Flow 13 --- Runtime Algorithm-Discovery Smoke-Test

/*
 * Copyright 2025 ANKATech Solutions Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
package co.ankatech.ankasecure.sdk.examples;

import co.ankatech.ankasecure.sdk.AuthenticatedSdk;
import co.ankatech.ankasecure.sdk.model.*;
import co.ankatech.ankasecure.sdk.util.FileIO;

import java.nio.file.Path;
import java.util.List;
import java.util.Objects;
import java.util.Properties;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import static co.ankatech.ankasecure.sdk.examples.ExampleUtil.*;
import static co.ankatech.ankasecure.sdk.model.AlgorithmInfo.Category.POST_QUANTUM;
import static co.ankatech.ankasecure.sdk.model.AlgorithmInfo.Status.RECOMMENDED;

/**
 * Scenario 13 — Runtime Discovery of PQC Algorithms.
 *
 * <p>This scenario discovers two platform-recommended <em>post-quantum</em>
 * algorithms at runtime, filtered by <strong>exact</strong> security levels
 * and the dual-standards requirement <q>NIST and ENISA</q>:</p>
 * <ol>
 *   <li>Select the first PQC signing algorithm with
 *       <code>securityLevel&nbsp;5</code>.</li>
 *   <li>Select the first PQC encryption algorithm with
 *       <code>securityLevel&nbsp;3</code>.</li>
 *   <li>Resolve pre-provisioned keys for the discovered algorithms and exercise
 *       Compact JWS / Compact JWE helpers (the SDK is data-plane-only — it does
 *       not create keys).</li>
 *   <li>Validate round-trip integrity and print verbose metadata.</li>
 * </ol>
 *
 * @author ANKATech Solutions Inc.
 * @since 3.0.0
 * @see ExampleUtil
 * @see ExamplePlaygroundKeys
 * @see AuthenticatedSdk
 */
public final class ExampleScenario13 {

    /** No instantiation &mdash; this class only exposes {@link #main(String[])}. */
    private ExampleScenario13() { }

    /**
     * Runs the runtime PQC algorithm discovery scenario.
     *
     * <p>Loads CLI properties, authenticates against ANKASecure&copy;,
     * and delegates to the scenario logic. On any unrecoverable error
     * the JVM terminates via
     * {@link ExampleUtil#fatal(String, Throwable)}.</p>
     *
     * @param args command-line arguments (ignored)
     */
    public static void main(final String[] args) {
        System.out.println("===== SCENARIO 13 START =====");
        System.out.println("""
                Purpose :
                  * Discover PQC signing & encryption algorithms with strict filters.
                  * Resolve pre-provisioned keys for the discovered algorithms.
                  * Perform compact JWS sign/verify and compact JWE encrypt/decrypt.
                --------------------------------------------------------------""");

        try {
            prepareWorkingDir();

            Properties            props      = loadProperties();
            AuthenticatedSdk      sdk        = authenticate(props);
            ExamplePlaygroundKeys playground = ExamplePlaygroundKeys.from(props, sdk);

            runScenario(sdk, playground);

        } catch (Exception ex) {
            fatal("Scenario 13 failed", ex);
        }

        System.out.println("===== SCENARIO 13 END =====");
    }

    /* ====================================================================== */
    /** Executes discovery, key resolution, and validation. */
    private static void runScenario(final AuthenticatedSdk sdk,
                                    final ExamplePlaygroundKeys playground) throws Exception {

        /* 1 – discover algorithms -------------------------------------- */
        List<AlgorithmInfo> algorithms = sdk.getSupportedAlgorithms();

        AlgorithmInfo signAlg = algorithms.stream()
                .filter(a -> a.getStatus() == RECOMMENDED)
                .filter(a -> a.getCategory() == POST_QUANTUM)
                .filter(a -> Integer.valueOf(5).equals(a.getSecurityLevel()))
                .filter(a -> supports(a, "sign", "verify"))
                .filter(a -> a.getStandards().containsAll(Set.of("NIST", "ENISA")))
                .findFirst()
                .orElseThrow(() ->
                        new IllegalStateException("No PQC signing algorithm level 5 (NIST & ENISA) found."));

        AlgorithmInfo encAlg = algorithms.stream()
                .filter(a -> a.getStatus() == RECOMMENDED)
                .filter(a -> a.getCategory() == POST_QUANTUM)
                .filter(a -> Integer.valueOf(3).equals(a.getSecurityLevel()))
                .filter(a -> supports(a, "encrypt", "decrypt"))
                .filter(a -> a.getStandards().containsAll(Set.of("NIST", "ENISA")))
                .findFirst()
                .orElseThrow(() ->
                        new IllegalStateException("No PQC encryption algorithm level 3 (NIST & ENISA) found."));

        System.out.println("[1] PQC signing algorithm    : " + signAlg.getAlg());
        System.out.println("[2] PQC encryption algorithm : " + encAlg.getAlg());

        /* prepare sample data ------------------------------------------ */
        Path plain = TEMP_DIR.resolve("scenario13_plain.txt");
        FileIO.writeUtf8(
                plain,
                "Scenario 13 – PQC discovery smoke-test.");
        System.out.println("[3] Plaintext prepared       -> " + plain.toAbsolutePath());

        /* 2 – Compact JWS sign / verify ------------------------------- */
        String signKid = playground.kidForAlgorithm(signAlg.getAlg());
        System.out.printf("    * Using pre-provisioned key -> kid=%s, alg=%s%n", signKid, signAlg.getAlg());

        Path jwsFile = TEMP_DIR.resolve("scenario13.jws");
        SignResult signMeta = sdk.signFileCompact(signKid, plain, jwsFile);
        System.out.println("[4] JWS created              -> " + jwsFile);
        printSignMeta(signMeta);

        VerifySignatureResult verifyMeta = sdk.verifySignature(jwsFile);
        System.out.println("[5] JWS valid?               -> " + verifyMeta.isValid());
        printVerifyMeta(verifyMeta);

        /* 3 – Compact JWE encrypt / decrypt --------------------------- */
        String encKid = playground.kidForAlgorithm(encAlg.getAlg());
        System.out.printf("    * Using pre-provisioned key -> kid=%s, alg=%s%n", encKid, encAlg.getAlg());

        Path jweFile = TEMP_DIR.resolve("scenario13.enc");
        EncryptResult encMeta = sdk.encryptFile(encKid, plain, jweFile);
        System.out.println("[6] JWE created              -> " + jweFile);
        printEncryptMeta(encMeta);

        Path decFile = TEMP_DIR.resolve("scenario13_dec.txt");
        DecryptResultMetadata decMeta = sdk.decryptFile(jweFile, decFile);
        System.out.println("[7] Decrypted file           -> " + decFile);
        printDecryptMeta(decMeta);

        /* 4 – round-trip validation ---------------------------------- */
        boolean match = Objects.equals(
                FileIO.readUtf8(plain),
                FileIO.readUtf8(decFile));
        System.out.println(match
                ? "[✔] SUCCESS – round-trip data matches."
                : "[✘] FAILURE – data mismatch!");
    }

    /* ====================================================================== */
    private static boolean supports(final AlgorithmInfo alg, final String... ops) {
        Set<String> caps = alg.getKeyOps().stream()
                .map(String::toLowerCase)
                .collect(Collectors.toSet());
        return Stream.of(ops)
                .map(String::toLowerCase)
                .allMatch(caps::contains);
    }
}