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#include <arpa/inet.h>

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#include <sys/socket.h>

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#include <sys/types.h>

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#include <fcntl.h>

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#include <netdb.h>

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#include <stdio.h>

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#include <unistd.h>

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#include <errno.h>

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#include <assert.h>

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#include "socket.h"

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#include "common.h"

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#define _SOCKOP_SOCKET 0x01

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#define _SOCKOP_ENDPOINT_BIND 0x02

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#define _SOCKOP_ENDPOINT_CONNECT 0x04

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#define _SOCKOP_LISTEN 0x08

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#define _SOCKOP_FLAGS_PASSIVE 0x10

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#define _SOCKOP_FCNTL_NONBLOCK 0x20

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enum socket_op {

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    /*

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     * Just resolve the address, don't create a socket

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     */

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    SOCKOP_RESOLVE = _SOCKOP_FLAGS_PASSIVE,

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    /*

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     * Create a socket whose local end is bound to the given endpoint, and listening

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     */

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    SOCKOP_LISTEN = _SOCKOP_FLAGS_PASSIVE | _SOCKOP_SOCKET | _SOCKOP_ENDPOINT_BIND | _SOCKOP_LISTEN,

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    /*

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     * Create a socket whose remote end is connected to the given endpoint, and connected

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     */

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    SOCKOP_CONNECT = _SOCKOP_SOCKET | _SOCKOP_ENDPOINT_CONNECT,

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    /*

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     * Create a socket and initiate a nonblocking connect to the given endpoint

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     */

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    SOCKOP_CONNECT_ASYNC = _SOCKOP_SOCKET | _SOCKOP_FCNTL_NONBLOCK | _SOCKOP_ENDPOINT_CONNECT,

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};

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static int _socket_do (struct config_endpoint *endpoint, int *sock, int sock_type, struct sockaddr_storage *addr, enum socket_op sockop);

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/*

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 * Create a socket of the given type that's listening on the given endpoint

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 */

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int socket_listen (struct config_endpoint *endpoint, int sock_type) {

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    int sock = -1;

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    struct sockaddr_storage addr;

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    // and then _socket_do

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    if (_socket_do(endpoint, &sock, sock_type, &addr, SOCKOP_LISTEN))

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        return -1;

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    // just return the socket, discard addr

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    return sock;

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}

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/*

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 * Initiate an async connect to the given endpoint for the given socket type. This should work for

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 * PF_INET and PF_LOCAL sockets, and in both cases, socket writeability should indicate that the

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 * connect succeeded.

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 *

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 * XXX: Currently it looks up the endpoint each time - the working addrinfo should be cached

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 */

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int socket_connect_async (struct config_endpoint *endpoint, int sock_type) {

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    int sock = -1;

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    struct sockaddr_storage addr;

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    // and then _socket_do

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    if (_socket_do(endpoint, &sock, sock_type, &addr, SOCKOP_CONNECT_ASYNC))

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        return -1;

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    // return the socket

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    return sock;

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}

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/*

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 * Do something to apply an endpoint to a socket

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 */

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static int _socket_do (struct config_endpoint *endpoint, int *sock, int sock_type, struct sockaddr_storage *addr, enum socket_op sockop) {

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    struct addrinfo *res = NULL, *info, _fake_res;

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    struct sockaddr_un _fake_addr_un;

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    if (endpoint->family == PF_UNIX) {

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        // getaddrinfo doesn't handle PF_UNIX, so we need to build a fake result

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        // build the sockaddr_un

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        _fake_addr_un.sun_family = endpoint->family;

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        memcpy(_fake_addr_un.sun_path, endpoint->af.local.path, sizeof(_fake_addr_un.sun_path));

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        // build the fake addrinfo res

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        _fake_res.ai_flags = 0;

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        _fake_res.ai_family = PF_UNIX;

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        _fake_res.ai_socktype = sock_type;

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        _fake_res.ai_protocol = 0;

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        _fake_res.ai_addrlen = SUN_LEN(&_fake_addr_un);

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        _fake_res.ai_addr = (struct sockaddr *) &_fake_addr_un;

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        _fake_res.ai_canonname = (char *) endpoint->af.local.path;  /* XXX: not const */

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        _fake_res.ai_next = NULL;

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        res = &_fake_res;

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    } else if (endpoint->family == PF_INET) {

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        // use the real getaddrinfo

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        struct addrinfo hints;

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        memset(&hints, 0, sizeof(hints));

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        hints.ai_socktype = sock_type;

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        hints.ai_protocol = 0;

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        hints.ai_flags = (sockop & _SOCKOP_FLAGS_PASSIVE ? AI_PASSIVE : 0) | AI_CANONNAME;

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        int err;

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        // check that we have a service, doesn't make any sense without

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        if (!endpoint->af.inet.port)

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            ERROR("no service specified");

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        if ((err = getaddrinfo(endpoint->af.inet.addr, endpoint->af.inet.port, &hints, &res)) != 0)

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            ERROR("getaddrinfo: %s#%s: %s", endpoint->af.inet.addr, endpoint->af.inet.port, gai_strerror(err));

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    } else {

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        ERROR("invalid endpoint");

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    }

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    for (info = res; info; info = info->ai_next) {

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        if (sockop & _SOCKOP_SOCKET && (*sock = socket(info->ai_family, info->ai_socktype, info->ai_protocol)) == -1) {

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            PWARNING("socket(%d, %s)", info->ai_family, info->ai_canonname);

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            continue;

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        }

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        if (sockop & _SOCKOP_FCNTL_NONBLOCK && fcntl(*sock, F_SETFL, O_NONBLOCK) == -1) {

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            PWARNING("fcntl(%d, %s, F_SETFL O_NONBLOCK)", info->ai_family, info->ai_canonname);

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            close(*sock); *sock = -1;

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            continue;

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        }

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        if (sockop & _SOCKOP_ENDPOINT_BIND && bind(*sock, info->ai_addr, info->ai_addrlen) == -1) {

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            PWARNING("bind(%d, %s)", info->ai_family, info->ai_canonname);

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            close(*sock); *sock = -1;

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            continue;

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        }

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        if (sockop & _SOCKOP_LISTEN && listen(*sock, SOCKET_LISTEN_BACKLOG) == -1) {

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            PWARNING("listen(%d, %s)", info->ai_family, info->ai_canonname);

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            close(*sock); *sock = -1;

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            continue;

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        }

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        if (sockop & _SOCKOP_ENDPOINT_CONNECT && connect(*sock, info->ai_addr, info->ai_addrlen) == -1) {

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            if (sockop & _SOCKOP_FCNTL_NONBLOCK && errno == EINPROGRESS) {

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                /* to be expected */

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            } else {

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                close(*sock); *sock = -1;

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                continue;

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            }

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        }

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        // copy the succesfull address over

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        memcpy(addr, info->ai_addr, info->ai_addrlen);

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        // exit the loop with a valid socket

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        assert(*sock != -1);

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        break;

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    }

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    if (*sock == -1)

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        ERROR("no working results from getaddrinfo: %s#%s", endpoint->af.inet.addr, endpoint->af.inet.port);

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    return 0;

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error:

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    if (res != 0 && res != &_fake_res)

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        freeaddrinfo(res);

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    return -1;

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}   

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