/*
 * <x-group>: a choice of a few options drawn as M3 Expressive's connected button group, the
 * successor of the segmented button — native radios (checkboxes with `data-md-multiple`) under
 * segments that share the row, or hug their labels with `data-md-inline`.
 *
 * The segments are M3's buttons at the group's `data-md-size` (Button*Tokens: 32/40/56/96/136px
 * tall, 16/16/24/48/64px either side, 8/8/8/12/16px between icon and label, label-large, label-
 * large, title-medium, headline-small, headline-large), with the connected shape from
 * button-group.css: 2px apart, small inner corners, the chosen segment fully round. At `xs` and
 * `sm` a segment carries M3's 48px target and a 48px minimum width, which M3 asks for by name.
 *
 * `data-md-variant` is the toggle button's colours: `tonal` (secondary-container, chosen in
 * secondary), `filled` (surface-container behind on-surface-variant, chosen in primary) or
 * `outlined` (an outline-variant edge, chosen in inverse-surface). A checked input picks the
 * chosen colours (`:has(:checked)`), a disabled one the disabled treatment — on-surface at 10%
 * behind 38% text. Corners move on the fast spatial spring and colours on the fast effects spring
 * beside it.
 *
 * A segment renders the foundation's `md-state-layer` (foundation/interaction.css) on the label
 * itself, which reaches the same `:hover`/`:active` as the class expects; below `medium`'s smallest
 * two sizes it renders `md-touch-target` too. The real control is the `<input>` inside, not the
 * label, so keyboard focus and the disabled state are read off it with `:has()` — the one
 * difference the class cannot draw, kept here as a refinement.
 *
 * The legend is label-large and the hint body-small, both in on-surface-variant; a validation
 * message takes the hint's place in error. `hint-class` lands on the hint, where a caller's class
 * outranks the colour here.
 */

@layer material.reset, material.tokens, material.base, material.layout, material.components, material.text, material.visibility;

@import './icon.css';
@import './button-group.css';

@layer material.components {
    [data-md-group] {
        min-inline-size: 0;
    }

    [data-md-group-legend] {
        margin-block-end: var(--md-sys-measurement-space100);
        color: var(--md-sys-color-on-surface-variant);
        font: var(--md-sys-typescale-label-lg);
        letter-spacing: var(--md-sys-typescale-label-lg-tracking);
        font-variation-settings: normal;
    }

    [data-md-group] > [data-md-button-group] {
        display: flex;
        align-items: normal;
        inline-size: 100%;
    }

    [data-md-group][data-md-inline] > [data-md-button-group] {
        inline-size: fit-content;
    }

    [data-md-group-segment] {
        --md-group-container: var(--md-sys-color-secondary-container);
        --md-group-label: var(--md-sys-color-on-secondary-container);

        display: flex;
        flex: 1 1 0%;
        align-items: center;
        justify-content: center;
        min-inline-size: 0;
        background-color: var(--md-group-container);
        color: var(--md-group-label);
        white-space: nowrap;
        cursor: pointer;
        -webkit-user-select: none;
        user-select: none;
        transition-property: border-radius, padding, margin, bottom, background-color, color, box-shadow;
        transition-duration:
            var(--md-sys-motion-spatial-fast-duration), var(--md-sys-motion-spatial-fast-duration),
            var(--md-sys-motion-spatial-fast-duration), var(--md-sys-motion-spatial-fast-duration),
            var(--md-sys-motion-effects-fast-duration), var(--md-sys-motion-effects-fast-duration), var(--md-sys-motion-effects-fast-duration);
        transition-timing-function:
            var(--md-sys-motion-spatial-fast), var(--md-sys-motion-spatial-fast),
            var(--md-sys-motion-spatial-fast), var(--md-sys-motion-spatial-fast),
            var(--md-sys-motion-effects-fast), var(--md-sys-motion-effects-fast), var(--md-sys-motion-effects-fast);

        /* Focus lands on the input inside, not the label, so it is read with :has(); the state
           layer's own opacity joins the ring, as the foundation class draws for a focused control. */
        &:has(:focus-visible) {
            outline: 3px solid var(--md-sys-color-secondary);
            outline-offset: 2px;

            &::before {
                opacity: var(--md-sys-state-focus-state-layer-opacity);
            }
        }

        /* Disabled is read off the input too: the class's own :disabled/aria-disabled rule never
           fires on the label it never reaches. */
        &:has(:disabled)::before {
            display: none;
        }

        /* The radio or checkbox stays in the page, for the form, the keyboard and a screen reader. */
        & > input {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip-path: inset(50%);
            white-space: nowrap;
            border-width: 0;
        }
    }

    [data-md-group][data-md-inline] [data-md-group-segment] {
        flex: initial;
    }

    [data-md-group]:is([data-md-size='xs'], [data-md-size='sm']) [data-md-group-segment] {
        min-inline-size: var(--md-sys-measurement-space600);
    }

    [data-md-group][data-md-size='xs'] [data-md-group-segment] {
        gap: var(--md-sys-measurement-space100);
        block-size: 32px;
        padding-inline: var(--md-sys-measurement-space200);
        font: var(--md-sys-typescale-label-lg);
        letter-spacing: var(--md-sys-typescale-label-lg-tracking);
        font-variation-settings: normal;
    }

    [data-md-group][data-md-size='sm'] [data-md-group-segment] {
        gap: var(--md-sys-measurement-space100);
        block-size: 40px;
        padding-inline: var(--md-sys-measurement-space200);
        font: var(--md-sys-typescale-label-lg);
        letter-spacing: var(--md-sys-typescale-label-lg-tracking);
        font-variation-settings: normal;
    }

    [data-md-group][data-md-size='md'] [data-md-group-segment] {
        gap: var(--md-sys-measurement-space100);
        block-size: 56px;
        padding-inline: var(--md-sys-measurement-space300);
        font: var(--md-sys-typescale-title-md);
        letter-spacing: var(--md-sys-typescale-title-md-tracking);
        font-variation-settings: normal;
    }

    [data-md-group][data-md-size='lg'] [data-md-group-segment] {
        gap: 12px;
        block-size: 96px;
        padding-inline: var(--md-sys-measurement-space600);
        font: var(--md-sys-typescale-headline-sm);
        letter-spacing: var(--md-sys-typescale-headline-sm-tracking);
        font-variation-settings: normal;
    }

    [data-md-group][data-md-size='xl'] [data-md-group-segment] {
        gap: var(--md-sys-measurement-space200);
        block-size: 136px;
        padding-inline: var(--md-sys-measurement-space800);
        font: var(--md-sys-typescale-headline-lg);
        letter-spacing: var(--md-sys-typescale-headline-lg-tracking);
        font-variation-settings: normal;
    }

    [data-md-group-segment]:has(:checked) {
        --md-group-container: var(--md-sys-color-secondary);
        --md-group-label: var(--md-sys-color-on-secondary);
    }

    [data-md-group][data-md-variant='filled'] [data-md-group-segment] {
        --md-group-container: var(--md-sys-color-surface-container);
        --md-group-label: var(--md-sys-color-on-surface-variant);

        &:has(:checked) {
            --md-group-container: var(--md-sys-color-primary);
            --md-group-label: var(--md-sys-color-on-primary);
        }
    }

    [data-md-group][data-md-variant='outlined'] [data-md-group-segment] {
        --md-group-container: transparent;
        --md-group-label: var(--md-sys-color-on-surface-variant);

        border: 1px solid var(--md-sys-color-outline-variant);

        &:has(:checked) {
            --md-group-container: var(--md-sys-color-inverse-surface);
            --md-group-label: var(--md-sys-color-inverse-on-surface);

            border-color: transparent;
        }
    }

    [data-md-group-segment]:has(:disabled) {
        background-color: color-mix(in srgb, var(--md-sys-color-on-surface) 10%, transparent);
        color: color-mix(in srgb, var(--md-sys-color-on-surface) calc(var(--md-sys-state-disabled-content-opacity) * 100%), transparent);
        cursor: not-allowed;
    }

    [data-md-group-label] {
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }

    [data-md-group-hint],
    [data-md-group-error] {
        margin-block-start: var(--md-sys-measurement-space50);
        font: var(--md-sys-typescale-body-sm);
        letter-spacing: var(--md-sys-typescale-body-sm-tracking);
        font-variation-settings: normal;
    }

    [data-md-group-hint] {
        color: var(--md-sys-color-on-surface-variant);
    }

    [data-md-group-error] {
        color: var(--md-sys-color-error);
    }
}