/*
 * Created by victoria on 2021-05-13.
 */

#include "database.h"

#include "bundle.h"

#include <QDebug>
#include <QDir>
#include <QException>
#include <QStandardPaths>
#include <QString>

using namespace QXmpp::Omemo;

Database::Database(QString jid) : jid(std::move(jid)) {
    auto cacheLocation =
            QStandardPaths::writableLocation(QStandardPaths::CacheLocation);
    auto path = QString("%1/.omemo/%2").arg(cacheLocation, jid);
    QDir cache(path);

    if (!cache.exists() && !cache.mkpath(path)) {
        qWarning() << "Could not create:" << path;
        throw QException();
    }

    mdb_env_create(&env);

    mdb_env_set_maxdbs(env, 5);
    mdb_env_set_mapsize(env, 512UL * 1024UL * 1024UL);
    mdb_env_open(env, path.toStdString().c_str(), 0, 0664);

    MDB_txn *txn;
    mdb_txn_begin(env, nullptr, 0, &txn);
    mdb_dbi_open(txn, "keys", MDB_CREATE, &dbiKeys);
    mdb_dbi_open(txn, "devices", MDB_CREATE, &dbiDevices);
    mdb_dbi_open(txn, "identity_keys", MDB_CREATE, &dbiIdentityKeys);
    mdb_txn_commit(txn);
}

Database::~Database() {
    mdb_dbi_close(env, dbiKeys);
    mdb_dbi_close(env, dbiDevices);
    mdb_dbi_close(env, dbiIdentityKeys);
    mdb_env_close(env);
}

std::optional<QByteArray> Database::loadIdentityKeySecret(int deviceId) { return std::nullopt; }

bool Database::saveIdentityKeySecret(int deviceId,
                                     const QByteArray &identityKeySecret) {
    MDB_val mdbKey, mdbValue;
    auto key = QString("%1/secret").arg(QString::number(deviceId)).toStdString();

    mdbKey.mv_data = key.data();
    mdbKey.mv_size = key.size();

    mdbValue.mv_data = const_cast<char *>(identityKeySecret.data());
    mdbValue.mv_size = identityKeySecret.size();

    MDB_txn *txn;
    mdb_txn_begin(env, nullptr, 0, &txn);
    auto err = mdb_put(txn, dbiIdentityKeys, &mdbKey, &mdbValue, MDB_NOOVERWRITE);
    if (!err) {
        mdb_txn_commit(txn);
        return true;
    }

    qWarning() << "could not save identity key secret:" << mdb_strerror(err);
    mdb_txn_abort(txn);

    return false;
}

std::optional<int> Database::loadActiveDeviceId() {
    MDB_val key, value;

    key.mv_data = (void *) "active";
    key.mv_size = sizeof("active");

    MDB_txn *txn;
    mdb_txn_begin(env, nullptr, 0, &txn);

    auto err = mdb_get(txn, dbiIdentityKeys, &key, &value);
    if (err) {
        qWarning() << "could not load active device id:" << mdb_strerror(err);
        mdb_txn_abort(txn);
        return std::nullopt;
    }

    if (value.mv_size != sizeof(int)) {
        qWarning() << "mv_size is" << value.mv_size << "instead of" << sizeof(int);
        mdb_txn_abort(txn);
        return std::nullopt;
    }

    auto id = *reinterpret_cast<int *>(value.mv_data);

    mdb_txn_abort(txn);

    return id;
}

bool Database::saveActiveDeviceId(int deviceId) {
    MDB_val key, value;

    key.mv_data = (void *) "active";
    key.mv_size = sizeof("active");

    value.mv_data = &deviceId;
    value.mv_size = sizeof(deviceId);

    MDB_txn *txn;
    mdb_txn_begin(env, nullptr, 0, &txn);

    auto err = mdb_put(txn, dbiIdentityKeys, &key, &value, 0);
    if (err) {
        qWarning() << "could not save active device id" << mdb_strerror(err);
        return false;
    }

    err = mdb_txn_commit(txn);
    if (err) {
        qWarning() << "could not save active device id" << mdb_strerror(err);
        return false;
    }

    return true;
}

bool Database::saveIdentityKey(int deviceId, const QByteArray &identityKey) {
    return false;
}

std::optional<QByteArray> Database::loadIdentityKey(int deviceId) {
    return std::nullopt;
}

bool Database::containsPreKey() {
    return false;
}

std::optional<KeyPair> Database::loadPreKey(int deviceId, int id) {
    return std::nullopt;
}

bool Database::savePreKey(int deviceId, int id, const KeyPair &preKey) {
    return false;
}

std::optional<Bundle> Database::loadBundle(int deviceId) {
    Bundle result{};

    auto ik = loadIdentityKey(deviceId);

    result.ik = ik.value();

    auto spk = loadSignedPreKey(deviceId);

    result.spk = spk->key.publicKey;
    result.spks = spk->signature;
    result.spkId = spk->id;

    // PreKeys

    return result;
}

bool Database::saveBundle(int deviceId, const Bundle &bundle) {
    return false;
}

std::optional<SignedPreKey> Database::loadSignedPreKey(int deviceId) {
    return std::optional<SignedPreKey>();
}

bool Database::saveSignedPreKey(int deviceId, const SignedPreKey &signedPreKey) {
    return false;
}