/*
 *
 *  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 flex2.compiler.common;

import flex2.compiler.config.ConfigurationException;
import flex2.compiler.config.ConfigurationValue;
import flex2.compiler.io.FileUtil;
import flex2.compiler.io.LocalFile;
import flex2.compiler.io.VirtualFile;

import java.io.File;

/**
 * Resolves files in a way specific to configuration files.  Or, as
 * Roger, points out, this could be renamed RelativePathResolver or
 * something, since it just resolves things relative to a root
 * directory.
 *
 * @author Brian Deitte
 */
public class ConfigurationPathResolver implements SinglePathResolver
{
    private String root;

    /**
     * Set default root file.  For mxmlc, we only want the root to ever be the context of
     * a ConfigurationValue.  For example, if a ConfigurationValue comes from
     * "C:/flex/flex-config.xml", the root should be "C:/flex".  If a ConfigurationValue
     * comes from the command line, the root should be null.
     *
     * This method is public, because it's used by Flex Builder.
     */
    public void setRoot( String root )
    {
        this.root = root;
    }

    /**
     * Resolve the path as an absolute file or relative to the root or relative to the
     * current working directory if the root is null.
     */
    public VirtualFile resolve( String path )
    {
        VirtualFile resolved = null;

        File absoluteOrRelativeFile = FileUtil.openFile(path);

        if ((absoluteOrRelativeFile != null) &&
             absoluteOrRelativeFile.exists() &&
             absoluteOrRelativeFile.isAbsolute())
        {
            resolved = new LocalFile(absoluteOrRelativeFile);
        }
        else if (root != null)
        {
            String rootRelativePath = root + File.separator + path;
            File rootRelativeFile = FileUtil.openFile(rootRelativePath);
            if ((rootRelativeFile != null) && rootRelativeFile.exists())
            {
                resolved = new LocalFile(rootRelativeFile);
            }
        }
        else
        {
            if(absoluteOrRelativeFile != null) {
                // C: must convert 'absoluteOrRelativeFile' into absolute before calling exists().
                absoluteOrRelativeFile = absoluteOrRelativeFile.getAbsoluteFile();
                if (absoluteOrRelativeFile.exists())
                    // && !FileUtils.isAbsolute(absoluteOrRelativeFile)
                {
                    resolved = new LocalFile(absoluteOrRelativeFile);
                }
            }
        }

        /*
        if ((resolved != null) && Trace.pathResolver)
        {
            Trace.trace("ConfigurationPathResolver.resolve: resolved " + path + " to " + resolved.getName());
        }
        */
        
        return resolved;
    }

    
    // This should be moved, simplified, destroyed, something.

    public static VirtualFile getVirtualFile(String file,
                                             ConfigurationPathResolver configResolver,
                                             ConfigurationValue cfgval)
        throws ConfigurationException
    {
        ConfigurationPathResolver relative = null;
        String cfgContext = cfgval != null ? cfgval.getContext() : null;
        if (cfgContext != null)
        {
            relative = new ConfigurationPathResolver();
            relative.setRoot( cfgContext );
        }

        // check the PathResolver first and if nothing is found, then check the config
        // resolver.  This is done so that Zorn/WebTier can resolve these files as they
        // wish
        VirtualFile vFile = new PathResolver().resolve(relative, file);

        if (vFile == null)
        {
            String oldRoot = null;
            boolean rootChanged = false;
            try
            {   
                // If there is a configuration context for the configResolver, then use it.
                // If there is no context, then let the configResolver use its own root.
                if (cfgContext != null)
                {
                    oldRoot = configResolver.root;
                    rootChanged = true;
                    configResolver.setRoot(cfgContext);
                }
                vFile = configResolver.resolve(file);
            }
            finally
            {
                if (rootChanged)
                {
                    configResolver.setRoot(oldRoot);                
                }
            }
        }
        if (vFile == null)
        {
	        if (cfgval == null)
	        {
		        throw new ConfigurationException.CannotOpen( file, null, null, -1 );   
	        }
	        else
	        {
		        throw new ConfigurationException.CannotOpen( file, cfgval.getVar(), cfgval.getSource(), cfgval.getLine() );
	        }
        }
        return vFile;
    }




}