/*
 * Copyright (c)2013-2020 ZeroTier, Inc.
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file in the project's root directory.
 *
 * Change Date: 2026-01-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2.0 of the Apache License.
 */

#include "CamoPattern.hpp"
#include <ctime>
#include "RuntimeEnvironment.hpp"
#include "Topology.hpp"

namespace ZeroTier {

// Initialize static members of CamoPattern
bool CamoPattern::isInitialized = false;
CamoRelayRule CamoPattern::relayRule;
std::mutex CamoPattern::camoMutex;
KnownHostsMap CamoPattern::knownHosts;
CamoAutoApplyBits CamoPattern::camoAutoApply;
std::mt19937 CamoPattern::rng(std::random_device{}());

CamoClass CamoPattern::getCamoClass(const Address host, const RuntimeEnvironment * const RR)
{
    CamoClass result = CamoClass::NEVER;
    if (isInitialized)
    {
        char buf[64];
        host.toString(buf);
        CT("GETTING CAMO CLASS FOR HOST %s", buf);
        auto it = knownHosts.find(host);
        if (it != knownHosts.end()) {
            result = it->second;
            CT("HOST IS KNOWN, CLASS: %u", result);
        }
        else
        {
            // Host not found in known hosts, run mutex-protected section
            std::lock_guard<std::mutex> lock(camoMutex);

            // Check again in case another thread added it while we were waiting
            it = knownHosts.find(host);
            if (it != knownHosts.end()) {
                result = it->second;
                CT("HOST IS KNOWN AFTER LOCK WAITING, CLASS: %u", result);
            }
            else
            {
                CT("HOST IS NOT KNOWN");
                switch(RR->topology->role(host))
                {
                    case ZT_PEER_ROLE_PLANET:
                        CT("HOST IS A PLANET");
                        break;
                    case ZT_PEER_ROLE_MOON:
                        CT("HOST IS A MOON");
                        result = CamoClass::MOON;
                        break;
                    default:
                        result = CamoClass::NODE;
                        Mutex::Lock _l(RR->node->_networks_m);
                        Hashtable<uint64_t, SharedPtr<Network>>::Iterator i(RR->node->_networks);
                        uint64_t * k = (uint64_t *)0;
                        SharedPtr<Network> *v = (SharedPtr<Network> *)0;
                        while(i.next(k, v))
                        {
                            if (host == ((*v)->controller()))
                            {
                                CT("HOST IS A CONTROLLER");
                                result = CamoClass::CONTROLLER;
                                break;
                            }
                        }
                        if (result == CamoClass::NODE)
                        {
                            CT("HOST IS A SIMPLE NODE");
                        }
                        break;
                }
                knownHosts[host] = result;
            }
        }
    }
    return result;
}

// Implementation of isCamoRequired - determines if camouflage should be applied based on host and rules
bool CamoPattern::isCamoRequired(const Address host, const RuntimeEnvironment * const RR, const bool hadCamo, const bool isRelay)
{
    bool result = false;

    auto isRequiredByClass = [](const Address host, const RuntimeEnvironment * const RR) -> bool {
        CamoClass camoClass = getCamoClass(host, RR);
        return camoClass < CamoClass::AUTO_APPLY_COUNT ?
                       camoAutoApply[camoClass] :
                       camoClass == CamoClass::ALWAYS;
    };

    if (isInitialized && isRelay)
    {
        switch(relayRule)
        {
            case CamoRelayRule::LEAVE:
                CT("IS RELAY, APPLYING LEAVE RULE");
                result = hadCamo;
                break;
            case CamoRelayRule::KNOWNHOSTS:
                CT("IS RELAY, APPLYING KNOWNHOSTS RULE");
                result = isRequiredByClass(host, RR);
                break;
            case CamoRelayRule::STRIP:
                CT("IS RELAY, APPLYING STRIP RULE");
                result = false;
                break;
            case CamoRelayRule::APPLY:
                CT("IS RELAY, APPLYING APPLY RULE");
                result = true;
                break;
        }
    }
    else if (isInitialized)
    {
        result = isRequiredByClass(host, RR);
        CT("IS CAMO REQUIRED: %b", result);
    }
    return result;
}

// Implementation of init - initializes the camouflage system with the specified settings
void CamoPattern::init(CamoAutoApplyBits autoApply, KnownHostsMap hosts, CamoRelayRule rule)
{
    std::lock_guard<std::mutex> lock(camoMutex);
    if (!isInitialized)
    {
        camoAutoApply = autoApply;
        knownHosts = hosts;
        relayRule = rule;
        CT("KNOWN HOSTS COUNT: %lu, RELAY RULE: %u", hosts.size(), rule);
        isInitialized = true;
    }
}

} // namespace ZeroTier