/*
    SPDX-FileCopyrightText: 2016 Volker Krause <vkrause@kde.org>

    SPDX-License-Identifier: MIT
*/

#include "timeaggregationmodel.h"
#include <core/sample.h>
#include <model/datamodel.h>

#include <QDebug>

#include <algorithm>
#include <numeric>

using namespace KUserFeedback::Console;

TimeAggregationModel::TimeAggregationModel(QObject *parent) :
    QAbstractTableModel(parent)
{
}

TimeAggregationModel::~TimeAggregationModel() = default;

void TimeAggregationModel::setSourceModel(QAbstractItemModel* model)
{
    Q_ASSERT(model);
    m_sourceModel = model;
    connect(model, &QAbstractItemModel::modelReset, this, [this]() { reload(); });
    reload();
}

TimeAggregationModel::AggregationMode TimeAggregationModel::aggregationMode() const
{
    return m_mode;
}

void TimeAggregationModel::setAggregationMode(AggregationMode mode)
{
    m_mode = mode;
    reload();
}

void TimeAggregationModel::reload()
{
    if (!m_sourceModel)
        return;

    // TODO use the fact that the source model is sorted by time!
    QHash<QDateTime, QVector<Sample>> aggregator;
    for (int i = 0; i < m_sourceModel->rowCount(); ++i) {
        const auto dt = m_sourceModel->index(i, 0).data().toDateTime();
        const auto aggr = aggregate(dt);
        aggregator[aggr].push_back(m_sourceModel->index(i, 0).data(DataModel::SampleRole).value<Sample>());
    }

    beginResetModel();
    m_data.clear();
    m_maxValue = 0;
    for (auto it = aggregator.constBegin(); it != aggregator.constEnd(); ++it) {
        m_data.push_back({ it.key(), it.value() });
        m_maxValue = std::max(m_maxValue, (int)it.value().size());
    }
    std::sort(m_data.begin(), m_data.end(), [](const Data &lhs, const Data &rhs) {
        return lhs.time < rhs.time;
    });
    endResetModel();
}

QDateTime TimeAggregationModel::aggregate(const QDateTime &dt) const
{
    switch (m_mode) {
        case AggregateYear:
            return QDateTime(QDate(dt.date().year(), 1, 1), QTime());
        case AggregateMonth:
            return QDateTime(QDate(dt.date().year(), dt.date().month(), 1), QTime());
        case AggregateWeek:
        {
            auto d = dt.date();
            d = d.addDays(1 - d.dayOfWeek());
            return QDateTime(d, QTime());
        }
        case AggregateDay:
            return QDateTime(dt.date(), QTime());
    }

    Q_UNREACHABLE();
}

QString TimeAggregationModel::timeToString(const QDateTime &dt) const
{
    switch (m_mode) {
        case AggregateYear:
            return QString::number(dt.date().year());
        case AggregateMonth:
            return dt.date().toString(QStringLiteral("yyyy-MM"));
        case AggregateWeek:
        {
            int year = 0;
            int week = dt.date().weekNumber(&year);
            return QString::number(year) + QStringLiteral("-w") + QString::number(week);
        }
        case AggregateDay:
            return dt.date().toString(Qt::ISODate);
    }

    Q_UNREACHABLE();
}

int TimeAggregationModel::columnCount(const QModelIndex& parent) const
{
    Q_UNUSED(parent);
    return 2;
}

int TimeAggregationModel::rowCount(const QModelIndex& parent) const
{
    if (parent.isValid())
        return 0;
    return m_data.size();
}

QVariant TimeAggregationModel::data(const QModelIndex& index, int role) const
{
    if (!index.isValid())
        return {};

    if (role == Qt::DisplayRole || role == DataDisplayRole || role == AccumulatedDisplayRole) {
        const auto d = m_data.at(index.row());
        switch (index.column()) {
            case 0: return d.time.toMSecsSinceEpoch(); // this is required by QtCharts...
            case 1: return d.samples.size();
        }
    } else if (role == DateTimeRole) {
        return m_data.at(index.row()).time;
    } else if (role == TimeDisplayRole) {
        return timeToString(m_data.at(index.row()).time);
    } else if (role == MaximumValueRole) {
        return m_maxValue;
    } else if (role == SamplesRole) {
        return QVariant::fromValue(m_data.at(index.row()).samples);
    } else if (role == AllSamplesRole) {
        return m_sourceModel->index(0, 0).data(DataModel::AllSamplesRole);
    }

    return {};
}

QVariant TimeAggregationModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    if (orientation == Qt::Horizontal && role == Qt::DisplayRole) {
        switch (section) {
            case 0: return tr("Time");
            case 1: return tr("Samples");
        }
    }
    return QAbstractTableModel::headerData(section, orientation, role);
}

#include "moc_timeaggregationmodel.cpp"