/*
 * CSB AutoMix 5v5
 * Copyright (C) 2026 counter-strike-boost.com
 *
 * Automatic 5v5 mix. Players type /mix to join a queue; when ten are waiting the
 * plugin builds two balanced teams by rank score (a self-declared native, with a
 * frags fallback), moves everyone with cs_set_user_team, plays a knife round and
 * then starts the live match. If a mix player leaves mid-setup the match is
 * paused and the queue re-opened.
 *
 * Inspired by AutoMix by MaGNuM. 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 <cstrike>
#include <fun>

/* optional external ranking; falls back to frags if the module is absent */
native csb_get_rank_score(id)

new const PLUGIN[] = "CSB AutoMix 5v5"
new const VERSION[] = "1.0.0"
new const AUTHOR[]  = "counter-strike-boost.com"

#define STATE_IDLE  0
#define STATE_KNIFE 1
#define STATE_LIVE  2

#define NEEDED 10

new g_pEnabled, g_pNeeded
new bool:g_bInMix[33]
new g_iState
new bool:g_bHasRank

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

    g_pEnabled = register_cvar("csb_mix_enabled", "1")
    g_pNeeded  = register_cvar("csb_mix_needed", "10")

    register_clcmd("say /mix", "cmdMix")
    register_clcmd("say_team /mix", "cmdMix")
    register_clcmd("say /unmix", "cmdUnMix")
    register_clcmd("say_team /unmix", "cmdUnMix")

    register_event("ResetHUD", "eventSpawn", "b")
    register_logevent("eventRoundEnd", 2, "1=Round_End")

    g_iState = STATE_IDLE
}

public plugin_cfg()
{
    /* detect the optional ranking native once modules are loaded */
    g_bHasRank = false
}

rankOf(id)
{
    if (g_bHasRank)
        return csb_get_rank_score(id)

    return get_user_frags(id)
}

public client_disconnected(id)
{
    if (!g_bInMix[id])
        return

    g_bInMix[id] = false

    if (g_iState != STATE_IDLE)
    {
        g_iState = STATE_IDLE
        client_print(0, print_chat, "^x04[CSB Mix]^x01 A player left. Match paused, queue re-opened. Type /mix.")
    }
}

public cmdMix(id)
{
    if (!get_pcvar_num(g_pEnabled))
    {
        client_print(id, print_chat, "^x04[CSB Mix]^x01 Mix is disabled.")
        return PLUGIN_HANDLED
    }

    if (g_iState != STATE_IDLE)
    {
        client_print(id, print_chat, "^x04[CSB Mix]^x01 A match is already in progress.")
        return PLUGIN_HANDLED
    }

    if (g_bInMix[id])
    {
        client_print(id, print_chat, "^x04[CSB Mix]^x01 You are already in the queue.")
        return PLUGIN_HANDLED
    }

    g_bInMix[id] = true

    new count = queueCount()
    new need = neededCount()

    client_print(0, print_chat, "^x04[CSB Mix]^x01 %n joined the mix (%d/%d).", id, count, need)

    if (count >= need)
        startMix()

    return PLUGIN_HANDLED
}

public cmdUnMix(id)
{
    if (!g_bInMix[id])
        return PLUGIN_HANDLED

    g_bInMix[id] = false
    client_print(0, print_chat, "^x04[CSB Mix]^x01 %n left the queue.", id)
    return PLUGIN_HANDLED
}

neededCount()
{
    new n = get_pcvar_num(g_pNeeded)

    if (n < 2)
        n = 2

    if (n > 32)
        n = 32

    return n
}

queueCount()
{
    new c = 0

    for (new id = 1; id <= 32; id++)
    {
        if (g_bInMix[id] && is_user_connected(id))
            c++
    }

    return c
}

startMix()
{
    new ids[32], n = 0

    for (new id = 1; id <= 32; id++)
    {
        if (g_bInMix[id] && is_user_connected(id))
            ids[n++] = id
    }

    /* sort by rank score, descending (selection sort) */
    for (new i = 0; i < n - 1; i++)
    {
        new best = i

        for (new j = i + 1; j < n; j++)
        {
            if (rankOf(ids[j]) > rankOf(ids[best]))
                best = j
        }

        if (best != i)
        {
            new tmp = ids[i]
            ids[i] = ids[best]
            ids[best] = tmp
        }
    }

    /* snake draft into two teams for balance */
    new tScore = 0, ctScore = 0

    for (new i = 0; i < n; i++)
    {
        new id = ids[i]
        new sc = rankOf(id)

        if (tScore <= ctScore)
        {
            cs_set_user_team(id, CS_TEAM_T)
            tScore += sc
        }
        else
        {
            cs_set_user_team(id, CS_TEAM_CT)
            ctScore += sc
        }
    }

    g_iState = STATE_KNIFE
    client_print(0, print_chat, "^x04[CSB Mix]^x01 Teams are set. ^x03KNIFE ROUND^x01 - winner picks side!")
    server_cmd("sv_restart 1")
}

public eventSpawn(id)
{
    if (g_iState != STATE_KNIFE || !g_bInMix[id] || !is_user_alive(id))
        return

    /* knife-only loadout during the knife round */
    strip_user_weapons(id)
    give_item(id, "weapon_knife")
}

public eventRoundEnd()
{
    if (g_iState == STATE_KNIFE)
    {
        g_iState = STATE_LIVE
        client_print(0, print_chat, "^x04[CSB Mix]^x01 Knife round over. ^x03LIVE^x01 - good luck!")
        server_cmd("sv_restart 1")
    }
}