//SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
//SPDX-License-Identifier: GPL-3.0-or-later

#include "magpie.h"

#include <QDebug>

#include "API/api.h"
#include "API/codes.h"
#include "utils/helpers.h"

Models::Magpie::Magpie (QObject* parent):
    QObject(parent),
    currencies(),
    assets(currencies),
    address(),
    state(State::Offline),
    accessToken(),
    renewToken(),
    api(),
    firstPoll(),
    pollRequestId(API::none),
    requestingCurrencies(false)
{
    firstPoll.setSingleShot(true);
    firstPoll.setInterval(2000);
    connect(&firstPoll, &QTimer::timeout, this, &Magpie::onPositivePoll);
    connect(&assets, &Assets::requestAssets, this, &Magpie::requestAssets);
}

QUrl Models::Magpie::getAddress () const {
    return address;
}

Models::Magpie::State Models::Magpie::getState () const {
    return state;
}

QString Models::Magpie::getAccessToken () const {
    return accessToken;
}

QString Models::Magpie::getRenewToken () const {
    return renewToken;
}

void Models::Magpie::installAPI (const std::shared_ptr<API>& api) {
    Magpie::api = api;
}

void Models::Magpie::setAddress (const QUrl& address) {
    if (Magpie::address == address)
        return;

    if (state == Authenticated) {
        //do something
    }

    Magpie::address = address;
    emit addressChanged(address);
    if (address.isEmpty())
        setState(NoServer);
    else
        setState(NotAuthenticated);
}

void Models::Magpie::forceAddress (const QUrl& address) {
    Magpie::address = "";
    setAddress(address);
}

void Models::Magpie::setTokens (const QString access, const QString& renew, bool notify) {
    accessToken = access;
    renewToken = renew;
    setState(Authenticating);
    startPolling();

    if (notify)
        emit storeTokens(accessToken, renewToken);
}

void Models::Magpie::setState (State newState) {
    if (newState == state)
        return;

    state = newState;
    emit stateChanged(state);
}

Models::Assets* Models::Magpie::getAssets () {
    return &assets;
}

Models::Currencies* Models::Magpie::getCurrencies () {
    return &currencies;
}

void Models::Magpie::requestAssets () {
    api->requestAssets(
        [this] (const QVariantList& list) {
            std::deque<Asset> result;
            bool res = Assets::deserialize(list, result);
            if (!res) {
                qDebug() << "Error deserializer received assets";
                result.clear();
            } else {
                qDebug() << "Assets successfully received";
            }

            assets.add(result);
        },
        [this] (const QString& error, const std::optional<QVariantMap>& data) {
            qDebug() << "Error receiving assets:" << error;
        }
    );
}

void Models::Magpie::onPositivePoll () {
    if (state == Authenticating)
        requestCurrencies();
}

void Models::Magpie::startPolling () {
    qDebug() << "Starting polling...";
    if (state != Authenticating)
        throw std::runtime_error("Can not start polling in this state: " + std::to_string(state));

    sendPoll();
    firstPoll.start();
}

void Models::Magpie::sendPoll (bool clear) {
    if (pollRequestId != API::none)
        throw std::runtime_error("an attempt to send second poll request while the other one is active");

    pollRequestId = api->poll(
        std::bind(&Magpie::onPollSuccess, this, std::placeholders::_1),
        std::bind(&Magpie::onPollError, this, std::placeholders::_1, std::placeholders::_2),
        clear
    );
}

void Models::Magpie::onPollSuccess (const QVariantMap& data) {
    pollRequestId = API::none;
    firstPoll.stop();

    Codes::Poll code = Codes::convertPoll(data.value("result").toInt());
    bool clear = false;
    switch (code) {
        case Codes::Poll::success:
            clear = handleChanges(qast<QVariantMap>(data.value("data")));
        //todo handle the result
        case Codes::Poll::timeout:
            onPositivePoll();
            if (state == Authenticating || state == Authenticated)
                return sendPoll(clear);

        case Codes::Poll::tokenProblem:
        case Codes::Poll::replace:
        case Codes::Poll::unknownError: //todo this one doesn't actually mean that we can't work for now, the network may be temporarily down or something
            return setState(NotAuthenticated);
    }
}

void Models::Magpie::onPollError (const QString& err, const std::optional<QVariantMap>& data) {
    qDebug() << "Poll error:" << err;
    pollRequestId = API::none;
    firstPoll.stop();
    setState(NotAuthenticated);
}

bool Models::Magpie::handleChanges (const QVariantMap& changes) {
    QVariantMap::ConstIterator itr = changes.constFind("system");
    if (itr != changes.constEnd() && itr.value().canConvert<QVariantMap>()) {
        const QVariantMap& sys = qast<QVariantMap>(itr.value());
        QVariantMap::ConstIterator invItr = sys.constFind("invalidate");
        if (invItr != sys.constEnd()) {
            const QVariant& vinv = invItr.value();
            if (vinv.canConvert<bool>() && vinv.toBool())
                resetAllModels();
        }
    }

    bool result = true;
    itr = changes.constFind("assets");
    if (itr != changes.constEnd() && itr.value().canConvert<QVariantMap>())
        result = handleAssetChanges(qast<QVariantMap>(itr.value()));

    itr = changes.constFind("currencies");
    if (itr != changes.constEnd() && itr.value().canConvert<QVariantMap>())
        result = result && handleCurrenciesChanges(qast<QVariantMap>(itr.value()));

    return result;
}

bool Models::Magpie::handleAssetChanges (const QVariantMap& changes) {
    QVariantMap::ConstIterator aItr = changes.constFind("invalidate");
    if (aItr != changes.constEnd()) {
        const QVariant& vinv = aItr.value();
        if (vinv.canConvert<bool>() && vinv.toBool())
            assets.clear();
    }

    aItr = changes.constFind("added");
    if (aItr != changes.constEnd() && aItr.value().canConvert<QVariantList>()) {
        std::deque<Models::Asset> added;
        if (!Models::Assets::deserialize(qast<QVariantList>(aItr.value()), added))
            qDebug() << "Error deserializng added assets";
        else
            assets.add(added);
    }

    aItr = changes.constFind("removed");
    if (aItr != changes.constEnd() && aItr.value().canConvert<QVariantList>()) {
        const QVariantList rem = qast<QVariantList>(aItr.value());
        for (const QVariant& vId : rem) {
            if (vId.isValid() && vId.canConvert<unsigned int>())
                assets.remove(vId.toUInt());
            else
                qDebug() << "Error deserializing removed assets";
        }
    }

    aItr = changes.constFind("changed");
    if (aItr != changes.constEnd() && aItr.value().canConvert<QVariantList>()) {
        std::deque<Models::Asset> changes;
        if (!Models::Assets::deserialize(qast<QVariantList>(aItr.value()), changes))
            qDebug() << "Error deserializng changed assets";
        else
            assets.change(changes);
    }

    return true;
}

bool Models::Magpie::handleCurrenciesChanges (const QVariantMap& changes) {
    QVariantMap::ConstIterator aItr = changes.constFind("invalidate");
    if (aItr != changes.constEnd()) {
        const QVariant& vinv = aItr.value();
        if (vinv.canConvert<bool>() && vinv.toBool())
            requestCurrencies();
    }

    return true;
}

void Models::Magpie::resetAllModels () {
    assets.clear();
    requestCurrencies();
}

void Models::Magpie::requestCurrencies () {
    if (requestingCurrencies)
        return;

    requestingCurrencies = true;
    currencies.clear();
    api->requestCurrencies(
        [this] (const QVariantList& list) {
            std::deque<Currency> result;
            bool res = Currencies::deserialize(list, result);
            if (!res) {
                qDebug() << "Error deserializer received currencies";
                result.clear();
            } else {
                qDebug() << "Currencies successfully received";
            }

            currencies.add(result);
            requestingCurrencies = false;
            setState(Authenticated);
        },
        [this] (const QString& error, const std::optional<QVariantMap>& data) {
            qDebug() << "Error receiving currencies:" << error;
            requestingCurrencies = false;
            setState(NotAuthenticated);
        }
    );
}