/*
 * Copyright 2022 Devin Lin <devin@kde.org>
 * SPDX-License-Identifier: LGPL-2.0-or-later
 */

import QtQuick
import QtQuick.Templates as T
import QtQuick.Controls as Controls
import QtQuick.Layouts

import org.kde.kirigami as Kirigami

import "private" as Private

/**
 * @brief A Form delegate that corresponds to a radio button.
 *
 * This component is used for creating multiple on/off toggles for the same
 * setting. In other words, by grouping multiple radio buttons under the same
 * parent, only one of the radio buttons should be checkable and applied to a
 * setting.
 *
 * Use the inherited QtQuick.Controls.AbstractButton.text property to define
 * the main text of the radio button.
 *
 * If you need multiple values for the same setting, use a
 * FormComboBoxDelegate instead.
 *
 * If you need a purely on/off toggle for a single setting, use a
 * FormSwitchDelegate instead.
 *
 * If you need an on/off/tristate toggle, use a FormCheckDelegate instead.
 *
 * @since KirigamiAddons 0.11.0
 *
 * @see QtQuick.Controls.AbstractButton
 * @see FormSwitchDelegate
 * @see FormCheckDelegate
 * @see FormComboBoxDelegate
 *
 * @inherit QtQuick.Controls.RadioDelegate
 */
T.RadioDelegate {
    id: root

    /**
     * @brief A label containing secondary text that appears under the
     * inherited text property.
     *
     * This provides additional information shown in a faint gray color.
     */
    property string description: ""

    /**
     * @brief This property holds an item that will be displayed to the left of the delegate's contents.
     */
    property var leading: null

    /**
     * @brief This property holds the padding after the leading item.
     */
    property real leadingPadding: Kirigami.Units.smallSpacing

    /**
     * @brief This property holds an item that will be displayed after the
     * delegate's contents.
     */
    property var trailing

    /**
     * @brief This property holds the padding before the trailing item.
     */
    property real trailingPadding: Kirigami.Units.smallSpacing

    /**
     * @brief This property allows to override the internal description
     * item (a QtQuick.Controls.Label) with a custom component.
     */
    property alias descriptionItem: internalDescriptionItem

    leftPadding: Kirigami.Units.gridUnit
    topPadding: Kirigami.Units.largeSpacing + Kirigami.Units.smallSpacing
    bottomPadding: Kirigami.Units.largeSpacing + Kirigami.Units.smallSpacing
    rightPadding: Kirigami.Units.gridUnit

    implicitWidth: contentItem.implicitWidth + leftPadding + rightPadding
    implicitHeight: contentItem.implicitHeight + topPadding + bottomPadding

    focusPolicy: Qt.StrongFocus
    hoverEnabled: true
    background: FormDelegateBackground { control: root }

    Layout.fillWidth: true

    contentItem: ColumnLayout {
        spacing: Kirigami.Units.smallSpacing

        RowLayout {
            id: innerRowLayout

            spacing: 0

            Layout.fillWidth: true

            Private.ContentItemLoader {
                Layout.rightMargin: visible ? root.leadingPadding : 0
                visible: root.leading
                implicitHeight: visible ? root.leading.implicitHeight : 0
                implicitWidth: visible ? root.leading.implicitWidth : 0
                contentItem: root.leading
            }

            Controls.RadioButton {
                id: radioButtonItem
                focusPolicy: Qt.NoFocus // provided by delegate
                Layout.rightMargin: Kirigami.Units.largeSpacing + Kirigami.Units.smallSpacing

                enabled: root.enabled
                checked: root.checked

                onToggled: root.toggled()
                onClicked: root.clicked()
                onPressAndHold: root.pressAndHold()
                onDoubleClicked: root.doubleClicked()

                onCheckedChanged: {
                    root.checked = checked;
                    checked = Qt.binding(() => root.checked);
                }
            }

            Kirigami.Icon {
                visible: root.icon.name.length > 0 || root.icon.source.toString().length > 0
                source: root.icon.name.length > 0 ? root.icon.name : root.icon.source
                color: root.icon.color
                Layout.rightMargin: visible ? Kirigami.Units.largeSpacing + Kirigami.Units.smallSpacing : 0
                implicitWidth: visible ? root.icon.width : 0
                implicitHeight: visible ? root.icon.height : 0
            }

            Controls.Label {
                Layout.fillWidth: true
                text: root.text
                color: root.enabled ? Kirigami.Theme.textColor : Kirigami.Theme.disabledTextColor
                elide: Text.ElideRight
                wrapMode: Text.Wrap
                maximumLineCount: 2
            }

            Private.ContentItemLoader {
                Layout.leftMargin: visible ? root.trailingPadding : 0
                visible: root.trailing
                implicitHeight: visible ? root.trailing.implicitHeight : 0
                implicitWidth: visible ? root.trailing.implicitWidth : 0
                contentItem: root.trailing
            }
        }

        Controls.Label {
            id: internalDescriptionItem

            visible: root.description !== ""
            Layout.fillWidth: true
            text: root.description
            color: Kirigami.Theme.disabledTextColor
            wrapMode: Text.Wrap
        }
    }
}