/*
 * Copyright 2008 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.system.components;

import org.wamblee.io.InputResource;

import org.wamblee.system.core.AbstractComponent;
import org.wamblee.system.core.DefaultProvidedInterface;
import org.wamblee.system.core.ProvidedInterface;
import org.wamblee.system.core.Scope;

import java.io.IOException;

import java.util.Properties;

/**
 * Property component that reads a property file and provides it to other
 * components through a provided interface. NOTE: when multiple property
 * components are used, disambiguation of provided and required interfaces is
 * needed.
 * 
 * @author Erik Brakkee
 */
public class PropertyComponent extends AbstractComponent<Properties> {
    private static ProvidedInterface PROPS = new DefaultProvidedInterface(
        "props", Properties.class);

    private Properties props;

    /**
     * Creates a new PropertyComponent object.
     * 
     * 
     */
    public PropertyComponent(String aName, InputResource aResource)
        throws IOException {
        this(aName, readProps(aResource));
    }

    /**
     * Creates a new PropertyComponent object.
     * 
     */
    public PropertyComponent(String aName, Properties aProps) {
        super(aName);
        props = aProps;

        addProvidedInterface(PROPS);
    }

    private static Properties readProps(InputResource aResource)
        throws IOException {
        Properties props = new Properties();
        props.load(aResource.getInputStream());

        return props;
    }

    @Override
    protected Properties doStart(Scope aScope) {
        addInterface(PROPS, props, aScope);

        return props;
    }

    @Override
    protected void doStop(Properties aRuntime) {
        // Empty
    }
}