/********************************************************************\
 * This program is free software; you can redistribute it and/or    *
 * modify it under the terms of the GNU General Public License as   *
 * published by the Free Software Foundation; either version 2 of   *
 * the License, or (at your option) any later version.              *
 *                                                                  *
 * This program 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 General Public License for more details.                     *
 *                                                                  *
 * You should have received a copy of the GNU General Public License*
 * along with this program; if not, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 59 Temple Place - Suite 330        Fax:    +1-617-542-2652       *
 * Boston, MA  02111-1307,  USA       gnu@gnu.org                   *
 *                                                                  *
\********************************************************************/
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>

#include <event2/bufferevent.h>
#include <event2/buffer.h>
#include <event2/listener.h>
#include <event2/util.h>

#include <syslog.h>

#include "xkcp_mon.h"
#include "xkcp_util.h"
#include "xkcp_config.h"
#include "debug.h"
#include "jwHash.h"

static int xkcp_server_flag = 0;

typedef void (*spy_cmd_process)(struct bufferevent *bev, void *ctx);

struct user_spy_cmd {
	char *command;
	spy_cmd_process cmd_process;
};

static void get_client_status(struct bufferevent *bev, void *ctx);
static void get_server_status(struct bufferevent *bev, void *ctx);
static void get_client_info(struct bufferevent *bev, void *ctx);

struct user_spy_cmd client_cmd[] = {
	{"status", get_client_status},
	{NULL, NULL}
};

struct user_spy_cmd server_cmd[] = {
	{"status", get_server_status},
	{"client", get_client_info},
	{NULL, NULL}
};

int set_xkcp_server_flag(int flag)
{
	xkcp_server_flag = flag;
    return 0;
}

static void get_client_status(struct bufferevent *bev, void *ctx)
{
	dump_task_list(ctx, bev);
}

static void get_client_info(struct bufferevent *bev, void *ctx)
{
	debug(LOG_DEBUG, "get_client_info  ");
	jwHashTable *xkcp_hash = ctx;
	struct evbuffer *output = bufferevent_get_output(bev);
	evbuffer_add_printf(output, "client list:\n");
	for(int i = 0; i < xkcp_hash->buckets; i++) {
		jwHashEntry *entry = xkcp_hash->bucket[i];
		while (entry) {
			evbuffer_add_printf(output, "hash_id [%d] connected client [%s] connection [%d] \n", 
								i, entry->key.strValue, get_task_list_size(entry->value.ptrValue));
			entry = entry->next;
		}
	}
}

static void get_server_status(struct bufferevent *bev, void *ctx)
{
	debug(LOG_DEBUG, "get_server_status  ");
	jwHashTable *xkcp_hash = ctx;
	struct evbuffer *output = bufferevent_get_output(bev);
	evbuffer_add_printf(output, "client detail list:\n");
	for(int i = 0; i < xkcp_hash->buckets; i++) {
		jwHashEntry *entry = xkcp_hash->bucket[i];
		while (entry) {
			evbuffer_add_printf(output, "hash_id [%d] connected client [%s]: \n", i, entry->key.strValue);
			dump_task_list(entry->value.ptrValue, bev);
			entry = entry->next;
		}
	}
}

static void process_user_cmd(struct bufferevent *bev, const char *cmd, void *ctx)
{
	debug(LOG_DEBUG, "cmd is %s", cmd);
	if (xkcp_server_flag) {
		for(int i = 0; server_cmd[i].command != NULL; i++) {
			if (strcmp(cmd, server_cmd[i].command) == 0) 
				server_cmd[i].cmd_process(bev, ctx);
		}
	} else {
		for(int i = 0; client_cmd[i].command != NULL; i++) {
			if (strcmp(cmd, client_cmd[i].command) == 0) 
				client_cmd[i].cmd_process(bev, ctx);
		}
	}
}

static void xkcp_mon_event_cb(struct bufferevent *bev, short what, void *ctx)
{
	if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
		bufferevent_free(bev);
	}
}

static void xkcp_mon_write_cb(struct bufferevent *bev, void *ctx)
{
	struct evbuffer *output = bufferevent_get_output(bev);
    if (evbuffer_get_length(output) == 0) {
		debug(LOG_INFO, "xkcp_mon_write_cb flush");
        bufferevent_free(bev);
    }

}

static void xkcp_mon_read_cb(struct bufferevent *bev, void *ctx)
{
	struct evbuffer *input = bufferevent_get_input(bev);
	int len = evbuffer_get_length(input);
	
	debug(LOG_DEBUG, "xkcp_mon_read_cb [%d]", len);
	
	if ( len > 0) { 
		char *buf = malloc(len+1);
		memset(buf, 0, len+1);
		if (evbuffer_remove(input, buf, len) > 0)
			process_user_cmd(bev, buf, ctx);
	} 
}

void xkcp_mon_accept_cb(struct evconnlistener *listener, evutil_socket_t fd,
    struct sockaddr *a, int slen, void *ptr)
{
	struct bufferevent *b_in = NULL;
	struct event_base *base = evconnlistener_get_base(listener);
	
	b_in = bufferevent_socket_new(base, fd,
	    BEV_OPT_CLOSE_ON_FREE|BEV_OPT_DEFER_CALLBACKS);
	assert(b_in);
	
	debug(LOG_INFO, "accept new mon client in");
	
	bufferevent_setcb(b_in, xkcp_mon_read_cb, xkcp_mon_write_cb, xkcp_mon_event_cb, ptr);
	bufferevent_enable(b_in,  EV_READ | EV_WRITE);
}

struct evconnlistener *set_xkcp_mon_listener(struct event_base *base, short port, void *ptr)
{
	struct sockaddr_in sin;
	char *addr = get_iface_ip(xkcp_get_param()->local_interface);
	if (!addr) {
		debug(LOG_ERR, "get_iface_ip [%s] failed", xkcp_get_param()->local_interface);
		exit(0);
	}

	memset(&sin, 0, sizeof(sin));
    sin.sin_family = AF_INET;
    sin.sin_addr.s_addr = inet_addr(addr);
    sin.sin_port = htons(port);

    struct evconnlistener * listener = evconnlistener_new_bind(base, xkcp_mon_accept_cb, ptr,
	    LEV_OPT_CLOSE_ON_FREE|LEV_OPT_CLOSE_ON_EXEC|LEV_OPT_REUSEABLE,
	    -1, (struct sockaddr*)&sin, sizeof(sin));
    if (!listener) {
    	debug(LOG_ERR, "Couldn't create listener: [%s]", strerror(errno));
    	exit(0);
    }

    return listener;
}