#include "mainwindow.h"
#include "ui_mainwindow.h"
using Xybrid::MainWindow;

#include <QDebug>
#include <QKeyEvent>
#include <QShortcut>
#include <QTabWidget>
#include <QFileDialog>
#include <QInputDialog>
#include <QMessageBox>
#include <QWindow>
#include <QUndoStack>
#include <QTimer>
#include <QOpenGLWidget>
#include <QGLWidget>

#include <QScroller>
#include <QGraphicsTextItem>

#include <QJsonObject>

#include "data/graph.h"

#include "util/strings.h"
#include "util/lambdaeventfilter.h"
#include "fileops.h"

#include "ui/patternlistmodel.h"
#include "ui/patternsequencermodel.h"
#include "ui/patterneditoritemdelegate.h"

#include "ui/patchboard/patchboardscene.h"

#include "editing/projectcommands.h"

#include "config/pluginregistry.h"
#include "audio/audioengine.h"

using Xybrid::Data::Project;
using Xybrid::Data::Pattern;
using Xybrid::Data::Graph;
using Xybrid::Data::Node;
using Xybrid::Data::Port;

using Xybrid::UI::PatternListModel;
using Xybrid::UI::PatternSequencerModel;
using Xybrid::UI::PatternEditorModel;
using Xybrid::UI::PatternEditorItemDelegate;

using Xybrid::UI::PatchboardScene;

using namespace Xybrid::Editing;
using namespace Xybrid::Config;
using namespace Xybrid::Audio;

namespace {
    constexpr const auto projectFilter = u8"Xybrid project (*.xyp)\nAll files (*)";
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow) {
    ui->setupUi(this);

    setAttribute(Qt::WA_DeleteOnClose);

    // remove tab containing system widgets
    ui->tabWidget->removeTab(ui->tabWidget->indexOf(ui->extra_));

    undoStack = new QUndoStack(this);
    //undoStack->setUndoLimit(256);
    connect(undoStack, &QUndoStack::cleanChanged, this, [this](bool) {
        updateTitle();
    });

    auto* undoAction = undoStack->createUndoAction(this, tr("&Undo"));
    undoAction->setShortcuts(QKeySequence::Undo);
    ui->menuEdit->addAction(undoAction);

    auto* redoAction = undoStack->createRedoAction(this, tr("&Redo"));
    redoAction->setShortcuts(QKeySequence::Redo);
    ui->menuEdit->addAction(redoAction);

    auto* t = ui->tabWidget;
    t->setCornerWidget(ui->menuBar);
    t->setCornerWidget(ui->logo, Qt::TopLeftCorner);
    //ui->menuBar->setStyleSheet("QMenuBar { background: transparent; vertical-align: center; } QMenuBar::item { } QMenuBar::item:!pressed { background: transparent; }");

    // prevent right pane of pattern view from being collapsed
    ui->patternViewSplitter->setCollapsible(1, false);
    connect(ui->patternViewSplitter, &QSplitter::splitterMoved, this, [this](int, int) {
        // and when the list is collapsed, make sure header size is updated
        ui->patternEditor->updateHeader();
    });

    { /* Set up pattern list */ } {
        // model
        ui->patternList->setModel(new PatternListModel(ui->patternList, this));

        // events
        // on selection change
        connect(ui->patternList->selectionModel(), &QItemSelectionModel::currentChanged, this, [this](const QModelIndex& index, const QModelIndex& old) {
            if (index == old) return; // no actual change
            size_t idx = static_cast<size_t>(index.row());
            if (idx >= project->patterns.size()) return;
            this->selectPatternForEditing(project->patterns[idx].get());
        });
        // on click
        connect(ui->patternList, &QListView::clicked, this, [this]() { // deselect on sequencer when list clicked
            ui->patternSequencer->setCurrentIndex(ui->patternSequencer->model()->index(0, -1));
        });

        // rightclick menu
        connect(ui->patternList, &QListView::customContextMenuRequested, this, [this](const QPoint& pt) {
            size_t idx = static_cast<size_t>(ui->patternList->indexAt(pt).row());
            std::shared_ptr<Pattern> p = nullptr;
            if (idx < project->patterns.size()) p = project->patterns[idx];

            QMenu* menu = new QMenu(this);
            menu->addAction("New Pattern", this, [this, idx]() {
                (new ProjectPatternAddCommand(project, static_cast<int>(idx)))->commit();
            });
            if (p) {
                menu->addAction("Duplicate Pattern", this, [this, p, idx]() {
                    (new ProjectPatternAddCommand(project, static_cast<int>(idx) + 1, -1, p))->commit();
                });
                menu->addSeparator();
                menu->addAction("Delete Pattern", this, [this, p]() {
                    if (QMessageBox::warning(this, "Are you sure?", QString("Remove pattern %1?").arg(Util::numAndName(p->index, p->name)), QMessageBox::Yes | QMessageBox::No, QMessageBox::No) != QMessageBox::Yes) return;
                    (new ProjectPatternDeleteCommand(project, p))->commit();
                });
            }
            menu->setAttribute(Qt::WA_DeleteOnClose);
            menu->popup(ui->patternList->mapToGlobal(pt));
        });//*/
    }

    { /* Set up sequencer */ } {
        // model
        ui->patternSequencer->setModel(new PatternSequencerModel(ui->patternSequencer, this));
        // some metrics that the designer doesn't seem to like doing
        ui->patternSequencer->horizontalHeader()->setSectionResizeMode(QHeaderView::Fixed);
        ui->patternSequencer->horizontalHeader()->setDefaultSectionSize(24);
        ui->patternSequencer->verticalHeader()->setSectionResizeMode(QHeaderView::Fixed);
        ui->patternSequencer->verticalHeader()->setDefaultSectionSize(24);

        // events
        // on selection change
        connect(ui->patternSequencer->selectionModel(), &QItemSelectionModel::currentChanged, this, [this](const QModelIndex& index, const QModelIndex&) {
            size_t idx = static_cast<size_t>(index.column());
            if (idx >= project->sequence.size()) return;
            this->selectPatternForEditing(project->sequence[idx]);
        });

        // rightclick menu
        connect(ui->patternSequencer, &QTableView::customContextMenuRequested, this, [this](const QPoint& pt) {
            size_t idx = static_cast<size_t>(ui->patternSequencer->indexAt(pt).column());

            QMenu* menu = new QMenu(this);
            menu->addAction("Insert Pattern", this, [this, idx]() {
                if (!editingPattern->validFor(project)) return; // nope
                int si = static_cast<int>(std::min(idx, project->sequence.size()));
                auto* c = new ProjectSequencerDeltaCommand(project);
                c->seq.insert(c->seq.begin() + si, editingPattern.get());
                c->seqSel = si+1;
                c->commit();
            });
            menu->addAction("Insert Separator", this, [this, idx]() {
                int si = static_cast<int>(std::min(idx, project->sequence.size()));
                auto* c = new ProjectSequencerDeltaCommand(project);
                c->seq.insert(c->seq.begin() + si, nullptr);
                c->seqSel = si+1;
                c->commit();
            });
            if (idx < project->sequence.size()) menu->addAction("Remove", this, [this, idx]() {
                auto* c = new ProjectSequencerDeltaCommand(project);
                c->seq.erase(c->seq.begin() + static_cast<ptrdiff_t>(idx));
                c->seqSel = static_cast<int>(idx)-1;
                c->commit();
            });
            menu->addSeparator();
            menu->addAction("Create New Pattern", this, [this, idx]() {
                int si = static_cast<int>(std::min(idx, project->sequence.size()));
                (new ProjectPatternAddCommand(project, -1, si))->commit();
            });
            if (idx < project->sequence.size() && project->sequence[idx]) {
                menu->addAction("Duplicate Pattern", this, [this, idx, p = project->patterns[project->sequence[idx]->index]]() {
                    int si = static_cast<int>(std::min(idx + 1, project->sequence.size()));
                    (new ProjectPatternAddCommand(project, static_cast<int>(p->index) + 1, si, p))->commit();
                });
            }

            menu->setAttribute(Qt::WA_DeleteOnClose);
            menu->popup(ui->patternSequencer->mapToGlobal(pt));
        });//*/
    }

    { /* Set up keyboard shortcuts for pattern view */ } {
        // Ctrl+PgUp/Down - previous or next pattern in sequencer
        connect(new QShortcut(QKeySequence("Ctrl+PgUp"), ui->pattern), &QShortcut::activated, this, [this]() {
            auto i = ui->patternSequencer->currentIndex();
            if (!i.isValid()) {
                ui->patternSequencer->setCurrentIndex(ui->patternSequencer->model()->index(ui->patternSequencer->horizontalHeader()->count() - 1, 0));
                return;
            }
            auto count = ui->patternSequencer->horizontalHeader()->count();
            ui->patternSequencer->setCurrentIndex(i.siblingAtColumn((count + i.column() - 1) % count));
        });
        connect(new QShortcut(QKeySequence("Ctrl+PgDown"), ui->pattern), &QShortcut::activated, this, [this]() {
            auto i = ui->patternSequencer->currentIndex();
            if (!i.isValid()) {
                ui->patternSequencer->setCurrentIndex(ui->patternSequencer->model()->index(0, 0));
                return;
            }
            auto count = ui->patternSequencer->horizontalHeader()->count();
            ui->patternSequencer->setCurrentIndex(i.siblingAtColumn((count + i.column() + 1) % count));
        });

        // TEMP - play/stop
        connect(new QShortcut(QKeySequence("Ctrl+P"), this), &QShortcut::activated, this, [this]() {
            if (audioEngine->playbackMode() == AudioEngine::Playing) audioEngine->stop();
            else audioEngine->play(project);
        });

        /* tmp test
        connect(new QShortcut(QKeySequence("Ctrl+F1"), ui->patchboard), &QShortcut::activated, this, [this]() {
          auto inp = QInputDialog::getText(this, "yes", "yes");
          WId id = inp.toULongLong();
          auto* w = QWindow::fromWinId(id);
          auto* w2 = new QWindow();
          auto* wc = QWidget::createWindowContainer(w2);
          w->setParent(w2);
          ui->patchboard->layout()->addWidget(wc);
        });
        */
    }

    { /* Set up patchboard view */ } {
        //ui->patchboardView->setDragMode(QGraphicsView::DragMode::RubberBandDrag);
        auto* view = ui->patchboardView;

        bool enableHWAccel = false; // disabled because QOpenGLWidget has some huge lag issues in this context
        if (enableHWAccel) {
            auto* vp = new QOpenGLWidget();
            view->setViewport(vp); // enable hardware acceleration
        }
        view->setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform | QPainter::HighQualityAntialiasing);
        glEnable(GL_MULTISAMPLE);
        glEnable(GL_LINE_SMOOTH);
        //QGL::FormatOption::Rgba


        view->setAlignment(Qt::AlignTop | Qt::AlignLeft);
        view->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
        view->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
        view->setAttribute(Qt::WA_AcceptTouchEvents, true);
        QScroller::grabGesture(view, QScroller::MiddleMouseButtonGesture);
        {
            auto prop = QScroller::scroller(view)->scrollerProperties();
            prop.setScrollMetric(QScrollerProperties::HorizontalOvershootPolicy, QScrollerProperties::OvershootAlwaysOff);
            prop.setScrollMetric(QScrollerProperties::VerticalOvershootPolicy, QScrollerProperties::OvershootAlwaysOff);
            prop.setScrollMetric(QScrollerProperties::AxisLockThreshold, 1);
            QScroller::scroller(view)->setScrollerProperties(prop);
            QScroller::scroller(view)->setSnapPositionsX({});
            QScroller::scroller(view)->setSnapPositionsY({});
        }

        // event filter to make drag-to-select only happen on left click
        view->viewport()->installEventFilter(new LambdaEventFilter(view, [view](QObject* w, QEvent* e) {
            if (e->type() == QEvent::MouseButtonPress) {
                auto* me = static_cast<QMouseEvent*>(e);
                // initiate drag
                if (me->button() == Qt::LeftButton) {
                    view->setDragMode(QGraphicsView::RubberBandDrag);
                }
            } else if (e->type() == QEvent::MouseButtonRelease) { // disable drag after end
                QTimer::singleShot(1, [view] {
                    view->setDragMode(QGraphicsView::NoDrag);
                });
            }
            return w->QObject::eventFilter(w, e);
        }));

    }

    // Set up signaling from project to UI
    socket = new UISocket();
    socket->setParent(this);
    socket->window = this;
    socket->undoStack = undoStack;
    connect(socket, &UISocket::updatePatternLists, this, &MainWindow::updatePatternLists);
    connect(socket, &UISocket::patternUpdated, this, [this](Pattern* p) {
        if (editingPattern.get() != p) return;
        ui->patternEditor->refresh();
    });
    connect(socket, &UISocket::rowUpdated, this, [this](Pattern* p, int ch, int r) {
        if (editingPattern.get() != p) return;
        const auto cpc = PatternEditorModel::colsPerChannel;
        auto ind = ui->patternEditor->model()->index(r, ch * cpc);
        emit ui->patternEditor->model()->dataChanged(ind, ind.siblingAtColumn((ch+1)*cpc-1));
        static_cast<PatternEditorModel*>(ui->patternEditor->model())->updateColumnDisplay();
    });
    connect(socket, &UISocket::openGraph, this, [this](Graph* g) {
        if (!g) return;
        auto gg = std::static_pointer_cast<Graph>(g->shared_from_this());
        QString name = QString::fromStdString(gg->name);
        if (name.isEmpty()) name = QString::fromStdString(gg->pluginName());
        ui->patchboardBreadcrumbs->push(name, this, [this, gg] {
            openGraph(gg);
        });
    });

    // and from audio engine
    connect(audioEngine, &AudioEngine::playbackModeChanged, this, [this, undoAction, redoAction]() {
        bool locked = project->editingLocked();
        undoAction->setEnabled(!locked);
        redoAction->setEnabled(!locked);
    });

    // and start with a new project
    menuFileNew();
}

MainWindow::~MainWindow() {
    delete ui;
}

bool MainWindow::eventFilter(QObject *obj [[maybe_unused]], QEvent *event) {
    if (event->type() == QEvent::KeyPress) {
        auto ke = static_cast<QKeyEvent*>(event);
        qDebug() << QString("key pressed: %1").arg((ke->key()));
        if (ke->key() == Qt::Key_Tab) {
            qDebug() << QString("tab");
            auto* t = this->ui->tabWidget;
            t->setTabPosition(QTabWidget::TabPosition::South);
            t->setCurrentIndex(t->currentIndex() + 1);
            return true;
        }
    }
    return false;
}

void MainWindow::menuFileNew() {
    auto hold = project; // keep alive until done
    if (audioEngine->playingProject() == project) audioEngine->stop();
    project = std::make_shared<Project>();
    project->sequence.push_back(project->newPattern().get());

    onNewProjectLoaded();
}

void MainWindow::menuFileOpen() {
    auto fileName = QFileDialog::getOpenFileName(this, "Open project...", QString(), projectFilter);
    if (fileName.isEmpty()) return; // canceled
    auto np = FileOps::loadProject(fileName);
    if (!np) {
        QMessageBox::critical(this, "Error", "Error loading project");
        return;
    }
    if (audioEngine->playingProject() == project) audioEngine->stop();
    project = np;
    onNewProjectLoaded();
}

void MainWindow::menuFileSave() {
    if (project->fileName.isEmpty()) menuFileSaveAs();
    else {
        FileOps::saveProject(project);
        undoStack->setClean();
    }
}

void MainWindow::menuFileSaveAs() {
    auto fileName = QFileDialog::getSaveFileName(this, "Save project as...", QString(), projectFilter);
    if (fileName.isEmpty()) return; // canceled
    FileOps::saveProject(project, fileName);
    undoStack->setClean();
    updateTitle();
}

void MainWindow::onNewProjectLoaded() {
    undoStack->clear();

    project->socket = socket;
    updatePatternLists();
    patternSelection(0);
    sequenceSelection(-1);
    for (size_t i = 0; i < project->sequence.size(); i++) { // find first non-spacer in sequence, else fall back to first pattern numerically
        if (project->sequence[i] == nullptr) continue;
        sequenceSelection(static_cast<int>(i));
        break;
    }

    //openGraph(project->rootGraph);
    ui->patchboardBreadcrumbs->clear();
    ui->patchboardBreadcrumbs->push("/", this, [this, gg = project->rootGraph] {
        openGraph(gg);
    });

    updateTitle();
}

int MainWindow::patternSelection(int n) {
    auto i = ui->patternList->currentIndex();
    if (n >= -1) ui->patternList->setCurrentIndex(ui->patternList->model()->index(n, 0));
    return i.isValid() ? i.row() : -1;
}

int MainWindow::sequenceSelection(int n) {
    auto i = ui->patternSequencer->currentIndex();
    if (n >= -1) ui->patternSequencer->setCurrentIndex(ui->patternSequencer->model()->index(0, n));
    return i.isValid() ? i.column() : -1;
}

void MainWindow::playbackPosition(int seq, int row) {
    sequenceSelection(seq);
    auto mi = ui->patternEditor->currentIndex().siblingAtRow(row);
    if (!mi.isValid()) mi = ui->patternEditor->model()->index(row, 0);
    ui->patternEditor->setCurrentIndex(mi);
    ui->patternEditor->selectionModel()->select(QItemSelection(mi.siblingAtColumn(0), mi.siblingAtColumn(ui->patternEditor->horizontalHeader()->count()-1)), QItemSelectionModel::SelectionFlag::ClearAndSelect);
    ui->patternEditor->scrollTo(mi, QAbstractItemView::PositionAtCenter);

}

void MainWindow::updatePatternLists() {
    emit ui->patternList->model()->layoutChanged();
    emit ui->patternSequencer->model()->layoutChanged();
    if (auto i = ui->patternList->currentIndex(); i.isValid() && !ui->patternSequencer->currentIndex().isValid())
        selectPatternForEditing(project->patterns[static_cast<size_t>(i.row())].get()); // make sure pattern editor matches selection
    if (editingPattern && !editingPattern->validFor(project)) // if current pattern invalidated, select new one
        selectPatternForEditing(project->patterns[std::min(editingPattern->index, project->patterns.size() - 1)].get());
}

void MainWindow::updateTitle() {
    QString title = u8"Xybrid - %1%2";
    if (project->fileName.isEmpty()) title = title.arg("(new project)");
    else title = title.arg(QFileInfo(project->fileName).baseName());
    if (undoStack->isClean()) title = title.arg("");
    else title = title.arg("*");
    this->setWindowTitle(title);
}

bool MainWindow::selectPatternForEditing(Pattern* pattern) {
    if (!pattern || pattern == editingPattern.get()) return false; // no u
    if (pattern->project != project.get()) return false; // wrong project
    if (project->patterns.size() <= pattern->index) return false; // invalid id
    auto sp = project->patterns[pattern->index];
    if (sp.get() != pattern) return false; // wrong index
    auto hold = editingPattern; // keep alive until done
    editingPattern = sp;

    ui->patternEditor->setPattern(editingPattern);
    ui->patternList->setCurrentIndex(ui->patternList->model()->index(static_cast<int>(editingPattern->index), 0));

    return true;
}

void MainWindow::openGraph(const std::shared_ptr<Data::Graph>& g) {
    if (!g) return; // invalid
    QPointF scrollPt(g->viewX, g->viewY);
    ui->patchboardView->setScene(new PatchboardScene(ui->patchboardView, g));
    QScroller::scroller(ui->patchboardView)->scrollTo(scrollPt, 0);
    QScroller::scroller(ui->patchboardView)->scrollTo(scrollPt, 1);
}