    int i;

    for (i=0; i<EOS_SOCK_MAX_SOCK; i++) {
        evt_handler[i] = NULL;
    }
    eos_net_set_handler(EOS_NET_MTYPE_SOCK, sock_handle_msg);
}

void eos_sock_set_handler(unsigned char sock, eos_evt_handler_t handler) {
    if (sock && (sock <= EOS_SOCK_MAX_SOCK)) evt_handler[sock - 1] = handler;
}

eos_evt_handler_t eos_sock_get_handler(unsigned char sock) {
    if (sock && (sock <= EOS_SOCK_MAX_SOCK)) return evt_handler[sock - 1];
    return NULL;
}

int eos_sock_open_udp(eos_evt_handler_t handler, unsigned char *buffer) {
    unsigned char type;
    uint16_t buf_len;
    int do_release;
    int rv, sock;

    do_release = 0;
    if (buffer == NULL) {
        buffer = eos_net_alloc();
        do_release = 1;
    }

    type = EOS_NET_MTYPE_SOCK;
    buf_len = 1;
    buffer[0] = EOS_SOCK_MTYPE_OPEN_DGRAM;

    rv = eos_net_xchg(&type, buffer, &buf_len);
    if (rv) goto sock_open_udp_fin;

    if (type != EOS_NET_MTYPE_SOCK) {
        rv = EOS_ERR_NET;
        goto sock_open_udp_fin;
    }
    if (buf_len < 2) {
        rv = EOS_ERR_SIZE;
        goto sock_open_udp_fin;
    }

    sock = buffer[1];
    if ((sock == 0) || (sock > EOS_SOCK_MAX_SOCK)) {
        rv = EOS_ERR_NET;
        goto sock_open_udp_fin;
    }

    rv = sock;
    eos_sock_set_handler(sock, handler);

sock_open_udp_fin:
    if (do_release) eos_net_free(buffer, 1);
    return rv;
}

void eos_sock_close(unsigned char sock, unsigned char *buffer) {
    int async;

    async = 0;
    if (buffer == NULL) {
        buffer = eos_net_alloc();
        async = 1;
    }
    buffer[0] = EOS_SOCK_MTYPE_CLOSE;
    buffer[1] = sock;
    _eos_net_send(EOS_NET_MTYPE_SOCK, buffer, 2, async, 1);
    eos_sock_set_handler(sock, NULL);
}

int eos_sock_pkt_alloc(unsigned char **buffer, unsigned char *pkt, size_t pkt_len) {
    *buffer = NULL;

    if (pkt && (pkt_len + EOS_SOCK_SIZE_UDP_HDR > EOS_NET_SIZE_BUF)) return EOS_ERR_SIZE;

    *buffer = eos_net_alloc();
    *buffer += EOS_SOCK_SIZE_UDP_HDR;
    if (pkt) memcpy(*buffer, pkt, pkt_len);

    return EOS_OK;
}

unsigned char *eos_sock_buf2pkt(unsigned char *buf, uint16_t buf_len) {
    if (buf_len < EOS_SOCK_SIZE_UDP_HDR) return NULL;

    return buf + EOS_SOCK_SIZE_UDP_HDR;
}

unsigned char *eos_sock_pkt2buf(unsigned char *pkt) {
    return pkt - EOS_SOCK_SIZE_UDP_HDR;
}

static void sock_sendto(unsigned char sock, EOSNetAddr *addr, unsigned char *buffer) {
    buffer[0] = EOS_SOCK_MTYPE_PKT;
    buffer[1] = sock;
    buffer += 2;
    memcpy(buffer, addr->host, sizeof(addr->host));
    buffer += sizeof(addr->host);
    buffer[0] = addr->port >> 8;
    buffer[1] = addr->port;
    buffer += sizeof(addr->port);
}

int eos_sock_sendto(unsigned char sock, EOSNetAddr *addr, unsigned char *buffer, uint16_t buf_len, unsigned char more) {
    int rv;

    buffer -= EOS_SOCK_SIZE_UDP_HDR;
    sock_sendto(sock, addr, buffer);

    rv = eos_net_send(EOS_NET_MTYPE_SOCK, buffer, buf_len + EOS_SOCK_SIZE_UDP_HDR, more);
    return rv;
}

int eos_sock_sendto_sync(unsigned char sock, EOSNetAddr *addr, unsigned char *buffer, uint16_t buf_len) {
    int rv;

    buffer -= EOS_SOCK_SIZE_UDP_HDR;
    sock_sendto(sock, addr, buffer);

    rv = eos_net_send_sync(EOS_NET_MTYPE_SOCK, buffer, buf_len + EOS_SOCK_SIZE_UDP_HDR);
    return rv;
}

int eos_sock_recvfrom(unsigned char *buffer, uint16_t buf_len, EOSNetAddr *addr, unsigned char *pkt, size_t pkt_size) {
    if (buf_len < EOS_SOCK_SIZE_UDP_HDR) return EOS_ERR_SIZE;

    if (buffer[0] == EOS_SOCK_MTYPE_CLOSE) return EOS_SOCK_ERR_CLOSED;
    if (buffer[0] != EOS_SOCK_MTYPE_PKT) return EOS_ERR_NET;

    buffer += 2;
    if (addr) {
        memcpy(addr->host, buffer, sizeof(addr->host));
    }
    buffer += sizeof(addr->host);
    if (addr) {
        addr->port  = (uint16_t)buffer[0] << 8;
        addr->port |= (uint16_t)buffer[1];
    }
    buffer += sizeof(addr->port);
    if (pkt) {
        if (pkt_size < buf_len - EOS_SOCK_SIZE_UDP_HDR) return EOS_ERR_SIZE;
        memcpy(pkt, buffer, buf_len - EOS_SOCK_SIZE_UDP_HDR);
    }

    return EOS_OK;
}