/*
 * Copyright 1999,2004 The Apache Software Foundation.
 * 
 * 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 net.java.strux.application.support;

import java.io.Serializable;
import java.util.Map;

import javax.faces.FacesException;
import javax.faces.application.ViewHandler;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;

import net.java.strux.Jsf;



/**
 * @author Jacob Hookom
 */
public class ActionMapping implements Serializable
{
    public static final String ACTION_MAPPING_KEY = ActionMapping.class.getName(); 
    public static final String DEFAULT_MAPPING = ".jsf";
    public static final int TYPE_UNKNOWN = -1;
    public static final int TYPE_SUFFIX = 1;
    public static final int TYPE_PREFIX = 0;
    
    protected int type = TYPE_SUFFIX;
    protected String mapping = DEFAULT_MAPPING;
    protected String defaultSuffix = null;
    
    public ActionMapping()
    {
        // do nothing
    }
    
    public static ActionMapping getCurrentInstance(FacesContext context, int scope) throws FacesException
    {
        Map scopeMap = Jsf.getScope(context, scope);
        ActionMapping actionMapping = (ActionMapping) scopeMap.get(ACTION_MAPPING_KEY);
        if (actionMapping == null)
        {
            actionMapping = new ActionMapping();
            scopeMap.put(ACTION_MAPPING_KEY, actionMapping);
        }
        return actionMapping;
    }
    
    public String getDefaultSuffix(FacesContext context) throws FacesException
    {
        if (this.defaultSuffix == null)
        {
            ExternalContext extCtx = context.getExternalContext();
            String viewSuffix = extCtx.getInitParameter(ViewHandler.DEFAULT_SUFFIX_PARAM_NAME);
            this.defaultSuffix = (viewSuffix != null) ? viewSuffix : ViewHandler.DEFAULT_SUFFIX;
        }
        return this.defaultSuffix;
    }
    
    /**
     * @param context
     * @param viewId
     * @return
     * @throws FacesException
     */
    public String convertToActionId(FacesContext context, String viewId) throws FacesException
    {
        String actionId = null;
        if (TYPE_PREFIX == this.type)
        {
            if (viewId.startsWith(this.mapping))
            {
                actionId = viewId;
            }
            else
            {
                actionId = this.mapping + viewId;
            }
        }
        else if (TYPE_SUFFIX == this.type)
        {
            actionId = viewId.replaceFirst(this.getDefaultSuffix(context), this.mapping);
        }
        else
        {
            throw new FacesException(Jsf.msg("view.error.actionId",viewId));
        }
        return actionId;
    }
    
    /**
     * Looks at the current context and updates its state while converting the actionId
     * to a viewId.  Previous state is ignored when this is called since we can't determine the
     * mapping for the life of the request.
     * 
     * @param context
     * @param actionId
     * @return
     * @throws FacesException
     */
    public String convertToViewId(FacesContext context, String actionId) throws FacesException
    {
        ExternalContext extCtx = context.getExternalContext();
        String viewId = extCtx.getRequestPathInfo();
        if (extCtx.getRequestPathInfo() == null)
        {
            // we know it's a suffix mapping
            String facesSuffix = actionId.substring(actionId.lastIndexOf('.'));
            String viewSuffix = this.getDefaultSuffix(context);
            viewId = actionId.replaceFirst(facesSuffix, viewSuffix);
            
            synchronized (this)
            {
                this.type = TYPE_SUFFIX;
            	this.mapping = facesSuffix;
            }
        }
        else
        {
            // else it's a prefix mapping
            synchronized (this)
            {
                this.type = TYPE_PREFIX;
                this.mapping = extCtx.getRequestServletPath();
            }
        }
        return viewId;
    }
    
    public String getMapping()
    {
        return this.mapping;
    }
    
    public synchronized void setMapping(String mapping)
    {
        this.mapping = mapping;
    }
    
    public int getType()
    {
        return this.type;
    }
    
    public synchronized void setType(int type)
    {
        this.type = type;
    }
}