import QtQuick
import QtQuick.Controls
import QtQuick.Shapes 1.6

import GraphEditor 1.0
import MaterialIcons 2.2

/**
 * A cubic spline representing an edge, going from point1 to point2, providing mouse interaction.
 */

Item {
    id: root

    property var edge
    property real point1x
    property real point1y
    property real point2x
    property real point2y
    property alias thickness: path.strokeWidth
    property alias color: path.strokeColor
    property bool isForLoop: false
    property int loopSize: 0
    property int iteration: 0

    // BUG: edgeArea is destroyed before path, need to test if not null to avoid warnings
    readonly property bool containsMouse: (loopArea && loopArea.containsMouse) || (edgeArea && edgeArea.containsMouse)

    signal pressed(var event)
    signal released(var event)

    x: point1x
    y: point1y
    width: point2x - point1x
    height: point2y - point1y

    property real startX: 0
    property real startY: 0
    property real endX: width
    property real endY: height


    Shape {
        anchors.fill: parent
        // Cause rendering artifacts when enabled (and don't support hot reload really well)
        vendorExtensionsEnabled: false
        opacity: 0.7

        ShapePath {
            id: path
            startX: root.startX
            startY: root.startY
            fillColor: "transparent"

            strokeColor: "#3E3E3E"
            strokeStyle: edge !== undefined && ((edge.src !== undefined && edge.src.isOutput) || edge.dst === undefined) ? ShapePath.SolidLine : ShapePath.DashLine
            strokeWidth: 1
            // Final visual width of this path (never below 1)
            readonly property real visualWidth: Math.max(strokeWidth, 1)
            dashPattern: [6 / visualWidth, 4 / visualWidth]
            capStyle: ShapePath.RoundCap

            PathCubic {
                id: cubic
                property real ctrlPtDist: 30
                x: root.isForLoop ? (root.startX + root.endX) / 2  - loopArea.width / 2 : root.endX
                y: root.isForLoop ? (root.startY + root.endY) / 2 : root.endY
                relativeControl1X: ctrlPtDist
                relativeControl1Y: 0
                control2X: x - ctrlPtDist
                control2Y: y
            }
        }

        ShapePath {
            id: pathSecondary
            startX: (root.startX + root.endX) / 2 + loopArea.width / 2
            startY: (root.startY + root.endY) / 2
            fillColor: "transparent"

            strokeColor: root.isForLoop ? root.color : "transparent"
            strokeStyle: edge !== undefined && ((edge.src !== undefined && edge.src.isOutput) || edge.dst === undefined) ? ShapePath.SolidLine : ShapePath.DashLine
            strokeWidth: root.thickness
            // Final visual width of this path (never below 1)
            readonly property real visualWidth: Math.max(strokeWidth, 1)
            dashPattern: [6 / visualWidth, 4 / visualWidth]
            capStyle: ShapePath.RoundCap

            PathCubic {
                id: cubicSecondary
                property real ctrlPtDist: 30
                x: root.endX
                y: root.endY
                relativeControl1X: ctrlPtDist
                relativeControl1Y: 0
                control2X: x - ctrlPtDist
                control2Y: y
            }
        }
    }

    Item {
        // Place the label at the middle of the edge
        x: (root.startX + root.endX) / 2
        y: (root.startY + root.endY) / 2
        visible: root.isForLoop

        Rectangle {
            anchors.centerIn: parent
            property int margin: 2
            width: icon.width + 2 * margin
            height: icon.height + 2 * margin
            radius: width
            color: path.strokeColor

            MaterialToolLabel {
                id: icon
                anchors.centerIn: parent

                iconText: MaterialIcons.loop
                label: (root.iteration + 1) + "/" + root.loopSize + " "

                labelIconColor: palette.base
                ToolTip.text: "Foreach Loop"
            }

            MouseArea {
                id: loopArea
                anchors.fill: parent
                hoverEnabled: true
                onClicked: root.pressed(arguments[0])
            }
        }
    }

    EdgeMouseArea {
        id: edgeArea
        anchors.fill: parent
        acceptedButtons: Qt.LeftButton | Qt.RightButton
        thickness: root.thickness + 4
        curveScale: cubic.ctrlPtDist / root.width  // Normalize by width
    }

    MouseArea {
        x: Math.min(0, root.width)
        y: Math.min(0, root.height)
        height: Math.abs(root.height)
        width: Math.abs(root.width)
        acceptedButtons: Qt.LeftButton | Qt.RightButton

        onPressed: function(event) {
            let xpos = root.width < 0 ? root.height + event.x : event.x;
            let ypos = root.height < 0 ? root.height + event.y: event.y;
            if (edgeArea.containsPoint(Qt.point(xpos, ypos))) {
                root.pressed(event);
            }
            else {
                event.accepted = false;
            }
        }

        onReleased: function(event) {
            let xpos = root.width < 0 ? root.height + event.x : event.x;
            let ypos = root.height < 0 ? root.height + event.y: event.y;
            if (edgeArea.containsPoint(Qt.point(xpos, ypos))) {
                root.released(event);
            }
            else {
                event.accepted = false;
            }
        }
    }
}