/* Copyright 2015-2021 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "VersionList.h"

#include <QDateTime>

#include "Version.h"
#include "JsonFormat.h"
#include "Version.h"

namespace Meta
{
VersionList::VersionList(const QString &uid, QObject *parent)
    : BaseVersionList(parent), m_uid(uid)
{
    setObjectName("Version list: " + uid);
}

Task::Ptr VersionList::getLoadTask()
{
    load(Net::Mode::Online);
    return getCurrentTask();
}

bool VersionList::isLoaded()
{
    return BaseEntity::isLoaded();
}

const BaseVersionPtr VersionList::at(int i) const
{
    return m_versions.at(i);
}
int VersionList::count() const
{
    return m_versions.size();
}

void VersionList::sortVersions()
{
    beginResetModel();
    std::sort(m_versions.begin(), m_versions.end(), [](const VersionPtr &a, const VersionPtr &b)
    {
        return *a.get() < *b.get();
    });
    endResetModel();
}

QVariant VersionList::data(const QModelIndex &index, int role) const
{
    if (!index.isValid() || index.row() < 0 || index.row() >= m_versions.size() || index.parent().isValid())
    {
        return QVariant();
    }

    VersionPtr version = m_versions.at(index.row());

    switch (role)
    {
    case VersionPointerRole: return QVariant::fromValue(std::dynamic_pointer_cast<BaseVersion>(version));
    case VersionRole:
    case VersionIdRole:
        return version->version();
    case ParentVersionRole:
    {
        // FIXME: HACK: this should be generic and be replaced by something else. Anything that is a hard 'equals' dep is a 'parent uid'.
        auto & reqs = version->required();
        auto iter = std::find_if(reqs.begin(), reqs.end(), [](const Require & req)
        {
            return req.uid == "net.minecraft";
        });
        if (iter != reqs.end())
        {
            return (*iter).equalsVersion;
        }
        return QVariant();
    }
    case TypeRole: return version->type();

    case UidRole: return version->uid();
    case TimeRole: return version->time();
    case RequiresRole: return QVariant::fromValue(version->required());
    case SortRole: return version->rawTime();
    case VersionPtrRole: return QVariant::fromValue(version);
    case RecommendedRole: return version->isRecommended();
    // FIXME: this should be determined in whatever view/proxy is used...
    // case LatestRole: return version == getLatestStable();
    default: return QVariant();
    }
}

BaseVersionList::RoleList VersionList::providesRoles() const
{
    return {VersionPointerRole, VersionRole, VersionIdRole, ParentVersionRole,
                TypeRole, UidRole, TimeRole, RequiresRole, SortRole,
                RecommendedRole, LatestRole, VersionPtrRole};
}

QHash<int, QByteArray> VersionList::roleNames() const
{
    QHash<int, QByteArray> roles = BaseVersionList::roleNames();
    roles.insert(UidRole, "uid");
    roles.insert(TimeRole, "time");
    roles.insert(SortRole, "sort");
    roles.insert(RequiresRole, "requires");
    return roles;
}

QString VersionList::localFilename() const
{
    return m_uid + "/index.json";
}

QString VersionList::humanReadable() const
{
    return m_name.isEmpty() ? m_uid : m_name;
}

VersionPtr VersionList::getVersion(const QString &version)
{
    VersionPtr out = m_lookup.value(version, nullptr);
    if(!out)
    {
        out = std::make_shared<Version>(m_uid, version);
        m_lookup[version] = out;
    }
    return out;
}

bool VersionList::hasVersion(QString version) const
{
    auto ver = std::find_if(m_versions.constBegin(), m_versions.constEnd(),
            [&](Meta::VersionPtr const& a){ return a->version() == version; });
    return (ver != m_versions.constEnd());
}

void VersionList::setName(const QString &name)
{
    m_name = name;
    emit nameChanged(name);
}

void VersionList::setVersions(const QVector<VersionPtr> &versions)
{
    beginResetModel();
    m_versions = versions;
    std::sort(m_versions.begin(), m_versions.end(), [](const VersionPtr &a, const VersionPtr &b)
    {
        return a->rawTime() > b->rawTime();
    });
    for (int i = 0; i < m_versions.size(); ++i)
    {
        m_lookup.insert(m_versions.at(i)->version(), m_versions.at(i));
        setupAddedVersion(i, m_versions.at(i));
    }

    // FIXME: this is dumb, we have 'recommended' as part of the metadata already...
    auto recommendedIt = std::find_if(m_versions.constBegin(), m_versions.constEnd(), [](const VersionPtr &ptr) { return ptr->type() == "release"; });
    m_recommended = recommendedIt == m_versions.constEnd() ? nullptr : *recommendedIt;
    endResetModel();
}

void VersionList::parse(const QJsonObject& obj)
{
    parseVersionList(obj, this);
}

// FIXME: this is dumb, we have 'recommended' as part of the metadata already...
static const Meta::VersionPtr &getBetterVersion(const Meta::VersionPtr &a, const Meta::VersionPtr &b)
{
    if(!a)
        return b;
    if(!b)
        return a;
    if(a->type() == b->type())
    {
        // newer of same type wins
        return (a->rawTime() > b->rawTime() ? a : b);
    }
    // 'release' type wins
    return (a->type() == "release" ? a : b);
}

void VersionList::mergeFromIndex(const VersionListPtr &other)
{
    if (m_name != other->m_name)
    {
        setName(other->m_name);
    }
}

void VersionList::merge(const VersionListPtr &other)
{
    if (m_name != other->m_name)
    {
        setName(other->m_name);
    }

    // TODO: do not reset the whole model. maybe?
    beginResetModel();
    m_versions.clear();
    if(other->m_versions.isEmpty())
    {
        qWarning() << "Empty list loaded ...";
    }
    for (const VersionPtr &version : other->m_versions)
    {
        // we already have the version. merge the contents
        if (m_lookup.contains(version->version()))
        {
            m_lookup.value(version->version())->mergeFromList(version);
        }
        else
        {
            m_lookup.insert(version->uid(), version);
        }
        // connect it.
        setupAddedVersion(m_versions.size(), version);
        m_versions.append(version);
        m_recommended = getBetterVersion(m_recommended, version);
    }
    endResetModel();
}

void VersionList::setupAddedVersion(const int row, const VersionPtr &version)
{
    // FIXME: do not disconnect from everythin, disconnect only the lambdas here
    version->disconnect();
    connect(version.get(), &Version::requiresChanged, this, [this, row]() { emit dataChanged(index(row), index(row), QVector<int>() << RequiresRole); });
    connect(version.get(), &Version::timeChanged, this, [this, row]() { emit dataChanged(index(row), index(row), QVector<int>() << TimeRole << SortRole); });
    connect(version.get(), &Version::typeChanged, this, [this, row]() { emit dataChanged(index(row), index(row), QVector<int>() << TypeRole); });
}

BaseVersionPtr VersionList::getRecommended() const
{
    return m_recommended;
}

}