/* Copyright (C) 2014 Timo Dritschler <timo.dritschler@kit.edu>
   (Karlsruhe Institute of Technology)

   This library is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by the
   Free Software Foundation; either version 2.1 of the License, or (at your
   option) any later version.

   This library is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
   details.

   You should have received a copy of the GNU Lesser General Public License along
   with this library; if not, write to the Free Software Foundation, Inc., 51
   Franklin St, Fifth Floor, Boston, MA 02110, USA
*/

/**
 * SECTION: kiro-server
 * @Short_description: KIRO RDMA Server / Consumer
 * @Title: KiroServer
 *
 * KiroServer implements the server / passive / provider side of the the RDMA
 * Communication Channel. It uses a KIRO-TRB to manage its data.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include <rdma/rdma_verbs.h>
#include <glib.h>
#include "kiro-server.h"
#include "kiro-rdma.h"
#include "kiro-trb.h"


/*
 * Definition of 'private' structures and members and macro to access them
 */

#define KIRO_SERVER_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE((obj), KIRO_TYPE_SERVER, KiroServerPrivate))

struct _KiroServerPrivate {

    /* Properties */
    // PLACEHOLDER //

    /* 'Real' private structures */
    /* (Not accessible by properties) */
    struct rdma_event_channel   *ec;            // Main Event Channel
    struct rdma_cm_id           *base;          // Base-Listening-Connection
    struct kiro_connection      *client;        // Connection to the client
    pthread_t                   event_listener; // Pointer to the completion-listener thread of this connection
    pthread_mutex_t             mtx;            // Mutex to signal the listener-thread termination
    void                        *mem;           // Pointer to the server buffer
    size_t                      mem_size;       // Server Buffer Size in bytes

};


G_DEFINE_TYPE (KiroServer, kiro_server, G_TYPE_OBJECT);


static void kiro_server_init (KiroServer *self)
{
    KiroServerPrivate *priv = KIRO_SERVER_GET_PRIVATE(self);
    memset(priv, 0, sizeof(&priv));
}


static void
kiro_server_finalize (GObject *object)
{
    KiroServer *self = KIRO_SERVER(object);
    KiroServerPrivate *priv = KIRO_SERVER_GET_PRIVATE(self);
    pthread_mutex_unlock(&(priv->mtx));
    pthread_join(priv->event_listener, NULL);
}


static void
kiro_server_class_init (KiroServerClass *klass)
{
    GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
    gobject_class->finalize = kiro_server_finalize;
    g_type_class_add_private(klass, sizeof(KiroServerPrivate));
}


static int connect_client (struct rdma_cm_id *client)
{
    if(!client)
        return -1;
        
    if( -1 == kiro_attach_qp(client))
    {
        printf("Could not create a QP for the new connection.\n");
        rdma_destroy_id(client);
        return -1;
    }
    
    struct kiro_connection_context *ctx = (struct kiro_connection_context *)calloc(1,sizeof(struct kiro_connection_context));
    if(!ctx)
    {
        printf("Failed to create connection context.\n");
        rdma_destroy_id(client);
        return -1;
    }
    
    ctx->cf_mr_send = (struct kiro_rdma_mem *)calloc(1, sizeof(struct kiro_rdma_mem));
    ctx->cf_mr_recv = (struct kiro_rdma_mem *)calloc(1, sizeof(struct kiro_rdma_mem));
    if(!ctx->cf_mr_recv || !ctx->cf_mr_send)
    {
        printf("Failed to allocate Control Flow Memory Container.\n");
        goto error;
    }
    
    ctx->cf_mr_recv = kiro_create_rdma_memory(client->pd, sizeof(struct kiro_ctrl_msg), IBV_ACCESS_LOCAL_WRITE);
    ctx->cf_mr_send = kiro_create_rdma_memory(client->pd, sizeof(struct kiro_ctrl_msg), IBV_ACCESS_LOCAL_WRITE);
    if(!ctx->cf_mr_recv || !ctx->cf_mr_send)
    {
        printf("Failed to register control message memory.\n");
        goto error;
    }
    ctx->cf_mr_recv->size = ctx->cf_mr_send->size = sizeof(struct kiro_ctrl_msg);
    client->context = ctx;
    
    if(rdma_post_recv(client, client, ctx->cf_mr_recv->mem, ctx->cf_mr_recv->size, ctx->cf_mr_recv->mr))
    {
        printf("Posting preemtive receive for connection failed.\n");
        goto error;
    }
    
    if(rdma_accept(client, NULL))
    {
        printf("Failed to establish connection to the client with error: %i.\n", errno);
        goto error;
    }
    printf("Client Connected.\n");
    return 0;


error:
    rdma_reject(client, NULL, 0);
    kiro_destroy_connection_context(&ctx);
    rdma_destroy_id(client);
    return -1;
}


static int welcome_client (struct rdma_cm_id *client, void *mem, size_t mem_size)
{
    struct kiro_connection_context *ctx = (struct kiro_connection_context *)(client->context);
    ctx->rdma_mr = (struct kiro_rdma_mem *)calloc(1, sizeof(struct kiro_rdma_mem));
    if(!ctx->rdma_mr)
    {
        printf("Failed to allocate RDMA Memory Container.\n");
        return -1;
    }
    
    ctx->rdma_mr->mem = mem;
    ctx->rdma_mr->size = mem_size;
    ctx->rdma_mr->mr = rdma_reg_read(client, ctx->rdma_mr->mem, ctx->rdma_mr->size);
    if(!ctx->rdma_mr->mr)
    {
        printf("Failed to register RDMA Memory Region.\n");
        kiro_destroy_rdma_memory(ctx->rdma_mr);
        return -1;
    }
    
    struct kiro_ctrl_msg *msg = (struct kiro_ctrl_msg *)(ctx->cf_mr_send->mem);
    msg->msg_type = KIRO_ACK_RDMA;
    msg->peer_mri = *(ctx->rdma_mr->mr);
    
    if(rdma_post_send(client, client, ctx->cf_mr_send->mem, ctx->cf_mr_send->size, ctx->cf_mr_send->mr, IBV_SEND_SIGNALED))
    {
        printf("Failure while trying to post SEND.\n");
        kiro_destroy_rdma_memory(ctx->rdma_mr);
        return -1;
    }
    
    struct ibv_wc wc;
    
    if(rdma_get_send_comp(client, &wc) < 0)
    {
        printf("Failed to post RDMA MRI to client.\n");
        kiro_destroy_rdma_memory(ctx->rdma_mr);
        return -1;
    }
    printf("RDMA MRI sent to client.\n");

    return 0;
}


void * event_loop (void *self)
{
    KiroServerPrivate *priv = KIRO_SERVER_GET_PRIVATE((KiroServer *)self);
    struct rdma_cm_event *active_event;

    int stop = 0;

    while(0 == stop) {
        if(0 <= rdma_get_cm_event(priv->ec, &active_event))
        {
            
            struct rdma_cm_event *ev = malloc(sizeof(*active_event));
            if(!ev)
            {
                printf("Unable to allocate memory for Event handling!\n");
                rdma_ack_cm_event(active_event); 
                continue;
            }
            memcpy(ev, active_event, sizeof(*active_event));
            rdma_ack_cm_event(active_event);            
            
            if (ev->event == RDMA_CM_EVENT_CONNECT_REQUEST)
            {

                /*
                priv->client = (struct kiro_connection *)calloc(1, sizeof(struct kiro_connection));
                if(!(priv->client))
                {
                    printf("Failed to create container for client connection.\n");
                    free(ev);
                    continue;
                }
                priv->client->identifier = 0; //First Client
                priv->client->id = ev->id;
                */
                
                if(0 == connect_client(ev->id))
                {
                    // Connection set-up successfully! (Server)
                    // Post a welcoming "Recieve" for handshaking
                    welcome_client(ev->id, priv->mem, priv->mem_size);
                }
            }
            else if(ev->event == RDMA_CM_EVENT_DISCONNECTED)
            {
                printf("Got disconnect request.\n");
                //pthread_mutex_unlock(&(priv->mtx));
                kiro_destroy_connection(&(ev->id));
                printf("Connection closed successfully\n");
            }            
            free(ev);
        }

        // Mutex will be freed as a signal to stop request
        if(0 == pthread_mutex_trylock(&(priv->mtx)))
            stop = 1;
    }

    printf("Closing Event Listener Thread\n");
    return NULL;
}




int kiro_server_start (KiroServer *self, char *address, char *port, void* mem, size_t mem_size)
{
    KiroServerPrivate *priv = KIRO_SERVER_GET_PRIVATE(self);

    if(priv->base)
    {
        printf("Server already started.\n");
        return -1;
    }
    
    if(!mem || mem_size == 0)
    {
        printf("Invalid memory given to provide.\n");
        return -1;
    }
    
    struct rdma_addrinfo hints, *res_addrinfo;
    memset(&hints, 0, sizeof(hints));
    hints.ai_port_space = RDMA_PS_IB;
    hints.ai_flags = RAI_PASSIVE;
    if(rdma_getaddrinfo(address, port, &hints, &res_addrinfo))
    {
        printf("Failed to create address information.");
        return -1;
    }
    
    struct ibv_qp_init_attr qp_attr;
    memset(&qp_attr, 0, sizeof(qp_attr));
    qp_attr.cap.max_send_wr = 10;
    qp_attr.cap.max_recv_wr = 10;
    qp_attr.cap.max_send_sge = 1;
    qp_attr.cap.max_recv_sge = 1;
    qp_attr.qp_context = priv->base;
    qp_attr.sq_sig_all = 1;
    
    if(rdma_create_ep(&(priv->base), res_addrinfo, NULL, &qp_attr))
    {
        printf("Endpoint creation failed.\n");
        return -1;
    }
    printf("Endpoint created.\n");
    
    char *addr_local = NULL;
    struct sockaddr* src_addr = rdma_get_local_addr(priv->base);
    if(!src_addr)
    {
        addr_local = "NONE";
    }
    else
    {
        addr_local = inet_ntoa(((struct sockaddr_in *)src_addr)->sin_addr);
        /*
        if(src_addr->sa_family == AF_INET)
            addr_local = &(((struct sockaddr_in*)src_addr)->sin_addr);
        else
            addr_local = &(((struct sockaddr_in6*)src_addr)->sin6_addr);
        */
    }
    
    printf("Bound to address %s:%s\n",addr_local, port);
    
    if(rdma_listen(priv->base, 0))
    {
        printf("Failed to put server into listening state.\n");
        rdma_destroy_ep(priv->base);
        return -1;
    }
    
    priv->mem = mem;
    priv->mem_size = mem_size;

    priv->ec = rdma_create_event_channel();
    int oldflags = fcntl (priv->ec->fd, F_GETFL, 0);
    /* Only change the FD Mode if we were able to get its flags */
    if (oldflags >= 0) {
        oldflags |= O_NONBLOCK;
        /* Store modified flag word in the descriptor. */
        fcntl (priv->ec->fd, F_SETFL, oldflags);
    }
    if(rdma_migrate_id(priv->base, priv->ec))
    {
        printf("Was unable to migrate connection to new Event Channel.\n");
        rdma_destroy_ep(priv->base);
        return -1;
    }

    pthread_mutex_init(&(priv->mtx), NULL);
    pthread_mutex_lock(&(priv->mtx));
    pthread_create(&(priv->event_listener), NULL, event_loop, self);

    printf("Enpoint listening.\n");
    
    sleep(1);
    return 0;
}