#include "connection.h"
#include "mainwindow.h"
#include "settings.h"
#include "ui_connection.h"
#include "rpc.h"

#include "precompiled.h"

using json = nlohmann::json;
/*
class LoadingDialog : public QDialog {
    //Q_OBJECT
public:
    LoadingDialog(QWidget* parent);
    ~LoadingDialog();
public slots:
    void reject();
};

LoadingDialog::LoadingDialog(QWidget* parent) : QDialog(parent) {}
LoadingDialog::~LoadingDialog() {}
void LoadingDialog::reject() {
    //event->ignore();
}
*/
ConnectionLoader::ConnectionLoader(MainWindow* main, RPC* rpc) {
    this->main = main;
    this->rpc  = rpc;

    d = new QDialog(main);
    connD = new Ui_ConnectionDialog();
    connD->setupUi(d);

    // Center on screen
    QRect screenGeometry = QApplication::desktop()->screenGeometry(d);
    int x = (screenGeometry.width() - d->width()) / 2;
    int y = (screenGeometry.height() - d->height()) / 2;
    d->move(x, y);
    connD->buttonBox->setEnabled(false);    
}

ConnectionLoader::~ConnectionLoader() {
    delete d;
    delete connD;
}

void ConnectionLoader::loadConnection() {    
    // Priority 1: Try to connect to detect zcash.conf and connect to it.
    auto config = autoDetectZcashConf();

    // If not autodetected, go and read the UI Settings
    if (config.get() == nullptr)  {
        config = loadFromSettings();

        if (config.get() == nullptr) {
            d->show();
            // Nothing configured, show an error
            auto explanation = QString()
                    % "A zcash.conf was not found on this machine.\n\n"
                    % "If you are connecting to a remote/non-standard node " 
                    % "please set the host/port and user/password in the File->Settings menu.";

            showError(explanation);
            rpc->setConnection(nullptr);

            return;
        }
    }

    auto connection = makeConnection(config);
    refreshZcashdState(connection);
}

Connection* ConnectionLoader::makeConnection(std::shared_ptr<ConnectionConfig> config) {
    QNetworkAccessManager* client = new QNetworkAccessManager(main);
         
    QUrl myurl;
    myurl.setScheme("http");
    myurl.setHost(config.get()->host);
    myurl.setPort(config.get()->port.toInt());

    QNetworkRequest* request = new QNetworkRequest();
    request->setUrl(myurl);
    request->setHeader(QNetworkRequest::ContentTypeHeader, "text/plain");
    
    QString userpass = config.get()->rpcuser % ":" % config.get()->rpcpassword;
    QString headerData = "Basic " + userpass.toLocal8Bit().toBase64();
    request->setRawHeader("Authorization", headerData.toLocal8Bit());    

    return new Connection(main, client, request, config);
}

void ConnectionLoader::refreshZcashdState(Connection* connection) {
    json payload = {
        {"jsonrpc", "1.0"},
        {"id", "someid"},
        {"method", "getinfo"}
    };
    connection->doRPC(payload,
        [=] (auto) {
            // Success, hide the dialog if it was shown. 
            d->hide();
            rpc->setConnection(connection);
        },
        [=] (auto reply, auto res) {
            d->show();

            auto err = reply->error();
            // Failed, see what it is. 
            qDebug() << err << ":" << QString::fromStdString(res.dump());

            if (err == QNetworkReply::NetworkError::ConnectionRefusedError) {    
                auto isZcashConfFound = connection->config.get()->usingZcashConf;
                auto explanation = QString()
                        % (isZcashConfFound ? "A zcash.conf file was found, but a" : "A") 
                        % " connection to zcashd could not be established.\n\n"
                        % "If you are connecting to a remote/non-standard node " 
                        % "please set the host/port and user/password in the File->Settings menu";

                this->showError(explanation);
            } else if (err == QNetworkReply::NetworkError::AuthenticationRequiredError) {
                auto explanation = QString() 
                        % "Authentication failed. The username / password you specified was "
                        % "not accepted by zcashd. Try changing it in the File->Settings menu";

                this->showError(explanation);
            } else if (err == QNetworkReply::NetworkError::InternalServerError && !res.is_discarded()) {
                // The server is loading, so just poll until it succeeds
                QString status = QString::fromStdString(res["error"]["message"]);

                QIcon icon = QApplication::style()->standardIcon(QStyle::SP_MessageBoxInformation);
                connD->icon->setPixmap(icon.pixmap(128, 128));
                connD->status->setText(status);

                // Refresh after one second
                QTimer::singleShot(1000, [=]() { this->refreshZcashdState(connection); });
            }
        }
    );
}

void ConnectionLoader::showError(QString explanation) {
    QIcon icon = QApplication::style()->standardIcon(QStyle::SP_MessageBoxCritical);
    connD->icon->setPixmap(icon.pixmap(128, 128));
    connD->status->setText(explanation);
    connD->title->setText("");

    connD->buttonBox->setEnabled(true);
}

/*
int ConnectionLoader::getProgressFromStatus(QString status) {
    if (status.startsWith("Loading block")) return 20;
    if (status.startsWith("Verifying")) return 40;
    if (status.startsWith("Loading Wallet")) return 60;
    if (status.startsWith("Activating")) return 80;
    if (status.startsWith("Rescanning")) return 90;
    return 0;
}
*/

/**
 * Try to automatically detect a zcash.conf file in the correct location and load parameters
 */ 
std::shared_ptr<ConnectionConfig> ConnectionLoader::autoDetectZcashConf() {    

#ifdef Q_OS_LINUX
    auto confLocation = QStandardPaths::locate(QStandardPaths::HomeLocation, ".zcash/zcash.conf");
#elif defined(Q_OS_DARWIN)
    auto confLocation = QStandardPaths::locate(QStandardPaths::HomeLocation, "/Library/Application Support/Zcash/zcash.conf");
#else
    auto confLocation = QStandardPaths::locate(QStandardPaths::AppDataLocation, "../../Zcash/zcash.conf");
#endif

    confLocation = QDir::cleanPath(confLocation);

    if (confLocation.isNull()) {
        // No zcash file, just return with nothing
        return nullptr;
    }

    QFile file(confLocation);
    if (!file.open(QIODevice::ReadOnly)) {
        qDebug() << file.errorString();
        return nullptr;
    }

    QTextStream in(&file);

    auto zcashconf = new ConnectionConfig();
    zcashconf->host     = "127.0.0.1";
    zcashconf->connType = ConnectionType::DetectedConfExternalZcashD;
    zcashconf->usingZcashConf = true;

    Settings::getInstance()->setUsingZcashConf(confLocation);

    while (!in.atEnd()) {
        QString line = in.readLine();
        auto s = line.indexOf("=");
        QString name  = line.left(s).trimmed().toLower();
        QString value = line.right(line.length() - s - 1).trimmed();

        if (name == "rpcuser") {
            zcashconf->rpcuser = value;
        }
        if (name == "rpcpassword") {
            zcashconf->rpcpassword = value;
        }
        if (name == "rpcport") {
            zcashconf->port = value;
        }
        if (name == "testnet" &&
            value == "1"  &&
            zcashconf->port.isEmpty()) {
                zcashconf->port = "18232";
        }
    }

    // If rpcport is not in the file, and it was not set by the testnet=1 flag, then go to default
    if (zcashconf->port.isEmpty()) zcashconf->port = "8232";

    file.close();

    return std::shared_ptr<ConnectionConfig>(zcashconf);
}

/**
 * Load connection settings from the UI, which indicates an unknown, external zcashd
 */ 
std::shared_ptr<ConnectionConfig> ConnectionLoader::loadFromSettings() {
    // Load from the QT Settings. 
    QSettings s;
    
    auto host        = s.value("connection/host").toString();
    auto port        = s.value("connection/port").toString();
    auto username    = s.value("connection/rpcuser").toString();
    auto password    = s.value("connection/rpcpassword").toString();    

    if (username.isEmpty() || password.isEmpty())
        return nullptr;

    auto uiConfig = new ConnectionConfig{ host, port, username, password, false, ConnectionType::UISettingsZCashD };

    return std::shared_ptr<ConnectionConfig>(uiConfig);
}








Connection::Connection(MainWindow* m, QNetworkAccessManager* c, QNetworkRequest* r, std::shared_ptr<ConnectionConfig> conf) {
    this->restclient  = c;
    this->request     = r;
    this->config      = conf;
    this->main        = m;
}

Connection::~Connection() {
    delete restclient;
    delete request;
}



void Connection::doRPC(const json& payload, const std::function<void(json)>& cb, 
                       const std::function<void(QNetworkReply*, const json&)>& ne) {
    QNetworkReply *reply = restclient->post(*request, QByteArray::fromStdString(payload.dump()));

    QObject::connect(reply, &QNetworkReply::finished, [=] {
        reply->deleteLater();
        
        if (reply->error() != QNetworkReply::NoError) {
            auto parsed = json::parse(reply->readAll(), nullptr, false);
            ne(reply, parsed);
            
            return;
        } 
        
        auto parsed = json::parse(reply->readAll(), nullptr, false);
        if (parsed.is_discarded()) {
            ne(reply, "Unknown error");
        }
        
        cb(parsed["result"]);        
    });
}

void Connection::doRPCWithDefaultErrorHandling(const json& payload, const std::function<void(json)>& cb) {
    doRPC(payload, cb, [=] (auto reply, auto parsed) {
        if (!parsed.is_discarded() && !parsed["error"]["message"].is_null()) {
            this->showTxError(QString::fromStdString(parsed["error"]["message"]));    
        } else {
            this->showTxError(reply->errorString());
        }
    });
}

void Connection::doRPCIgnoreError(const json& payload, const std::function<void(json)>& cb) {
    doRPC(payload, cb, [=] (auto, auto) {
        // Ignored error handling
    });
}

void Connection::showTxError(const QString& error) {
    if (error.isNull()) return;

    QMessageBox msg(main);
    msg.setIcon(QMessageBox::Icon::Critical); 
    msg.setWindowTitle("Transaction Error");
    
    msg.setText("There was an error sending the transaction. The error was: \n\n" 
                + error);        

    msg.exec();
}