/*
 * CSB Bhop Script Detection
 * Copyright (C) 2026 counter-strike-boost.com
 *
 * Flags scripted bunnyhopping by watching FL_ONGROUND transitions and +jump
 * presses in PlayerPreThink: a run of frame-perfect jumps (jumping on the
 * first ground frame every time) is not humanly repeatable, so it is logged.
 *
 * 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 <fakemeta>

new const PLUGIN[] = "CSB Bhop Script Detection"
new const VERSION[] = "1.0.0"
new const AUTHOR[]  = "counter-strike-boost.com"

new g_pEnabled, g_pPerfect, g_pAction

new bool:g_bOnGround[33]
new bool:g_bJumpHeld[33]
new g_iGroundFrames[33]
new g_iPerfect[33]

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

    g_pEnabled = register_cvar("csb_bhop_enabled", "1")
    g_pPerfect = register_cvar("csb_bhop_perfect", "12")
    g_pAction  = register_cvar("csb_bhop_action", "0")

    register_forward(FM_PlayerPreThink, "fwPreThink")
}

public client_putinserver(id)
{
    g_bOnGround[id]     = false
    g_bJumpHeld[id]     = false
    g_iGroundFrames[id] = 0
    g_iPerfect[id]      = 0
}

public fwPreThink(id)
{
    if (!get_pcvar_num(g_pEnabled) || !is_user_alive(id) || is_user_bot(id))
        return FMRES_IGNORED

    new bool:onGround = (pev(id, pev_flags) & FL_ONGROUND) != 0
    new bool:jump     = (pev(id, pev_button) & IN_JUMP) != 0

    if (onGround)
    {
        // count how long we've been standing since we landed
        if (!g_bOnGround[id])
            g_iGroundFrames[id] = 0
        else
            g_iGroundFrames[id]++

        // rising edge of the jump button while grounded
        if (jump && !g_bJumpHeld[id])
        {
            if (g_iGroundFrames[id] <= 1)
            {
                g_iPerfect[id]++

                if (g_iPerfect[id] >= get_pcvar_num(g_pPerfect))
                    flag(id)
            }
            else
            {
                g_iPerfect[id] = 0
            }
        }
    }

    g_bOnGround[id] = onGround
    g_bJumpHeld[id] = jump

    return FMRES_IGNORED
}

flag(id)
{
    g_iPerfect[id] = 0

    new name[32], authid[35]
    get_user_name(id, name, charsmax(name))
    get_user_authid(id, authid, charsmax(authid))

    log_amx("[CSB Bhop] frame-perfect bunnyhop pattern from %s <%s>", name, authid)

    if (get_pcvar_num(g_pAction) == 1)
    {
        server_cmd("kick #%d ^"CSB: scripted bunnyhopping^"", get_user_userid(id))
        server_exec()
    }
    else
    {
        client_print(0, print_chat, "[CSB] %s is suspected of scripted bunnyhopping.", name)
    }
}