import QtQuick
import QtQuick.Controls

GridView {
    id: gridView

    // Kinetic scrolling momentum properties
    property real momentumVelocity: 0
    property bool isMomentumActive: false
    property real friction: 0.95
    property real minMomentumVelocity: 50
    property real maxMomentumVelocity: 2500

    flickDeceleration: 1500
    maximumFlickVelocity: 2000
    boundsBehavior: Flickable.StopAtBounds
    boundsMovement: Flickable.FollowBoundsBehavior
    pressDelay: 0
    flickableDirection: Flickable.VerticalFlick

    WheelHandler {
        id: wheelHandler

        // Tunable parameters for responsive scrolling
        property real mouseWheelSpeed: 60
        // Higher = faster mouse wheel
        property real touchpadSpeed: 1.8
        // Touchpad sensitivity
        property real momentumRetention: 0.92
        property real lastWheelTime: 0
        property real momentum: 0
        property var velocitySamples: []

        function startMomentum() {
            isMomentumActive = true;
            momentumTimer.start();
        }

        acceptedDevices: PointerDevice.Mouse | PointerDevice.TouchPad
        onWheel: (event) => {
            let currentTime = Date.now();
            let timeDelta = currentTime - lastWheelTime;
            lastWheelTime = currentTime;
            
            // Detect mouse wheel vs touchpad
            const deltaY = event.angleDelta.y;
            const isMouseWheel = Math.abs(deltaY) >= 120 && (Math.abs(deltaY) % 120) === 0;
            
            if (isMouseWheel) {
                // Fixed scrolling for mouse wheel - 2 cells per click
                momentumTimer.stop();
                isMomentumActive = false;
                velocitySamples = [];
                momentum = 0;
                
                const lines = Math.floor(Math.abs(deltaY) / 120);
                const scrollAmount = (deltaY > 0 ? -lines : lines) * cellHeight * 0.15; // 0.15 cells per wheel click
                let newY = contentY + scrollAmount;
                newY = Math.max(0, Math.min(contentHeight - height, newY));
                
                if (flicking)
                    cancelFlick();
                
                contentY = newY;
            } else {
                // Touchpad - existing smooth kinetic scrolling
                // Stop any existing momentum
                momentumTimer.stop();
                isMomentumActive = false;
                
                // Calculate scroll delta based on input type
                let delta = 0;
                if (event.pixelDelta.y !== 0)
                    // Touchpad with pixel precision
                    delta = event.pixelDelta.y * touchpadSpeed;
                else
                    // Fallback for touchpad without pixel delta
                    delta = event.angleDelta.y / 120 * cellHeight * 1.2;
                    
                // Track velocity for momentum
                velocitySamples.push({
                    "delta": delta,
                    "time": currentTime
                });
                velocitySamples = velocitySamples.filter((s) => {
                    return currentTime - s.time < 100;
                });
                
                // Calculate momentum velocity from samples
                if (velocitySamples.length > 1) {
                    let totalDelta = velocitySamples.reduce((sum, s) => {
                        return sum + s.delta;
                    }, 0);
                    let timeSpan = currentTime - velocitySamples[0].time;
                    if (timeSpan > 0)
                        momentumVelocity = Math.max(-maxMomentumVelocity, Math.min(maxMomentumVelocity, totalDelta / timeSpan * 1000));
                }
                
                // Apply momentum for touchpad (smooth continuous scrolling)
                if (event.pixelDelta.y !== 0 && timeDelta < 50) {
                    momentum = momentum * momentumRetention + delta * 0.15;
                    delta += momentum;
                } else {
                    momentum = 0;
                }
                
                // Apply scrolling with proper bounds checking
                let newY = contentY - delta;
                newY = Math.max(0, Math.min(contentHeight - height, newY));
                
                // Cancel any conflicting flicks and apply new position
                if (flicking)
                    cancelFlick();

                contentY = newY;
            }
            
            event.accepted = true;
        }
        onActiveChanged: {
            if (!active && Math.abs(momentumVelocity) >= minMomentumVelocity) {
                startMomentum();
            } else if (!active) {
                velocitySamples = [];
                momentumVelocity = 0;
            }
        }
    }

    // Physics-based momentum timer for kinetic scrolling
    Timer {
        id: momentumTimer

        interval: 16 // ~60 FPS
        repeat: true
        onTriggered: {
            // Apply velocity to position
            let newY = contentY - momentumVelocity * 0.016;
            let maxY = Math.max(0, contentHeight - height);
            
            // Stop momentum at boundaries instead of bouncing
            if (newY < 0) {
                contentY = 0;
                stop();
                isMomentumActive = false;
                momentumVelocity = 0;
                return;
            } else if (newY > maxY) {
                contentY = maxY;
                stop();
                isMomentumActive = false;
                momentumVelocity = 0;
                return;
            }
            
            contentY = newY;
            
            // Apply friction
            momentumVelocity *= friction;
            
            // Stop if velocity too low
            if (Math.abs(momentumVelocity) < 5) {
                stop();
                isMomentumActive = false;
                momentumVelocity = 0;
            }
        }
    }

    // Smooth return to bounds animation
    NumberAnimation {
        id: returnToBoundsAnimation

        target: gridView
        property: "contentY"
        duration: 300
        easing.type: Easing.OutQuad
    }
}