/*
    SPDX-FileCopyrightText: Milian Wolff <milian.wolff@kdab.com>
    SPDX-FileCopyrightText: 2016 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#include "timelinewidget.h"

#include "filterandzoomstack.h"
#include "models/eventmodel.h"
#include "resultsutil.h"
#include "timelinedelegate.h"

#include "data.h"
#include "parsers/perf/perfparser.h"

#include <QLabel>
#include <QPointer>
#include <QProgressBar>
#include <QSortFilterProxyModel>
#include <QVBoxLayout>

#include <KLocalizedString>
#include <ThreadWeaver/ThreadWeaver>

#include <timeaxisheaderview.h>

#include <ui_timelinewidget.h>

namespace {
template<typename Context, typename Job, typename SetData>
void scheduleJob(Context* context, std::atomic<uint>* currentJobId, Job&& job, SetData&& setData)
{
    using namespace ThreadWeaver;
    const auto jobId = ++(*currentJobId);
    const auto smartContext = QPointer<Context>(context);
    auto jobCancelled = [=]() { return !smartContext || jobId != (*currentJobId); };
    stream() << make_job([=]() {
        auto results = job(jobCancelled);

        QMetaObject::invokeMethod(
            smartContext.data(),
            [results, jobCancelled, setData]() {
                if (!jobCancelled()) {
                    setData(results);
                }
            },
            Qt::QueuedConnection);
    });
}
}

TimeLineWidget::TimeLineWidget(PerfParser* parser, QMenu* filterMenu, FilterAndZoomStack* filterAndZoomStack,
                               QWidget* parent)
    : QWidget(parent)
    , ui(new Ui::TimeLineWidget)
    , m_parser(parser)
    , m_filterAndZoomStack(filterAndZoomStack)
{
    ui->setupUi(this);

    auto* eventModel = new EventModel(this);
    auto* timeLineProxy = new QSortFilterProxyModel(this);
    timeLineProxy->setRecursiveFilteringEnabled(true);
    timeLineProxy->setSourceModel(eventModel);
    timeLineProxy->setSortRole(EventModel::SortRole);
    timeLineProxy->setFilterKeyColumn(EventModel::ThreadColumn);
    timeLineProxy->setFilterRole(Qt::DisplayRole);
    ResultsUtil::connectFilter(ui->timeLineSearch, timeLineProxy, ui->regexCheckBox);
    ui->timeLineView->setModel(timeLineProxy);
    ui->timeLineView->setSortingEnabled(true);
    // ensure the vertical scroll bar is always shown, otherwise the timeline
    // view would get more or less space, which leads to odd jumping when filtering
    // due to the increased width leading to a zoom effect
    ui->timeLineView->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);

    m_timeLineDelegate = new TimeLineDelegate(m_filterAndZoomStack, ui->timeLineView, ui->timeLineView);
    ui->timeLineEventFilterButton->setMenu(filterMenu);
    ui->timeLineView->setItemDelegateForColumn(EventModel::EventsColumn, m_timeLineDelegate);

    m_timeAxisHeaderView = new TimeAxisHeaderView(m_filterAndZoomStack, ui->timeLineView);
    ui->timeLineView->setHeader(m_timeAxisHeaderView);

    connect(timeLineProxy, &QAbstractItemModel::rowsInserted, this, [this]() { ui->timeLineView->expandToDepth(1); });
    connect(timeLineProxy, &QAbstractItemModel::modelReset, this, [this]() { ui->timeLineView->expandToDepth(1); });

    connect(m_parser, &PerfParser::bottomUpDataAvailable, this, [this](const Data::BottomUpResults& data) {
        ResultsUtil::fillEventSourceComboBox(ui->timeLineEventSource, data.costs, tr("Show timeline for %1 events."));
    });

    connect(m_parser, &PerfParser::eventsAvailable, this, [this, eventModel](const Data::EventResults& data) {
        eventModel->setData(data);
        ui->timeLineView->sortByColumn(EventModel::ThreadColumn, Qt::AscendingOrder);
        m_timeAxisHeaderView->setTimeRange(eventModel->timeRange());
        if (data.offCpuTimeCostId != -1) {
            // remove the off-CPU time event source, we only want normal sched switches
            for (int i = 0, c = ui->timeLineEventSource->count(); i < c; ++i) {
                if (ui->timeLineEventSource->itemData(i).toInt() == data.offCpuTimeCostId) {
                    ui->timeLineEventSource->removeItem(i);
                    break;
                }
            }
        }
    });

    connect(m_parser, &PerfParser::tracepointDataAvailable, this,
            [this](const Data::TracepointResults& data) { m_timeAxisHeaderView->setTracepoints(data); });

    connect(ui->timeLineEventSource, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this,
            [this](int index) {
                const auto typeId = ui->timeLineEventSource->itemData(index).toInt();
                m_timeLineDelegate->setEventType(typeId);
            });

    connect(m_timeLineDelegate, &TimeLineDelegate::stacksHovered, this, [this](const QSet<qint32>& stackIds) {
        if (stackIds.isEmpty()) {
            ++m_currentHoverStacksJobId;
            emit stacksHovered({});
            return;
        }

        const auto& stacks = m_parser->eventResults().stacks;
        const auto& bottomUpResults = m_parser->bottomUpResults();

        scheduleJob(
            this, &m_currentHoverStacksJobId,
            [stacks, bottomUpResults, stackIds](auto jobCancelled) -> QVector<QVector<Data::Symbol>> {
                QVector<QVector<Data::Symbol>> hovered;
                hovered.reserve(stackIds.size());
                for (auto stackId : stackIds) {
                    if (jobCancelled())
                        return {};
                    const auto& stack = stacks[stackId];
                    QVector<Data::Symbol> symbols;
                    symbols.reserve(stack.size());
                    bottomUpResults.foreachFrame(stack, [&](const Data::Symbol& frame, const Data::Location&) {
                        if (jobCancelled())
                            return false;
                        symbols.append(frame);
                        return true;
                    });
                    hovered.append(std::move(symbols));
                }

                return hovered;
            },
            [this](const QVector<QVector<Data::Symbol>>& hovered) { emit stacksHovered(hovered); });
    });
}

TimeLineWidget::~TimeLineWidget() = default;

void TimeLineWidget::selectSymbol(const Data::Symbol& symbol)
{
    if (!symbol.isValid()) {
        ++m_currentSelectStackJobId;
        m_timeLineDelegate->setSelectedStacks({});
        return;
    }

    const auto& stacks = m_parser->eventResults().stacks;
    const auto& bottomUpResults = m_parser->bottomUpResults();

    scheduleJob(
        m_timeLineDelegate, &m_currentSelectStackJobId,
        [stacks, bottomUpResults, symbol](auto jobCancelled) -> QSet<qint32> {
            const auto numStacks = stacks.size();
            QSet<qint32> selectedStacks;
            selectedStacks.reserve(numStacks);
            for (int i = 0; i < numStacks; ++i) {
                if (jobCancelled())
                    return {};
                bool symbolFound = false;
                bottomUpResults.foreachFrame(stacks[i], [&](const Data::Symbol& frame, const Data::Location&) {
                    if (jobCancelled())
                        return false;
                    symbolFound = (frame == symbol);
                    // break once we find the symbol we are looking for
                    return !symbolFound;
                });
                if (symbolFound)
                    selectedStacks.insert(i);
            }

            return selectedStacks;
        },
        [this](const QSet<qint32>& selectedStacks) { m_timeLineDelegate->setSelectedStacks(selectedStacks); });
}

void TimeLineWidget::selectStack(const QVector<Data::Symbol>& stack, bool bottomUp)
{
    if (stack.isEmpty()) {
        ++m_currentSelectStackJobId;
        m_timeLineDelegate->setSelectedStacks({});
        return;
    }

    const auto& stacks = m_parser->eventResults().stacks;
    const auto& bottomUpResults = m_parser->bottomUpResults();

    scheduleJob(
        m_timeLineDelegate, &m_currentSelectStackJobId,
        [stacks, bottomUpResults, stack, bottomUp](auto jobCancelled) -> QSet<qint32> {
            const auto numStacks = stacks.size();
            QSet<qint32> selectedStacks;
            selectedStacks.reserve(numStacks);
            QVarLengthArray<Data::Symbol, 64> frames;
            for (int i = 0; i < numStacks; ++i) {
                if (jobCancelled())
                    return {};

                frames.clear();
                bottomUpResults.foreachFrame(stacks[i], [&](const Data::Symbol& frame, const Data::Location&) {
                    if (jobCancelled())
                        return false;
                    frames.append(frame);
                    return true;
                });

                if (jobCancelled())
                    return {};

                if (frames.size() < stack.size())
                    continue;

                const auto matches = [&]() {
                    if (bottomUp) {
                        return std::equal(frames.begin(), std::next(frames.begin(), stack.size()), stack.rbegin(),
                                          stack.rend());
                    } else {
                        return std::equal(frames.rbegin(), std::next(frames.rbegin(), stack.size()), stack.rbegin(),
                                          stack.rend());
                    }
                }();
                if (matches)
                    selectedStacks.insert(i);
            }

            return selectedStacks;
        },
        [this](const QSet<qint32>& selectedStacks) { m_timeLineDelegate->setSelectedStacks(selectedStacks); });
}
