import java.util.*;

/**
 * CWE-407 unit test for digikam-0001: Haar similarity search targetAlbums
 * QList<int>::contains() called for every image in DB during similarity search.
 * O(N * A) where N = images, A = target albums → O(N) with QSet.
 *
 * Simulates fulfillsRestrictions called N times with targetAlbums.contains().
 */
public class DigikamHaarTargetAlbumsTest {

    // --- DEFECTIVE: List contains in inner loop ---
    static int searchDefective(int numImages, List<Integer> targetAlbums, int[] imageAlbums) {
        int matches = 0;
        for (int i = 0; i < numImages; i++) {
            int albumId = imageAlbums[i];
            if (targetAlbums.isEmpty() || targetAlbums.contains(albumId)) {  // O(A)
                matches++;
            }
        }
        return matches;
    }

    // --- PATCHED: Set contains in inner loop ---
    static int searchPatched(int numImages, Set<Integer> targetAlbumsSet, int[] imageAlbums) {
        int matches = 0;
        for (int i = 0; i < numImages; i++) {
            int albumId = imageAlbums[i];
            if (targetAlbumsSet.isEmpty() || targetAlbumsSet.contains(albumId)) {  // O(1)
                matches++;
            }
        }
        return matches;
    }

    public static void main(String[] args) {
        int N = 50000;   // images in database
        int A = 200;     // target albums
        int totalAlbums = 500;

        // Build target albums list/set
        List<Integer> targetAlbumsList = new ArrayList<>();
        Set<Integer> targetAlbumsSet = new HashSet<>();
        for (int i = 0; i < A; i++) {
            targetAlbumsList.add(i);
            targetAlbumsSet.add(i);
        }

        // Build image album assignments
        Random rng = new Random(42);
        int[] imageAlbums = new int[N];
        for (int i = 0; i < N; i++) {
            imageAlbums[i] = rng.nextInt(totalAlbums);
        }

        // Warm up
        for (int w = 0; w < 3; w++) {
            searchDefective(N, targetAlbumsList, imageAlbums);
            searchPatched(N, targetAlbumsSet, imageAlbums);
        }

        // Benchmark defective
        int iterations = 20;
        long startDef = System.nanoTime();
        int resultDef = 0;
        for (int i = 0; i < iterations; i++) {
            resultDef = searchDefective(N, targetAlbumsList, imageAlbums);
        }
        long defectiveNs = System.nanoTime() - startDef;

        // Benchmark patched
        long startPat = System.nanoTime();
        int resultPat = 0;
        for (int i = 0; i < iterations; i++) {
            resultPat = searchPatched(N, targetAlbumsSet, imageAlbums);
        }
        long patchedNs = System.nanoTime() - startPat;

        double ratio = (double) defectiveNs / patchedNs;

        System.out.println("digikam-0001: Haar searchDatabase targetAlbums.contains()");
        System.out.println("N=" + N + " images, A=" + A + " target albums");
        System.out.println("Defective matches: " + resultDef + "  Patched matches: " + resultPat);
        System.out.printf("Defective: %.3f ms%n", defectiveNs / 1e6);
        System.out.printf("Patched:   %.3f ms%n", patchedNs / 1e6);
        System.out.printf("Ratio:     %.1fx%n", ratio);

        assert resultDef == resultPat : "Results must match!";

        boolean pass = ratio > 2.0;
        System.out.println(pass ? "PASS" : "FAIL");
        if (!pass) System.exit(1);
    }
}