// Copyright (c) 2021 Ultimaker B.V.
// Cura is released under the terms of the LGPLv3 or higher.

import QtQuick 2.2
import QtQuick.Layouts 1.1

import UM 1.0 as UM
import Cura 1.0 as Cura

Item
{
    id: sliderRoot

    // handle properties
    property real handleSize: UM.Theme.getSize("slider_handle").width
    property real handleRadius: handleSize / 2
    property color handleColor: UM.Theme.getColor("slider_handle")
    property color handleActiveColor: UM.Theme.getColor("slider_handle_active")
    property color rangeColor: UM.Theme.getColor("slider_groove_fill")
    property real handleLabelWidth: width

    // track properties
    property real trackThickness: UM.Theme.getSize("slider_groove").width
    property real trackRadius: UM.Theme.getSize("slider_groove_radius").width
    property color trackColor: UM.Theme.getColor("slider_groove")

    // value properties
    property real maximumValue: 100
    property real minimumValue: 0
    property bool roundValues: true
    property real handleValue: maximumValue

    property bool pathsVisible: true
    property bool manuallyChanged: true     // Indicates whether the value was changed manually or during simulation

    function getHandleValueFromSliderHandle()
    {
        return handle.getValue()
    }

    function setHandleValue(value)
    {
        handle.setValue(value)
        updateRangeHandle()
    }

    function updateRangeHandle()
    {
        rangeHandle.width = handle.x - sliderRoot.handleSize
    }

    function normalizeValue(value)
    {
        return Math.min(Math.max(value, sliderRoot.minimumValue), sliderRoot.maximumValue)
    }

    onWidthChanged : {
        // After a width change, the pixel-position of the handle is out of sync with the property value
        setHandleValue(handleValue)
    }

    // slider track
    Rectangle
    {
        id: track

        width: sliderRoot.width - sliderRoot.handleSize
        height: sliderRoot.trackThickness
        radius: sliderRoot.trackRadius
        anchors.centerIn: sliderRoot
        color: sliderRoot.trackColor
        visible: sliderRoot.pathsVisible
    }

    // Progress indicator
    Item
    {
        id: rangeHandle

        x: handle.width
        height: sliderRoot.handleSize
        width: handle.x - sliderRoot.handleSize
        anchors.verticalCenter: sliderRoot.verticalCenter
        visible: sliderRoot.pathsVisible

        Rectangle
        {
            height: sliderRoot.trackThickness
            width: parent.width + sliderRoot.handleSize
            anchors.centerIn: parent
            radius: sliderRoot.trackRadius
            color: sliderRoot.rangeColor
        }
    }

    // Handle
    Rectangle
    {
        id: handle

        x: sliderRoot.handleSize
        width: sliderRoot.handleSize
        height: sliderRoot.handleSize
        anchors.verticalCenter: sliderRoot.verticalCenter
        radius: sliderRoot.handleRadius
        color: handleLabel.activeFocus ? sliderRoot.handleActiveColor : sliderRoot.handleColor
        visible: sliderRoot.pathsVisible

        function onHandleDragged()
        {
            sliderRoot.manuallyChanged = true

            // update the range handle
            sliderRoot.updateRangeHandle()

            // set the new value after moving the handle position
            UM.SimulationView.setCurrentPath(getValue())
        }

        // get the value based on the slider position
        function getValue()
        {
            var result = x / (sliderRoot.width - sliderRoot.handleSize)
            result = result * sliderRoot.maximumValue
            result = sliderRoot.roundValues ? Math.round(result) : result
            return result
        }

        function setValueManually(value)
        {
            sliderRoot.manuallyChanged = true
            handle.setValue(value)
        }

        // set the slider position based on the value
        function setValue(value)
        {
            // Normalize values between range, since using arrow keys will create out-of-the-range values
            value = sliderRoot.normalizeValue(value)

            UM.SimulationView.setCurrentPath(value)

            var diff = value / sliderRoot.maximumValue
            var newXPosition = Math.round(diff * (sliderRoot.width - sliderRoot.handleSize))
            x = newXPosition

            // update the range handle
            sliderRoot.updateRangeHandle()
        }

        Keys.onRightPressed: handleLabel.setValue(handleLabel.value + ((event.modifiers & Qt.ShiftModifier) ? 10 : 1))
        Keys.onLeftPressed: handleLabel.setValue(handleLabel.value - ((event.modifiers & Qt.ShiftModifier) ? 10 : 1))

        // dragging
        MouseArea
        {
            anchors.fill: parent

            drag
            {
                target: parent
                axis: Drag.XAxis
                minimumX: 0
                maximumX: sliderRoot.width - sliderRoot.handleSize
            }
            onPressed: handleLabel.forceActiveFocus()
            onPositionChanged: parent.onHandleDragged()
        }

        SimulationSliderLabel
        {
            id: handleLabel

            height: sliderRoot.handleSize + UM.Theme.getSize("default_margin").height
            y: parent.y + sliderRoot.handleSize + UM.Theme.getSize("default_margin").height
            anchors.horizontalCenter: parent.horizontalCenter
            target: Qt.point(x + width / 2, sliderRoot.height)
            visible: false
            startFrom: 0

            // custom properties
            maximumValue: sliderRoot.maximumValue
            value: sliderRoot.handleValue
            busy: UM.SimulationView.busy
            setValue: handle.setValueManually // connect callback functions
        }
    }
}