#include <log/LogUtils.h>
#include <misc/endianness.h>
#include <misc/base64.h>
#include <ThreadPool/Timer.h>
#include <openssl/sha.h>
#include <src/client/SpeakingClient.h>

#include "../../InstanceHandler.h"
#include "VoiceClient.h"

using namespace std;
using namespace std::chrono;
using namespace ts::server;
using namespace ts::protocol;
using namespace ts;

void VoiceClient::handlePacketCommand(const pipes::buffer_view& command_string) {
    std::unique_ptr<Command> command;
    command_result result{};
    try {
        command = make_unique<Command>(Command::parse(command_string, true, !ts::config::server::strict_ut8_mode));
    } catch(std::invalid_argument& ex) {
        result.reset(command_result{error::parameter_convert, std::string{ex.what()}});
        goto handle_error;
    } catch(std::exception& ex) {
        result.reset(command_result{error::parameter_convert, std::string{ex.what()}});
        goto handle_error;
    }

    this->handleCommandFull(*command, true);
    return;
    handle_error:
    this->notifyError(result);
    result.release_data();
}

command_result VoiceClient::handleCommand(ts::Command &command) {
    threads::MutexLock l2(this->command_lock);
    if(this->state == ConnectionState::DISCONNECTED) return command_result{error::client_not_logged_in};
    if(!this->voice_server) return command_result{error::server_unbound};

    if(this->state == ConnectionState::INIT_HIGH && this->handshake.state == HandshakeState::SUCCEEDED) {
        if(command.command() == "clientinit")
            return this->handleCommandClientInit(command);
    } else if(command.command() == "clientdisconnect")
        return this->handleCommandClientDisconnect(command);
    return SpeakingClient::handleCommand(command);
}

inline bool calculate_security_level(int& result, ecc_key* pubKey, size_t offset) {
    size_t pubLength = 256;
    char pubBuffer[256];
    if((result = ecc_export(reinterpret_cast<unsigned char *>(pubBuffer), &pubLength, PK_PUBLIC, pubKey)) != CRYPT_OK)
        return false;

    std::string hashStr = base64_encode(pubBuffer, pubLength) + to_string(offset);
    char shaBuffer[SHA_DIGEST_LENGTH];
    SHA1((const unsigned char *) hashStr.data(), hashStr.length(), (unsigned char *) shaBuffer);

    //Leading zero bits
    int zeroBits = 0;
    int i;
    for(i = 0; i < SHA_DIGEST_LENGTH; i++)
        if(shaBuffer[i] == 0) zeroBits += 8;
        else break;
    if(i < SHA_DIGEST_LENGTH) {
        for(uint8_t bit = 0; bit < 8; bit++) {
            if((shaBuffer[i] & (1U << bit)) == 0) zeroBits++;
            else break;
        }
    }
    result = zeroBits;
    return true;
}

command_result VoiceClient::handleCommandClientInit(Command &cmd) {
    if(this->getType() == ClientType::CLIENT_TEAMSPEAK) {
        auto client_identity = this->connection->crypt_setup_handler().identity_key();

        int security_level;
        if(!calculate_security_level(security_level, &*client_identity, cmd["client_key_offset"])) {
            logError(this->getServerId(), "[{}] Failed to calculate security level. Error code: {}", CLIENT_STR_LOG_PREFIX, security_level);
            return command_result{error::vs_critical};
        }

        if(security_level < 8) {
            return command_result{error::client_could_not_validate_identity};
        }

        auto requiredLevel = this->getServer()->properties()[property::VIRTUALSERVER_NEEDED_IDENTITY_SECURITY_LEVEL].as<uint8_t>();
        if(security_level < requiredLevel) {
            return command_result{error::client_could_not_validate_identity, to_string(requiredLevel)};
        }
    }

    return SpeakingClient::handleCommandClientInit(cmd);
}

command_result VoiceClient::handleCommandClientDisconnect(Command& cmd) {
    auto reason = cmd["reasonmsg"].size() > 0 ? cmd["reasonmsg"].as<string>() : "";
    this->notifyClientLeftView(this->ref(), nullptr, VREASON_SERVER_LEFT, reason, nullptr, false); //Before we're moving us out of the channel tree!
    if(this->state == CONNECTED) {
        unique_lock channel_lock(this->server->channel_tree_lock);
        this->server->client_move(this->ref(), nullptr, nullptr, reason, VREASON_SERVER_LEFT, true, channel_lock);
    }
    logMessage(this->getServerId(), "{} Got remote disconnect with the reason '{}'", CLIENT_STR_LOG_PREFIX, reason);
    this->postCommandHandler.push_back([&]{
        this->close_connection(std::chrono::system_clock::now() + std::chrono::seconds{1}); /* send acknowledge and close connection */
    });
    return command_result{error::ok};
}