/*
 * [The "BSD license"]
 *  Copyright (c) 2011 Terence Parr
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.stringtemplate.v4;

import org.stringtemplate.v4.compiler.CompiledST;
import org.stringtemplate.v4.compiler.STException;
import org.stringtemplate.v4.misc.ErrorType;
import org.stringtemplate.v4.misc.Misc;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;

The internal representation of a single group file (which must end in
 ".stg").  If we fail to find a group file, look for it via the
 CLASSPATH as a resource.  Templates are only looked up in this file
 or an import.
/** The internal representation of a single group file (which must end in
 *  ".stg").  If we fail to find a group file, look for it via the
 *  CLASSPATH as a resource.  Templates are only looked up in this file
 *  or an import.
 */
public class STGroupFile extends STGroup {
	
Just records how user "spelled" the file name they wanted to load.
 The url is the key field here for loading content.
 If they use ctor with URL arg, this field is null.
/** Just records how user "spelled" the file name they wanted to load.
	 *  The url is the key field here for loading content.
	 *
	 *  If they use ctor with URL arg, this field is null.
	 */
    public String fileName;

	
Where to find the group file. NonNull. /** Where to find the group file. NonNull. */
    public URL url;

    protected boolean alreadyLoaded = false;

    
Load a file relative to current directory or from root or via CLASSPATH. /** Load a file relative to current directory or from root or via CLASSPATH. */
	public STGroupFile(String fileName) { this(fileName, '<', '>'); }

	public STGroupFile(String fileName, char delimiterStartChar, char delimiterStopChar) {
		super(delimiterStartChar, delimiterStopChar);
		if ( !fileName.endsWith(GROUP_FILE_EXTENSION) ) {
			throw new IllegalArgumentException("Group file names must end in .stg: "+fileName);
		}
		//try {
		File f = new File(fileName);
		if ( f.exists() ) {
			try {
				url = f.toURI().toURL();
			}
			catch (MalformedURLException e) {
				throw new STException("can't load group file "+fileName, e);
			}
			if ( verbose ) System.out.println("STGroupFile(" + fileName + ") == file "+f.getAbsolutePath());
		}
		else { // try in classpath
			url = getURL(fileName);
			if ( url==null ) {
				throw new IllegalArgumentException("No such group file: "+
													   fileName);
			}
			if ( verbose ) System.out.println("STGroupFile(" + fileName + ") == url "+url);
		}
		this.fileName = fileName;
	}

	public STGroupFile(String fullyQualifiedFileName, String encoding) {
        this(fullyQualifiedFileName, encoding, '<', '>');
    }

    public STGroupFile(String fullyQualifiedFileName, String encoding,
                       char delimiterStartChar, char delimiterStopChar)
    {
        this(fullyQualifiedFileName, delimiterStartChar, delimiterStopChar);
        this.encoding = encoding;
    }

	
Pass in a URL with the location of a group file. E.g.,
	STGroup g = new STGroupFile(loader.getResource("org/foo/templates/g.stg"), "UTF-8", '<', '>');
/** Pass in a URL with the location of a group file. E.g.,
	 * 	STGroup g = new STGroupFile(loader.getResource("org/foo/templates/g.stg"), "UTF-8", '<', '>');
	  */
	public STGroupFile(URL url, String encoding,
					   char delimiterStartChar, char delimiterStopChar)
	{
		super(delimiterStartChar, delimiterStopChar);
		if ( url==null ) {
			throw new IllegalArgumentException("URL to group file cannot be null");
		}
		this.url = url;
		this.encoding = encoding;
		this.fileName = null;
	}

	
Convenience ctor /** Convenience ctor */
	public STGroupFile(URL url) { this(url, "UTF-8",'<', '>'); }

	@Override
	public boolean isDictionary(String name) {
		if ( !alreadyLoaded ) load();
		return super.isDictionary(name);
	}

	@Override
    public boolean isDefined(String name) {
        if ( !alreadyLoaded ) load();
        return super.isDefined(name);
    }

	@Override
	public synchronized void unload() {
		super.unload();
		alreadyLoaded = false;
	}

	@Override
	protected synchronized CompiledST load(String name) {
        if ( !alreadyLoaded ) load();
        return rawGetTemplate(name);
    }

	@Override
    public synchronized void load() {
        if ( alreadyLoaded ) return;
        alreadyLoaded = true; // do before actual load to say we're doing it
		// no prefix since this group file is the entire group, nothing lives
		// beneath it.
		if ( verbose ) System.out.println("loading group file "+url.toString());
        loadGroupFile("/", url.toString());
		if ( verbose ) System.out.println("found "+templates.size()+" templates in "+url.toString()+" = "+templates.keySet());
    }

	@Override
    public String show() {
        if ( !alreadyLoaded ) load();
        return super.show();
    }

	@Override
    public String getName() { return Misc.getFileNameNoSuffix(getFileName()); }

	@Override
	public String getFileName() {
		if ( fileName!=null ) {
			return fileName;
		}
		return url.getFile();
	}

	@Override
	public URL getRootDirURL() {
//		System.out.println("url of "+fileName+" is "+url.toString());
		String parent = Misc.stripLastPathElement(url.toString());
		if ( parent.endsWith(".jar!") ) {
			parent = parent + "/."; // whooops. at the root so add "current dir" after jar spec
		}
		try {
			URL parentURL = new URL(parent);
//			System.out.println("parent URL "+parentURL.toString());
			return parentURL;
		}
		catch (MalformedURLException mue) {
			errMgr.runTimeError(null, null, ErrorType.INVALID_TEMPLATE_NAME,
								mue, parent);
		}
		return null;
	}
}