#include <QFocusEvent>
#include <QQmlComponent>
#include <QQmlEngine>
#include <QQuickItem>
#include <QQuickRenderControl>
#include <QQuickWindow>
#include <QtTest>

#include "input/OverlayInputBridge.h"

// Feeds synthetic SteamVR overlay events into OverlayInputBridge and checks
// that the QML scene reacts. No graphics are initialized; event delivery
// doesn't need them.
class InputBridgeTest : public QObject {
  Q_OBJECT
 private slots:
  void init() {
    m_renderControl = std::make_unique<QQuickRenderControl>();
    m_window = std::make_unique<QQuickWindow>(m_renderControl.get());
    m_window->setGeometry(0, 0, kSize.width(), kSize.height());

    QQmlComponent component(&m_engine);
    component.setData(R"(
            import QtQuick
            Item {
                width: 400; height: 300
                property int clicks: 0
                MouseArea {
                    objectName: "top"; width: 400; height: 100
                    onClicked: parent.clicks++
                }
                Flickable {
                    objectName: "flick"; y: 100; width: 400; height: 100
                    contentHeight: 1000
                }
                TextInput {
                    objectName: "input"; y: 250; width: 400; height: 50
                }
            })",
                      QUrl());
    m_root.reset(qobject_cast<QQuickItem*>(component.create()));
    QVERIFY2(m_root, qPrintable(component.errorString()));
    m_root->setParentItem(m_window->contentItem());

    QFocusEvent focusIn(QEvent::FocusIn, Qt::ActiveWindowFocusReason);
    QCoreApplication::sendEvent(m_window.get(), &focusIn);

    m_bridge =
        std::make_unique<OverlayInputBridge>(m_window.get(), kSize, kOverlay);
  }

  void cleanup() {
    m_bridge.reset();
    m_root.reset();
    m_window.reset();
    m_renderControl.reset();
  }

  void clickUsesGlCoordinates() {
    // GL y=250 (from bottom) is Qt y=50: inside the top MouseArea.
    click(200, 250);
    QCOMPARE(m_root->property("clicks").toInt(), 1);
    // GL y=50 is Qt y=250: below it, must not count.
    click(200, 50);
    QCOMPARE(m_root->property("clicks").toInt(), 1);
  }

  void smoothScrollMovesFlickable() {
    auto* flick = m_root->findChild<QQuickItem*>("flick");
    mouse(vr::VREvent_MouseMove, 200, kSize.height() - 150);
    for (int i = 0; i < 5; ++i) send(scrollEvent(0.f, -1.f));
    QTRY_VERIFY(flick->property("contentY").toReal() > 0);
  }

  void keyboardCharsReachFocusedTextInput() {
    auto* input = m_root->findChild<QQuickItem*>("input");
    input->forceActiveFocus();
    QVERIFY(input->hasActiveFocus());

    send(keyboardEvent("ab", kOverlay));
    send(keyboardEvent("\xc3\xa4", kOverlay));  // UTF-8 'ä'
    send(keyboardEvent("\b", kOverlay));
    // Other overlay: ignored
    QVERIFY(!m_bridge->handleEvent(keyboardEvent("c", kOverlay + 1)));
    QCOMPARE(input->property("text").toString(), QStringLiteral("ab"));
  }

 private:
  static constexpr QSize kSize{400, 300};
  static constexpr vr::VROverlayHandle_t kOverlay = 42;

  void send(const vr::VREvent_t& event) {
    QVERIFY(m_bridge->handleEvent(event));
  }

  void mouse(uint32_t type, float x, float y) {
    vr::VREvent_t event{};
    event.eventType = type;
    event.data.mouse.x = x;
    event.data.mouse.y = y;
    event.data.mouse.button = vr::VRMouseButton_Left;
    send(event);
  }

  void click(float x, float y) {
    mouse(vr::VREvent_MouseMove, x, y);
    mouse(vr::VREvent_MouseButtonDown, x, y);
    mouse(vr::VREvent_MouseButtonUp, x, y);
  }

  static vr::VREvent_t scrollEvent(float dx, float dy) {
    vr::VREvent_t event{};
    event.eventType = vr::VREvent_ScrollSmooth;
    event.data.scroll.xdelta = dx;
    event.data.scroll.ydelta = dy;
    return event;
  }

  static vr::VREvent_t keyboardEvent(const char* utf8,
                                     vr::VROverlayHandle_t overlay) {
    vr::VREvent_t event{};
    event.eventType = vr::VREvent_KeyboardCharInput;
    qstrncpy(event.data.keyboard.cNewInput, utf8,
             sizeof(event.data.keyboard.cNewInput));
    event.data.keyboard.overlayHandle = overlay;
    return event;
  }

  QQmlEngine m_engine;
  std::unique_ptr<QQuickRenderControl> m_renderControl;
  std::unique_ptr<QQuickWindow> m_window;
  std::unique_ptr<QQuickItem> m_root;
  std::unique_ptr<OverlayInputBridge> m_bridge;
};

QTEST_MAIN(InputBridgeTest)
#include "tst_inputbridge.moc"