/*
    Copyright (c) 2018 Michael Bohlender <michael.bohlender@kdemail.net>
    Copyright (c) 2018 Christian Mollekopf <mollekopf@kolabsys.com>
    Copyright (c) 2018 Rémi Nicole <minijackson@riseup.net>

    This library is free software; you can redistribute it and/or modify it
    under the terms of the GNU Library General Public License as published by
    the Free Software Foundation; either version 2 of the License, or (at your
    option) any later version.

    This library 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 Library General Public
    License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to the
    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301, USA.
*/

#include "perioddayeventmodel.h"

#include <sink/log.h>
#include <sink/query.h>
#include <sink/store.h>

#include <QJsonArray>
#include <QJsonObject>
#include <QMetaEnum>

PeriodDayEventModel::PeriodDayEventModel(QObject *parent) : QAbstractItemModel(parent), partitionedEvents(7)
{
    Sink::Query query;
    query.setFlags(Sink::Query::LiveQuery);
    query.request<Event::Summary>();
    query.request<Event::Description>();
    query.request<Event::StartTime>();
    query.request<Event::EndTime>();

    eventModel = Sink::Store::loadModel<Event>(query);

    QObject::connect(eventModel.data(), &QAbstractItemModel::dataChanged, this, &PeriodDayEventModel::partitionData);
    QObject::connect(eventModel.data(), &QAbstractItemModel::layoutChanged, this, &PeriodDayEventModel::partitionData);
    QObject::connect(eventModel.data(), &QAbstractItemModel::modelReset, this, &PeriodDayEventModel::partitionData);
    QObject::connect(eventModel.data(), &QAbstractItemModel::rowsInserted, this, &PeriodDayEventModel::partitionData);
    QObject::connect(eventModel.data(), &QAbstractItemModel::rowsMoved, this, &PeriodDayEventModel::partitionData);
    QObject::connect(eventModel.data(), &QAbstractItemModel::rowsRemoved, this, &PeriodDayEventModel::partitionData);

    partitionData();
}

void PeriodDayEventModel::partitionData()
{
    SinkLog() << "Partitioning event data";

    beginResetModel();

    partitionedEvents = QVector<QList<QSharedPointer<Event>>>(mViewLength);

    for (int i = 0; i < eventModel->rowCount(); ++i) {
        auto event = eventModel->index(i, 0).data(Sink::Store::DomainObjectRole).value<Event::Ptr>();
        QDate eventDate = event->getStartTime().date();

        if(!eventDate.isValid()) {
            SinkWarning() << "Invalid date in the eventModel, ignoring...";
            continue;
        }

        int bucket = bucketOf(eventDate);

        if(bucket >= 0) {
            SinkTrace() << "Adding event:" << event->getSummary() << "in bucket #" << bucket;
            partitionedEvents[bucket].append(event);
        }
    }

    endResetModel();
}

int PeriodDayEventModel::bucketOf(QDate const &candidate) const
{
    int bucket = mViewStart.daysTo(candidate);
    if(bucket >= mViewLength || bucket < 0) {
        return -1;
    }

    return bucket;
}

QModelIndex PeriodDayEventModel::index(int row, int column, const QModelIndex &parent) const
{
    if (!hasIndex(row, column, parent)) {
        return {};
    }

    if (!parent.isValid()) {
        // Asking for a day

        if (!(0 <= row && row < mViewLength)) {
            return {};
        }

        return createIndex(row, column, DAY_ID);
    }

    // Asking for an Event
    auto day = static_cast<int>(parent.row());

    Q_ASSERT(0 <= day && day <= mViewLength);
    if (row >= partitionedEvents[day].size()) {
        return {};
    }

    return createIndex(row, column, day);
}

QModelIndex PeriodDayEventModel::parent(const QModelIndex &index) const
{
    if (!index.isValid()) {
        return {};
    }

    if (index.internalId() == DAY_ID) {
        return {};
    }

    auto day = index.internalId();

    return this->index(day, 0);
}

int PeriodDayEventModel::rowCount(const QModelIndex &parent) const
{
    if (!parent.isValid()) {
        return mViewLength;
    }

    auto day = parent.row();

    return partitionedEvents[day].size();
}

int PeriodDayEventModel::columnCount(const QModelIndex &parent) const
{
    if (!parent.isValid()) {
        return 1;
    }

    return eventModel->columnCount();
}

QVariant PeriodDayEventModel::data(const QModelIndex &id, int role) const
{
    if (id.internalId() == DAY_ID) {
        auto day = id.row();

        SinkTrace() << "Fetching data for day" << day << "with role"
                    << QMetaEnum::fromType<Roles>().valueToKey(role);

        switch (role) {
            case Qt::DisplayRole:
                return mViewStart.addDays(day).toString();
            case Events: {
                auto result = QVariantList{};

                for (int i = 0; i < partitionedEvents[day].size(); ++i) {
                    auto eventId = index(i, 0, id);
                    SinkTrace() << "Appending event:" << data(eventId, Summary);

                    auto startTime = data(eventId, StartTime).toDateTime().time();

                    result.append(QVariantMap{
                        {"text", data(eventId, Summary)},
                        {"description", data(eventId, Description)},
                        {"starts", startTime.hour() + startTime.minute() / 60.},
                        {"duration", data(eventId, Duration)},
                        {"color", "#134bab"},
                        {"indention", 0},
                    });
                }

                return result;
            }
            default:
                SinkWarning() << "Unknown role for day:" << QMetaEnum::fromType<Roles>().valueToKey(role);
                return {};
        }
    } else {
        auto day = id.internalId();
        SinkTrace() << "Fetching data for event on day" << day << "with role"
                    << QMetaEnum::fromType<Roles>().valueToKey(role);
        auto event = partitionedEvents[day].at(id.row());

        switch (role) {
            case Summary:
                return event->getSummary();
            case Description:
                return event->getDescription();
            case StartTime:
                return event->getStartTime();
            case Duration: {
                auto start = event->getStartTime();
                auto end   = event->getEndTime();
                return start.secsTo(end) / 3600;
            }
            default:
                SinkWarning() << "Unknown role for event:" << QMetaEnum::fromType<Roles>().valueToKey(role);
                return {};
        }
    }
}

QHash<int, QByteArray> PeriodDayEventModel::roleNames() const
{
    QHash<int, QByteArray> roles;

    roles[Events]      = "events";
    roles[Summary]     = "summary";
    roles[Description] = "description";
    roles[StartTime]   = "starts";
    roles[Duration]    = "duration";

    return roles;
}

QDate PeriodDayEventModel::viewStart() const
{
    return mViewStart;
}

void PeriodDayEventModel::setViewStart(QDate start)
{
    if (!start.isValid()) {
        SinkWarning() << "Passed an invalid starting date in setViewStart, ignoring...";
        return;
    }

    mViewStart = std::move(start);
    partitionData();
}

void PeriodDayEventModel::setViewStart(QVariant start)
{
    setViewStart(start.toDate());
}

int PeriodDayEventModel::viewLength() const
{
    return mViewLength;
}

void PeriodDayEventModel::setViewLength(int length)
{
    mViewLength = std::move(length);
    partitionData();
}