#include "./connection.h"

#include "../alpm/manager.h"
#include "../alpm/upgradelookup.h"
#include "../alpm/suggestionslookup.h"
#include "../alpm/packageinfolookup.h"
#include "../alpm/config.h"

#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QWebSocket>
#include <QCoreApplication>

#include <iostream>

using namespace std;

namespace RepoIndex {

Connection::Connection(Manager &manager, QWebSocket *socket, QObject *parent) :
    QObject(parent),
    m_socket(socket),
    m_manager(manager),
    m_repoInfoUpdatesRequested(false),
    m_groupInfoUpdatesRequested(false)
{
    socket->setParent(this);
    connect(socket, &QWebSocket::textMessageReceived, this, &Connection::processTextMessage);
    connect(socket, &QWebSocket::binaryMessageReceived, this, &Connection::processBinaryMessage);
    connect(socket, &QWebSocket::disconnected, this, &Connection::socketDisconnected);
    connect(&manager, &Manager::updatesAvailable, this, &Connection::updatedAvailable);
}

void Connection::sendJson(const QJsonObject &obj)
{
    m_socket->sendTextMessage(QJsonDocument(obj).toJson(QJsonDocument::Compact));
}

void Connection::sendError(const QString &msg, const QJsonValue &id)
{
    QJsonObject response;
    response.insert(QStringLiteral("class"), QStringLiteral("error"));
    response.insert(QStringLiteral("msg"), msg);
    if(!id.isNull() && !id.isUndefined()) {
        response.insert(QStringLiteral("id"), id);
    }
    sendJson(response);
}

void Connection::sendResult(const QJsonValue &what, const QJsonValue &id, const QJsonValue &value)
{
    QJsonObject response;
    response.insert(QStringLiteral("class"), QStringLiteral("results"));
    response.insert(QStringLiteral("what"), what);
    response.insert(QStringLiteral("value"), value);
    if(!id.isNull() && !id.isUndefined()) {
        response.insert("id", id);
    }
    sendJson(response);
}

void Connection::sendResults(const QJsonValue &what, const QJsonValue &id, const QJsonValue &values)
{
    QJsonObject response;
    response.insert(QStringLiteral("class"), QStringLiteral("results"));
    response.insert(QStringLiteral("what"), what);
    response.insert(QStringLiteral("values"), values);
    if(!id.isNull() && !id.isUndefined()) {
        response.insert("id", id);
    }
    sendJson(response);
}

void Connection::updatedAvailable()
{
    if(m_repoInfoUpdatesRequested) {
        sendResult(QStringLiteral("basicrepoinfo"), QJsonValue(), m_manager.basicRepoInfo());
    }
    if(m_groupInfoUpdatesRequested) {
        sendResults(QStringLiteral("groupinfo"), QJsonValue(), m_manager.groupInfo());
    }
}

template<class Lookup, typename... Args>
void Connection::performLookup(const QJsonObject &request, Args &&...args)
{
    auto *lookup = new Lookup(forward<Args>(args)...);
    if(lookup->finished()) {
        // the lookup has already finished when constructing the lookup object
        // -> send the results immidiately
        sendResult(request.value(QStringLiteral("what")), request.value(QStringLiteral("id")), lookup->results());
    } else if(!lookup->errors().isEmpty()) {
        // error occured during the construction of the lookup object
        // -> send the errors immidiately
        QJsonObject results;
        results.insert(QStringLiteral("errors"), lookup->errors());
        sendResult(request.value(QStringLiteral("what")), request.value(QStringLiteral("id")), results);
    } else {
        // the lookup object has been created without errors but the lookup is not done yet
        // -> send results when available
        connect(lookup, &Lookup::resultsAvailable, this, &Connection::sendResult);
    }
    // in any case: the lookup object destroys itself
}

void Connection::handleQuery(const QJsonObject &obj)
{
    const auto what = obj.value(QStringLiteral("what")).toString();
    const auto id = obj.value(QStringLiteral("id"));
    if(what == QLatin1String("basicrepoinfo")) {
        m_repoInfoUpdatesRequested = obj.value(QStringLiteral("updates")).toBool(m_repoInfoUpdatesRequested);
        sendResult(what, id, m_manager.basicRepoInfo());
    } else if(what == QLatin1String("basicpkginfo") || what == QLatin1String("pkgdetails") || what == QLatin1String("fullpkginfo")) {
        performLookup<PackageInfoLookup>(obj, m_manager, obj);
    } else if(what == QLatin1String("groupinfo")) {
        m_groupInfoUpdatesRequested = obj.value(QStringLiteral("updates")).toBool(m_groupInfoUpdatesRequested);
        sendResults(what, id, m_manager.groupInfo());
    } else if(what == QLatin1String("suggestions")) {
        performLookup<SuggestionsLookup>(obj, m_manager, obj);
    } else if(what == QLatin1String("upgradelookup")) {
        performLookup<UpgradeLookupJson>(obj, m_manager, obj);
    } else if(what == QLatin1String("ping")) {
        sendResult(what, id, QStringLiteral("pong"));
    } else {
        sendError(QStringLiteral("unknown query"), id);
    }
}

void Connection::handleCmd(const QJsonObject &obj)
{
    const auto what = obj.value(QStringLiteral("what")).toString();
    const auto id = obj.value(QStringLiteral("id"));
    if(what == QLatin1String("stop")) {
        if(m_socket->peerAddress().isLoopback()) {
            cerr << shchar << "Info: Server stopped via web interface." << endl;
            QCoreApplication::quit();
        } else {
            sendError(QStringLiteral("rejected"), id);
        }
    } else if(what == QLatin1String("reinitalpm")) {
        if(m_socket->peerAddress().isLoopback()) {
            cerr << shchar << "Info: Re-initializing ALPM databases (triggered via web interface) ..." << endl;
            m_manager.removeAllDatabases();
            if(m_manager.config().isLocalDatabaseEnabled()) {
                m_manager.addLocalDatabase();
            }
            if(m_manager.config().areReposFromPacmanConfEnabled()) {
                m_manager.addDataBasesFromPacmanConfig();
            }
            m_manager.addDatabasesFromRepoIndexConfig();
            m_manager.initAlpmDataBases();
        } else {
            sendError(QStringLiteral("rejected"), id);
        }
    } else if(what == QLatin1String("updatealpm")) {
        if(m_socket->peerAddress().isLoopback()) {
            cerr << shchar << "Info: Forcing update of all ALPM databases (triggered via web interface) ..." << endl;
            m_manager.forceUpdateAlpmDatabases();
        } else {
            sendError(QStringLiteral("rejected"), id);
        }
    } else {
        sendError(QStringLiteral("unknown command"), id);
    }
}

void Connection::processTextMessage(const QString &message)
{
    QJsonParseError error;
    QByteArray jsonData;
    jsonData.append(message);
    const QJsonDocument doc = QJsonDocument::fromJson(jsonData, &error);
    if(error.error == QJsonParseError::NoError) {
        const QJsonObject obj = doc.object();
        const QString msgClass = obj.value(QStringLiteral("class")).toString();
        if(msgClass == QLatin1String("query")) {
            handleQuery(obj);
        } else if(msgClass == QLatin1String("cmd")) {
            handleCmd(obj);
        } else {
            sendError(QStringLiteral("no message class specified"));
        }
    } else {
        sendError(QStringLiteral("unable to parse JSON: ") + error.errorString());
    }
}

void Connection::processBinaryMessage(const QByteArray &)
{
    sendError(QStringLiteral("unable to parse binary messages"));
}

void Connection::socketDisconnected()
{
    deleteLater();
}

}