// TRACES: FR-CAT-5 | NFR-A11Y-3
// Colour labels: the mark that shows one, and the row that chooses one.
//
// **A label is named, not only tinted.** NFR-A11Y-3 names colour labels as
// the first thing that must not be told apart by hue alone, and a colour
// label is the one status here whose *name* is a colour — so the temptation
// is exactly a swatch. Every mark therefore carries the label's initial
// (R, Y, G, B, P) in dark ink on the fill, and every place a label can be
// chosen or filtered on says its name in words. Red and green are the pair
// the commonest colour-vision deficiency merges, and they are "R" and "G"
// here before they are anything else.
//
// The integers are `versions.label`'s own codes (`dr_catalog::rating::
// label_code`): 0 for none, 1 red, 2 yellow, 3 green, 4 blue, 5 purple. One
// numbering from the column to the pixel, so nothing translates between them.

import { Theme } from "theme.slint";

/// TRACES: FR-CAT-5 | NFR-A11Y-3
/// What each label code is called, and the letter its mark carries.
export global Labels {
    /// Indexed by code. "None" at 0 is what the picker's clearing choice says.
    out property <[string]> names: ["None", "Red", "Yellow", "Green", "Blue", "Purple"];
    /// The glyph on the mark, indexed by code. Distinct for every label: this
    /// is what carries the label for an eye that does not separate the fills.
    out property <[string]> letters: ["", "R", "Y", "G", "B", "P"];

    /// The fill for a code. Data rather than chrome, the same exception the
    /// histogram's traces take (see `style.yaml`): the label *is* a colour.
    public pure function fill(code: int) -> color {
        if (code == 1) { return Theme.label-red; }
        if (code == 2) { return Theme.label-yellow; }
        if (code == 3) { return Theme.label-green; }
        if (code == 4) { return Theme.label-blue; }
        if (code == 5) { return Theme.label-purple; }
        return transparent;
    }
}

/// TRACES: FR-CAT-5 | NFR-A11Y-3
/// One label, drawn: a rounded tag in the label's colour with its initial
/// on it. Invisible for code 0, so a caller can place it unconditionally.
export component LabelMark inherits Rectangle {
    in property <int> code: 0;
    in property <length> size: 16px;

    accessible-role: text;
    accessible-label: Labels.names[root.code] + " label";

    visible: root.code > 0 && root.code <= 5;
    width: root.size;
    height: root.size;
    border-radius: root.size / 4;
    background: Labels.fill(root.code);
    // A rim in the ground colour, so a yellow tag on a pale sky still has an
    // edge.
    border-width: 1px;
    border-color: Theme.ground;

    Text {
        // The letter is the label. Dark ink on every fill: the fills are held
        // to mid-tones in `style.yaml` so one ink reads on all five.
        text: Labels.letters[root.code];
        color: Theme.ground;
        font-size: root.size * 0.62;
        font-weight: 800;
        width: 100%;
        height: 100%;
        horizontal-alignment: center;
        vertical-alignment: center;
    }
}

/// TRACES: FR-CAT-5 | FR-UI-4 | NFR-A11Y-3
/// The six choices — none, then the five labels — each a mark and a word.
///
/// Inline rather than a popup: it opens in the bar that asked for it, where
/// a finger already is, and there is no second surface to dismiss.
export component LabelPicker inherits HorizontalLayout {
    /// The code currently carried, drawn as pressed. -1 where the photographs
    /// being labelled disagree, so nothing is shown as chosen.
    in property <int> current: -1;

    callback chosen(int);

    spacing: 4px;

    for code in [0, 1, 2, 3, 4, 5]: Rectangle {
        accessible-role: button;
        accessible-label: code == 0 ? "No label" : Labels.names[code] + " label";
        accessible-checkable: true;
        accessible-checked: root.current == code;
        accessible-action-default => { root.chosen(code); }

        height: Theme.control-height - 4px;
        width: row.preferred-width + 2 * Theme.gap-sm;
        y: (parent.height - self.height) / 2;
        border-radius: Theme.radius;
        border-width: 1px;
        border-color: root.current == code ? Theme.active : Theme.rule;
        background: touch.pressed ? Theme.pressed
                    : (touch.has-hover ? Theme.hover : Theme.surface-raised);

        touch := TouchArea {
            width: 100%;
            height: max(parent.height, Theme.touch-target);
            y: (parent.height - self.height) / 2;
            mouse-cursor: pointer;
            clicked => { root.chosen(code); }
        }

        row := HorizontalLayout {
            padding-left: Theme.gap-sm;
            padding-right: Theme.gap-sm;
            spacing: 4px;

            if code > 0: LabelMark {
                code: code;
                size: 14px;
                y: (parent.height - self.height) / 2;
            }

            Text {
                text: Labels.names[code];
                color: Theme.ink;
                font-size: Theme.text-sm;
                vertical-alignment: center;
            }
        }
    }
}