/*
 * Copyright 2004-2014 ICEsoft Technologies Canada Corp.
 *
 * 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.icepush.servlet;

import org.icepush.Configuration;
import org.icepush.ConfigurationException;

import javax.servlet.ServletContext;

public class ServletContextConfiguration extends Configuration {
    private final String name;
    private ServletContext context;

    public ServletContextConfiguration(ServletContext context) {
        this(null, context);
    }

    public ServletContextConfiguration(String prefix, ServletContext context) {
        this.name = prefix;
        this.context = context;
    }

    public String getName() {
        return name;
    }

    public Configuration getChild(String child) throws ConfigurationException {
        String childName = postfixWith(child);
        String value = context.getInitParameter(childName);
        if (value == null) {
            throw new ConfigurationException("Cannot find parameter: " + childName);
        } else {
            return new ServletContextConfiguration(childName, context);
        }
    }

    public Configuration[] getChildren(String name) throws ConfigurationException {
        return new Configuration[]{getChild(name)};
    }

    public String getAttribute(String paramName) throws ConfigurationException {
        String attributeName = postfixWith(paramName);
        String value = context.getInitParameter(attributeName);
        if (value == null) {
            throw new ConfigurationException("Cannot find parameter: " + attributeName);
        } else {
            return value;
        }
    }

    public String getValue() throws ConfigurationException {
        String value = context.getInitParameter(name);
        if (value == null) {
            throw new ConfigurationException("Cannot find parameter: " + name);
        } else {
            return value;
        }
    }

    private String postfixWith(String child) {
        return (name == null || name.trim().length() == 0) ? child : name + '.' + child;
    }
}
