// 👆 Added a ".js" to this filename just to get the syntax highlighting on GitHub Gists.
// You should remove the ".js" part when using it.

/**
 * This Arcade script is used to generate labels for the milepost layer.
 */

/**
 * Gets the SRMP and Ahead/Back indicator attributes and
 * concatenates them into a single string.
 * @returns A string containing a number with up to three decimal places
 * and an optional "B" indicator.
 */
function getMilepost() {
    var output = Text($feature.SRMP, "#.###");
    if ($feature.AheadBackInd == "B") {
        output += "B"
    }
    return output;
}

/**
 * Gets the route prefix "I-", "US ", or "SR " corresponding to the
 * route associated with the current milepost feature.
 * @returns "I-", "US ", or "SR "
 */
function getShield() {
    var isRoutes = [5, 82, 90, 182, 205, 405, 705];

    var usRoutes = [2, 12, 97, 101, 195, 197, 395, 730];

    var shield = "SR ";

    var srNum = Number($feature.StateRouteNumber);

    if (Includes(isRoutes, srNum)) {
        shield = "I-";
    } else if (Includes(usRoutes, srNum)) {
        shield = "US ";
    }

    return shield;
}

/**
 * Gets the route label for the current milepost feature:
 * an integer with a suffix returned by {@link getShield()}.
 * @returns The route label for the current milepost feature.
 */
function getRouteLabel() {
    var output = $feature.RouteID;

    if ($feature.StateRouteNumber == $feature.RouteID) {
        output = `${getShield()}${Number($feature.StateRouteNumber)}`
    }

    return output;
}

// Concatenate the route label and milepost into a single string, along with
// corresponding labels, separated by a newline.
Concatenate([`Route: ${getRouteLabel()} (${$feature.Direction})`, `Milepost: ${getMilepost()}`], "\n");