/*
    SPDX-FileCopyrightText: 2012-2013 Eike Hein <hein@kde.org>

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

.import org.kde.kirigami as Kirigami

const iconMargin = Math.round(Kirigami.Units.smallSpacing / 4);
const labelMargin = Kirigami.Units.smallSpacing;

function horizontalMargins() {
    const spacingAdjustment = (tasks.plasmoid.pluginName === "org.kde.plasma.icontasks") ? tasks.plasmoid.configuration.iconSpacing : 1
    return (taskFrame.margins.left + taskFrame.margins.right) * (tasks.vertical ? 1 : spacingAdjustment);
}

function verticalMargins() {
    const spacingAdjustment = (tasks.plasmoid.pluginName === "org.kde.plasma.icontasks") ? tasks.plasmoid.configuration.iconSpacing : 1
    return (taskFrame.margins.top + taskFrame.margins.bottom) * (tasks.vertical ? spacingAdjustment : 1);
}

function adjustMargin(height, margin) {
    const available = height - verticalMargins();

    if (available < Kirigami.Units.iconSizes.small) {
        return Math.floor((margin * (Kirigami.Units.iconSizes.small / available)) / 3);
    }

    return margin;
}

function maxStripes() {
    const length = tasks.vertical ? tasks.width : tasks.height;
    const minimum = tasks.vertical ? preferredMinWidth() : preferredMinHeight();

    return Math.min(tasks.plasmoid.configuration.maxStripes, Math.max(1, Math.floor(length / minimum)));
}

function optimumCapacity(width, height) {
    const length = tasks.vertical ? height : width;
    const maximum = tasks.vertical ? preferredMaxHeight() : preferredMaxWidth();

    if (!tasks.vertical) {
        //  Fit more tasks in this case, that is possible to cut text, before combining tasks.
        return Math.ceil(length / maximum) * maxStripes() + 1;
    }

    return Math.floor(length / maximum) * maxStripes();
}

function preferredMinWidth() {
    let width = preferredMinLauncherWidth();

    if (!tasks.vertical && !tasks.iconsOnly) {
      width +=
          (Kirigami.Units.smallSpacing * 2) +
          (Kirigami.Units.gridUnit * 8);
    }

    return width;
}

function preferredMaxWidth() {
    if (tasks.iconsOnly) {
        if (tasks.vertical) {
            if (tasks.width === 0) {
                return 0
            }
            return tasks.width + verticalMargins();
        } else {
            if (tasks.height === 0) {
                return 0
            }
            return tasks.height + horizontalMargins();
        }
    }

    // Avoid doing a bunch of unnecessary work below in vertical mode
    if (tasks.vertical) {
        return preferredMinWidth();
    }

    // Visually, a large max item width on a tall panel looks cluttered even
    // with just a task or two open. This clutter is less pronounced on panels
    // lower in height, as there is generally more horizontal space.
    //
    // This allows for one default value for max item width where clutter is
    // reduced at low task counts for tall panels, while leaving low height
    // panels less affected (unaffected at 20px).
    const laneHeight = tasks.height / maxStripes(); // correct for multiple rows
    let baseFactor = 1; // sane default in case something goes wrong
    switch (tasks.plasmoid.configuration.taskMaxWidth) {
    case 0: // narrow
        baseFactor = 1.2;
        break;
    case 1: // medium
        baseFactor = 1.6;
        break;
    case 2: // wide
        baseFactor = 2;
        break;
    }
    // For every pixel of height above 20, knock the factor down by 0.01. This
    // produces nice results for 20~50 pixels. Above 50, it suddenly feels like
    // it's shrinking a lot, and above 80 the Medium and Narrow settings would
    // end up setting the same width, so don't apply further reduction above 50.
    const factorReduction = (Math.min(50, laneHeight) - 20) * 0.01;
    // Clamp the minimum factor to 1 to ensure max width is always >= min width.
    // and the factor reduction to 0 so we don't ever increase the factor
    const factor = Math.max(1, baseFactor - Math.max(0, factorReduction));
    return Math.floor(preferredMinWidth() * factor);
}

function preferredMinHeight() {
    // TODO FIXME UPSTREAM: Port to proper font metrics for descenders once we have access to them.
    return Kirigami.Units.iconSizes.sizeForLabels + 4;
}

function preferredMaxHeight() {
    if (tasks.vertical) {
        let taskPreferredSize = 0;
        if (tasks.iconsOnly) {
            taskPreferredSize = tasks.width / maxStripes();
        } else {
            taskPreferredSize = Math.max(Kirigami.Units.iconSizes.sizeForLabels,
                                         Kirigami.Units.iconSizes.medium);
        }
        return verticalMargins() +
            Math.min(
                // Do not allow the preferred icon size to exceed the width of
                // the vertical task manager.
                tasks.width / maxStripes(),
                taskPreferredSize);
    } else {
        return verticalMargins() +
            Math.min(
                Kirigami.Units.iconSizes.small * 3,
                Kirigami.Units.iconSizes.sizeForLabels * 3);
    }
}

function preferredHeightInPopup() {
    return verticalMargins() + Math.max(Kirigami.Units.iconSizes.sizeForLabels,
                                        Kirigami.Units.iconSizes.medium);
}

function spaceRequiredToShowText() {
    // gridUnit is the height of the default font, but only one isn't enough to
    // show anything but the elision character. 2 is too high and results in
    // text appearing only at excessively high widths.
    return Math.round(Kirigami.Units.gridUnit * 1.5);
}

function preferredMinLauncherWidth() {
    const baseWidth = tasks.vertical ? preferredMinHeight() : Math.min(tasks.height, Kirigami.Units.iconSizes.small * 3);

    return (baseWidth + horizontalMargins())
        - (adjustMargin(baseWidth, taskFrame.margins.top) + adjustMargin(baseWidth, taskFrame.margins.bottom));
}

function maximumContextMenuTextWidth() {
    return (Kirigami.Units.iconSizes.sizeForLabels * 28);
}

