package com.evsuite.abrp;

import java.io.File;
import java.util.Locale;

/**
 * Installing a car build from a USB stick — UNSTABLE BUILDS ONLY. For development: copy
 * {@code NilsMG4-unstable-<version>.apk} and its {@code .sha256} (both from build-car) to the top
 * folder of a stick, plug it in, press the button on the Settings tab.
 *
 * The same checks as the over-the-air update apply, minus the server: the newest such file that
 * is newer than the installed version, a matching SHA-256 sidecar, this app's package, and the
 * installer's own signature check. The pure parts are here, unit-tested; UpdateHook does the IO.
 */
final class UsbUpdate {

    private UsbUpdate() { }

    /** The top folder of the volume [appFilesDir] lives on; see {@link UsbVolume#root}. */
    static File volumeRoot(File appFilesDir) {
        return UsbVolume.root(appFilesDir);
    }

    /**
     * The car-build APK to install among [names]: the highest version that is newer than
     * [currentVersion], or null. Only names build-car writes count.
     */
    static String pickNewest(String[] names, String currentVersion) {
        String best = null, bestVersion = null;
        if (names == null) return null;
        for (String name : names) {
            if (name == null || !name.toLowerCase(Locale.US).startsWith("nilsmg4-unstable-")) continue;
            String version = OtaUpdater.versionFromAssetName(name);
            if (version == null || !OtaUpdater.isNewer(version, currentVersion)) continue;
            if (bestVersion == null || OtaUpdater.isNewer(version, bestVersion)) {
                best = name;
                bestVersion = version;
            }
        }
        return best;
    }
}