package unit;

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

/**
 * CWE-407 unit test: keystone-0001
 * Implied-role deduplication: list comprehension vs set.
 *
 * Slow: `if imp_role_obj['id'] not in [x['id'] for x in roles]`
 *       rebuilds list every check — O(n) per implied role.
 * Fast: maintain a seen_role_ids set — O(1) per check.
 */
public class KeystoneImpliedRoleAlgorithm {

    // Simulates the implied-role graph: role_id -> list of implied role_ids
    static Map<String, List<String>> buildImpliedGraph(int R, int I) {
        Map<String, List<String>> graph = new HashMap<>();
        for (int i = 0; i < R; i++) {
            List<String> implied = new ArrayList<>();
            for (int j = 0; j < I; j++) {
                implied.add("implied-" + i + "-" + j);
            }
            graph.put("role-" + i, implied);
            // implied roles themselves have no further implications
            for (int j = 0; j < I; j++) {
                graph.put("implied-" + i + "-" + j, new ArrayList<>());
            }
        }
        return graph;
    }

    // Defective: list comprehension for deduplication
    static long expandRolesSlow(List<Map<String, String>> roles,
                                 Map<String, List<String>> impliedGraph) {
        long ops = 0;
        // NOTE: iterating over a mutable list that grows — simulating the defect
        for (int idx = 0; idx < roles.size(); idx++) {
            Map<String, String> role = roles.get(idx);
            List<String> implied = impliedGraph.getOrDefault(role.get("id"),
                                                              new ArrayList<>());
            for (String impId : implied) {
                ops++;
                // O(n) list scan — rebuild the id list each time
                boolean found = false;
                for (Map<String, String> r : roles) {  // O(current size)
                    ops++;
                    if (r.get("id").equals(impId)) { found = true; break; }
                }
                if (!found) {
                    Map<String, String> newRole = new HashMap<>();
                    newRole.put("id", impId);
                    roles.add(newRole);
                }
            }
        }
        return ops;
    }

    // Fixed: set for deduplication
    static long expandRolesFast(List<Map<String, String>> roles,
                                 Map<String, List<String>> impliedGraph) {
        long ops = 0;
        Set<String> seenIds = new HashSet<>();
        for (Map<String, String> r : roles) seenIds.add(r.get("id"));

        List<Map<String, String>> snapshot = new ArrayList<>(roles);
        for (Map<String, String> role : snapshot) {
            List<String> implied = impliedGraph.getOrDefault(role.get("id"),
                                                              new ArrayList<>());
            for (String impId : implied) {
                ops++;
                if (!seenIds.contains(impId)) {   // O(1)
                    seenIds.add(impId);
                    Map<String, String> newRole = new HashMap<>();
                    newRole.put("id", impId);
                    roles.add(newRole);
                }
            }
        }
        return ops;
    }

    static List<Map<String, String>> makeRoles(int count) {
        List<Map<String, String>> roles = new ArrayList<>();
        for (int i = 0; i < count; i++) {
            Map<String, String> r = new HashMap<>();
            r.put("id", "role-" + i);
            roles.add(r);
        }
        return roles;
    }

    public static void main(String[] args) {
        int R = 50;   // initial roles
        int I = 10;   // implied roles per role

        int passed = 0;
        int total = 0;

        Map<String, List<String>> graph = buildImpliedGraph(R, I);

        // Test 1: op count slow vs fast
        List<Map<String, String>> rolesSlow = makeRoles(R);
        List<Map<String, String>> rolesFast = makeRoles(R);
        long slowOps = expandRolesSlow(rolesSlow, graph);
        long fastOps = expandRolesFast(rolesFast, graph);
        total++;
        assert slowOps > fastOps * 5 :
            "slow=" + slowOps + " fast=" + fastOps + " speedup insufficient";
        System.out.println("Test 1 PASS: implied-role expand slow=" + slowOps +
            " ops, fast=" + fastOps + " ops, speedup=" + (slowOps / Math.max(1, fastOps)) + "x");
        passed++;

        // Test 2: correctness — same final role set
        Set<String> slowIds = new HashSet<>();
        for (Map<String, String> r : rolesSlow) slowIds.add(r.get("id"));
        Set<String> fastIds = new HashSet<>();
        for (Map<String, String> r : rolesFast) fastIds.add(r.get("id"));
        total++;
        assert slowIds.equals(fastIds) :
            "role sets differ: slow=" + slowIds.size() + " fast=" + fastIds.size();
        System.out.println("Test 2 PASS: role sets agree (" + slowIds.size() + " roles)");
        passed++;

        // Test 3: no duplicates in fast result
        total++;
        assert rolesFast.size() == fastIds.size() :
            "fast result contains duplicates: list=" + rolesFast.size() +
            " set=" + fastIds.size();
        System.out.println("Test 3 PASS: no duplicates in fast result");
        passed++;

        // Test 4: token_roles deduplication — list vs set
        // Simulate `token_roles = [r['id'] for r in token.roles]` + loop check
        List<String> tokenRolesListBuild = new ArrayList<>();
        for (int i = 0; i < R; i++) tokenRolesListBuild.add("role-" + i);
        Set<String> tokenRolesSet = new HashSet<>(tokenRolesListBuild);

        long listCheckOps = 0;
        long setCheckOps = 0;
        List<Map<String, String>> allRoles = makeRoles(R * 2);  // some not in token
        for (Map<String, String> role : allRoles) {
            listCheckOps += tokenRolesListBuild.size();  // O(T) list scan
            setCheckOps++;  // O(1) set lookup
            @SuppressWarnings("unused") boolean listContains =
                tokenRolesListBuild.contains(role.get("id"));
            @SuppressWarnings("unused") boolean setContains =
                tokenRolesSet.contains(role.get("id"));
        }
        total++;
        assert listCheckOps > setCheckOps * 5 :
            "token_roles: list=" + listCheckOps + " set=" + setCheckOps;
        System.out.println("Test 4 PASS: token_roles list=" + listCheckOps +
            " ops, set=" + setCheckOps + " ops");
        passed++;

        System.out.println(passed + "/" + total + " PASS");
    }
}