/****************************************************************************
 *
 *   (c) 2009-2016 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
 *
 * QGroundControl is licensed according to the terms in the file
 * COPYING.md in the root of the source code directory.
 *
 ****************************************************************************/

import QtQuick                          2.11
import QtQuick.Controls                 2.4
import QtLocation                       5.3
import QtPositioning                    5.3
import QtQuick.Dialogs                  1.2
import QtQuick.Layouts                  1.11

import QGroundControl                   1.0
import QGroundControl.ScreenTools       1.0
import QGroundControl.Palette           1.0
import QGroundControl.Controls          1.0
import QGroundControl.FlightMap         1.0
import QGroundControl.ShapeFileHelper   1.0

/// QGCMapPolygon map visuals
Item {
    id: _root

    property var    mapControl                                  ///< Map control to place item in
    property var    mapPolygon                                  ///< QGCMapPolygon object
    property bool   interactive:        mapPolygon.interactive
    property color  interiorColor:      "transparent"
    property real   interiorOpacity:    1
    property int    borderWidth:        0
    property color  borderColor:        "black"

    property bool   _circleMode:                false
    property real   _circleRadius
    property bool   _circleRadiusDrag:          false
    property var    _circleRadiusDragCoord:     QtPositioning.coordinate()
    property bool   _editCircleRadius:          false
    property bool   _traceMode:                 false
    property string _instructionText:           _polygonToolsText
    property var    _savedVertices:             [ ]
    property bool   _savedCircleMode

    property real _zorderDragHandle:    QGroundControl.zOrderMapItems + 3   // Highest to prevent splitting when items overlap
    property real _zorderSplitHandle:   QGroundControl.zOrderMapItems + 2
    property real _zorderCenterHandle:  QGroundControl.zOrderMapItems + 1   // Lowest such that drag or split takes precedence

    readonly property string _polygonToolsText: qsTr("Polygon Tools")
    readonly property string _traceText:        qsTr("Click in the map to add vertices. Click 'Done Tracing' when finished.")

    function addCommonVisuals() {
        if (_objMgrCommonVisuals.empty) {
            _objMgrCommonVisuals.createObject(polygonComponent, mapControl, true)
        }
    }

    function removeCommonVisuals() {
        _objMgrCommonVisuals.destroyObjects()
    }

    function addEditingVisuals() {
        if (_objMgrEditingVisuals.empty) {
            _objMgrEditingVisuals.createObjects([ dragHandlesComponent, splitHandlesComponent, centerDragHandleComponent ], mapControl, false /* addToMap */)
        }
    }

    function removeEditingVisuals() {
        _objMgrEditingVisuals.destroyObjects()
    }


    function addToolbarVisuals() {
        if (_objMgrToolVisuals.empty) {
            _objMgrToolVisuals.createObject(toolbarComponent, mapControl)
        }
    }

    function removeToolVisuals() {
        _objMgrToolVisuals.destroyObjects()
    }

    function addCircleVisuals() {
        if (_objMgrCircleVisuals.empty) {
            _objMgrCircleVisuals.createObject(radiusVisualsComponent, mapControl)
        }
    }

    /// Calculate the default/initial 4 sided polygon
    function defaultPolygonVertices() {
        // Initial polygon is inset to take 2/3rds space
        var rect = Qt.rect(mapControl.centerViewport.x, mapControl.centerViewport.y, mapControl.centerViewport.width, mapControl.centerViewport.height)
        rect.x += (rect.width * 0.25) / 2
        rect.y += (rect.height * 0.25) / 2
        rect.width *= 0.75
        rect.height *= 0.75

        var centerCoord =       mapControl.toCoordinate(Qt.point(rect.x + (rect.width / 2), rect.y + (rect.height / 2)),   false /* clipToViewPort */)
        var topLeftCoord =      mapControl.toCoordinate(Qt.point(rect.x, rect.y),                                          false /* clipToViewPort */)
        var topRightCoord =     mapControl.toCoordinate(Qt.point(rect.x + rect.width, rect.y),                             false /* clipToViewPort */)
        var bottomLeftCoord =   mapControl.toCoordinate(Qt.point(rect.x, rect.y + rect.height),                            false /* clipToViewPort */)
        var bottomRightCoord =  mapControl.toCoordinate(Qt.point(rect.x + rect.width, rect.y + rect.height),               false /* clipToViewPort */)

        // Initial polygon has max width and height of 3000 meters
        var halfWidthMeters =   Math.min(topLeftCoord.distanceTo(topRightCoord), 3000) / 2
        var halfHeightMeters =  Math.min(topLeftCoord.distanceTo(bottomLeftCoord), 3000) / 2
        topLeftCoord =      centerCoord.atDistanceAndAzimuth(halfWidthMeters, -90).atDistanceAndAzimuth(halfHeightMeters, 0)
        topRightCoord =     centerCoord.atDistanceAndAzimuth(halfWidthMeters, 90).atDistanceAndAzimuth(halfHeightMeters, 0)
        bottomLeftCoord =   centerCoord.atDistanceAndAzimuth(halfWidthMeters, -90).atDistanceAndAzimuth(halfHeightMeters, 180)
        bottomRightCoord =  centerCoord.atDistanceAndAzimuth(halfWidthMeters, 90).atDistanceAndAzimuth(halfHeightMeters, 180)

        return [ topLeftCoord, topRightCoord, bottomRightCoord, bottomLeftCoord, centerCoord  ]
    }

    /// Reset polygon back to initial default
    function _resetPolygon() {
        mapPolygon.beginReset()
        mapPolygon.clear()
        var initialVertices = defaultPolygonVertices()
        for (var i=0; i<4; i++) {
            mapPolygon.appendVertex(initialVertices[i])
        }
        mapPolygon.endReset()
        _circleMode = false
    }

    function _createCircularPolygon(center, radius) {
        var unboundCenter = center.atDistanceAndAzimuth(0, 0)
        var segments = 16
        var angleIncrement = 360 / segments
        var angle = 0
        mapPolygon.beginReset()
        mapPolygon.clear()
        _circleRadius = radius
        for (var i=0; i<segments; i++) {
            var vertex = unboundCenter.atDistanceAndAzimuth(radius, angle)
            mapPolygon.appendVertex(vertex)
            angle += angleIncrement
        }
        mapPolygon.endReset()
        _circleMode = true
    }

    /// Reset polygon to a circle which fits within initial polygon
    function _resetCircle() {
        var initialVertices = defaultPolygonVertices()
        var width = initialVertices[0].distanceTo(initialVertices[1])
        var height = initialVertices[1].distanceTo(initialVertices[2])
        var radius = Math.min(width, height) / 2
        var center = initialVertices[4]
        _createCircularPolygon(center, radius)
    }

    function _handleInteractiveChanged() {
        if (interactive) {
            addEditingVisuals()
            addToolbarVisuals()
        } else {
            _traceMode = false
            removeEditingVisuals()
            removeToolVisuals()
        }
    }

    function _saveCurrentVertices() {
        _savedVertices = [ ]
        _savedCircleMode = _circleMode
        for (var i=0; i<mapPolygon.count; i++) {
            _savedVertices.push(mapPolygon.vertexCoordinate(i))
        }
    }

    function _restorePreviousVertices() {
        mapPolygon.beginReset()
        mapPolygon.clear()
        for (var i=0; i<_savedVertices.length; i++) {
            mapPolygon.appendVertex(_savedVertices[i])
        }
        mapPolygon.endReset()
        _circleMode = _savedCircleMode
    }

    onInteractiveChanged: _handleInteractiveChanged()

    on_TraceModeChanged: {
        if (_traceMode) {
            _instructionText = _traceText
            _objMgrTraceVisuals.createObject(traceMouseAreaComponent, mapControl, false)
        } else {
            _instructionText = _polygonToolsText
            _objMgrTraceVisuals.destroyObjects()
        }
    }

    on_CircleModeChanged: {
        if (_circleMode) {
            addCircleVisuals()
        } else {
            _objMgrCircleVisuals.destroyObjects()
        }
    }

    Component.onCompleted: {
        addCommonVisuals()
        _handleInteractiveChanged()
    }

    QGCDynamicObjectManager { id: _objMgrCommonVisuals }
    QGCDynamicObjectManager { id: _objMgrToolVisuals }
    QGCDynamicObjectManager { id: _objMgrEditingVisuals }
    QGCDynamicObjectManager { id: _objMgrTraceVisuals }
    QGCDynamicObjectManager { id: _objMgrCircleVisuals }

    QGCPalette { id: qgcPal }

    KMLOrSHPFileDialog {
        id:             kmlOrSHPLoadDialog
        title:          qsTr("Select Polygon File")
        selectExisting: true

        onAcceptedForLoad: {
            mapPolygon.loadKMLOrSHPFile(file)
            mapFitFunctions.fitMapViewportToMissionItems()
            close()
        }
    }

    QGCMenu {
        id: menu

        property int _editingVertexIndex: -1

        function popupVertex(curIndex) {
            menu._editingVertexIndex = curIndex
            removeVertexItem.visible = (mapPolygon.count > 3 && menu._editingVertexIndex >= 0)
            menu.popup()
        }

        function popupCenter() {
            menu.popup()
        }

        QGCMenuItem {
            id:             removeVertexItem
            visible:        !_circleMode
            text:           qsTr("Remove vertex")
            onTriggered: {
                if (menu._editingVertexIndex >= 0) {
                    mapPolygon.removeVertex(menu._editingVertexIndex)
                }
            }
        }

        QGCMenuSeparator {
            visible:        removeVertexItem.visible
        }

        QGCMenuItem {
            text:           qsTr("Set radius..." )
            visible:        _circleMode
            onTriggered:    _editCircleRadius = true
        }

        QGCMenuItem {
            text:           qsTr("Edit position..." )
            visible:        _circleMode
            onTriggered:    mainWindow.showComponentDialog(editCenterPositionDialog, qsTr("Edit Center Position"), mainWindow.showDialogDefaultWidth, StandardButton.Close)
        }

        QGCMenuItem {
            text:           qsTr("Edit position..." )
            visible:        !_circleMode && menu._editingVertexIndex >= 0
            onTriggered:    mainWindow.showComponentDialog(editVertexPositionDialog, qsTr("Edit Vertex Position"), mainWindow.showDialogDefaultWidth, StandardButton.Close)
        }
    }

    Component {
        id: polygonComponent

        MapPolygon {
            color:          interiorColor
            opacity:        interiorOpacity
            border.color:   borderColor
            border.width:   borderWidth
            path:           mapPolygon.path
        }
    }

    Component {
        id: splitHandleComponent

        MapQuickItem {
            id:             mapQuickItem
            anchorPoint.x:  sourceItem.width / 2
            anchorPoint.y:  sourceItem.height / 2
            visible:        !_circleMode

            property int vertexIndex

            sourceItem: SplitIndicator {
                z: _zorderSplitHandle
            }
        }
    }

    Component {
        id: splitHandlesComponent

        Repeater {
            model: mapPolygon.path

            delegate: Item {
                property var _splitHandle
                property var _vertices:     mapPolygon.path

                function _setHandlePosition() {
                    var nextIndex = index + 1
                    if (nextIndex > _vertices.length - 1) {
                        nextIndex = 0
                    }
                    var distance = _vertices[index].distanceTo(_vertices[nextIndex])
                    var azimuth = _vertices[index].azimuthTo(_vertices[nextIndex])
                    _splitHandle.coordinate = _vertices[index].atDistanceAndAzimuth(distance / 2, azimuth)
                }

                Component.onCompleted: {
                    _splitHandle = splitHandleComponent.createObject(mapControl)
                    _splitHandle.vertexIndex = index
                    _setHandlePosition()
                    mapControl.addMapItem(_splitHandle)
                }

                Component.onDestruction: {
                    if (_splitHandle) {
                        _splitHandle.destroy()
                    }
                }
            }
        }
    }

    // Control which is used to drag polygon vertices
    Component {
        id: dragAreaComponent

        MissionItemIndicatorDrag {
            id:         dragArea
            mapControl: _root.mapControl
            z:          _zorderDragHandle
            visible:    !_circleMode
            onDragStop: mapPolygon.verifyClockwiseWinding()

            property int polygonVertex

            property bool _creationComplete: false

            Component.onCompleted: _creationComplete = true

            onItemCoordinateChanged: {
                if (_creationComplete) {
                    // During component creation some bad coordinate values got through which screws up draw
                    mapPolygon.adjustVertex(polygonVertex, itemCoordinate)
                }
            }

            onClicked: menu.popupVertex(polygonVertex)
        }
    }

    Component {
        id: centerDragHandle
        MapQuickItem {
            id:             mapQuickItem
            anchorPoint.x:  dragHandle.width  * 0.5
            anchorPoint.y:  dragHandle.height * 0.5
            z:              _zorderDragHandle
            sourceItem: Rectangle {
                id:             dragHandle
                width:          ScreenTools.defaultFontPixelHeight * 1.5
                height:         width
                radius:         width * 0.5
                color:          Qt.rgba(1,1,1,0.8)
                border.color:   Qt.rgba(0,0,0,0.25)
                border.width:   1
                QGCColoredImage {
                    width:      parent.width
                    height:     width
                    color:      Qt.rgba(0,0,0,1)
                    mipmap:     true
                    fillMode:   Image.PreserveAspectFit
                    source:     "/qmlimages/MapCenter.svg"
                    sourceSize.height:  height
                    anchors.centerIn:   parent
                }
            }
        }
    }

    Component {
        id: dragHandleComponent

        MapQuickItem {
            id:             mapQuickItem
            anchorPoint.x:  dragHandle.width  / 2
            anchorPoint.y:  dragHandle.height / 2
            z:              _zorderDragHandle
            visible:        !_circleMode

            property int polygonVertex

            sourceItem: Rectangle {
                id:             dragHandle
                width:          ScreenTools.defaultFontPixelHeight * 1.5
                height:         width
                radius:         width * 0.5
                color:          Qt.rgba(1,1,1,0.8)
                border.color:   Qt.rgba(0,0,0,0.25)
                border.width:   1
            }
        }
    }

    // Add all polygon vertex drag handles to the map
    Component {
        id: dragHandlesComponent

        Repeater {
            model: mapPolygon.pathModel

            delegate: Item {
                property var _visuals: [ ]

                Component.onCompleted: {
                    var dragHandle = dragHandleComponent.createObject(mapControl)
                    dragHandle.coordinate = Qt.binding(function() { return object.coordinate })
                    dragHandle.polygonVertex = Qt.binding(function() { return index })
                    mapControl.addMapItem(dragHandle)
                    var dragArea = dragAreaComponent.createObject(mapControl, { "itemIndicator": dragHandle, "itemCoordinate": object.coordinate })
                    dragArea.polygonVertex = Qt.binding(function() { return index })
                    _visuals.push(dragHandle)
                    _visuals.push(dragArea)
                }

                Component.onDestruction: {
                    for (var i=0; i<_visuals.length; i++) {
                        _visuals[i].destroy()
                    }
                    _visuals = [ ]
                }
            }
        }
    }

    Component {
        id: editCenterPositionDialog

        EditPositionDialog {
            coordinate: mapPolygon.center
            onCoordinateChanged: {
                // Prevent spamming signals on vertex changes by setting centerDrag = true when changing center position.
                // This also fixes a bug where Qt gets confused by all the signalling and draws a bad visual.
                mapPolygon.centerDrag = true
                mapPolygon.center = coordinate
                mapPolygon.centerDrag = false
            }
        }
    }

    Component {
        id: editVertexPositionDialog

        EditPositionDialog {
            coordinate:             mapPolygon.vertexCoordinate(menu._editingVertexIndex)
            onCoordinateChanged: {
                mapPolygon.adjustVertex(menu._editingVertexIndex, coordinate)
                mapPolygon.verifyClockwiseWinding()
            }
        }
    }

    Component {
        id: centerDragAreaComponent

        MissionItemIndicatorDrag {
            mapControl:                 _root.mapControl
            z:                          _zorderCenterHandle
            onItemCoordinateChanged:    mapPolygon.center = itemCoordinate
            onDragStart:                mapPolygon.centerDrag = true
            onDragStop:                 mapPolygon.centerDrag = false
        }
    }

    Component {
        id: centerDragHandleComponent

        Item {
            property var dragHandle
            property var dragArea

            Component.onCompleted: {
                dragHandle = centerDragHandle.createObject(mapControl)
                dragHandle.coordinate = Qt.binding(function() { return mapPolygon.center })
                mapControl.addMapItem(dragHandle)
                dragArea = centerDragAreaComponent.createObject(mapControl, { "itemIndicator": dragHandle, "itemCoordinate": mapPolygon.center })
            }

            Component.onDestruction: {
                dragHandle.destroy()
                dragArea.destroy()
            }
        }
    }

    Component {
        id: toolbarComponent

        PlanEditToolbar {
            anchors.horizontalCenter:       mapControl.left
            anchors.horizontalCenterOffset: mapControl.centerViewport.left + (mapControl.centerViewport.width / 2)
            y:                              mapControl.centerViewport.top
            z:                              QGroundControl.zOrderMapItems + 2
            availableWidth:                 mapControl.centerViewport.width

            QGCButton {
                _horizontalPadding: 0
                text:               qsTr("Basic")
                visible:            !_traceMode
                onClicked:          _resetPolygon()
            }

            QGCButton {
                _horizontalPadding: 0
                text:               qsTr("Circular")
                visible:            !_traceMode
                onClicked:          _resetCircle()
            }

            QGCButton {
                _horizontalPadding: 0
                text:               _traceMode ? qsTr("Done Tracing") : qsTr("Trace Polygon")
                onClicked: {
                    if (_traceMode) {
                        if (mapPolygon.count < 3) {
                            _restorePreviousVertices()
                        }
                        _traceMode = false
                    } else {
                        _saveCurrentVertices()
                        _circleMode = false
                        _traceMode = true
                        mapPolygon.clear();
                    }
                }
            }

            QGCButton {
                _horizontalPadding: 0
                text:               qsTr("Load KML/SHP...")
                onClicked:          kmlOrSHPLoadDialog.openForLoad()
                visible:            !_traceMode
            }
        }
    }

    // Mouse area to capture clicks for tracing a polygon
    Component {
        id:  traceMouseAreaComponent

        MouseArea {
            anchors.fill:       mapControl
            preventStealing:    true
            z:                  QGroundControl.zOrderMapItems + 1   // Over item indicators

            onClicked: {
                if (mouse.button === Qt.LeftButton) {
                    mapPolygon.appendVertex(mapControl.toCoordinate(Qt.point(mouse.x, mouse.y), false /* clipToViewPort */))
                }
            }
        }
    }

    Component {
        id: radiusDragHandleComponent

        MapQuickItem {
            id:             mapQuickItem
            anchorPoint.x:  dragHandle.width / 2
            anchorPoint.y:  dragHandle.height / 2
            z:              QGroundControl.zOrderMapItems + 2

            sourceItem: Rectangle {
                id:         dragHandle
                width:      ScreenTools.defaultFontPixelHeight * 1.5
                height:     width
                radius:     width / 2
                color:      "white"
                opacity:    .90
            }
        }
    }

    Component {
        id: radiusDragAreaComponent

        MissionItemIndicatorDrag {
            mapControl: _root.mapControl

            property real _lastRadius

            onItemCoordinateChanged: {
                var radius = mapPolygon.center.distanceTo(itemCoordinate)
                // Prevent signalling re-entrancy
                if (!_circleRadiusDrag && Math.abs(radius - _lastRadius) > 0.1) {
                    _circleRadiusDrag = true
                    _createCircularPolygon(mapPolygon.center, radius)
                    _circleRadiusDragCoord = itemCoordinate
                    _circleRadiusDrag = false
                    _lastRadius = radius
                }
            }
        }
    }

    Component {
        id: radiusVisualsComponent

        Item {
            property var    circleCenterCoord:  mapPolygon.center

            function _calcRadiusDragCoord() {
                _circleRadiusDragCoord = circleCenterCoord.atDistanceAndAzimuth(_circleRadius, 90)
            }

            onCircleCenterCoordChanged: {
                if (!_circleRadiusDrag) {
                    _calcRadiusDragCoord()
                }
            }

            QGCDynamicObjectManager {
                id: _objMgr
            }

            Component.onCompleted: {
                _calcRadiusDragCoord()
                var radiusDragHandle = _objMgr.createObject(radiusDragHandleComponent, mapControl, true)
                radiusDragHandle.coordinate = Qt.binding(function() { return _circleRadiusDragCoord })
                var radiusDragIndicator = radiusDragAreaComponent.createObject(mapControl, { "itemIndicator": radiusDragHandle, "itemCoordinate": _circleRadiusDragCoord })
                _objMgr.addObject(radiusDragIndicator)
            }
        }
    }
}