import java.util.*;

/**
 * CWE-407 unit test for Asterisk app_queue.c defect.
 *
 * asterisk-0001: apps/app_queue.c interface_exists()
 *   ao2_iterator_init + while(ao2_iterator_next) + strcasecmp — O(M) walk
 *   over all queue members to find one by interface string.
 *   Fix: ao2_find(q->members, interface, OBJ_KEY) — O(1) hash lookup using
 *   the container's existing key function (members already keyed by interface).
 */
public class AsteriskTest {

    // Simulate defect: O(M) iterator walk
    static String interfaceExists_iterator(List<String> members, String iface) {
        for (String m : members) {                  // O(M) linear scan
            if (m.equalsIgnoreCase(iface)) return m;
        }
        return null;
    }

    // Simulate fix: O(1) hash lookup
    static String interfaceExists_ao2find(Map<String, String> membersMap, String iface) {
        return membersMap.get(iface.toLowerCase());  // O(1)
    }

    static void testAsterisk0001() throws Exception {
        int M = 2000;   // queue members
        List<String> members = new ArrayList<>();
        Map<String, String> membersMap = new HashMap<>();
        for (int i = 0; i < M; i++) {
            String iface = "SIP/agent-" + String.format("%04d", i);
            members.add(iface);
            membersMap.put(iface.toLowerCase(), iface);
        }

        // target near end of list (worst case for linear scan)
        String target = "SIP/agent-" + String.format("%04d", M - 1);

        // correctness
        String r1 = interfaceExists_iterator(members, target);
        String r2 = interfaceExists_ao2find(membersMap, target);
        assert r1 != null && r1.equalsIgnoreCase(target) : "iterator must find target";
        assert r2 != null && r2.equalsIgnoreCase(target) : "ao2find must find target";
        assert interfaceExists_iterator(members, "SIP/nonexistent") == null;
        assert interfaceExists_ao2find(membersMap, "SIP/nonexistent") == null;

        // performance: simulate C calls per second
        int REPS = 20_000;
        long t0 = System.nanoTime();
        for (int r = 0; r < REPS; r++) interfaceExists_iterator(members, target);
        long tIter = System.nanoTime() - t0;

        t0 = System.nanoTime();
        for (int r = 0; r < REPS; r++) interfaceExists_ao2find(membersMap, target);
        long tHash = System.nanoTime() - t0;

        double ratio = (double) tIter / tHash;
        System.out.printf("asterisk-0001: iter=%.3fs ao2find=%.3fs ratio=%.1f×%n",
                tIter / 1e9, tHash / 1e9, ratio);
        assert ratio > 10 : "Expected >10× speedup, got " + ratio;
        System.out.println("PASS asterisk-0001");
    }

    public static void main(String[] args) throws Exception {
        testAsterisk0001();
        System.out.println("ALL PASS");
    }
}