/* This module is used to test the server events hooks API.
 *
 * -----------------------------------------------------------------------------
 *
 * Copyright (c) 2019, Salvatore Sanfilippo <antirez at gmail dot com>
 * 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 Redis 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 THE COPYRIGHT OWNER OR 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.
 */

#define REDISMODULE_EXPERIMENTAL_API
#include "redismodule.h"

/* Client state change callback. */
void clientChangeCallback(RedisModuleCtx *ctx, RedisModuleEvent e, uint64_t sub, void *data)
{
    REDISMODULE_NOT_USED(ctx);
    REDISMODULE_NOT_USED(e);

    RedisModuleClientInfo *ci = data;
    char *keyname = (sub == REDISMODULE_SUBEVENT_CLIENT_CHANGE_CONNECTED) ?
        "connected" : "disconnected";
    RedisModuleCallReply *reply;
    RedisModule_SelectDb(ctx,9);
    reply = RedisModule_Call(ctx,"RPUSH","cl",keyname,(long)ci->id);
    RedisModule_FreeCallReply(reply);
}

void flushdbCallback(RedisModuleCtx *ctx, RedisModuleEvent e, uint64_t sub, void *data)
{
    REDISMODULE_NOT_USED(ctx);
    REDISMODULE_NOT_USED(e);

    RedisModuleFlushInfo *fi = data;
    char *keyname = (sub == REDISMODULE_SUBEVENT_FLUSHDB_START) ?
        "flush-start" : "flush-end";
    RedisModuleCallReply *reply;
    RedisModule_SelectDb(ctx,9);
    reply = RedisModule_Call(ctx,"RPUSH","cl",keyname,(long)fi->dbnum);
    RedisModule_FreeCallReply(reply);
}

/* This function must be present on each Redis module. It is used in order to
 * register the commands into the Redis server. */
int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
    REDISMODULE_NOT_USED(argv);
    REDISMODULE_NOT_USED(argc);

    if (RedisModule_Init(ctx,"testhook",1,REDISMODULE_APIVER_1)
        == REDISMODULE_ERR) return REDISMODULE_ERR;

    RedisModule_SubscribeToServerEvent(ctx,
        RedisModuleEvent_ClientChange, clientChangeCallback);
    RedisModule_SubscribeToServerEvent(ctx,
        RedisModuleEvent_FlushDB, flushdbCallback);
    return REDISMODULE_OK;
}