/*
 * nheko Copyright (C) 2017  Konstantinos Sideris <siderisk@auth.gr>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <QDebug>
#include <QFile>
#include <QImageReader>
#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonObject>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QPixmap>
#include <QSettings>
#include <QUrl>
#include <QUrlQuery>

#include "Login.h"
#include "MatrixClient.h"
#include "Profile.h"
#include "Register.h"
#include "Versions.h"

MatrixClient::MatrixClient(QString server, QObject *parent)
  : QNetworkAccessManager(parent)
  , clientApiUrl_{ "/_matrix/client/r0" }
  , mediaApiUrl_{ "/_matrix/media/r0" }
  , server_{ "https://" + server }
{
        QSettings settings;
        txn_id_ = settings.value("client/transaction_id", 1).toInt();

        connect(this, SIGNAL(finished(QNetworkReply *)), this, SLOT(onResponse(QNetworkReply *)));
}

void
MatrixClient::reset() noexcept
{
        next_batch_ = "";
        server_     = "";
        token_      = "";

        txn_id_ = 0;
}

void
MatrixClient::onVersionsResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status_code = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status_code == 404) {
                emit versionError("Versions endpoint was not found on the server. Possibly "
                                  "not a Matrix server");
                return;
        }

        if (status_code >= 400) {
                qWarning() << "API version error: " << reply->errorString();
                emit versionError("An unknown error occured. Please try again.");
                return;
        }

        auto data = reply->readAll();
        auto json = QJsonDocument::fromJson(data);

        VersionsResponse response;

        try {
                response.deserialize(json);
                if (!response.isVersionSupported(0, 2, 0))
                        emit versionError("Server does not support required API version.");
                else
                        emit versionSuccess();
        } catch (DeserializationException &e) {
                qWarning() << "Malformed JSON response" << e.what();
                emit versionError("Malformed response. Possibly not a Matrix server");
        }
}

void
MatrixClient::onLoginResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status_code = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status_code == 403) {
                emit loginError(tr("Wrong username or password"));
                return;
        }

        if (status_code == 404) {
                emit loginError(tr("Login endpoint was not found on the server"));
                return;
        }

        if (status_code >= 400) {
                qWarning() << "Login error: " << reply->errorString();
                emit loginError(tr("An unknown error occured. Please try again."));
                return;
        }

        auto data = reply->readAll();
        auto json = QJsonDocument::fromJson(data);

        LoginResponse response;

        try {
                response.deserialize(json);

                auto hostname = server_.host();

                if (server_.port() > 0)
                        hostname = QString("%1:%2").arg(server_.host()).arg(server_.port());

                emit loginSuccess(response.getUserId(), hostname, response.getAccessToken());
        } catch (DeserializationException &e) {
                qWarning() << "Malformed JSON response" << e.what();
                emit loginError(tr("Malformed response. Possibly not a Matrix server"));
        }
}

void
MatrixClient::onLogoutResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status != 200) {
                qWarning() << "Logout error: " << reply->errorString();
                return;
        }

        emit loggedOut();
}

void
MatrixClient::onRegisterResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        auto data = reply->readAll();
        auto json = QJsonDocument::fromJson(data);

        if (status == 0 || status >= 400) {
                if (json.isObject() && json.object().contains("error"))
                        emit registerError(json.object().value("error").toString());
                else
                        emit registerError(reply->errorString());

                return;
        }

        RegisterResponse response;

        try {
                response.deserialize(json);
                emit registerSuccess(
                  response.getUserId(), response.getHomeServer(), response.getAccessToken());
        } catch (DeserializationException &e) {
                qWarning() << "Register" << e.what();
                emit registerError("Received malformed response.");
        }
}

void
MatrixClient::onGetOwnProfileResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status >= 400) {
                qWarning() << reply->errorString();
                return;
        }

        auto data = reply->readAll();
        auto json = QJsonDocument::fromJson(data);

        ProfileResponse response;

        try {
                response.deserialize(json);
                emit getOwnProfileResponse(response.getAvatarUrl(), response.getDisplayName());
        } catch (DeserializationException &e) {
                qWarning() << "Profile:" << e.what();
        }
}

void
MatrixClient::onInitialSyncResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                qWarning() << reply->errorString();
                return;
        }

        auto data = reply->readAll();

        if (data.isEmpty())
                return;

        auto json = QJsonDocument::fromJson(data);

        SyncResponse response;

        try {
                response.deserialize(json);
        } catch (DeserializationException &e) {
                qWarning() << "Sync malformed response" << e.what();
                return;
        }

        emit initialSyncCompleted(response);
}

void
MatrixClient::onImageUploadResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                emit syncFailed(reply->errorString());
                return;
        }

        auto data = reply->readAll();

        if (data.isEmpty())
                return;

        auto json = QJsonDocument::fromJson(data);

        if (!json.isObject()) {
                qDebug() << "Media upload: Response is not a json object.";
                return;
        }

        QJsonObject object = json.object();
        if (!object.contains("content_uri")) {
                qDebug() << "Media upload: Missing content_uri key";
                qDebug() << object;
                return;
        }

        emit imageUploaded(reply->property("room_id").toString(),
                           reply->property("filename").toString(),
                           object.value("content_uri").toString());
}

void
MatrixClient::onSyncResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                emit syncFailed(reply->errorString());
                return;
        }

        auto data = reply->readAll();

        if (data.isEmpty())
                return;

        auto json = QJsonDocument::fromJson(data);

        SyncResponse response;

        try {
                response.deserialize(json);
                emit syncCompleted(response);
        } catch (DeserializationException &e) {
                qWarning() << "Sync malformed response" << e.what();
        }
}

void
MatrixClient::onSendRoomMessage(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                qWarning() << reply->errorString();
                return;
        }

        auto data = reply->readAll();

        if (data.isEmpty())
                return;

        auto json = QJsonDocument::fromJson(data);

        if (!json.isObject()) {
                qDebug() << "Send message response is not a JSON object";
                return;
        }

        auto object = json.object();

        if (!object.contains("event_id")) {
                qDebug() << "SendTextMessage: missing event_id from response";
                return;
        }

        emit messageSent(object.value("event_id").toString(),
                         reply->property("roomid").toString(),
                         reply->property("txn_id").toInt());
}

void
MatrixClient::onRoomAvatarResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                qWarning() << reply->errorString();
                return;
        }

        auto img = reply->readAll();

        if (img.size() == 0)
                return;

        auto roomid = reply->property("roomid").toString();

        QPixmap pixmap;
        pixmap.loadFromData(img);

        emit roomAvatarRetrieved(roomid, pixmap);
}

void
MatrixClient::onUserAvatarResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                qWarning() << reply->errorString();
                return;
        }

        auto data = reply->readAll();

        if (data.size() == 0)
                return;

        auto roomid = reply->property("userid").toString();

        QImage img;
        img.loadFromData(data);

        emit userAvatarRetrieved(roomid, img);
}
void
MatrixClient::onGetOwnAvatarResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                qWarning() << reply->errorString();
                return;
        }

        auto img = reply->readAll();

        if (img.size() == 0)
                return;

        QPixmap pixmap;
        pixmap.loadFromData(img);

        emit ownAvatarRetrieved(pixmap);
}

void
MatrixClient::onImageResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                qWarning() << reply->errorString();
                return;
        }

        auto img = reply->readAll();

        if (img.size() == 0)
                return;

        QPixmap pixmap;
        pixmap.loadFromData(img);

        auto event_id = reply->property("event_id").toString();

        emit imageDownloaded(event_id, pixmap);
}

void
MatrixClient::onMessagesResponse(QNetworkReply *reply)
{
        reply->deleteLater();

        int status = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

        if (status == 0 || status >= 400) {
                qWarning() << reply->errorString();
                return;
        }

        auto data    = reply->readAll();
        auto room_id = reply->property("room_id").toString();

        RoomMessages msgs;

        try {
                msgs.deserialize(QJsonDocument::fromJson(data));
        } catch (const DeserializationException &e) {
                qWarning() << "Room messages from" << room_id << e.what();
                return;
        }

        emit messagesRetrieved(room_id, msgs);
}

void
MatrixClient::onResponse(QNetworkReply *reply)
{
        switch (static_cast<Endpoint>(reply->property("endpoint").toInt())) {
        case Endpoint::Versions:
                onVersionsResponse(reply);
                break;
        case Endpoint::Login:
                onLoginResponse(reply);
                break;
        case Endpoint::Logout:
                onLogoutResponse(reply);
                break;
        case Endpoint::Register:
                onRegisterResponse(reply);
                break;
        case Endpoint::GetOwnProfile:
                onGetOwnProfileResponse(reply);
                break;
        case Endpoint::Image:
                onImageResponse(reply);
                break;
        case Endpoint::InitialSync:
                onInitialSyncResponse(reply);
                break;
        case Endpoint::ImageUpload:
                onImageUploadResponse(reply);
                break;
        case Endpoint::Sync:
                onSyncResponse(reply);
                break;
        case Endpoint::SendRoomMessage:
                onSendRoomMessage(reply);
                break;
        case Endpoint::RoomAvatar:
                onRoomAvatarResponse(reply);
                break;
        case Endpoint::UserAvatar:
                onUserAvatarResponse(reply);
                break;
        case Endpoint::GetOwnAvatar:
                onGetOwnAvatarResponse(reply);
                break;
        case Endpoint::Messages:
                onMessagesResponse(reply);
                break;
        default:
                break;
        }
}

void
MatrixClient::login(const QString &username, const QString &password) noexcept
{
        QUrl endpoint(server_);
        endpoint.setPath(clientApiUrl_ + "/login");

        QNetworkRequest request(endpoint);
        request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");

        LoginRequest body(username, password);

        QNetworkReply *reply = post(request, body.serialize());
        reply->setProperty("endpoint", static_cast<int>(Endpoint::Login));
}

void
MatrixClient::logout() noexcept
{
        QUrlQuery query;
        query.addQueryItem("access_token", token_);

        QUrl endpoint(server_);
        endpoint.setPath(clientApiUrl_ + "/logout");
        endpoint.setQuery(query);

        QNetworkRequest request(endpoint);
        request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");

        QJsonObject body{};
        QNetworkReply *reply = post(request, QJsonDocument(body).toJson(QJsonDocument::Compact));
        reply->setProperty("endpoint", static_cast<int>(Endpoint::Logout));
}

void
MatrixClient::registerUser(const QString &user, const QString &pass, const QString &server) noexcept
{
        setServer(server);

        QUrlQuery query;
        query.addQueryItem("kind", "user");

        QUrl endpoint(server_);
        endpoint.setPath(clientApiUrl_ + "/register");
        endpoint.setQuery(query);

        QNetworkRequest request(QString(endpoint.toEncoded()));
        request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");

        RegisterRequest body(user, pass);

        QNetworkReply *reply = post(request, body.serialize());
        reply->setProperty("endpoint", static_cast<int>(Endpoint::Register));
}

void
MatrixClient::sync() noexcept
{
        QJsonObject filter{ { "room",
                              QJsonObject{ { "ephemeral", QJsonObject{ { "limit", 0 } } } } },
                            { "presence", QJsonObject{ { "limit", 0 } } } };

        QUrlQuery query;
        query.addQueryItem("set_presence", "online");
        query.addQueryItem("filter", QJsonDocument(filter).toJson(QJsonDocument::Compact));
        query.addQueryItem("timeout", "30000");
        query.addQueryItem("access_token", token_);

        if (next_batch_.isEmpty()) {
                qDebug() << "Sync requires a valid next_batch token. Initial sync should "
                            "be performed.";
                return;
        }

        query.addQueryItem("since", next_batch_);

        QUrl endpoint(server_);
        endpoint.setPath(clientApiUrl_ + "/sync");
        endpoint.setQuery(query);

        QNetworkRequest request(QString(endpoint.toEncoded()));

        QNetworkReply *reply = get(request);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::Sync));
}

void
MatrixClient::sendRoomMessage(matrix::events::MessageEventType ty,
                              const QString &roomid,
                              const QString &msg,
                              const QString &url) noexcept
{
        QUrlQuery query;
        query.addQueryItem("access_token", token_);

        QUrl endpoint(server_);
        endpoint.setPath(clientApiUrl_ +
                         QString("/rooms/%1/send/m.room.message/%2").arg(roomid).arg(txn_id_));
        endpoint.setQuery(query);

        QString msgType("");
        QJsonObject body;

        switch (ty) {
        case matrix::events::MessageEventType::Text:
                body = { { "msgtype", "m.text" }, { "body", msg } };
                break;
        case matrix::events::MessageEventType::Emote:
                body = { { "msgtype", "m.emote" }, { "body", msg } };
                break;
        case matrix::events::MessageEventType::Image:
                body = { { "msgtype", "m.image" }, { "body", msg }, { "url", url } };
                break;
        default:
                qDebug() << "SendRoomMessage: Unknown message type for" << msg;
                return;
        }

        QNetworkRequest request(QString(endpoint.toEncoded()));
        request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");

        QNetworkReply *reply = put(request, QJsonDocument(body).toJson(QJsonDocument::Compact));
        reply->setProperty("endpoint", static_cast<int>(Endpoint::SendRoomMessage));
        reply->setProperty("txn_id", txn_id_);
        reply->setProperty("roomid", roomid);

        incrementTransactionId();
}

void
MatrixClient::initialSync() noexcept
{
        QJsonArray excluded_presence = {
                QString("m.presence"),
        };

        QJsonObject filter{ { "room",
                              QJsonObject{ { "timeline", QJsonObject{ { "limit", 20 } } },
                                           { "ephemeral", QJsonObject{ { "limit", 0 } } } } },
                            { "presence", QJsonObject{ { "not_types", excluded_presence } } } };

        QUrlQuery query;
        query.addQueryItem("full_state", "true");
        query.addQueryItem("set_presence", "online");
        query.addQueryItem("filter", QJsonDocument(filter).toJson(QJsonDocument::Compact));
        query.addQueryItem("access_token", token_);

        QUrl endpoint(server_);
        endpoint.setPath(clientApiUrl_ + "/sync");
        endpoint.setQuery(query);

        QNetworkRequest request(QString(endpoint.toEncoded()));

        QNetworkReply *reply = get(request);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::InitialSync));
}

void
MatrixClient::versions() noexcept
{
        QUrl endpoint(server_);
        endpoint.setPath("/_matrix/client/versions");

        QNetworkRequest request(endpoint);

        QNetworkReply *reply = get(request);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::Versions));
}

void
MatrixClient::getOwnProfile() noexcept
{
        // FIXME: Remove settings from the matrix client. The class should store the
        // user's matrix ID.
        QSettings settings;
        auto userid = settings.value("auth/user_id", "").toString();

        QUrlQuery query;
        query.addQueryItem("access_token", token_);

        QUrl endpoint(server_);
        endpoint.setPath(clientApiUrl_ + "/profile/" + userid);
        endpoint.setQuery(query);

        QNetworkRequest request(QString(endpoint.toEncoded()));

        QNetworkReply *reply = get(request);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::GetOwnProfile));
}

void
MatrixClient::fetchRoomAvatar(const QString &roomid, const QUrl &avatar_url)
{
        QList<QString> url_parts = avatar_url.toString().split("mxc://");

        if (url_parts.size() != 2) {
                qDebug() << "Invalid format for room avatar " << avatar_url.toString();
                return;
        }

        QUrlQuery query;
        query.addQueryItem("width", "512");
        query.addQueryItem("height", "512");
        query.addQueryItem("method", "crop");

        QString media_url =
          QString("%1/_matrix/media/r0/thumbnail/%2").arg(getHomeServer().toString(), url_parts[1]);

        QUrl endpoint(media_url);
        endpoint.setQuery(query);

        QNetworkRequest avatar_request(endpoint);

        QNetworkReply *reply = get(avatar_request);
        reply->setProperty("roomid", roomid);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::RoomAvatar));
}

void
MatrixClient::fetchUserAvatar(const QString &userId, const QUrl &avatarUrl)
{
        QList<QString> url_parts = avatarUrl.toString().split("mxc://");

        if (url_parts.size() != 2) {
                qDebug() << "Invalid format for user avatar " << avatarUrl.toString();
                return;
        }

        QUrlQuery query;
        query.addQueryItem("width", "128");
        query.addQueryItem("height", "128");
        query.addQueryItem("method", "crop");

        QString media_url =
          QString("%1/_matrix/media/r0/thumbnail/%2").arg(getHomeServer().toString(), url_parts[1]);

        QUrl endpoint(media_url);
        endpoint.setQuery(query);

        QNetworkRequest avatar_request(endpoint);

        QNetworkReply *reply = get(avatar_request);
        reply->setProperty("userid", userId);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::UserAvatar));
}

void
MatrixClient::downloadImage(const QString &event_id, const QUrl &url)
{
        QNetworkRequest image_request(url);

        QNetworkReply *reply = get(image_request);
        reply->setProperty("event_id", event_id);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::Image));
}

void
MatrixClient::fetchOwnAvatar(const QUrl &avatar_url)
{
        QList<QString> url_parts = avatar_url.toString().split("mxc://");

        if (url_parts.size() != 2) {
                qDebug() << "Invalid format for media " << avatar_url.toString();
                return;
        }

        QUrlQuery query;
        query.addQueryItem("width", "512");
        query.addQueryItem("height", "512");
        query.addQueryItem("method", "crop");

        QString media_url =
          QString("%1/_matrix/media/r0/thumbnail/%2").arg(getHomeServer().toString(), url_parts[1]);

        QUrl endpoint(media_url);
        endpoint.setQuery(query);

        QNetworkRequest avatar_request(endpoint);

        QNetworkReply *reply = get(avatar_request);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::GetOwnAvatar));
}

void
MatrixClient::messages(const QString &room_id, const QString &from_token, int limit) noexcept
{
        QUrlQuery query;
        query.addQueryItem("access_token", token_);
        query.addQueryItem("from", from_token);
        query.addQueryItem("dir", "b");
        query.addQueryItem("limit", QString::number(limit));

        QUrl endpoint(server_);
        endpoint.setPath(clientApiUrl_ + QString("/rooms/%1/messages").arg(room_id));
        endpoint.setQuery(query);

        QNetworkRequest request(QString(endpoint.toEncoded()));

        QNetworkReply *reply = get(request);
        reply->setProperty("endpoint", static_cast<int>(Endpoint::Messages));
        reply->setProperty("room_id", room_id);
}

void
MatrixClient::uploadImage(const QString &roomid, const QString &filename)
{
        QUrlQuery query;
        query.addQueryItem("access_token", token_);

        QUrl endpoint(server_);
        endpoint.setPath(mediaApiUrl_ + "/upload");
        endpoint.setQuery(query);

        QFile file(filename);
        if (!file.open(QIODevice::ReadWrite)) {
                qDebug() << "Error while reading" << filename;
                return;
        }

        auto imgFormat = QString(QImageReader::imageFormat(filename));

        QNetworkRequest request(QString(endpoint.toEncoded()));
        request.setHeader(QNetworkRequest::ContentLengthHeader, file.size());
        request.setHeader(QNetworkRequest::ContentTypeHeader, QString("image/%1").arg(imgFormat));

        QNetworkReply *reply = post(request, file.readAll());
        reply->setProperty("endpoint", static_cast<int>(Endpoint::ImageUpload));
        reply->setProperty("room_id", roomid);
        reply->setProperty("filename", filename);
}