// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

import QtQuick
import QtQuick.Controls as Controls
import QtQuick.Layouts
import StudioControls as StudioControls
import StudioTheme as StudioTheme

Item {
    id: section

    readonly property bool __isSection: true // used by property search logic

    property string caption: "Title"
    property string captionTooltip: ""
    property color labelColor: StudioTheme.Values.themeTextColor
    property int labelCapitalization: Font.AllUppercase
    property alias sectionHeight: header.height
    property alias sectionBackgroundColor: header.color
    property int sectionFontSize: StudioTheme.Values.myFontSize
    property alias showTopSeparator: topSeparator.visible
    property alias showArrow: arrow.visible
    property alias showLeftBorder: leftBorder.visible
    property alias showCloseButton: closeButton.visible
    property alias closeButtonToolTip: closeButton.tooltip
    property alias closeButtonIcon: closeButton.icon
    property alias showEyeButton: eyeButton.visible
    property alias eyeButtonToolTip: eyeButton.tooltip
    property alias spacing: column.spacing
    property alias draggable: dragButton.visible
    property alias fillBackground: sectionBackground.visible
    property alias highlightBorder: sectionBorder.visible

    property Item content: Controls.Label {
        id: label
        text: section.caption
        color: section.labelColor
        elide: Text.ElideRight
        font.pixelSize: section.sectionFontSize
        font.capitalization: section.labelCapitalization
        anchors.verticalCenter: parent?.verticalCenter
        textFormat: Text.RichText

        MouseArea {
            id: labelMouseArea

            anchors.fill: parent
            acceptedButtons: Qt.NoButton
            hoverEnabled: true
            enabled: section.captionTooltip !== ""
        }

        StudioControls.ToolTip {
            visible: labelMouseArea.containsMouse
            text: section.captionTooltip
        }
    }

    property Item icons

    property int leftPadding: StudioTheme.Values.sectionLeftPadding
    property int rightPadding: 0
    property int topPadding: StudioTheme.Values.sectionHeadSpacerHeight
    property int bottomPadding: StudioTheme.Values.sectionHeadSpacerHeight

    property bool defaultExpanded: true
    property bool expanded: defaultExpanded
    property int level: 0
    property int levelShift: 10
    property bool hideHeader: false
    property bool collapsible: true
    property bool expandOnClick: true // if false, toggleExpand signal will be emitted instead
    property bool addTopPadding: true
    property bool addBottomPadding: true
    property bool dropEnabled: false
    property bool highlight: false
    property bool eyeEnabled: true // eye button enabled (on)
    property bool searchHide: false

    property bool useDefaulContextMenu: true

    property string category: "properties"

    clip: true

    Component.onCompleted: {
        updateExpansion()
    }

    function updateExpansion() {
        // Check if function 'loadExpandedState' exists in current context
        if (typeof loadExpandedState === "function") {
            if (section.expandOnClick)
                section.expanded = loadExpandedState(section.caption, section.defaultExpanded)
            else if (loadExpandedState(section.caption, section.defaultExpanded))
                section.expand()
            else
                section.collapse()
        } else {
            // Fallback to default value
            if (section.expandOnClick)
                section.expanded = section.defaultExpanded
            else if (section.defaultExpanded)
                section.expand()
            else
                section.collapse()
        }
    }

    Connections {
        target: this.modelNodeBackend ?? null
        ignoreUnknownSignals: true

        function onSelectionChanged() {
            updateExpansion()
        }
    }

    Connections {
        id: connection
        target: section
        enabled: section.useDefaulContextMenu
        function onShowContextMenu() { contextMenu.popup() }
    }

    Connections {
        target: Controller
        function onCollapseAll(cat) {
            if (section.collapsible && cat === section.category) {
                if (section.expandOnClick)
                    section.expanded = false
                else
                    section.collapse()
            }
        }
        function onExpandAll(cat) {
            if (cat === section.category) {
                if (section.expandOnClick)
                    section.expanded = true
                else
                    section.expand()
            }
        }
        function onCloseContextMenu() {
            contextMenu.close()
        }
        function onCountChanged(cat, count) {
            if (section.showEyeButton && cat === section.category)
                dragButton.enabled = count > 1
        }
    }

    signal drop(var drag)
    signal dropEnter(var drag)
    signal dropExit()
    signal showContextMenu()
    signal toggleExpand()
    signal expand()
    signal collapse()
    signal closeButtonClicked()
    signal eyeButtonClicked()
    signal startDrag(var section)
    signal stopDrag()

    DropArea {
        id: dropArea

        enabled: section.dropEnabled
        anchors.fill: parent

        onEntered: (drag) => section.dropEnter(drag)
        onDropped: (drag) => section.drop(drag)
        onExited: section.dropExit()
    }

    StudioControls.Menu {
        id: contextMenu

        StudioControls.MenuItem {
            text: qsTr("Expand All")
            onTriggered: Controller.expandAll(section.category)
        }

        StudioControls.MenuItem {
            text: qsTr("Collapse All")
            onTriggered: Controller.collapseAll(section.category)
        }

        onOpenedChanged: Controller.contextMenuOpened = contextMenu.opened
    }

    Rectangle {
        id: header
        height: section.hideHeader ? 0 : StudioTheme.Values.sectionHeadHeight
        visible: !section.hideHeader
        anchors.left: parent.left
        anchors.right: parent.right
        color: section.highlight ? StudioTheme.Values.themeInteraction
                                 : Qt.lighter(StudioTheme.Values.themeSectionHeadBackground, 1.0
                                              + (0.2 * section.level))

        MouseArea {
            id: mouseArea
            anchors.fill: parent
            acceptedButtons: Qt.LeftButton | Qt.RightButton
            onClicked: function(mouse) {
                if (mouse.button === Qt.LeftButton) {
                    if (!section.collapsible && section.expanded)
                        return

                    transition.enabled = true
                    if (section.expandOnClick)
                        section.expanded = !section.expanded
                    else
                        section.toggleExpand()

                    // Check if function 'saveExpandedState' exists in current context
                    if (typeof saveExpandedState === "function")
                        saveExpandedState(section.caption, section.expanded)
                } else {
                    section.showContextMenu()
                }
            }
        }

        RowLayout {
            spacing: 1
            anchors.fill: parent

            IconButton {
                id: dragButton
                visible: false
                icon: StudioTheme.Constants.dragmarks
                buttonSize: 21
                iconScale: dragButton.enabled && dragButton.containsMouse ? 1.2 : 1
                transparentBg: true

                Layout.alignment: Qt.AlignVCenter
                Layout.preferredWidth: dragButton.width
                Layout.maximumWidth: dragButton.width

                drag.target: dragButton.enabled ? section : null
                drag.axis: Drag.YAxis

                onPressed: {
                    section.startDrag(section)
                    section.z = ++section.parent.z // put the dragged section on top
                }

                onReleased: {
                    section.stopDrag()
                }
            }

            IconButton {
                id: eyeButton

                visible: false
                icon: section.eyeEnabled ? StudioTheme.Constants.visible_small
                                         : StudioTheme.Constants.invisible_small
                buttonSize: 21
                iconScale: eyeButton.containsMouse ? 1.2 : 1
                transparentBg: true

                Layout.alignment: Qt.AlignVCenter
                Layout.preferredWidth: eyeButton.width
                Layout.maximumWidth: eyeButton.width

                onClicked: {
                    section.eyeEnabled = !section.eyeEnabled
                    section.eyeButtonClicked()
                }
            }

            Item {
                id: iconsContent
                height: header.height
                children: [ section.icons ]
                Layout.preferredWidth: childrenRect.width
            }

            IconButton {
                id: arrow
                icon: StudioTheme.Constants.sectionToggle
                transparentBg: true

                buttonSize: 21
                iconSize: StudioTheme.Values.smallIconFontSize
                iconColor: StudioTheme.Values.themeTextColor

                Layout.alignment: Qt.AlignVCenter
                Layout.preferredWidth: arrow.width
                Layout.maximumWidth: arrow.width

                onClicked: function(mouse) {
                    if (!section.collapsible && section.expanded)
                        return

                    transition.enabled = true
                    if (section.expandOnClick)
                        section.expanded = !section.expanded
                    else
                        section.toggleExpand()

                    // Check if function 'saveExpandedState' exists in current context
                    if (typeof saveExpandedState === "function")
                        saveExpandedState(section.caption, section.expanded)
                }
            }

            Item {
                id: headerContent
                height: header.height
                Layout.fillWidth: true
                children: [ section.content ]
            }

            IconButton {
                id: closeButton

                visible: false
                icon: StudioTheme.Constants.closeCross
                buttonSize: 21
                iconScale: closeButton.containsMouse ? 1.2 : 1
                transparentBg: true

                Layout.alignment: Qt.AlignVCenter
                Layout.preferredWidth: closeButton.width
                Layout.maximumWidth: closeButton.width
                Layout.rightMargin: 10

                onClicked: section.closeButtonClicked()
            }
        }
    }

    Drag.active: dragButton.drag.active
    Drag.source: dragButton

    Rectangle {
        id: topSeparator
        height: 1
        anchors.left: parent.left
        anchors.right: parent.right
        anchors.rightMargin: 5 + section.leftPadding
        anchors.leftMargin: 5 - section.leftPadding
        visible: false
        color: StudioTheme.Values.themeControlOutline
    }

    default property alias __content: column.children

    readonly property alias contentItem: column

    implicitHeight: Math.round(column.height + header.height + topSpacer.height + bottomSpacer.height)

    Rectangle {
        id: sectionBackground
        anchors.top: header.bottom
        width: section.width
        height: topSpacer.height + column.height + bottomSpacer.height
        color: StudioTheme.Values.themePanelBackground
        visible: false
    }

    Rectangle {
        id: sectionBorder
        anchors.fill: parent
        color: "transparent"
        border.color: StudioTheme.Values.themeInteraction
        border.width: 1
        visible: false
    }

    Item {
        id: topSpacer
        height: section.addTopPadding && column.height > 0 ? section.topPadding : 0
        anchors.top: header.bottom
    }

    Column {
        id: column
        anchors.left: parent.left
        anchors.leftMargin: section.leftPadding
        anchors.right: parent.right
        anchors.rightMargin: section.rightPadding
        anchors.top: topSpacer.bottom
    }

    Rectangle {
        id: leftBorder
        visible: false
        width: 1
        height: parent.height - section.bottomPadding
        color: header.color
    }

    Item {
        id: bottomSpacer
        height: section.addBottomPadding && column.height > 0 ? section.bottomPadding : 0
        anchors.top: column.bottom
    }

    states: [
        State {
            name: "Hide"
            when: section.searchHide
            PropertyChanges {
                target: section
                visible: false
            }
        },
        State {
            name: "Collapsed"
            when: !section.expanded
            PropertyChanges {
                target: section
                implicitHeight: header.height
            }
            PropertyChanges {
                target: arrow
                rotation: -90
            }
        }
    ]

    transitions: Transition {
        id: transition
        enabled: false
        NumberAnimation {
            properties: "implicitHeight,rotation"
            duration: 120
            easing.type: Easing.OutCubic
        }

        onRunningChanged: {
            if (!transition.running)
                transition.enabled = false
        }
    }
}
