// Copyright (c) 2018 Ultimaker B.V.
// Cura is released under the terms of the LGPLv3 or higher.

import QtQuick 2.7
import QtQuick.Controls 2.3

import UM 1.5 as UM
import Cura 1.0 as Cura

// The expandable component has 2 major sub components:
//      * The headerItem; Always visible and should hold some info about what happens if the component is expanded
//      * The contentItem; The content that needs to be shown if the component is expanded.
Item
{
    id: base

    // Enumeration with the different possible alignments of the content with respect of the headerItem
    enum ContentAlignment
    {
        AlignLeft,
        AlignRight
    }

    // The headerItem holds the QML item that is always displayed.
    property alias headerItem: headerItemLoader.sourceComponent

    // The contentItem holds the QML item that is shown when the "open" button is pressed
    property alias contentItem: content.contentItem

    property color contentBackgroundColor: UM.Theme.getColor("action_button")

    property color headerBackgroundColor: UM.Theme.getColor("action_button")
    property color headerActiveColor: UM.Theme.getColor("expandable_active")
    property color headerHoverColor: UM.Theme.getColor("expandable_hover")

    property alias enabled: mouseArea.enabled

    // Text to show when this component is disabled
    property alias disabledText: disabledLabel.text

    // Defines the alignment of the content with respect of the headerItem, by default to the right
    // Note that this only has an effect if the panel is draggable
    property int contentAlignment: ExpandableComponent.ContentAlignment.AlignRight

    // How much spacing is needed around the contentItem
    property alias contentPadding: content.padding

    // Adds a title to the content item
    property alias contentHeaderTitle: contentHeader.headerTitle

    // How much spacing is needed for the contentItem by Y coordinate
    property var contentSpacingY: UM.Theme.getSize("narrow_margin").width

    // How much padding is needed around the header & button
    property alias headerPadding: background.padding

    property alias headerBackgroundBorder: background.border

    // Whether or not to show the background border
    property bool enableHeaderBackgroundBorder: true

    // What icon should be displayed on the right.
    property alias iconSource: collapseButton.source

    property alias iconColor: collapseButton.color

    // The icon size (it's always drawn as a square)
    property alias iconSize: collapseButton.height

    // Is the "drawer" open?
    property alias expanded: contentContainer.visible

    // What should the radius of the header be. This is also influenced by the headerCornerSide
    property alias headerRadius: background.radius

    // On what side should the header corners be shown? 1 is down, 2 is left, 3 is up and 4 is right.
    property alias headerCornerSide: background.cornerSide

    // Distance between the header and the content.
    property int popupOffset: 2 * UM.Theme.getSize("default_lining").height

    // Prefix used for the dragged position preferences. Preferences not used if empty. Don't translate!
    property string dragPreferencesNamePrefix: ""

    function toggleContent()
    {
        contentContainer.visible = !expanded
    }

    function updateDragPosition()
    {
        contentContainer.trySetPosition(contentContainer.x, contentContainer.y);
    }

    onEnabledChanged:
    {
        if (!base.enabled && expanded)
        {
            toggleContent();
            updateDragPosition();
        }
    }

    // Add this binding since the background color is not updated otherwise
    Binding
    {
        target: background
        property: "color"
        value:
        {
            return base.enabled ? (expanded ? headerActiveColor : headerBackgroundColor) : UM.Theme.getColor("disabled")
        }
    }

    implicitHeight: 100 * screenScaleFactor
    implicitWidth: 400 * screenScaleFactor

    RoundedRectangle
    {
        id: background
        property real padding: UM.Theme.getSize("default_margin").width

        border.width: base.enableHeaderBackgroundBorder ? UM.Theme.getSize("default_lining").width : 0
        border.color: UM.Theme.getColor("lining")

        color: base.enabled ? (base.expanded ? headerActiveColor : headerBackgroundColor) : UM.Theme.getColor("disabled")
        anchors.fill: parent

        UM.Label
        {
            id: disabledLabel
            visible: !base.enabled
            anchors.fill: parent
            leftPadding: background.padding
            rightPadding: background.padding
            text: ""
            wrapMode: Text.WordWrap
        }

        Item
        {
            anchors.fill: parent
            visible: base.enabled

            Loader
            {
                id: headerItemLoader
                anchors
                {
                    left: parent.left
                    right: collapseButton.visible ? collapseButton.left : parent.right
                    top: parent.top
                    bottom: parent.bottom
                    margins: background.padding
                }
            }

            UM.RecolorImage
            {
                id: collapseButton
                anchors
                {
                    right: parent.right
                    verticalCenter: parent.verticalCenter
                    margins: background.padding
                }
                source: UM.Theme.getIcon("ChevronSingleDown")
                visible: source != ""
                width: UM.Theme.getSize("standard_arrow").width
                height: UM.Theme.getSize("standard_arrow").height
                color: UM.Theme.getColor("small_button_text")
            }
        }

        MouseArea
        {
            id: mouseArea
            anchors.fill: parent
            onClicked: toggleContent()
            hoverEnabled: true
            onEntered: background.color = headerHoverColor
            onExited: background.color = base.enabled ? (base.expanded ? headerActiveColor : headerBackgroundColor) : UM.Theme.getColor("disabled")
        }
    }

    Cura.RoundedRectangle
    {
        id: contentContainer
        property string dragPreferencesNameX: "_xpos"
        property string dragPreferencesNameY: "_ypos"

        visible: false
        width: childrenRect.width
        height: childrenRect.height

        // Ensure that the content is located directly below the headerItem
        y: dragPreferencesNamePrefix === "" ? (background.height + base.popupOffset + base.contentSpacingY) : UM.Preferences.getValue(dragPreferencesNamePrefix + dragPreferencesNameY)

        // Make the content aligned with the rest, using the property contentAlignment to decide whether is right or left.
        // In case of right alignment, the 3x padding is due to left, right and padding between the button & text.
        x: dragPreferencesNamePrefix === "" ? (contentAlignment == ExpandableComponent.ContentAlignment.AlignRight ? -width + collapseButton.width + headerItemLoader.width + 3 * background.padding : 0) : UM.Preferences.getValue(dragPreferencesNamePrefix + dragPreferencesNameX)

        cornerSide: Cura.RoundedRectangle.Direction.All
        color: contentBackgroundColor
        border.width: UM.Theme.getSize("default_lining").width
        border.color: UM.Theme.getColor("lining")
        radius: UM.Theme.getSize("default_radius").width

        function trySetPosition(posNewX, posNewY)
        {
            var margin = UM.Theme.getSize("narrow_margin");
            var minPt = base.mapFromItem(null, margin.width, margin.height);
            var maxPt = base.mapFromItem(null,
                CuraApplication.appWidth() - (contentContainer.width + margin.width),
                CuraApplication.appHeight() - (contentContainer.height + margin.height));
            var initialY = background.height + base.popupOffset + margin.height;

            contentContainer.x = Math.max(minPt.x, Math.min(maxPt.x, posNewX));
            contentContainer.y = Math.max(initialY, Math.min(maxPt.y, posNewY));

            if (dragPreferencesNamePrefix !== "")
            {
                UM.Preferences.setValue(dragPreferencesNamePrefix + dragPreferencesNameX, contentContainer.x);
                UM.Preferences.setValue(dragPreferencesNamePrefix + dragPreferencesNameY, contentContainer.y);
            }
        }

        ExpandableComponentHeader
        {
            id: contentHeader
            headerTitle: ""
            anchors
            {
                top: parent.top
                right: parent.right
                left: parent.left
            }

            MouseArea
            {
                id: dragRegion
                cursorShape: Qt.SizeAllCursor
                anchors
                {
                    top: parent.top
                    bottom: parent.bottom
                    left: parent.left
                    right: contentHeader.xPosCloseButton
                }
                property var clickPos: Qt.point(0, 0)
                property bool dragging: false
                onPressed:
                {
                    clickPos = Qt.point(mouse.x, mouse.y);
                    dragging = true
                }

                onPositionChanged:
                {
                    if(dragging)
                    {
                        var delta = Qt.point(mouse.x - clickPos.x, mouse.y - clickPos.y);
                        if (delta.x !== 0 || delta.y !== 0)
                        {
                            contentContainer.trySetPosition(contentContainer.x + delta.x, contentContainer.y + delta.y);
                        }
                    }
                }
                onReleased:
                {
                     dragging = false
                }

                onDoubleClicked:
                {
                    dragging = false
                    contentContainer.trySetPosition(0, 0);
                }

                Connections
                {
                    target: UM.Preferences
                    function onPreferenceChanged(preference)
                    {
                        if
                        (
                            preference !== "general/window_height" &&
                            preference !== "general/window_width" &&
                            preference !== "general/window_state"
                        )
                        {
                            return;
                        }
                        contentContainer.trySetPosition(contentContainer.x, contentContainer.y);
                    }
                }
            }
        }

        Control
        {
            id: content

            anchors.top: contentHeader.bottom
            padding: UM.Theme.getSize("default_margin").width

            contentItem: Item {}

            onContentItemChanged:
            {
                // Since we want the size of the content to be set by the size of the content,
                // we need to do it like this.
                content.width = contentItem.width + 2 * content.padding
                content.height = contentItem.height + 2 * content.padding
            }
        }
    }

    // DO NOT MOVE UP IN THE CODE: This connection has to be here, after the definition of the content item.
    // Apparently the order in which these are handled matters and so the height is correctly updated if this is here.
    Connections
    {
        // Since it could be that the content is dynamically populated, we should also take these changes into account.
        target: content.contentItem
        function onWidthChanged() { content.width = content.contentItem.width + 2 * content.padding }
        function onHeightChanged()
        {
            content.height = content.contentItem.height + 2 * content.padding
            contentContainer.height = contentHeader.height + content.height
        }
    }
}