/*
    SPDX-FileCopyrightText: 2013 Heena Mahour <heena393@gmail.com>
    SPDX-FileCopyrightText: 2013 Sebastian Kügler <sebas@kde.org>
    SPDX-FileCopyrightText: 2015 Kai Uwe Broulik <kde@privat.broulik.de>
    SPDX-FileCopyrightText: 2021 Jan Blackquill <uhhadd@gmail.com>
    SPDX-FileCopyrightText: 2021 Carl Schwan <carlschwan@kde.org>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

pragma ComponentBehavior: Bound

import QtQuick

import org.kde.kirigami as Kirigami
import org.kde.ksvg as KSvg
import org.kde.plasma.components as PlasmaComponents
import org.kde.plasma.extras as PlasmaExtras
import org.kde.plasma.workspace.calendar as PlasmaCalendar

PlasmaComponents.AbstractButton {
    id: dayStyle

    required property int index
    /*
     * Possible row types:
     *
     * - year: ListModel
     *   * label: string
     *   * yearNumber: int
     *   * isCurrent: bool
     * - month: ListModel
     *   * label: string
     *   * monthNumber: int
     *   * yearNumber: int
     *   * isCurrent: bool
     * - day: PlasmaCalendar.DaysModel
     *   * no "label" role
     */
    required property var model

    // These two roles are defined for all row types. Other roles would have
    // to be fetched through the `model` row object.
    required property bool isCurrent
    required property int yearNumber

    required property /*PlasmaCalendar.Calendar.DateMatchingPrecision*/int dateMatchingPrecision
    /*
     * The layout of this button is
     * [label]
     * [eventIndicatorsRow]
     * [subDayLabel]
     */
    property double mainLabelFontPixelSize: Math.max(
        Kirigami.Theme.defaultFont.pixelSize * 1.35 /* Level 1 Heading */,
        height / (dateMatchingPrecision === PlasmaCalendar.Calendar.MatchYearMonthAndDay ? 3 /* weeksColumn */ : 6))
    property double eventIndicatorsRowSize: Math.min(
        Kirigami.Units.smallSpacing,
        height / 6
    )
    // This is set to such that `subDayLabel` does not overlap with `label`
    // and `eventIndicatorsRow`.
    property double subDayLabelFontPixelSize: Math.min(
        Math.max(
            Kirigami.Theme.smallFont.pixelSize,
            height / (dateMatchingPrecision === PlasmaCalendar.Calendar.MatchYearMonthAndDay ? 6 : 12)),
        (height - mainLabelFontPixelSize) / 2 - eventIndicatorsRowSize
    )

    objectName: {
        switch (dateMatchingPrecision) {
        case PlasmaCalendar.Calendar.MatchYear:
            return "calendarCell-" + yearNumber;
        case PlasmaCalendar.Calendar.MatchYearAndMonth:
            return "calendarCell-" + yearNumber + "-" + model.monthNumber;
        case PlasmaCalendar.Calendar.MatchYearMonthAndDay:
        default:
            return "calendarCell-" + yearNumber + "-" + model.monthNumber + "-" + model.dayNumber;
        }
    }
    hoverEnabled: true

    // type: either PlasmaCalendar.DaysModel or an equivalent ListModel
    required property QtObject dayModel

    readonly property date thisDate: {
        const monthNumber = (dateMatchingPrecision >= PlasmaCalendar.Calendar.MatchYearAndMonth) ? model.monthNumber - 1 : 0;
        const dayNumber = (dateMatchingPrecision >= PlasmaCalendar.Calendar.MatchYearMonthAndDay) ? model.dayNumber : 1;
        return new Date(yearNumber, monthNumber, dayNumber);
    }

    Accessible.name: thisDate.toLocaleDateString(Qt.locale(), Locale.LongFormat)
    Accessible.description: {
        const eventDescription = (model.eventCount !== undefined && model.eventCount > 0)
            ? i18ndp("plasmashellprivateplugin", "%1 event", "%1 events", model.eventCount)
            : i18nd("plasmashellprivateplugin", "No events");
        const subLabelDescription = model.subLabel || model.subDayLabel || "";
        return `${eventDescription} ${subLabelDescription ? `; ${subLabelDescription}` : ""}`;
    }

    readonly property bool today: {
        const today = root.today;
        let result = true;
        if (dateMatchingPrecision >= PlasmaCalendar.Calendar.MatchYear) {
            result &= today.getFullYear() === thisDate.getFullYear();
        }
        if (dateMatchingPrecision >= PlasmaCalendar.Calendar.MatchYearAndMonth) {
            result &= today.getMonth() === thisDate.getMonth();
        }
        if (dateMatchingPrecision >= PlasmaCalendar.Calendar.MatchYearMonthAndDay) {
            result &= today.getDate() === thisDate.getDate();
        }
        return result;
    }
    readonly property bool selected: {
        const current = root.currentDate;
        let result = true;
        if (dateMatchingPrecision >= PlasmaCalendar.Calendar.MatchYear) {
            result &= current.getFullYear() === thisDate.getFullYear();
        }
        if (dateMatchingPrecision >= PlasmaCalendar.Calendar.MatchYearAndMonth) {
            result &= current.getMonth() === thisDate.getMonth();
        }
        if (dateMatchingPrecision >= PlasmaCalendar.Calendar.MatchYearMonthAndDay) {
            result &= current.getDate() === thisDate.getDate();
        }
        return result;
    }

    Loader {
        anchors.fill: parent

        active: dayStyle.activeFocus
        asynchronous: true

        sourceComponent: KSvg.FrameSvgItem {
            anchors {
                leftMargin: -margins.left
                topMargin: -margins.top
                rightMargin: -margins.right
                bottomMargin: -margins.bottom
            }
            imagePath: "widgets/button"
            prefix: ["toolbutton-focus", "focus"]
        }
    }

    Loader {
        anchors.fill: parent

        active: today || selected || dayStyle.hovered || dayStyle.activeFocus
        asynchronous: true
        z: -1

        sourceComponent: PlasmaExtras.Highlight {
            hovered: true
            opacity: {
                if (today) {
                    return 1;
                } else if (selected) {
                    return 0.6;
                } else if (dayStyle.hovered) {
                    return 0.3;
                } else if (dayStyle.activeFocus) {
                    return 0.1;
                }
                return 0;
            }
        }
    }

    Loader {
        // Basically, only active when dayStyle.dayModel is PlasmaCalendar.DaysModel
        // and thus dateMatchingPrecision is PlasmaCalendar.Calendar.MatchYearMonthAndDay
        active: dayStyle.model.eventCount !== undefined && dayStyle.model.eventCount > 0
        anchors.bottom: parent.bottom
        anchors.bottomMargin: subDayLabel.item?.implicitHeight ?? Kirigami.Units.smallSpacing
        anchors.horizontalCenter: parent.horizontalCenter
        sourceComponent: Row {
            id: eventIndicatorsRow

            spacing: Kirigami.Units.smallSpacing

            Repeater {
                model: DelegateModel {
                    model: dayStyle.dayModel
                    delegate: Rectangle {
                        required property string eventColor

                        width: dayStyle.eventIndicatorsRowSize
                        height: width
                        radius: width / 2
                        color: eventColor
                            ? Kirigami.ColorUtils.linearInterpolation(eventColor, Kirigami.Theme.textColor, 0.2)
                            : Kirigami.Theme.highlightColor
                    }

                    Component.onCompleted: {
                        rootIndex = modelIndex(dayStyle.index);
                    }
                }
            }
        }
    }

    contentItem: Item {
        // ColumnLayout makes scrolling too slow, so use anchors to position labels

        PlasmaComponents.ToolTip.delay: Kirigami.Units.toolTipDelay
        PlasmaComponents.ToolTip.text: dayStyle.model.subLabel || ""
        PlasmaComponents.ToolTip.visible: !!dayStyle.model.subLabel && (Kirigami.Settings.isMobile ? dayStyle.pressed : dayStyle.hovered)

        PlasmaComponents.Label {
            id: label
            anchors {
                left: parent.left
                right: parent.right
                top: parent.top
                bottom: parent.bottom
            }
            font.pixelSize: dayStyle.mainLabelFontPixelSize
            horizontalAlignment: Text.AlignHCenter
            verticalAlignment: Text.AlignVCenter
            text: dayStyle.model.label || dayStyle.model.dayLabel
            textFormat: Text.PlainText
            opacity: dayStyle.isCurrent ? 1.0 : 0.5
            wrapMode: Text.NoWrap
            elide: Text.ElideRight
        }

        // This is always displayed to align the position of eventIndicatorsRow
        // even when it is empty.
        Loader {
            id: subDayLabel
            anchors {
                left: parent.left
                right: parent.right
                top: parent.bottom
            }
            asynchronous: true
            opacity: 0

            sourceComponent: PlasmaComponents.Label {
                elide: Text.ElideRight
                font.pixelSize: dayStyle.subDayLabelFontPixelSize
                horizontalAlignment: Text.AlignHCenter
                verticalAlignment: Text.AlignVCenter
                maximumLineCount: 1
                opacity: label.opacity
                // Prefer sublabel over day number
                text: dayStyle.model.subDayLabel || dayStyle.model.alternateDayNumber?.toString() || ''
                textFormat: Text.PlainText
                wrapMode: Text.NoWrap
            }

            states: State {
                when: subDayLabel.status === Loader.Ready && subDayLabel.implicitHeight > 1
                AnchorChanges {
                    target: subDayLabel
                    anchors.top: undefined
                    anchors.bottom: subDayLabel.parent.bottom
                }
                PropertyChanges {
                    target: subDayLabel
                    opacity: 1
                }
            }

            transitions: Transition {
                NumberAnimation {
                    property: "opacity"
                    easing.type: Easing.OutCubic
                    duration: Kirigami.Units.longDuration
                }
                AnchorAnimation {
                    easing.type: Easing.OutCubic
                    duration: Kirigami.Units.longDuration
                }
            }
        }

        Component.onCompleted: {
            if (dayStyle.today) {
                root.todayAuxilliaryText = Qt.binding(() => dayStyle.model.subLabel || "");
            }
        }
    }
}