/*******************************************************************************
 * Copyright (C) 2004-2006 Intel Corp. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  - Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 *  - Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 *  - Neither the name of Intel Corp. nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL Intel Corp. OR THE CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *******************************************************************************/

/**
 * @author Anas Nashif
 */


#ifdef HAVE_CONFIG_H
#include <wsman_config.h>
#endif

#include "stdlib.h"
#include "stdio.h"
#include <string.h>
#ifdef HAVE_DIRENT_H
#include <dirent.h>
#endif

#ifndef WIN32
#include <dlfcn.h>
#endif
#include "u/libu.h"
#include "wsman-plugins.h"


static list_t*
scan_files_in_dir ( const char *dir, int (*select)(const struct dirent *))
{
    struct dirent **namelist;
    int n;
    list_t *files = list_create(LISTCOUNT_T_MAX);

    if (0 > (n = scandir (dir, &namelist, 0, alphasort)))
    {
        return files;
    } else {
        while (n--)
        {
			lnode_t *node;
            char *tmp = u_strdup(namelist[n]->d_name);
            node = lnode_create(tmp);
            list_append(files, node );
            //debug("plugin file found: %s", namelist[n]->d_name );
            u_free(namelist[n]);
        }
        u_free(namelist);
    }
    return files;
}


static WsManPlugin*
plugin_new(void)
{
    WsManPlugin *self = u_malloc(sizeof(WsManPlugin));
    if (self) {
        memset(self, 0, sizeof(WsManPlugin));
    }
    return self ;
}

static void
plugin_free(WsManPlugin *self)
{
    message( "Un-loading plugins: %s", self->p_name );

    if( self->p_handle && self->cleanup ) {
        (*self->cleanup)( self->p_handle, self->data );
    }
    if(self->p_name)
        u_free(self->p_name);
    if( self->p_handle )
        dlclose( self->p_handle );
}

static WsManPluginError
plugin_init(WsManPlugin *self, const char *p_name)
{
    WsManPluginError PluginError = PLUGIN_ERROR_OK ;
    self->p_name = u_strdup(p_name) ;
    if (NULL != (self->p_handle = dlopen(p_name, RTLD_LAZY))) {
        self->init = dlsym(self->p_handle, "init");
        self->get_endpoints = dlsym(self->p_handle, "get_endpoints");
        if ( ! self->get_endpoints
                && ! self->init)
        {
            self->init			        = 0 ;
	    PluginError = PLUGIN_ERROR_SYMBOLSNOTFOUND ;
        }
    } else {
        PluginError = PLUGIN_ERROR_NOTLOADED ;
    }
    return PluginError ;
}

static int
load_plugin(WsManPlugin *self, const char *p_name)
{
    int retv = -1;
    WsManPluginError err = plugin_init(self, p_name);
    const char	*plugin_err = dlerror();
    message("Loading plugin: %s", p_name );

	if( NULL == plugin_err )
        plugin_err = "";
    switch( err )
    {
    default:
        debug(  "Unable to load plugin %s. Error: %s", p_name, plugin_err );
        break;
    case PLUGIN_ERROR_NOTLOADED:
        debug( "Unable to load plugin %s. Error: %s", p_name, plugin_err );
        break;
    case PLUGIN_ERROR_SYMBOLSNOTFOUND:
        debug( "Plugin protocol %s unknown Error:%s", p_name, plugin_err );
        break;
    case PLUGIN_ERROR_INITFAILED:
        debug("Unable to start plugin %s", p_name );
        break;
    case PLUGIN_ERROR_BADPARMS:
        debug( "Bad parameters to plugin %s. Error: %s", p_name, plugin_err );
        break;
    case PLUGIN_ERROR_OK:
        retv = 0 ;
        break;
    }
    if( retv < 0  )
        debug("Unable to load plugin %s.Error: %s", p_name, plugin_err);
    return retv ;
}

static void
free_plugins(list_t * plugin_list)
{
	lnode_t *p;
    if (plugin_list == NULL) {
        return;
    }
    if (list_isempty(plugin_list)) {
        return;
    }
    p = list_first(plugin_list);
    while (p) {
         WsManPlugin *plugin = (WsManPlugin *)p->list_data;
         plugin_free(plugin);
         p = list_next(plugin_list, p);
    }
    list_destroy_nodes(plugin_list);
    list_destroy(plugin_list);
}

static int
select_all_files (const struct dirent *e)
{
    return 1;
}

static void
scan_plugins_in_directory ( WsManListenerH *listener,
                            const char *dir_name)
{
	list_t *files = scan_files_in_dir ( dir_name, select_all_files);
	lnode_t *node = list_first(files);
    listener->plugins = list_create(LISTCOUNT_T_MAX);

    while (node != NULL)
    {
        const char* entry_name;
        int retv = -1;
        entry_name = (const char*) node->list_data;
        node = list_next(files, node);

        if ((NULL != entry_name) && strlen (entry_name) > strlen(PLUGIN_EXT)
                && (0 == strcmp (&entry_name[strlen(entry_name)-strlen(PLUGIN_EXT)], PLUGIN_EXT)))
        {
            char *plugin_path = u_strdup_printf ("%s/%s", dir_name, entry_name);
            WsManPlugin *plugin = plugin_new();

            if ((NULL != plugin) && (NULL != plugin_path))
            {
                if (load_plugin(plugin, plugin_path) == 0 )
                {
                    lnode_t *plg = lnode_create (plugin);
                    list_append (listener->plugins, plg);
                    retv = 0 ;
                }
            } else {
                error("Out of memory scanning for plugins.");
            }
			if (plugin_path)
            	u_free (plugin_path);
            if (retv != 0  && (NULL != plugin))
                plugin_free(plugin);
        }
    }
    list_destroy_nodes(files);
    list_destroy(files);
    return;
}

int
wsman_plugins_load(WsManListenerH *listener)
{
    char *plugin_dir = iniparser_getstring(listener->config, "server:plugin_dir", PACKAGE_PLUGIN_DIR);
    debug("using plugin directory: %s", plugin_dir);
    scan_plugins_in_directory(listener, plugin_dir);
    return 0;
}

int
wsman_plugins_unload(WsManListenerH *listener)
{

    free_plugins(listener->plugins);
    // list_destroy(listener->plugins);
    return 0;
}