package com.codebyte.api.common.util;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.HexFormat;

/** Small hashing helpers. Tokens are stored as SHA-256 hex, never in the clear. */
public final class HashUtil {

    private HashUtil() {}

    /** Returns the lowercase hex SHA-256 of the UTF-8 bytes of {@code value}. */
    public static String sha256Hex(String value) {
        try {
            byte[] digest =
                    MessageDigest.getInstance("SHA-256")
                            .digest(value.getBytes(StandardCharsets.UTF_8));
            return HexFormat.of().formatHex(digest);
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalStateException("SHA-256 is required but unavailable", e);
        }
    }
}