/*
 * Copyright 2005-2010 the original author or authors.
 * 
 * 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.wamblee.security.authorization;

import java.util.ArrayList;
import java.util.Map;
import java.util.TreeMap;

/**
 * Operation registry implementation. This implementation ignores the
 * distinction between different types of resources and simply assumes that
 * every operation is applicable to every type of resource.
 * 
 * @author Erik Brakkee
 */
public class DefaultOperationRegistry implements OperationRegistry {
    private Map<String, Operation> operations;

    /**
     * Creates a new DefaultOperationRegistry object.
     * 
     */
    public DefaultOperationRegistry(Operation[] aOperations) {
        operations = new TreeMap<String, Operation>();

        for (Operation operation : aOperations) {
            operations.put(operation.getName(), operation);
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.wamblee.security.authorization.OperationRegistry#getOperations(java
     * .lang.Class)
     */
    public Operation[] getOperations(Class aResourceClass) {
        return operations.values().toArray(new Operation[0]);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.wamblee.security.authorization.OperationRegistry#encode(org.wamblee
     * .security.authorization.Operation[])
     */
    public String encode(Operation[] aOperations) {
        StringBuffer buffer = new StringBuffer();

        for (Operation operation : aOperations) {
            if (buffer.length() > 0) {
                buffer.append(',');
            }

            buffer.append(operation.getName());
        }

        return buffer.toString();
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.wamblee.security.authorization.OperationRegistry#decode(java.lang
     * .Class, java.lang.String)
     */
    public Operation[] decode(Class aResourceClass, String aOperationsString) {
        return decode(aOperationsString);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.wamblee.security.authorization.OperationRegistry#decode(java.lang
     * .String)
     */
    public Operation[] decode(String aOperationsString) {
        if (aOperationsString.length() == 0) {
            return new Operation[0];
        }

        String[] names = aOperationsString.split(",");
        ArrayList<Operation> result = new ArrayList<Operation>();

        for (String name : names) {
            Operation operation = operations.get(name);

            if (operation == null) {
                throw new IllegalArgumentException("Unknown operation '" +
                    name + "'");
            }

            result.add(operation);
        }

        return result.toArray(new Operation[0]);
    }
}