#include "tcp_internal.h"
#include "log.h"

/*
 * Our transport methods
 */
static void tcp_client__deinit (transport_t *transport)
{
    struct tcp_client *client = transport_check(transport, &tcp_client_type);
    
    // proxy
    tcp_client_deinit(client);
}

/*
 * Our transport_type
 */
const struct transport_type tcp_client_type = {
    .base_type = {
        .parent             = &tcp_transport_type.base_type,
    },
    .methods                = {
        .read               = transport_fd__read,
        .write              = transport_fd__write,
        .events             = transport_fd__events,
        .deinit             = tcp_client__deinit,
    },
};

/*
 * Forward-declare 
 */
static void tcp_client_on_connect (struct transport_fd *fd, short what, void *arg);

/*
 * Function implementations
 */
void tcp_client_init (struct tcp_client *client)
{
    tcp_transport_init(&client->base_trans, -1);
    
    resolve_result_init(&client->rr);
}

/*
 * Start connecting to the given address in a non-blocking fashion. Returns any errors that immediately crop up,
 * otherwise eventually calls tcp_client_connect_done().
 */
static err_t tcp_client_connect_addr (struct tcp_client *client, struct addrinfo *addr, error_t *err)
{
    struct transport_fd *_fd = &client->base_trans.base_fd;
    int ret;
    evutil_socket_t sock;
    err_t tmp;

    // first, create the socket
    if ((sock = tcp_sock_create(addr, err)) < 0)
        return ERROR_CODE(err);

    // set it as our sock
    if ((ERROR_CODE(err) = transport_fd_set(_fd, sock)))
        goto error;

    // then, set it up as nonblocking
    if ((ERROR_CODE(err) = transport_fd_nonblock(_fd, true)))
        goto error;

    // then, initiate the connect
    if ((ret = connect(sock, addr->ai_addr, addr->ai_addrlen)) < 0 && errno != EINPROGRESS) 
        JUMP_SET_ERROR_ERRNO(err, ERR_CONNECT);
    
    if (ret < 0) {
        // ok, connect started, setup our completion callback
        if ((ERROR_CODE(err) = transport_fd_setup(_fd, tcp_client_on_connect, client)))
            goto error;
    
        // enable for write
        if ((ERROR_CODE(err) = transport_fd_enable(_fd, TRANSPORT_WRITE)))
            goto error;

    } else {
        // oops... blocking connect - fail to avoid confusion
        // XXX: come up with a better error name to use
        // XXX: support non-async connects as well
        JUMP_SET_ERROR_EXTRA(err, ERR_CONNECT, EINPROGRESS);
    }
    
    // ok
    return SUCCESS;

error:
    // close the stuff we did open
    if ((tmp = transport_fd_close(_fd)))
        log_warn("error closing socket after connect error: %s", error_name(tmp));

    return ERROR_CODE(err);
}


/*
 * Attempt to connect to the next addrinfo, or the next one, if that fails, etc.
 *
 * This does not call transport_connected().
 */
static err_t tcp_client_connect_continue (struct tcp_client *client, error_t *err)
{
    struct addrinfo *addr;

    // try and connect to each one until we find one that works
    while ((addr = resolve_result_next(&client->rr))) {
        // attempt to start connect
        if (tcp_client_connect_addr(client, addr, err) == SUCCESS)
            break;

        // log a warning on the failed connect
        log_warn_error(err, "%s", resolve_addr_text(addr));
    }
    

    if (addr)
        // we succesfully did a tcp_client_connect_addr on valid address
        return SUCCESS;

    else
        // all of the connect_async_addr's failed, return the last error
        return ERROR_CODE(err);
}

/*
 * Cleanup our resolver state and any connect callbacks after a connect
 */
static void tcp_client_connect_cleanup (struct tcp_client *client)
{
    // drop the resolver stuff
    resolve_result_deinit(&client->rr);
    
    // remove our event handler
    transport_fd_clear(&client->base_trans.base_fd);
}

/*
 * Our async connect operation has completed, clean up, set up state for event-based operation with user callbacks, and
 * invoke transport_connected().
 *
 * The given \a err should be NULL for successful completion, or the error for failures.
 */
static void tcp_client_connect_done (struct tcp_client *client, error_t *conn_err)
{
    error_t err;

    // cleanup
    tcp_client_connect_cleanup(client);

    if (conn_err)
        JUMP_SET_ERROR_INFO(&err, conn_err);

    // let the transport handle the rest
    if (tcp_transport_connected(&client->base_trans, &err))
        goto error;
    
    // ok
    return;

error:    
    // pass the error on to transport
    transport_connected(&client->base_trans.base_fd.base, &err, false);
}

/*
 * Our async connect callback
 */
static void tcp_client_on_connect (struct transport_fd *fd, short what, void *arg)
{
    struct tcp_client *client = arg;
    error_t err;
    err_t tmp;

    // XXX: timeouts
    (void) what;
    
    // read socket error code
    if (tcp_sock_error(client->base_trans.base_fd.fd, &err))
        goto error;

    // did the connect fail?
    if (ERROR_EXTRA(&err))
        JUMP_SET_ERROR(&err, ERR_CONNECT);
    
    // done, success
    return tcp_client_connect_done(client, NULL);

error:
    // close the socket
    if ((tmp = transport_fd_close(fd)))
        log_warn("error closing socket after connect error: %s", error_name(tmp));

    // log a warning
    log_warn_error(&err, "connect to %s failed", "???");

    // try the next one or fail completely
    if (tcp_client_connect_continue(client, &err))
        tcp_client_connect_done(client, &err);
}

err_t tcp_client_connect_async (struct tcp_client *client, const char *hostname, const char *service, error_t *err)
{
    // do the resolving
    if (resolve_addr(&client->rr, hostname, service, SOCK_STREAM, 0, err))
        return ERROR_CODE(err);

    // start connecting with the first result
    if (tcp_client_connect_continue(client, err))
        goto error;

    // ok
    return SUCCESS;

error:
    // cleanup
    resolve_result_deinit(&client->rr);
    
    return ERROR_CODE(err);
}

void tcp_client_deinit (struct tcp_client *client)
{
    // cleanup our stuff
    resolve_result_deinit(&client->rr);
    
    // deinit lower transport
    tcp_transport_deinit(&client->base_trans);
}

/*
 * Deinit and free, not using the transport interface
 */
static void tcp_client_destroy (struct tcp_client *client)
{
    tcp_client_deinit(client);

    free(client);
}

/*
 * Public interface
 */
err_t tcp_connect (const struct transport_info *info, transport_t **transport_ptr, 
        const char *host, const char *service, error_t *err)
{
    struct tcp_client *client;
 
    // alloc
    if ((client = calloc(1, sizeof(*client))) == NULL)
        return ERR_CALLOC;

    // init transport
    transport_init(&client->base_trans.base_fd.base, &tcp_client_type, info);
    
    // init our state
    tcp_client_init(client);
 
    // begin connect
    if (tcp_client_connect_async(client, host, service, err))
        goto error;

    // good
    *transport_ptr = &client->base_trans.base_fd.base;

    return 0;

error:
    // cleanup
    tcp_client_destroy(client);
        
    // return error code
    return ERROR_CODE(err);
}