#include "LicenseClient.h"

#include "CryptoUtils.h"
#include "HashUtils.h"
#include "JSONSerialization.h"

#include <cryptopp/cryptlib.h>
#include <cryptopp/aes.h>
#include <cryptopp/gcm.h>
#include <cryptopp/osrng.h>
#include <cryptopp/eccrypto.h>
#include <cryptopp/oids.h>
#include <cryptopp/files.h>
#include <cryptopp/hex.h>
#include <cryptopp/dsa.h>

#include <boost/filesystem.hpp>
#include <boost/iostreams/device/array.hpp>
#include <boost/iostreams/filtering_stream.hpp>
#include <boost/iostreams/filter/zlib.hpp>
#include <boost/property_tree/json_parser.hpp>
#include <boost/property_tree/ptree.hpp>


#include <fstream>
#include <iomanip>
#include <sstream>
#include <streambuf>
#include <string>
#include <vector>

namespace pt = boost::property_tree;
namespace fs = boost::filesystem;

using CryptoPP::AES;
using CryptoPP::GCM;
using CryptoPP::byte;
using CryptoPP::SecByteBlock;
using CryptoPP::AutoSeededRandomPool;
using CryptoPP::AuthenticatedDecryptionFilter;
using CryptoPP::StringSink;
using CryptoPP::StringSource;
using CryptoPP::Redirector;
using CryptoPP::ECDSA;
using CryptoPP::EC2N;
using CryptoPP::SHA256;
using CryptoPP::HexDecoder;
namespace ASN1 = CryptoPP::ASN1;


namespace
{

static const std::string productId = "coc";
static const std::string serverPath = "https://license.apis.sk/api/v1";

static const uint32_t initializationVectorSize = AES::BLOCKSIZE;
static const uint32_t macTagSize = 16;
static const uint32_t ecdsaSignatureSize = 72;

template< typename T >
std::string intToHex(T i)
{
    std::stringstream stream;
    stream
        << std::setfill('0') << std::setw(sizeof(T) * 2)
        << std::hex << i;
    return stream.str();
}

typedef std::string ParamHash;
ParamHash fletcher64(const std::string& input)
{
    std::vector<uint32_t> buf((input.size() + sizeof(uint32_t) - 1) / sizeof(uint32_t), 0);
    std::copy_n(std::begin(input), input.size(), stdext::make_checked_array_iterator((std::string::pointer)buf.data(), buf.size() * sizeof(uint32_t)));
    auto resInt = ::fletcher64(buf.data(), buf.size());
    return intToHex(resInt);
}

SystemParams skipEmptyParams(const SystemParams& systemParams)
{
    SystemParams result;
    for (const auto& entry : systemParams)
    {
        if (!entry.second.empty())
        {
            result[entry.first] = entry.second;
        }
    }
    return result;
}


SystemParams hashParams(const SystemParams& systemParams)
{
    SystemParams result;
    for (const auto& entry : systemParams)
    {
        result[entry.first] = fletcher64(entry.second);
    }
    return result;
}

typedef std::string Signature;

struct SignedData
{
    std::string data;
    std::string signature;
};

std::string readBinaryFile(const std::string& filename)
{
    std::ifstream t(filename, std::istream::binary);
    std::string str;

    t.seekg(0, std::ios::end);
    str.reserve(static_cast<size_t>(t.tellg()));
    t.seekg(0, std::ios::beg);

    str.assign((std::istreambuf_iterator<char>(t)),
        std::istreambuf_iterator<char>());

    return str;
}

struct PreactivationRequest
{
    std::string productId = productId;
    SystemParams systemParams;
};

struct ActivationRequest
{
    std::string productId = productId;
    SystemParams systemParams;
    std::string licenseNumber;
};

struct ActivationResponse
{
    bool success;
    std::optional<std::string> licenseFile;
};

struct CheckUpdatesRequest
{
    SystemParams systemParams;
    std::string activationId;
    std::string productId = productId;
    std::map<std::string, ModuleVersion> moduleVersions;
};

struct CheckUpdatesResponse
{
    bool success;
    std::optional<std::string> licenseFile;
    std::vector<ModuleUpdate> moduleUpdates;
};

} // anonymous namespace

void serialize(std::ostream& os, const ActivationData& a)
{
    os << "{";
    os << "\"activationId\":";
    serialize(os, a.activationId);
    os << ",\"productId\":";
    serialize(os, a.productId);
    os << ",\"systemParams\":";
    serialize(os, a.systemParams);
    os << ",\"licensedModules\":";
    serialize(os, a.licensedModules);
    os << "}";
}

void deserialize(const pt::ptree& tree, ActivationData& a)
{
    deserialize(tree.get_child("activationId"), a.activationId);
    deserialize(tree.get_child("productId"), a.productId);
    deserialize(tree.get_child("systemParams"), a.systemParams);
    deserialize(tree.get_child("licensedModules"), a.licensedModules);
}

void serialize(std::ostream& os, const SignedData& d)
{
    os << "{";
    os << "\"data\":";
    serialize(os, d.data);
    os << ",\"signature\":";
    serialize(os, d.signature);
    os << "}";
}

void deserialize(const pt::ptree& tree, SignedData& d)
{
    deserialize(tree.get_child("data"), d.data);
    deserialize(tree.get_child("signature"), d.signature);
}

void serialize(std::ostream& os, const PreactivationRequest& a)
{
    os << "{";
    os << "\"productId\":";
    ::serialize(os, a.productId);
    os << ",\"systemParams\":";
    ::serialize(os, a.systemParams);
    os << "}";
}

void serialize(std::ostream& os, const ActivationRequest& a)
{
    os << "{";
    os << "\"productId\":";
    ::serialize(os, a.productId);
    os << ",\"systemParams\":";
    ::serialize(os, a.systemParams);
    os << ",\"licenseNumber\":";
    ::serialize(os, a.licenseNumber);
    os << "}";
}

void deserialize(const pt::ptree& tree, ActivationResponse& a)
{
    deserialize(tree.get_child("success"), a.success);
    auto licenseFileOpt = tree.get_child_optional("licenseFile");
    if (licenseFileOpt)
    {
        std::string res;
        deserialize(licenseFileOpt.value(), res);
        a.licenseFile = base64Decode(res);
    }
    else
    {
        a.licenseFile = {};
    }
}

void serialize(std::ostream& os, const CheckUpdatesRequest& r)
{
    os << "{";
    os << "\"systemParams\":";
    ::serialize(os, r.systemParams);
    os << ",\"activationId\":";
    ::serialize(os, r.activationId);
    os << ",\"productId\":";
    serialize(os, r.productId);
    os << ",\"moduleVersions\":";
    ::serialize(os, r.moduleVersions);
    os << "}";
}

void deserialize(const pt::ptree& tree, CheckUpdatesResponse& r)
{
    deserialize(tree.get_child("success"), r.success);
    auto licenseFileOpt = tree.get_child_optional("licenseFile");
    if (licenseFileOpt)
    {
        std::string res;
        deserialize(licenseFileOpt.value(), res);
        r.licenseFile = base64Decode(res);
    }
    else
    {
        r.licenseFile = {};
    }
    if (r.success)
    {
        deserialize(tree.get_child("moduleUpdates"), r.moduleUpdates);
    }
}


std::optional<std::string> validateLicenseKey(const std::string& licenseKey)
{
    auto result = base32Decode(licenseKey);
    if (result.size() != 15)
        return {};
    return base32Encode(result);
}

LicenseClient::LicenseClient(SystemParamsProvider& systemParamsProvider, const std::string& licenseFile)
: m_systemParamsProvider(systemParamsProvider)
, m_licenseFile(licenseFile)
{
}

LicenseClient::~LicenseClient()
{
}

void LicenseClient::init()
{
    m_systemParams = hashParams(skipEmptyParams(m_systemParamsProvider.retrieveSystemParams()));

    loadActivationData();
}

bool LicenseClient::tryPreactivate(HTTPClient &httpClient)
{
    PreactivationRequest req{ productId, m_systemParams };

    std::string jsonReq;
    {
        std::ostringstream ss1;
        serialize(ss1, req);
        jsonReq = ss1.str();
    }

    std::string jsonRes;
    {
        std::ostringstream ss2;
        httpClient.postJson(serverPath + "/activate0", jsonReq, ss2);
        jsonRes = ss2.str();
    }

    ActivationResponse activationResponse;
    pt::ptree root;
    std::istringstream ss2(jsonRes);
    pt::read_json(ss2, root);
    deserialize(root, activationResponse);
    if (activationResponse.success)
    {
        {
            const auto& licenseData = activationResponse.licenseFile.value();
            std::ofstream os(m_licenseFile, std::ofstream::binary);
            os.write(licenseData.data(), licenseData.size());
        }
        return loadActivationData();
    }
    return false;
}

bool LicenseClient::activate(HTTPClient &httpClient, const std::string & licenseNumber)
{
    std::string jsonReq;

    std::ostringstream ss1;

    ActivationRequest req{ productId, m_systemParams, licenseNumber };
    serialize(ss1, req);

    std::stringstream ss2;
    httpClient.postJson(serverPath + "/activate", ss1.str() , ss2);

    ActivationResponse activationResponse;
    pt::ptree root;
    pt::read_json(ss2, root);
    deserialize(root, activationResponse);
    if (activationResponse.success)
    {
        {
            const auto& licenseData = activationResponse.licenseFile.value();
            std::ofstream os(m_licenseFile, std::ofstream::binary);
            os.write(licenseData.data(), licenseData.size());
        }
        return loadActivationData();
    }
    return false;
}

std::vector<ModuleUpdate> LicenseClient::checkForUpdates(HTTPClient & httpClient, const std::map<std::string, ModuleVersion>& currentVersions)
{
    if (!isActivated()) { throw std::runtime_error("Not active"); }
    
    CheckUpdatesRequest req{ m_systemParams, m_activationData->activationId, productId, currentVersions };
    
    std::ostringstream ss1;
    serialize(ss1, req);

    std::stringstream ss2;
    httpClient.postJson(serverPath + "/check", ss1.str(), ss2);

    CheckUpdatesResponse checkUpdatesResponse;
    pt::ptree root;
    pt::read_json(ss2, root);
    deserialize(root, checkUpdatesResponse);

    if (!checkUpdatesResponse.success)
    {
        throw std::runtime_error("Could not check for updates");
    }

    if (checkUpdatesResponse.licenseFile)
    {
        // Something changes - Server sent us updated licenseFile
        {
            const auto& licenseData = checkUpdatesResponse.licenseFile.value();
            std::ofstream os(m_licenseFile, std::ofstream::binary);
            os.write(licenseData.data(), licenseData.size());
        }
        loadActivationData();
    }
    
    return checkUpdatesResponse.moduleUpdates;
}

bool LicenseClient::loadActivationData()
{
    if (fs::is_regular_file(m_licenseFile))
    {
        // Encrypt in nodejs
        /*
        let activationData = {
            activationId: '1234567890',
            systemParams: {
                biosSerialNum: '1234567797980980',
                diskSerialNum: '1234567857845764'
            },
            licensedModules: ['ccengine', 'cc-data-usd', 'cc-data-rub']
        };
        
        let algorithm = 'aes-256-gcm';
        let password = Buffer.from('e73db572349005f1c41979baf8166a0900745119fa096b9c3efbcee11ddd8b88', 'hex');
        let privateKey = '-----BEGIN EC PRIVATE KEY-----' + "\n" +
            'MIGAAgEBBCQBPIZnOt/mEsgtH3S9XZMGRuHkB5hYbMJ/BxcGmAc/pZLdxDWgBwYF' + "\n" +
            'K4EEABGhTANKAAQHyyrnJFywb+B0pcaVRHIOcEao3OtSMSJJZiluIMme1aE+20UA' + "\n" +
            '0c0+2u+M6bMi072XrXLf8KudcAxihG/aqCqbVVZS6i10SSM=' + "\n" + 
            '-----END EC PRIVATE KEY-----';
        crypto.randomBytes(16, (err, nonce) => {
            activationData.nonce = nonce.toString('base64');
            let data = JSON.stringify(activationData);
            let sign = crypto.createSign('SHA256');
            sign.write(data);
            sign.end();
            let signature = sign.sign(privateKey, 'hex');
            data = JSON.stringify({ data, signature });
            crypto.randomBytes(16, (err, iv) => {
                zlib.deflateRaw(data, (err, compressed) => {
                    let cipher = crypto.createCipheriv(algorithm, password, iv);
                    let encrypted = cipher.update(compressed);
                    encrypted = Buffer.concat([encrypted, cipher.final()]);
                    let tag = cipher.getAuthTag();
                    let output = Buffer.concat([iv, tag, encrypted]);
                    console.log(output.toString('hex'));
                });
            });
        });

        */

        /*unsigned char publicKey[] = {
            0x04, 0x07, 0xcb, 0x2a, 0xe7, 0x24, 0x5c, 0xb0, 0x6f, 0xe0, 0x74, 0xa5, 0xc6, 0x95, 0x44, 0x72,
            0x0e, 0x70, 0x46, 0xa8, 0xdc, 0xeb, 0x52, 0x31, 0x22, 0x49, 0x66, 0x29, 0x6e, 0x20, 0xc9, 0x9e,
            0xd5, 0xa1, 0x3e, 0xdb, 0x45, 0x00, 0xd1, 0xcd, 0x3e, 0xda, 0xef, 0x8c, 0xe9, 0xb3, 0x22, 0xd3,
            0xbd, 0x97, 0xad, 0x72, 0xdf, 0xf0, 0xab, 0x9d, 0x70, 0x0c, 0x62, 0x84, 0x6f, 0xda, 0xa8, 0x2a,
            0x9b, 0x55, 0x56, 0x52, 0xea, 0x2d, 0x74, 0x49, 0x23 }; */

        unsigned char publicKey[] = { 
            0x30, 0x5e, 0x30, 0x10, 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01, 0x06, 0x05, 0x2b,
            0x81, 0x04, 0x00, 0x11, 0x03, 0x4a, 0x00, 0x04, 0x07, 0xcb, 0x2a, 0xe7, 0x24, 0x5c, 0xb0, 0x6f,
            0xe0, 0x74, 0xa5, 0xc6, 0x95, 0x44, 0x72, 0x0e, 0x70, 0x46, 0xa8, 0xdc, 0xeb, 0x52, 0x31, 0x22,
            0x49, 0x66, 0x29, 0x6e, 0x20, 0xc9, 0x9e, 0xd5, 0xa1, 0x3e, 0xdb, 0x45, 0x00, 0xd1, 0xcd, 0x3e,
            0xda, 0xef, 0x8c, 0xe9, 0xb3, 0x22, 0xd3, 0xbd, 0x97, 0xad, 0x72, 0xdf, 0xf0, 0xab, 0x9d, 0x70,
            0x0c, 0x62, 0x84, 0x6f, 0xda, 0xa8, 0x2a, 0x9b, 0x55, 0x56, 0x52, 0xea, 0x2d, 0x74, 0x49, 0x23 };

        unsigned char password[] = { 
            0xe7, 0x3d, 0xb5, 0x72, 0x34, 0x90, 0x05, 0xf1, 0xc4, 0x19, 0x79, 0xba, 0xf8, 0x16, 0x6a, 0x09,
            0x00, 0x74, 0x51, 0x19, 0xfa, 0x09, 0x6b, 0x9c, 0x3e, 0xfb, 0xce, 0xe1, 0x1d, 0xdd, 0x8b, 0x88 };
/*        unsigned char encrypted[] = { 
            0x5d, 0xc1, 0x4e, 0xaf, 0x95, 0xf0, 0x1d, 0x84, 0x09, 0x71, 0x66, 0x0f, 0x87, 0x19, 0x7a, 0xa1,
            0x6a, 0x77, 0x39, 0x1e, 0x0a, 0xde, 0x93, 0x0c, 0xda, 0xa8, 0x62, 0x76, 0x53, 0xcb, 0xa7, 0x9f,
            0x8d, 0x36, 0x2a, 0x74, 0xcd, 0x5d, 0x78, 0x6e, 0x83, 0x14, 0xa4, 0x21, 0x3c }; */
/*        {
        unsigned char encrypted[] = { 
            0x88, 0x5d, 0x38, 0xfe, 0xfc, 0x51, 0x7d, 0x3c, 0xb5, 0x95, 0x49, 0xae, 0xa4, 0x6a, 0xa4, 0x7e,
            0xda, 0x5d, 0x29, 0x84, 0xc2, 0x85, 0xb6, 0x18, 0x6b, 0xd6, 0x40, 0x77, 0x28, 0xc3, 0xa4, 0x0c,
            0xd1, 0x47, 0x78, 0xf9, 0xce, 0xe4, 0x22, 0xec, 0x68, 0x3f, 0x34, 0xe3, 0xa0, 0x23, 0x42, 0xcc,
            0x35, 0x50, 0x2a, 0x34, 0xa5, 0xc3, 0x0b, 0x77, 0xa6, 0xb1, 0x00, 0x53, 0xf7, 0x86, 0x08, 0x94,
            0x72, 0x99, 0x88, 0xc6, 0x07, 0x18, 0x2b, 0xb0, 0xd9, 0xd2, 0x1d, 0xea, 0x5c, 0x96, 0x14, 0x25,
            0x70, 0xd8, 0x02, 0xb6, 0xc7, 0xa2, 0xae, 0x9e, 0x89, 0x87, 0xb9, 0x9f, 0xad, 0xd6, 0xc6, 0x8a,
            0xb2, 0x53, 0x8f, 0xfb, 0x3d, 0x4b, 0x21, 0xd3, 0xa1, 0x43, 0x88, 0xef, 0x16, 0x20, 0x19, 0xa2,
            0x6c, 0x36, 0xc4, 0xfd, 0x17, 0x0c, 0xad, 0x30, 0xef, 0xfc, 0x6c, 0xe8, 0x2c, 0x3a, 0x55, 0x18,
            0x00, 0x8a, 0x15, 0x46, 0xd6, 0x36, 0x03, 0xb6, 0x8f, 0xb9, 0x86, 0x29, 0x1f, 0x9e, 0xc2, 0x89,
            0xa2, 0x71, 0x49, 0x64, 0xc7, 0xa6, 0x70, 0x80, 0x00, 0x4c, 0x5d, 0x7c, 0x22, 0x6b, 0xdd, 0x0e,
            0x2d, 0x17, 0xab, 0xe6, 0xf8, 0x75, 0x8b, 0xd2, 0x5d, 0x2d, 0x40, 0xd6, 0xea, 0x1b, 0x4f, 0xca,
            0x02, 0x2e, 0x98, 0x16, 0x99, 0xdb, 0x14, 0x67, 0x90, 0xd6, 0x8f, 0xbf, 0xc6, 0x4d, 0xd2, 0x92,
            0xd2, 0x7b, 0x37, 0x5c, 0x60, 0x7b, 0x78, 0x90, 0x47, 0x73, 0x0a, 0xda, 0x4d, 0xa5, 0x31, 0x51,
            0x0c, 0xb6, 0x88, 0x93, 0x37, 0x4e, 0x39, 0x5c, 0x06, 0x90, 0x49, 0xd7, 0x48, 0x67, 0x60, 0xfc,
            0x9f, 0x40, 0xaf, 0x50, 0x67, 0xc0, 0xf5, 0xb4, 0xab, 0xac, 0xa1, 0x1c, 0x95, 0xd8, 0x57, 0x15,
            0x7d, 0xe8, 0xa7, 0x7f, 0x1a, 0xad, 0x64, 0x7d, 0xa9, 0x3d, 0x38, 0xa6, 0x06, 0xc2, 0x5a, 0x46,
            0xae, 0x07, 0x53, 0x97, 0x68, 0x6c, 0xc5, 0xf8, 0x2a, 0xb4, 0x86, 0x8e, 0x9a, 0x7b, 0x48, 0x51,
            0xb4, 0x76, 0x8d, 0x9e, 0x6d, 0x47, 0xa8, 0x55, 0x39, 0x73, 0x1d, 0x35, 0x7c, 0xd2, 0xc1, 0x6a,
            0x22, 0x91, 0x59, 0x4d, 0xaa, 0x69, 0x11, 0xdf, 0xf3, 0x4f, 0x41, 0x04, 0xff, 0xb4, 0x5d, 0x42,
            0x42, 0x73, 0x07, 0xc4, 0xfc, 0xac, 0xa4, 0x98, 0x40, 0x24, 0x1f, 0x0a, 0x86, 0xda, 0x06  };

        
            std::ofstream ofs("license.dat", std::ofstream::binary);
            ofs.write((const char*)encrypted, sizeof(encrypted));
        } */

        SecByteBlock key(sizeof(password));
        key.Assign(password, sizeof(password));

        std::string encrypted = readBinaryFile(m_licenseFile);
        if (std::size(encrypted) < initializationVectorSize)
        {
            throw std::runtime_error("Invalid license file");
        }

        std::string recoveredData;

        GCM<AES>::Decryption d;
        d.SetKeyWithIV(key, key.size(), (const CryptoPP::byte*)encrypted.data(), initializationVectorSize);

        AuthenticatedDecryptionFilter df(d,
            new StringSink(recoveredData),
            AuthenticatedDecryptionFilter::MAC_AT_BEGIN |
            AuthenticatedDecryptionFilter::THROW_EXCEPTION, macTagSize
        ); // AuthenticatedDecryptionFilter

           // The StringSource dtor will be called immediately
           //  after construction below. This will cause the
           //  destruction of objects it owns. To stop the
           //  behavior so we can get the decoding result from
           //  the DecryptionFilter, we must use a redirector
           //  or manually Put(...) into the filter without
           //  using a StringSource.
        StringSource ss2((const CryptoPP::byte*)encrypted.data() + initializationVectorSize, encrypted.size() - initializationVectorSize, true,
            new Redirector(df /*, PASS_EVERYTHING */)
        ); // StringSource

        if (!df.GetLastResult())
        {
            throw std::runtime_error("Unable to decrypt data");
        }

        boost::iostreams::array_source src{ recoveredData.data(), recoveredData.size() };
        boost::iostreams::filtering_istream is;
        boost::iostreams::zlib_params zlibParams;
        zlibParams.noheader = true;
        is.push(boost::iostreams::zlib_decompressor{zlibParams});
        is.push(src);

        SignedData signedData;
        {
            pt::ptree root;
            pt::read_json(is, root);
            deserialize(root, signedData);
        }

        ECDSA<EC2N, SHA256>::PublicKey pubKey;
        //CryptoPP::FileSource fs("c:\\work\\ccengine\\openssl\\bin\\ccengine-pub.der", true /*binary*/);
        CryptoPP::ArraySource arraySource(static_cast<const CryptoPP::byte*>(publicKey), sizeof(publicKey), true);
        pubKey.Load(arraySource);
        ECDSA<EC2N, SHA256>::Verifier verifier(pubKey);

        std::string signatureDer;
        StringSource ss(signedData.signature, true,
            new HexDecoder(
                new StringSink(signatureDer)
            ) // HexDecoder
        ); // StringSource

        byte signature[ecdsaSignatureSize] = { 0 };
        size_t signLength = CryptoPP::DSAConvertSignatureFormat(signature, sizeof(signature), CryptoPP::DSA_P1363,
            (const CryptoPP::byte*)signatureDer.data(), signatureDer.size(), CryptoPP::DSA_DER);

        bool result = verifier.VerifyMessage((const byte*)signedData.data.data(), signedData.data.size(), signature, signLength);
        if (!result)
        {
            throw std::runtime_error("Signature could not be verified");
        }

        ActivationData activationData;
        std::istringstream iss(signedData.data);
        {
            pt::ptree root;
            pt::read_json(iss, root);
            deserialize(root, activationData);
        }

        if (!validateActivationData(activationData))
        {
            throw std::runtime_error("You system is not genuine. Please contact support!");
        }

        m_activationData = std::move(activationData);
        return true;
    }
    return false;
}

bool LicenseClient::validateActivationData(const ActivationData & activationData)
{
    if (activationData.systemParams.empty())
    {
        return false;
    }

    if (activationData.productId != productId)
    {
        return false;
    }

    // activation parameters must match system parameters
    for (const auto& entry : activationData.systemParams)
    {
        auto it = m_systemParams.find(entry.first);
        if (it == m_systemParams.end() || it->second != entry.second)
        {
            return false;
        }
    }

    return true;
}