/*
 * CSB High Ping Kicker
 * Copyright (C) 2026 counter-strike-boost.com
 *
 * Samples every player's ping on a timer, keeps a rolling average and kicks the
 * ones that stay above the limit for several samples in a row. A connect grace
 * period stops false positives while a client is still loading, and admins with
 * a configurable flag are never touched.
 *
 * Inspired by "High Ping Kicker" by Nomexous. This is an independent GPL
 * re-implementation; no original code is reused.
 *
 * 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 3 of the License, or (at your option) any later
 * version. It 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 <https://www.gnu.org/licenses/> for details.
 */

#include <amxmodx>
#include <amxmisc>

new const PLUGIN[] = "CSB High Ping Kicker"
new const VERSION[] = "1.0.0"
new const AUTHOR[]  = "counter-strike-boost.com"

#define SAMPLES 5

new g_pEnabled, g_pMaxPing, g_pInterval, g_pStrikes, g_pGrace, g_pImmunity, g_pMinPlayers

new g_iPing[33][SAMPLES]
new g_iSampleCount[33]
new g_iSampleIdx[33]
new g_iStrikes[33]
new Float:g_fJoinTime[33]

public plugin_init()
{
    register_plugin(PLUGIN, VERSION, AUTHOR)

    g_pEnabled    = register_cvar("csb_ping_enabled", "1")
    g_pMaxPing    = register_cvar("csb_ping_max", "150")       /* average ping allowed */
    g_pInterval   = register_cvar("csb_ping_interval", "5.0")  /* seconds between samples */
    g_pStrikes    = register_cvar("csb_ping_strikes", "3")     /* consecutive bad samples before a kick */
    g_pGrace      = register_cvar("csb_ping_grace", "60")      /* seconds after connect that are ignored */
    g_pImmunity   = register_cvar("csb_ping_immunity", "a")    /* flag that is never kicked */
    g_pMinPlayers = register_cvar("csb_ping_minplayers", "0")  /* only enforce above this player count */

    register_clcmd("say /ping", "cmdPing")
    register_clcmd("say_team /ping", "cmdPing")
    register_concmd("amx_pinglist", "cmdPingList", ADMIN_KICK, "- shows every player's average ping")
}

public plugin_cfg()
{
    new Float:interval = get_pcvar_float(g_pInterval)

    if (interval < 1.0)
        interval = 1.0

    set_task(interval, "taskSample", 0, "", 0, "b")
}

public client_putinserver(id)
{
    resetPlayer(id)
}

public client_disconnected(id)
{
    resetPlayer(id)
}

resetPlayer(id)
{
    g_iSampleCount[id] = 0
    g_iSampleIdx[id]   = 0
    g_iStrikes[id]     = 0
    g_fJoinTime[id]    = get_gametime()

    for (new i = 0; i < SAMPLES; i++)
        g_iPing[id][i] = 0
}

public taskSample()
{
    if (!get_pcvar_num(g_pEnabled))
        return

    new players[32], num, id
    get_players(players, num, "ch")

    if (num <= get_pcvar_num(g_pMinPlayers))
        return

    new maxPing = get_pcvar_num(g_pMaxPing)
    new maxStrikes = get_pcvar_num(g_pStrikes)
    new Float:grace = float(get_pcvar_num(g_pGrace))

    new flagStr[8]
    get_pcvar_string(g_pImmunity, flagStr, charsmax(flagStr))
    new immunity = read_flags(flagStr)

    if (maxPing <= 0 || maxStrikes <= 0)
        return

    for (new i = 0; i < num; i++)
    {
        id = players[i]

        new ping, loss
        get_user_ping(id, ping, loss)

        g_iPing[id][g_iSampleIdx[id]] = ping
        g_iSampleIdx[id] = (g_iSampleIdx[id] + 1) % SAMPLES

        if (g_iSampleCount[id] < SAMPLES)
            g_iSampleCount[id]++

        if (immunity && (get_user_flags(id) & immunity))
            continue

        if (get_gametime() - g_fJoinTime[id] < grace)
            continue

        if (g_iSampleCount[id] < SAMPLES)
            continue

        new avg = averagePing(id)

        if (avg <= maxPing)
        {
            g_iStrikes[id] = 0
            continue
        }

        g_iStrikes[id]++

        if (g_iStrikes[id] >= maxStrikes)
        {
            new name[32]
            get_user_name(id, name, charsmax(name))

            announce("^x04[CSB]^x03 %s^x01 was kicked: average ping^x04 %d^x01 (limit^x04 %d^x01).", name, avg, maxPing)
            log_amx("[CSB Ping] kicked %s - average ping %d over %d samples (limit %d)", name, avg, SAMPLES, maxPing)

            server_cmd("kick #%d ^"Your ping (%d) is too high for this server (max %d)^"", get_user_userid(id), avg, maxPing)
            resetPlayer(id)
            continue
        }

        client_print(id, print_chat, "[CSB] Your average ping is %d, the limit is %d. You will be kicked in %d checks.",
            avg, maxPing, maxStrikes - g_iStrikes[id])
    }
}

averagePing(id)
{
    new count = g_iSampleCount[id]

    if (!count)
        return 0

    new sum = 0

    for (new i = 0; i < count; i++)
        sum += g_iPing[id][i]

    return sum / count
}

public cmdPing(id)
{
    new ping, loss
    get_user_ping(id, ping, loss)

    client_print(id, print_chat, "[CSB] Ping: %d (average %d, loss %d%%). Server limit: %d.",
        ping, averagePing(id), loss, get_pcvar_num(g_pMaxPing))

    return PLUGIN_HANDLED
}

public cmdPingList(id, level, cid)
{
    if (!cmd_access(id, level, cid, 1))
        return PLUGIN_HANDLED

    new players[32], num, pid, name[32], ping, loss
    get_players(players, num, "ch")

    console_print(id, "[CSB] Ping report (limit %d):", get_pcvar_num(g_pMaxPing))

    for (new i = 0; i < num; i++)
    {
        pid = players[i]
        get_user_name(pid, name, charsmax(name))
        get_user_ping(pid, ping, loss)

        console_print(id, "  %-24s now: %4d  avg: %4d  loss: %3d  strikes: %d",
            name, ping, averagePing(pid), loss, g_iStrikes[pid])
    }

    return PLUGIN_HANDLED
}

announce(const fmt[], any:...)
{
    new buf[192]
    vformat(buf, charsmax(buf), fmt, 2)

    new players[32], num, msgid = get_user_msgid("SayText")
    get_players(players, num, "ch")

    for (new i = 0; i < num; i++)
    {
        message_begin(MSG_ONE, msgid, _, players[i])
        write_byte(players[i])
        write_string(buf)
        message_end()
    }
}