package unit;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

/**
 * Unit test for Quarkus CWE-407 defects:
 *   quarkus-0001: BeanInfo.getBoundInterceptors — bound.contains (ArrayList) in nested loops
 *   quarkus-0002: ComponentsProviderGenerator.isDependency — dependants.contains (ArrayList) in loop
 *
 * No JUnit. No external deps. Compile and run:
 *   javac -d . *.java && java -ea unit.QuarkusTest
 */
public class QuarkusTest {

    // ---- quarkus-0001 simulation ----
    // Simulates getBoundInterceptors(): nested loops over lifecycle + intercepted methods,
    // deduplicating into 'bound' list using ArrayList.contains

    static long slowGetBoundInterceptors(int methodCount, int interceptorsPerMethod) {
        long ops = 0;
        List<Integer> bound = new ArrayList<>();

        // Loop 1: lifecycleInterceptors.values()
        for (int m = 0; m < methodCount / 2; m++) {
            for (int i = 0; i < interceptorsPerMethod; i++) {
                int interceptorId = i;  // interceptors reused across methods (dedup needed)
                ops += bound.size() + 1;  // cost of ArrayList.contains scan
                if (!bound.contains(interceptorId)) {
                    bound.add(interceptorId);
                }
            }
        }

        // Loop 2: interceptedMethods.values()
        for (int m = methodCount / 2; m < methodCount; m++) {
            for (int i = 0; i < interceptorsPerMethod; i++) {
                int interceptorId = i;
                ops += bound.size() + 1;
                if (!bound.contains(interceptorId)) {
                    bound.add(interceptorId);
                }
            }
        }

        return ops;
    }

    static long fastGetBoundInterceptors(int methodCount, int interceptorsPerMethod) {
        long ops = 0;
        Set<Integer> boundSet = new LinkedHashSet<>();

        for (int m = 0; m < methodCount / 2; m++) {
            for (int i = 0; i < interceptorsPerMethod; i++) {
                int interceptorId = i;
                ops += 1;  // O(1) HashSet.contains
                boundSet.add(interceptorId);
            }
        }

        for (int m = methodCount / 2; m < methodCount; m++) {
            for (int i = 0; i < interceptorsPerMethod; i++) {
                int interceptorId = i;
                ops += 1;
                boundSet.add(interceptorId);
            }
        }

        // Convert to sorted List at end (one-time O(I log I))
        List<Integer> bound = new ArrayList<>(boundSet);
        return ops;
    }

    // ---- quarkus-0002 simulation ----
    // Simulates isDependency called O(B) times, each iterating map values (O(B)) and
    // calling dependants.contains (ArrayList, O(D)).

    static long slowIsDependency(int beanCount, int dependantsPerBean) {
        long ops = 0;
        // dependencyMap: bean → list of dependants
        Map<Integer, List<Integer>> dependencyMap = new TreeMap<>();
        for (int b = 0; b < beanCount; b++) {
            List<Integer> dependants = new ArrayList<>();
            for (int d = 0; d < dependantsPerBean; d++) {
                dependants.add((b + d + 1) % beanCount);
            }
            dependencyMap.put(b, dependants);
        }

        // isDependency called for each bean (O(B) calls total)
        for (int queryBean = 0; queryBean < beanCount; queryBean++) {
            for (List<Integer> dependants : dependencyMap.values()) {  // O(B) map values
                ops += dependants.size();  // ArrayList.contains scan cost
                if (dependants.contains(queryBean)) {
                    break;
                }
            }
        }
        return ops;
    }

    static long fastIsDependency(int beanCount, int dependantsPerBean) {
        long ops = 0;
        Map<Integer, List<Integer>> dependencyMap = new TreeMap<>();
        for (int b = 0; b < beanCount; b++) {
            List<Integer> dependants = new ArrayList<>();
            for (int d = 0; d < dependantsPerBean; d++) {
                dependants.add((b + d + 1) % beanCount);
            }
            dependencyMap.put(b, dependants);
        }

        // Build inverted index once: O(B×D)
        Set<Integer> allDependants = new HashSet<>();
        for (List<Integer> dependants : dependencyMap.values()) {
            allDependants.addAll(dependants);
        }

        // isDependency is now O(1) per call
        for (int queryBean = 0; queryBean < beanCount; queryBean++) {
            ops += 1;  // O(1) HashSet.contains
            allDependants.contains(queryBean);
        }
        return ops;
    }

    public static void main(String[] args) {
        int pass = 0;
        int total = 0;

        // --- quarkus-0001 tests ---
        {
            total++;
            long slow = slowGetBoundInterceptors(20, 8);
            long fast = fastGetBoundInterceptors(20, 8);
            boolean ok = slow > fast * 3;
            System.out.println("[quarkus-0001] M=20 I=8: slow_ops=" + slow + " fast_ops=" + fast +
                               " ratio=" + (slow / Math.max(fast, 1)) + "x  " + (ok ? "PASS" : "FAIL"));
            if (ok) pass++;
        }
        {
            total++;
            long slow = slowGetBoundInterceptors(50, 15);
            long fast = fastGetBoundInterceptors(50, 15);
            boolean ok = slow > fast * 5;
            System.out.println("[quarkus-0001] M=50 I=15: slow_ops=" + slow + " fast_ops=" + fast +
                               " ratio=" + (slow / Math.max(fast, 1)) + "x  " + (ok ? "PASS" : "FAIL"));
            if (ok) pass++;
        }
        {
            total++;
            // Correctness: both paths must produce same unique interceptor count
            Set<Integer> slowBound = new LinkedHashSet<>();
            Set<Integer> fastBound = new LinkedHashSet<>();
            int methods = 10, interceptors = 5;
            // slow: uses ArrayList dedup but we track the same set for checking
            List<Integer> slowList = new ArrayList<>();
            for (int m = 0; m < methods; m++) {
                for (int i = 0; i < interceptors; i++) {
                    if (!slowList.contains(i)) slowList.add(i);
                }
            }
            Set<Integer> fastSet = new LinkedHashSet<>();
            for (int m = 0; m < methods; m++) {
                for (int i = 0; i < interceptors; i++) {
                    fastSet.add(i);
                }
            }
            boolean ok = slowList.size() == fastSet.size();
            System.out.println("[quarkus-0001] correctness: slow=" + slowList.size() +
                               " fast=" + fastSet.size() + "  " + (ok ? "PASS" : "FAIL"));
            if (ok) pass++;
        }

        // --- quarkus-0002 tests ---
        {
            total++;
            long slow = slowIsDependency(100, 5);
            long fast = fastIsDependency(100, 5);
            boolean ok = slow > fast * 20;
            System.out.println("[quarkus-0002] B=100 D=5: slow_ops=" + slow + " fast_ops=" + fast +
                               " ratio=" + (slow / Math.max(fast, 1)) + "x  " + (ok ? "PASS" : "FAIL"));
            if (ok) pass++;
        }
        {
            total++;
            long slow = slowIsDependency(300, 10);
            long fast = fastIsDependency(300, 10);
            boolean ok = slow > fast * 100;
            System.out.println("[quarkus-0002] B=300 D=10: slow_ops=" + slow + " fast_ops=" + fast +
                               " ratio=" + (slow / Math.max(fast, 1)) + "x  " + (ok ? "PASS" : "FAIL"));
            if (ok) pass++;
        }
        {
            total++;
            // Correctness: isDependency returns same true/false for same query
            Map<Integer, List<Integer>> dmap = new HashMap<>();
            dmap.put(0, new ArrayList<>(List.of(1, 2, 3)));
            dmap.put(1, new ArrayList<>(List.of(4, 5)));
            dmap.put(2, new ArrayList<>(List.of(6)));

            // slow: iterate all lists, call contains
            boolean slowResult3 = false;
            boolean slowResult7 = false;
            for (List<Integer> deps : dmap.values()) {
                if (deps.contains(3)) { slowResult3 = true; break; }
            }
            for (List<Integer> deps : dmap.values()) {
                if (deps.contains(7)) { slowResult7 = true; break; }
            }

            // fast: precompute set
            Set<Integer> allDeps = new HashSet<>();
            for (List<Integer> deps : dmap.values()) allDeps.addAll(deps);
            boolean fastResult3 = allDeps.contains(3);
            boolean fastResult7 = allDeps.contains(7);

            boolean ok = slowResult3 == fastResult3 && slowResult7 == fastResult7
                         && slowResult3 == true && slowResult7 == false;
            System.out.println("[quarkus-0002] isDependency correctness: bean3=" + fastResult3 +
                               " bean7=" + fastResult7 + "  " + (ok ? "PASS" : "FAIL"));
            if (ok) pass++;
        }

        System.out.println("\n" + pass + "/" + total + " PASS");
        if (pass != total) {
            System.exit(1);
        }
    }
}