package com.thoughtworks.xstream.core;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * A class mapper that allows aliasing entire packages.
 *
 * The aliases are used in the same order as they are registered, ie, if you register "com.thoughworks.xstream"
 * then "com.thoughworks.xstream.core", the ClassMapper class will be aliased as "core.ClassMapper",
 * while if you register "com.thoughworks.xstream.core" first, then "com.thoughworks.xstream",
 * the ClassMapper class will be aliased as "ClassMapper".
 * Primary aliases (with full class names) have priority over package aliases.
 *
 * @author greg
 * @author $Author: $ (last edit)
 * @version $Revision: $
 */
public class PackageAliasClassMapper extends DefaultClassMapper {
    private List packages;

    public PackageAliasClassMapper() {
        super();
        this.packages = new ArrayList();
    }

    public PackageAliasClassMapper(Package pakkage) {
        this();
        aliasPackage(pakkage);
    }

    public void aliasPackage(Package pakkage) {
        packages.add(pakkage.getName());
    }

    public String lookupName(Class type) {
        // first get full class name or aliased name
        String result = super.lookupName(type);

        Iterator it = packages.iterator();
        while (it.hasNext()) {
            String pakkage = (String) it.next();
            if (result.startsWith(pakkage)) {
                return result.substring(pakkage.length() + 1); // remove trailing dot too
            }
        }

        return result;
    }

    protected Class loadClass(String className) throws ClassNotFoundException {
        try {
            // first try with full class name
            return super.loadClass(className);
        } catch (ClassNotFoundException e) {
            Iterator it = packages.iterator();
            while (it.hasNext()) {
                String pakkage = (String) it.next();
                try {
                    return super.loadClass(pakkage + '.' + className);
                } catch (ClassNotFoundException e1) {
                    // try next package alias
                }
            }
        }
        throw new ClassNotFoundException(className);
    }

    protected Class loadArrayClass(int arrayDepth, String elementName) throws ClassNotFoundException {
        try {
            return super.loadArrayClass(arrayDepth, elementName);
        } catch (ClassNotFoundException e) {
            Iterator it = packages.iterator();
            while (it.hasNext()) {
                String pakkage = (String) it.next();
                String className = pakkage + '.' + elementName;
                String arrayClassName = buildArrayClassName(arrayDepth, className);
                try {
                    return super.loadClass(arrayClassName);
                } catch (ClassNotFoundException e1) {
                    // try next package alias
                }
            }
        }
        throw new ClassNotFoundException(elementName);
    }
}