# PolicyManager.java

    /*
     * Copyright (c) 2008, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *      http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
    package org.wso2.carbon.governance.api.policies;

    import org.apache.commons.logging.Log;
    import org.apache.commons.logging.LogFactory;
    import org.wso2.carbon.governance.api.common.dataobjects.GovernanceArtifact;
    import org.wso2.carbon.governance.api.exception.GovernanceException;
    import org.wso2.carbon.governance.api.policies.dataobjects.Policy;
    import org.wso2.carbon.governance.api.policies.dataobjects.PolicyImpl;
    import org.wso2.carbon.governance.api.util.GovernanceConstants;
    import org.wso2.carbon.governance.api.util.GovernanceUtils;
    import org.wso2.carbon.registry.core.Registry;
    import org.wso2.carbon.registry.core.Resource;
    import org.wso2.carbon.registry.core.exceptions.RegistryException;
    import org.wso2.carbon.registry.core.utils.RegistryUtils;

    import java.net.MalformedURLException;
    import java.net.URL;
    import java.util.*;

    /**
     * This provides the management functionality for policy artifacts stored on the
     * registry.
     */
    public class PolicyManager {

        private static final Log log = LogFactory.getLog(PolicyManager.class);
        private Registry registry;

        /**
         * Constructor accepting an instance of the registry to use.
         *
         * @param registry the instance of the registry.
         */
        public PolicyManager(Registry registry) {
            this.registry = registry;
        }

        /**
         * Create a new Schema based on content either embedded or passed to a service.
         *
         * @param content  the schema content
         *
         * @return the artifact added.
         * @throws GovernanceException if the operation failed.
         */
        public Policy newPolicy(byte[] content) throws RegistryException {
            return newPolicy(content, null);
        }

        /**
         * Create a new Schema based on content either embedded or passed to a service.
         *
         * @param content  the schema content
         * @param name     the schema name
         *
         * @return the artifact added.
         * @throws GovernanceException if the operation failed.
         */
        public Policy newPolicy(byte[] content, String name)
                throws RegistryException {
            String policyId = UUID.randomUUID().toString();
            PolicyImpl policy = new PolicyImpl(policyId, name != null ? "name://" + name : null);
            policy.associateRegistry(registry);
            policy.setPolicyContent(RegistryUtils.decodeBytes(content));
            return policy;
        }

        /**
         * Creates a new policy artifact from the given URL.
         *
         * @param url the given URL.
         *
         * @return the artifact added.
         * @throws GovernanceException if the operation failed.
         */
        public Policy newPolicy(String url) throws GovernanceException {
            String policyId = UUID.randomUUID().toString();
            PolicyImpl policy = new PolicyImpl(policyId, url);
            policy.associateRegistry(registry);
            return policy;
        }

        /**
         * Adds the given policy artifact to the registry. Please do not use this method to update an
         * existing artifact use the update method instead. If this method is used to update an existing
         * artifact, all existing properties (such as lifecycle details) will be removed from the
         * existing artifact.
         *
         * @param policy the policy artifact.
         *
         * @throws GovernanceException if the operation failed.
         */
        public void addPolicy(Policy policy) throws GovernanceException {
            boolean succeeded = false;
            String url = ((PolicyImpl)policy).getUrl();
            try {
                registry.beginTransaction();
                Resource policyResource = registry.newResource();
                policyResource.setMediaType(GovernanceConstants.POLICY_XML_MEDIA_TYPE);

               policyResource.setUUID(policy.getId());
                // setting the policy content
                setContent(policy, policyResource);
                String tmpPath;
                if (policy.getQName() != null) {
                    tmpPath = "/" + policy.getQName().getLocalPart();
                } else if (url != null && !url.startsWith("name://")) {
                    tmpPath = RegistryUtils.getResourceName(new URL(url).getFile().replace("~", ""));
                } else if (url != null) {
                    tmpPath = url.substring("name://".length());
                } else {
                    tmpPath = policy.getId() + ".xml";
                }
                // OK this is a hack to get the UUID of the newly added artifact. This needs to be fixed
                // properly with the fix for UUID support at Kernel-level - Janaka.
    //            Resource resource;
                if (url == null || url.startsWith("name://")) {
    //                resource = registry.get(registry.put("/" + tmpPath, policyResource));
                    registry.put("/" + tmpPath, policyResource);
                } else {
    //                resource = registry.get(registry.importResource(tmpPath, url, policyResource));
                    registry.importResource(tmpPath, url, policyResource);
                }
    //            policy.setId(policyResource.getUUID());
                ((PolicyImpl)policy).updatePath();
                ((PolicyImpl)policy).loadPolicyDetails();
                succeeded = true;
            } catch (RegistryException e) {
                String msg = "Error in adding the Policy. policy id: " + policy.getId() + ".";
                log.error(msg, e);
                throw new GovernanceException(msg, e);
            } catch (MalformedURLException e) {
                String msg = "Malformed policy url provided. url: " + url + ".";
                log.error(msg, e);
                throw new GovernanceException(msg, e);
            } finally {
                if (succeeded) {
                    try {
                        registry.commitTransaction();
                    } catch (RegistryException e) {
                        String msg =
                                "Error in committing transactions. Add policy failed: policy id: " +
                                        policy.getId() + ", path: " + policy.getPath() + ".";
                        log.error(msg, e);
                    }
                } else {
                    try {
                        registry.rollbackTransaction();
                    } catch (RegistryException e) {
                        String msg =
                                "Error in rolling back transactions. Add policy failed: policy id: " +
                                        policy.getId() + ", path: " + policy.getPath() + ".";
                        log.error(msg, e);
                    }
                }
            }
        }

        /**
         * Updates the given policy artifact on the registry.
         *
         * @param policy the policy artifact.
         *
         * @throws GovernanceException if the operation failed.
         */
        public void updatePolicy(Policy policy) throws GovernanceException {
            if (policy.getPolicyContent() == null) {
                // there won't be any updates
                String msg =
                        "Updates are only accepted if the policy content is available. " +
                                "So no updates will be done. " + "policy id: " + policy.getId() +
                                ", policy path: " + policy.getPath() + ".";
                log.error(msg);
                throw new GovernanceException(msg);
            }
            boolean succeeded = false;
            String url = ((PolicyImpl)policy).getUrl();
            try {
                registry.beginTransaction();

                // getting the old policy.
                Policy oldPolicy = getPolicy(policy.getId());
                if (oldPolicy == null) {
                    addPolicy(policy);
                    return;
                }
                Resource policyResource = registry.newResource();
                policyResource.setMediaType(GovernanceConstants.POLICY_XML_MEDIA_TYPE);

                // setting the policy content
                setContent(policy, policyResource);

                String tmpPath;
                if (policy.getQName() != null) {
                    tmpPath = "/" + policy.getQName().getLocalPart();
                } else if (url != null) {
                    tmpPath = RegistryUtils.getResourceName(new URL(url).getFile().replace("~", ""));
                } else {
                    String msg =
                            "Error in identifying the name for the policy. State the name for the policy.";
                    log.error(msg);
                    throw new GovernanceException(msg);
                }
                policyResource.setUUID(policy.getId());
                registry.put(tmpPath, policyResource);
    //            policy.setId(policyResource.getUUID());
                ((PolicyImpl)policy).updatePath();

                succeeded = true;
            } catch (RegistryException e) {
                String msg =
                        "Error in updating the policy, policy id: " + policy.getId() +
                                ", policy path: " + policy.getPath() + ".";
                log.error(msg, e);
                throw new GovernanceException(msg, e);
            } catch (MalformedURLException e) {
                String msg = "Malformed url found, url " + url + ".";
                log.error(msg, e);
                throw new GovernanceException(msg, e);
            } finally {
                if (succeeded) {
                    try {
                        registry.commitTransaction();
                    } catch (RegistryException e) {
                        String msg =
                                "Error in committing transactions. Update policy failed: " +
                                        "policy id: " + policy.getId() + ", path: " + policy.getPath() +
                                        ".";
                        log.error(msg, e);
                    }
                } else {
                    try {
                        registry.rollbackTransaction();
                    } catch (RegistryException e) {
                        String msg =
                                "Error in rolling back transactions. Update policy failed: " +
                                        "policy id: " + policy.getId() + ", path: " + policy.getPath() +
                                        ".";
                        log.error(msg, e);
                    }
                }
            }
        }

        /**
         * Fetches the given policy artifact on the registry.
         *
         * @param policyId the identifier of the policy artifact.
         *
         * @return the policy artifact.
         * @throws GovernanceException if the operation failed.
         */
        public Policy getPolicy(String policyId) throws GovernanceException {
            GovernanceArtifact artifact =
                    GovernanceUtils.retrieveGovernanceArtifactById(registry, policyId);
            if (artifact != null && !(artifact instanceof Policy)) {
                String msg = "The artifact request is not a policy. id: " + policyId + ".";
                log.error(msg);
                throw new GovernanceException(msg);
            }
            return (Policy) artifact;
        }

        /**
         * Removes the given policy artifact from the registry.
         *
         * @param policyId the identifier of the policy artifact.
         *
         * @throws GovernanceException if the operation failed.
         */
        public void removePolicy(String policyId) throws GovernanceException {
            GovernanceUtils.removeArtifact(registry, policyId);
        }

        /**
         * Sets content of the given policy artifact to the given resource on the
         * registry.
         *
         * @param policy the policy artifact.
         * @param policyResource the content resource.
         *
         * @throws GovernanceException if the operation failed.
         */
        protected void setContent(Policy policy, Resource policyResource) throws GovernanceException {
            if (policy.getPolicyContent() != null) {
                String policyContent = policy.getPolicyContent();
                try {
                    policyResource.setContent(policyContent);
                } catch (RegistryException e) {
                    String msg =
                            "Error in setting the content from policy, policy id: " + policy.getId() +
                                    ", policy path: " + policy.getPath() + ".";
                    log.error(msg, e);
                    throw new GovernanceException(msg, e);
                }
            }
            // and set all the attributes as properties.
            String[] attributeKeys = policy.getAttributeKeys();
            if (attributeKeys != null) {
                Properties properties = new Properties();
                for (String attributeKey : attributeKeys) {
                    String[] attributeValues = policy.getAttributes(attributeKey);
                    if (attributeValues != null) {
                        // The list obtained from the Arrays#asList method is
                        // immutable. Therefore,
                        // we create a mutable object out of it before adding it as
                        // a property.
                        properties.put(attributeKey,
                                new ArrayList<String>(Arrays.asList(attributeValues)));
                    }
                }
                policyResource.setProperties(properties);
            }
            policyResource.setUUID(policy.getId());
        }

        /**
         * Finds all policy artifacts matching the given filter criteria.
         *
         * @param criteria the filter criteria to be matched.
         *
         * @return the policy artifacts that match.
         * @throws GovernanceException if the operation failed.
         */
        public Policy[] findPolicies(PolicyFilter criteria) throws GovernanceException {
            List<Policy> policies = new ArrayList<Policy>();
            for (Policy policy : getAllPolicies()) {
                if (policy != null) {
                    if (criteria.matches(policy)) {
                        policies.add(policy);
                    }
                }
            }
            return policies.toArray(new Policy[policies.size()]);
        }

        /**
         * Finds all policy artifacts on the registry.
         *
         * @return all policy artifacts on the registry.
         * @throws GovernanceException if the operation failed.
         */
        public Policy[] getAllPolicies() throws GovernanceException {
            List<String> policyPaths =
                    Arrays.asList(GovernanceUtils.getResultPaths(registry,
                            GovernanceConstants.POLICY_XML_MEDIA_TYPE));
            Collections.sort(policyPaths, new Comparator<String>() {
                public int compare(String o1, String o2) {
                    return RegistryUtils.getResourceName(o1).compareToIgnoreCase(
                            RegistryUtils.getResourceName(o2));
                }
            });
            List<Policy> policies = new ArrayList<Policy>();
            for (String policyPath : policyPaths) {
                GovernanceArtifact artifact =
                        GovernanceUtils.retrieveGovernanceArtifactByPath(registry, policyPath);
                policies.add((Policy) artifact);
            }
            return policies.toArray(new Policy[policies.size()]);
        }
    }