/*
 * Copyright (c) 2018 HUACHENTEL and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "sc_plugins.h"
#include "sc_model.h"
#include <dirent.h>

static int vpp_pid_start;

/* get vpp pid in system */
int get_vpp_pid()
{
    DIR *dir;
    struct dirent *ptr;
    FILE *fp;
    char filepath[50];
    char filetext[20];

    dir = opendir("/proc");
    int vpp_pid = 0;
    /* read vpp pid file in proc, return pid of vpp */
    if (NULL != dir)
    {
        while (NULL != (ptr =readdir(dir)))
        {
            if ((0 == strcmp(ptr->d_name, ".")) || (0 == strcmp(ptr->d_name, "..")))
                continue;

            if (DT_DIR != ptr->d_type)
                continue;

            sprintf(filepath, "/proc/%s/cmdline",ptr->d_name);
            fp = fopen(filepath, "r");

            if (NULL != fp)
            {
                fread(filetext, 1, 13, fp);
                filetext[12] = '\0';

                if (filetext == strstr(filetext, "/usr/bin/vpp"))
                    vpp_pid = atoi(ptr->d_name);

                fclose(fp);
            }
        }
        closedir(dir);
    }
    return vpp_pid;
}


int sr_plugin_init_cb(sr_session_ctx_t *session, void **private_ctx)
{
    plugin_main_t plugin_main;
    int rc;

    rc = sc_connect_vpp();
    if (0 != rc) {
        SRP_LOG_ERR("vpp connect error , with return %d.", rc);
        return SR_ERR_INTERNAL;
    }

    plugin_main.session = session;
    plugin_main.subscription = NULL;

    /* Use the same sr_subscription_ctx for all models */
    model_register(&plugin_main, ietf_interfaces_xpaths, IETF_INTERFACES_SIZE);
    model_register(&plugin_main, ietf_nat_xpaths, IETF_NAT_SIZE);
    model_register(&plugin_main, oc_interfaces_xpaths, OC_INTERFACES_SIZE);
    model_register(&plugin_main, oc_local_routing_xpaths, OC_LROUTING_SIZE);

    /* set subscription as our private context */
    *private_ctx = plugin_main.subscription;
    /* get the vpp pid sweetcomb connected, we assumed that only one vpp is run in system */
    vpp_pid_start = get_vpp_pid();
    return SR_ERR_OK;
}

void sr_plugin_cleanup_cb(sr_session_ctx_t *session, void *private_ctx)
{
    /* subscription was set as our private context */
    if (private_ctx != NULL)
        sr_unsubscribe(session, private_ctx);
    SRP_LOG_DBG_MSG("unload plugin ok.");

    sc_disconnect_vpp();
    SRP_LOG_DBG_MSG("plugin disconnect vpp ok.");
}

int sr_plugin_health_check_cb(sr_session_ctx_t *session, void *private_ctx)
{
   /* health check, will use shell to detect vpp when plugin is loaded */
   /* health_check will run every 10 seconds in loop*/
   int vpp_pid_now = get_vpp_pid();

   if(vpp_pid_now == vpp_pid_start)
       {
       return SR_ERR_OK;
       }
   else
   {
       return -1;
   }
}