/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.tuscany.sca.host.webapp.jsp;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;

import org.apache.tuscany.sca.host.embedded.SCADomain;
import org.apache.tuscany.sca.host.webapp.WebAppServletHost;
import org.osoa.sca.ComponentContext;

/**
 * Tag to handle SCA references
 * <sca:reference name="service" type="test.MyService" scope="1" />
 *
 * @version $Rev$ $Date$
 */
public class ReferenceTag extends TagSupport {
    private static final long serialVersionUID = 1L;

    protected String name;
    protected String type;
    protected Integer scope = PageContext.PAGE_SCOPE;

    @Override
    public int doStartTag() throws JspException {
        return SKIP_BODY;
    }

    @Override
    public int doEndTag() throws JspException {

        try {
            WebAppServletHost.getInstance().init(pageContext.getServletConfig());
        } catch (ServletException e) {
            throw new JspException("Exception initializing Tuscany webapp: " + e, e);
        }
 
        ServletContext servletContext = pageContext.getServletContext();
        ComponentContext componentContext = (ComponentContext)servletContext.getAttribute("org.osoa.sca.ComponentContext");
        SCADomain scaDomain = null;
        if (componentContext == null) {
            scaDomain = (SCADomain)servletContext.getAttribute(WebAppServletHost.SCA_DOMAIN_ATTRIBUTE);
            if (scaDomain == null) {
                throw new JspException("SCADomain is null. Check Tuscany configuration in web.xml");
            }
        }

        Class<?> typeClass;
        try {
            typeClass = Class.forName(type, true, Thread.currentThread().getContextClassLoader());
        } catch (ClassNotFoundException e) {
            throw new JspException("Reference '" + name + "' type class not found: " + type);
        }

        Object o;
        try {
            if (componentContext != null) {
                o = componentContext.getService(typeClass, name);
            } else {
                o = scaDomain.getService(typeClass, name);
            }
        } catch (Exception e) {
            throw new JspException("Exception getting service for reference'" + name + "': " + e, e);
        }
        if (o == null) {
            throw new JspException("Reference '" + name + "' not found");
        }

        pageContext.setAttribute(name, o, scope);

        return EVAL_PAGE;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getScope() {
        return scope;
    }

    public void setScope(Integer scope) {
        this.scope = scope;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }
}