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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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 * accompanied this code).

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package sun.security.provider.certpath;

import java.util.Collections;

import java.util.HashSet;

import java.util.Iterator;

import java.util.Set;

import java.security.cert.*;

/**

 * Implements the <code>PolicyNode</code> interface.

 * <p>

 * This class provides an implementation of the <code>PolicyNode</code>

 * interface, and is used internally to build and search Policy Trees.

 * While the implementation is mutable during construction, it is immutable

 * before returning to a client and no mutable public or protected methods

 * are exposed by this implementation, as per the contract of PolicyNode.

 *

 * @since       1.4

 * @author      Seth Proctor

 * @author      Sean Mullan

 */

final class PolicyNodeImpl implements PolicyNode {

    /**

     * Use to specify the special policy "Any Policy"

     */

    private static final String ANY_POLICY = "2.5.29.32.0";

    // every node has one parent, and zero or more children

    private PolicyNodeImpl mParent;

    private HashSet<PolicyNodeImpl> mChildren;

    private String mValidPolicy;

    private HashSet<PolicyQualifierInfo> mQualifierSet;

    private boolean mCriticalityIndicator;

    private HashSet<String> mExpectedPolicySet;

    private boolean mOriginalExpectedPolicySet;

    // the tree depth

    private int mDepth;

    // immutability flag

    private boolean isImmutable = false;

    /**

     * Constructor which takes a <code>PolicyNodeImpl</code> representing the

     * parent in the Policy Tree to this node. If null, this is the

     * root of the tree. The constructor also takes the associated data

     * for this node, as found in the certificate. It also takes a boolean

     * argument specifying whether this node is being created as a result

     * of policy mapping.

     *

     * @param parent the PolicyNode above this in the tree, or null if this

     *               node is the tree's root node

     * @param validPolicy a String representing this node's valid policy OID

     * @param qualifierSet the Set of qualifiers for this policy

     * @param criticalityIndicator a boolean representing whether or not the

     *                             extension is critical

     * @param expectedPolicySet a Set of expected policies

     * @param generatedByPolicyMapping a boolean indicating whether this

     * node was generated by a policy mapping

     */

    PolicyNodeImpl(PolicyNodeImpl parent, String validPolicy,

                Set<PolicyQualifierInfo> qualifierSet,

                boolean criticalityIndicator, Set<String> expectedPolicySet,

                boolean generatedByPolicyMapping) {

        mParent = parent;

        mChildren = new HashSet<PolicyNodeImpl>();

        if (validPolicy != null)

            mValidPolicy = validPolicy;

        else

            mValidPolicy = "";

        if (qualifierSet != null)

            mQualifierSet = new HashSet<PolicyQualifierInfo>(qualifierSet);

        else

            mQualifierSet = new HashSet<PolicyQualifierInfo>();

        mCriticalityIndicator = criticalityIndicator;

        if (expectedPolicySet != null)

            mExpectedPolicySet = new HashSet<String>(expectedPolicySet);

        else

            mExpectedPolicySet = new HashSet<String>();

        mOriginalExpectedPolicySet = !generatedByPolicyMapping;

        // see if we're the root, and act appropriately

        if (mParent != null) {

            mDepth = mParent.getDepth() + 1;

            mParent.addChild(this);

        } else {

            mDepth = 0;

        }

    }

    /**

     * Alternate constructor which makes a new node with the policy data

     * in an existing <code>PolicyNodeImpl</code>.

     *

     * @param parent a PolicyNode that's the new parent of the node, or

     *               null if this is the root node

     * @param node a PolicyNode containing the policy data to copy

     */

    PolicyNodeImpl(PolicyNodeImpl parent, PolicyNodeImpl node) {

        this(parent, node.mValidPolicy, node.mQualifierSet,

             node.mCriticalityIndicator, node.mExpectedPolicySet, false);

    }

    @Override

    public PolicyNode getParent() {

        return mParent;

    }

    @Override

    public Iterator<PolicyNodeImpl> getChildren() {

        return Collections.unmodifiableSet(mChildren).iterator();

    }

    @Override

    public int getDepth() {

        return mDepth;

    }

    @Override

    public String getValidPolicy() {

        return mValidPolicy;

    }

    @Override

    public Set<PolicyQualifierInfo> getPolicyQualifiers() {

        return Collections.unmodifiableSet(mQualifierSet);

    }

    @Override

    public Set<String> getExpectedPolicies() {

        return Collections.unmodifiableSet(mExpectedPolicySet);

    }

    @Override

    public boolean isCritical() {

        return mCriticalityIndicator;

    }

    /**

     * Return a printable representation of the PolicyNode.

     * Starting at the node on which this method is called,

     * it recurses through the tree and prints out each node.

     *

     * @return a String describing the contents of the Policy Node

     */

    @Override

    public String toString() {

        StringBuilder buffer = new StringBuilder(this.asString());

        for (PolicyNodeImpl node : mChildren) {

            buffer.append(node);

        }

        return buffer.toString();

    }

    // private methods and package private operations

    boolean isImmutable() {

        return isImmutable;

    }

    /**

     * Sets the immutability flag of this node and all of its children

     * to true.

     */

    void setImmutable() {

        if (isImmutable)

            return;

        for (PolicyNodeImpl node : mChildren) {

            node.setImmutable();

        }

        isImmutable = true;

    }

    /**

     * Private method sets a child node. This is called from the child's

     * constructor.

     *

     * @param child new <code>PolicyNodeImpl</code> child node

     */

    private void addChild(PolicyNodeImpl child) {

        if (isImmutable) {

            throw new IllegalStateException("PolicyNode is immutable");

        }

        mChildren.add(child);

    }

    /**

     * Adds an expectedPolicy to the expected policy set.

     * If this is the original expected policy set initialized

     * by the constructor, then the expected policy set is cleared

     * before the expected policy is added.

     *

     * @param expectedPolicy a String representing an expected policy.

     */

    void addExpectedPolicy(String expectedPolicy) {

        if (isImmutable) {

            throw new IllegalStateException("PolicyNode is immutable");

        }

        if (mOriginalExpectedPolicySet) {

            mExpectedPolicySet.clear();

            mOriginalExpectedPolicySet = false;

        }

        mExpectedPolicySet.add(expectedPolicy);

    }

    /**

     * Removes all paths which don't reach the specified depth.

     *

     * @param depth an int representing the desired minimum depth of all paths

     */

    void prune(int depth) {

        if (isImmutable)

            throw new IllegalStateException("PolicyNode is immutable");

        // if we have no children, we can't prune below us...

        if (mChildren.size() == 0)

            return;

        Iterator<PolicyNodeImpl> it = mChildren.iterator();

        while (it.hasNext()) {

            PolicyNodeImpl node = it.next();

            node.prune(depth);

            // now that we've called prune on the child, see if we should

            // remove it from the tree

            if ((node.mChildren.size() == 0) && (depth > mDepth + 1))

                it.remove();

        }

    }

    /**

     * Deletes the specified child node of this node, if it exists.

     *

     * @param childNode the child node to be deleted

     */

    void deleteChild(PolicyNode childNode) {

        if (isImmutable) {

            throw new IllegalStateException("PolicyNode is immutable");

        }

        mChildren.remove(childNode);

    }

    /**

     * Returns a copy of the tree, without copying the policy-related data,

     * rooted at the node on which this was called.

     *

     * @return a copy of the tree

     */

    PolicyNodeImpl copyTree() {

        return copyTree(null);

    }

    private PolicyNodeImpl copyTree(PolicyNodeImpl parent) {

        PolicyNodeImpl newNode = new PolicyNodeImpl(parent, this);

        for (PolicyNodeImpl node : mChildren) {

            node.copyTree(newNode);

        }

        return newNode;

    }

    /**

     * Returns all nodes at the specified depth in the tree.

     *

     * @param depth an int representing the depth of the desired nodes

     * @return a <code>Set</code> of all nodes at the specified depth

     */

    Set<PolicyNodeImpl> getPolicyNodes(int depth) {

        Set<PolicyNodeImpl> set = new HashSet<>();

        getPolicyNodes(depth, set);

        return set;

    }

    /**

     * Add all nodes at depth depth to set and return the Set.

     * Internal recursion helper.

     */

    private void getPolicyNodes(int depth, Set<PolicyNodeImpl> set) {

        // if we've reached the desired depth, then return ourself

        if (mDepth == depth) {

            set.add(this);

        } else {

            for (PolicyNodeImpl node : mChildren) {

                node.getPolicyNodes(depth, set);

            }

        }

    }

    /**

     * Finds all nodes at the specified depth whose expected_policy_set

     * contains the specified expected OID (if matchAny is false)

     * or the special OID "any value" (if matchAny is true).

     *

     * @param depth an int representing the desired depth

     * @param expectedOID a String encoding the valid OID to match

     * @param matchAny a boolean indicating whether an expected_policy_set

     * containing ANY_POLICY should be considered a match

     * @return a Set of matched <code>PolicyNode</code>s

     */

    Set<PolicyNodeImpl> getPolicyNodesExpected(int depth,

        String expectedOID, boolean matchAny) {

        if (expectedOID.equals(ANY_POLICY)) {

            return getPolicyNodes(depth);

        } else {

            return getPolicyNodesExpectedHelper(depth, expectedOID, matchAny);

        }

    }

    private Set<PolicyNodeImpl> getPolicyNodesExpectedHelper(int depth,

        String expectedOID, boolean matchAny) {

        HashSet<PolicyNodeImpl> set = new HashSet<>();

        if (mDepth < depth) {

            for (PolicyNodeImpl node : mChildren) {

                set.addAll(node.getPolicyNodesExpectedHelper(depth,

                                                             expectedOID,

                                                             matchAny));

            }

        } else {

            if (matchAny) {

                if (mExpectedPolicySet.contains(ANY_POLICY))

                    set.add(this);

            } else {

                if (mExpectedPolicySet.contains(expectedOID))

                    set.add(this);

            }

        }

        return set;

    }

    /**

     * Finds all nodes at the specified depth that contains the

     * specified valid OID

     *

     * @param depth an int representing the desired depth

     * @param validOID a String encoding the valid OID to match

     * @return a Set of matched <code>PolicyNode</code>s

     */

    Set<PolicyNodeImpl> getPolicyNodesValid(int depth, String validOID) {

        HashSet<PolicyNodeImpl> set = new HashSet<>();

        if (mDepth < depth) {

            for (PolicyNodeImpl node : mChildren) {

                set.addAll(node.getPolicyNodesValid(depth, validOID));

            }

        } else {

            if (mValidPolicy.equals(validOID))

                set.add(this);

        }

        return set;

    }

    private static String policyToString(String oid) {

        if (oid.equals(ANY_POLICY)) {

            return "anyPolicy";

        } else {

            return oid;

        }

    }

    /**

     * Prints out some data on this node.

     */

    String asString() {

        if (mParent == null) {

            return "anyPolicy  ROOT\n";

        } else {

            StringBuilder sb = new StringBuilder();

            for (int i = 0, n = getDepth(); i < n; i++) {

                sb.append("  ");

            }

            sb.append(policyToString(getValidPolicy()));

            sb.append("  CRIT: ");

            sb.append(isCritical());

            sb.append("  EP: ");

            for (String policy : getExpectedPolicies()) {

                sb.append(policyToString(policy));

                sb.append(" ");

            }

            sb.append(" (");

            sb.append(getDepth());

            sb.append(")\n");

            return sb.toString();

        }

    }

}