#include <memory>
#include <QDebug>
#include <QFile>
#include <QDir>
#include <QtCore/QStandardPaths>

#include <gpgme.h>
#include <gpgme++/data.h>
#include <gpgme++/global.h>
#include <gpgme++/context.h>
#include <gpgme++/engineinfo.h>
#include <gpgme++/keylistresult.h>
#include <gpgme++/importresult.h>
#include <gpgme++/encryptionresult.h>
#include <gpgme++/decryptionresult.h>

#include <qgpgme/importjob.h>
#include <qgpgme/deletejob.h>
#include <qgpgme/decryptjob.h>
#include <qgpgme/encryptjob.h>
#include <qgpgme/protocol.h>
#include <qgpgme/keylistjob.h>
#include <qgpgme/changeownertrustjob.h>

#include "gpg.h"
#include "pass.h"
#include "passphraseprovider.h"




using namespace GpgME;
using namespace QGpgME;

Gpg::Gpg()
{
    m_window = nullptr;

    initializeLibrary();

    Gpg::initGpgConfig();

    auto  error = checkEngine(OpenPGP);
    if (error) {
        qDebug() << "Code Error : " << error.code();
        qDebug() << "Error str : " << error.asString();
        qFatal("GNUPG Engine check Fail");
    }

    qDebug() << "GNUPG Engine Version is :" << engineInfo(OpenPGP).version();
    qDebug() << "GNUPG Executable is :" << engineInfo(OpenPGP).fileName();
    qDebug() << "GNUPG Home is :" << engineInfo(OpenPGP).homeDirectory();
}


QString Gpg::initGpgHome()
{
    QString path = QStandardPaths::writableLocation(
                       QStandardPaths::AppDataLocation).append("/.gpghome");
    QDir dir(path);
    if (!dir.exists()) {
        dir.mkpath(".");
    }
    return path;
}


QString Gpg::initGpgExec()
{
    QString path =  QDir::currentPath().append("/lib/bin/gpg");
    QFileInfo file(path);
    if (!file.isFile()) {
        qFatal("GNUPGEXEC file not found !");
    }
    if (!file.isExecutable()) {
        qFatal("GNUPGEXEC file not executable !");
    }
    return path;
}


void Gpg::initGpgConfig()
{
    auto home = initGpgHome();
    auto exec = initGpgExec();

    QFile agentConf(home + QStringLiteral("/gpg-agent.conf"));
    agentConf.remove();
    agentConf.open(QIODevice::WriteOnly);
    agentConf.write("allow-loopback-pinentry");
    agentConf.close();

    gpgme_set_engine_info (
        GPGME_PROTOCOL_OpenPGP,
        exec.toLocal8Bit().data(),
        home.toLocal8Bit().data()
    );
}


QPair<Error, QString> Gpg::decrypt(QByteArray cipherText)
{
    auto job = openpgp()->decryptJob();
    auto ctx = DecryptJob::context(job);

    auto provider = new UTPassphraseProvider;
    ctx->setPassphraseProvider(provider);
    ctx->setPinentryMode(Context::PinentryLoopback);

    QByteArray plain_text;
    auto decResult = job->exec(cipherText, plain_text);

    delete job;

    if (decResult.error()) {
        qWarning() << "something gone wrong on decrypt";
        qDebug() << "Code Error : " << decResult.error().code();
        qDebug() << "Error str : " << decResult.error().asString();
    }
    return QPair<Error, QString>(decResult.error(), QString::fromUtf8(plain_text));
}


QPair<Error, QString> Gpg::decryptFromFile(QString path)
{
    qDebug() << "Decrypt from " << path;
    QFile file(path);
    if (!file.open(QIODevice::ReadOnly)) {
        qWarning() << "Can't open the File";
        return QPair<Error, QString>(Error(), QString());;
    }
    QByteArray cipherText = file.readAll();
    file.close();
    return decrypt(cipherText);
}


QPair<Error, QByteArray> Gpg::encrypt(QString str, QString uid, bool ascii_armor, bool text_mode)
{

    qDebug() << "Encrypt to QByteArray";
    auto keys = getKeys(uid);
    if (keys.first) {
        return QPair<Error, QByteArray>(keys.first, QByteArray());
    }

    auto job = std::unique_ptr<EncryptJob>(openpgp()->encryptJob(ascii_armor, text_mode));

    QByteArray cipherText;
    auto result = job->exec(keys.second, str.toUtf8(), Context::AlwaysTrust, cipherText);

    qDebug() << "Encrypted to QByteArray";
    return QPair<Error, QByteArray>(result.error(), cipherText);
}


Error Gpg::encryptToFile(QString str, QString path, QString uid, bool ascii_armor,
                         bool text_mode)
{
    qDebug() << "Encrypting to file  " << path;
    QFile file(path);
    if (!file.open(QIODevice::WriteOnly)) {
        qWarning() << "Can't open the file to write it" ;
        return Error();
    }
    auto encrypt_ret = encrypt(str, uid, ascii_armor, text_mode);
    if (encrypt_ret.first) {
        file.write(encrypt_ret.second);
    }
    qDebug() << "Encrypting to file  " << path;
    return encrypt_ret.first;
}


QPair<Error, std::vector< GpgME::Key >> Gpg::getAllKeys ( bool remote, const bool include_sigs,
                                                          bool validate )
{
    return getKeys(QString(""), remote, include_sigs, validate);
}

QPair<Error, std::vector<Key>> Gpg::getKeys(QString pattern_uid, bool remote, bool include_sigs,
                                            bool validate)
{
    qDebug() << "Getting the keys " << pattern_uid;
    auto job = std::unique_ptr<KeyListJob>(openpgp()->keyListJob(remote, include_sigs, validate));

    std::vector<Key> keys;
    auto result = job->exec(QStringList() << pattern_uid, false, keys);

    qDebug() << "Got the keys " << pattern_uid;
    return QPair<Error, std::vector< Key >>(result.error(), keys);
}


QPair<Error, Key> Gpg::getKey(QString uid, bool remote, bool include_sigs, bool validate)
{
    qDebug() << "Getting the key " << uid;
    auto keys = getKeys(uid, remote, include_sigs, validate);

    if (keys.first or keys.second.size() != 1) {
        qWarning() << "Bad id";
        return QPair<Error, Key>(keys.first, Key::null);
    }
    qDebug() << "Got the key " << uid;
    return QPair<Error, Key>(keys.first, keys.second.front());
}


Error Gpg::importKeysFromFile(QString path)
{
    qDebug() << "Importing the key file" << path;
    qDebug() << "Decrypt from " << path;
    QFile file(path);
    if (!file.open(QIODevice::ReadOnly)) {
        qWarning() << "Can't open the File";
        return Error();
    }

    auto job = openpgp()->importJob();
    auto ctx = ImportJob::context(job);

    auto provider = new UTPassphraseProvider;
    ctx->setPassphraseProvider(provider);
    ctx->setPinentryMode(Context::PinentryLoopback);
    auto result = job->exec(file.readAll());

    qDebug() << "numImported" << result.numImported();
    qDebug() << "numSecretKeysImported" << result.numSecretKeysImported();
    qDebug() << "numSecretKeysConsidered" << result.numSecretKeysConsidered();
    qDebug() << "numSecretKeysUnchanged" << result.numSecretKeysUnchanged();
    qDebug() << "numUnchanged" << result.numUnchanged();

    file.close();
    delete job;
    delete provider;

    if (result.error()) {
        qWarning() << "Import go wrong";
        qDebug() << "Code Error : " << result.error().code();
        qDebug() << "Error str : " << result.error().asString();
    }
    qDebug() << "Imported the key file" << path;
    return result.error();
}

Error Gpg::deleteKeyId(QString uid)
{
    qDebug() << "Deleting key id " << uid;
    auto key = getKey(uid);

    if (key.first) {
        return key.first;
    }

    auto ctx = std::unique_ptr<Context>(Context::createForProtocol(OpenPGP));
    auto err = ctx->deleteKey(key.second, true);

    if (err) {
        qWarning() << "Delete go wrong";
        qDebug() << "Code Error : " << err.code();
        qDebug() << "Error str : " << err.asString();
        return err;
    }

    qDebug() << "Deleted key id" << uid;
    return err;
}