package unit;

import support.Moad0004Algorithm;
import support.Moad0004Algorithm.Result;

import java.util.Map;

/**
 * Unit tests for MOAD-0004: A Logged Secret.
 *
 * Proves from first principles:
 *   1. Defective: Authorization and Cookie headers appear verbatim in the log line —
 *      bearer token and session cookie exposed in cleartext.
 *   2. Defective: leak count equals the number of credential headers present.
 *   3. Fixed: credential header values are replaced with [REDACTED] —
 *      log line contains header names (for debugging) but not values.
 *   4. Fixed: non-credential headers (Host, Content-Type) pass through unchanged.
 *   5. Both handle empty header maps without error.
 *
 * No build tool required. Compile and run:
 *
 *   cd tests
 *   java -m jdk.compiler/com.sun.tools.javac.Main -cp . \
 *        support/Moad0004Algorithm.java unit/Moad0004UnitTest.java
 *   java -cp . unit.Moad0004UnitTest
 */
public class Moad0004UnitTest {

    private static int passed = 0;
    private static int failed = 0;

    public static void main(String[] args) {
        System.out.println("=== Moad0004UnitTest (A Logged Secret) ===\n");

        System.out.println("-- Correctness: both handle headers without throwing --");
        testBothHandleEmpty();

        System.out.println("\n-- Defect: credential headers appear in cleartext log --");
        testDefectiveAuthorizationLeaks();
        testDefectiveCookieLeaks();
        testDefectiveCountsAllCredentialHeaders();
        testDefectiveNonCredentialHeadersPresent();

        System.out.println("\n-- Fix: credential headers redacted, non-credential headers intact --");
        testFixedAuthorizationRedacted();
        testFixedCookieRedacted();
        testFixedNonCredentialHeadersPassThrough();
        testFixedZeroLeakCount();

        System.out.printf("\n%d passed, %d failed%n", passed, failed);
        if (failed > 0) System.exit(1);
    }

    // ── Correctness ───────────────────────────────────────────────────────────

    static void testBothHandleEmpty() {
        Map<String, String> empty = Map.of();
        Result def = Moad0004Algorithm.logDefective(empty);
        Result fix = Moad0004Algorithm.logFixed(empty);
        assertEqual("defective: empty headers, zero leaks", 0, def.credentialLeakCount);
        assertEqual("fixed: empty headers, zero leaks",     0, fix.credentialLeakCount);
    }

    // ── Defect ────────────────────────────────────────────────────────────────

    static void testDefectiveAuthorizationLeaks() {
        Map<String, String> headers = Moad0004Algorithm.sampleHeaders();
        Result result = Moad0004Algorithm.logDefective(headers);

        // DEFECT: bearer token appears in the log line verbatim
        assertContains("defective: Authorization value in log (bearer token exposed)",
            result.logLine, "eyJhbGciOiJSUzI1NiJ9.secret.token");
    }

    static void testDefectiveCookieLeaks() {
        Map<String, String> headers = Moad0004Algorithm.sampleHeaders();
        Result result = Moad0004Algorithm.logDefective(headers);

        // DEFECT: session cookie and CSRF token appear in the log line
        assertContains("defective: Cookie value in log (session cookie exposed)",
            result.logLine, "session=abc123def456");
    }

    static void testDefectiveCountsAllCredentialHeaders() {
        Map<String, String> headers = Moad0004Algorithm.sampleHeaders();
        Result result = Moad0004Algorithm.logDefective(headers);

        // sampleHeaders() contains: Authorization, Cookie, X-Api-Key = 3 credential headers
        assertEqual("defective: counts 3 credential header leaks", 3, result.credentialLeakCount);
    }

    static void testDefectiveNonCredentialHeadersPresent() {
        Map<String, String> headers = Moad0004Algorithm.sampleHeaders();
        Result result = Moad0004Algorithm.logDefective(headers);

        // Non-credential headers should appear (correct behavior for logging)
        assertContains("defective: Host header present in log", result.logLine, "api.example.com");
        assertContains("defective: X-Request-Id present in log", result.logLine, "req-7f3a9c");
    }

    // ── Fix ───────────────────────────────────────────────────────────────────

    static void testFixedAuthorizationRedacted() {
        Map<String, String> headers = Moad0004Algorithm.sampleHeaders();
        Result result = Moad0004Algorithm.logFixed(headers);

        // FIX: bearer token must NOT appear in the log line
        assertNotContains("fixed: bearer token NOT in log",
            result.logLine, "eyJhbGciOiJSUzI1NiJ9.secret.token");

        // The header name should still appear (useful for debugging)
        assertContains("fixed: Authorization header name present (redacted value)",
            result.logLine, "Authorization");
    }

    static void testFixedCookieRedacted() {
        Map<String, String> headers = Moad0004Algorithm.sampleHeaders();
        Result result = Moad0004Algorithm.logFixed(headers);

        // FIX: session cookie must NOT appear
        assertNotContains("fixed: session cookie NOT in log", result.logLine, "session=abc123def456");

        // The header name should still appear
        assertContains("fixed: Cookie header name present", result.logLine, "Cookie");
    }

    static void testFixedNonCredentialHeadersPassThrough() {
        Map<String, String> headers = Moad0004Algorithm.sampleHeaders();
        Result result = Moad0004Algorithm.logFixed(headers);

        // Non-credential headers must pass through unchanged
        assertContains("fixed: Host value passes through",       result.logLine, "api.example.com");
        assertContains("fixed: X-Request-Id passes through",     result.logLine, "req-7f3a9c");
        assertContains("fixed: Content-Type passes through",     result.logLine, "application/json");
    }

    static void testFixedZeroLeakCount() {
        Map<String, String> headers = Moad0004Algorithm.sampleHeaders();
        Result result = Moad0004Algorithm.logFixed(headers);
        assertEqual("fixed: zero credential leaks", 0, result.credentialLeakCount);
    }

    // ── Helpers ───────────────────────────────────────────────────────────────

    static void assertEqual(String label, int expected, int actual) {
        if (expected == actual) {
            System.out.printf("  PASS: %s%n", label);
            passed++;
        } else {
            System.out.printf("  FAIL: %s — expected %d, got %d%n", label, expected, actual);
            failed++;
        }
    }

    static void assertContains(String label, String haystack, String needle) {
        if (haystack.contains(needle)) {
            System.out.printf("  PASS: %s%n", label);
            passed++;
        } else {
            System.out.printf("  FAIL: %s — '%s' not found in: %s%n", label, needle, haystack);
            failed++;
        }
    }

    static void assertNotContains(String label, String haystack, String needle) {
        if (!haystack.contains(needle)) {
            System.out.printf("  PASS: %s%n", label);
            passed++;
        } else {
            System.out.printf("  FAIL: %s — '%s' should NOT be in: %s%n", label, needle, haystack);
            failed++;
        }
    }
}