/*******************************************************************************
 * Copyright (c) 2006, 2011 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Sebastian Davids: sdavids@gmx.de - see bug 25376
 *******************************************************************************/
package org.eclipse.che.ide.ext.java.jdt.templates;

import org.eclipse.che.ide.ext.java.jdt.templates.api.TemplateContext;
import org.eclipse.che.ide.ext.java.jdt.templates.api.TemplateVariable;
import org.eclipse.che.ide.ext.java.jdt.templates.api.TemplateVariableResolver;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * Resolves template variables to non-conflicting names that adhere to the naming conventions and match the parameter (fully
 * qualified name).
 *
 * @since 3.3
 */
public class NameResolver extends TemplateVariableResolver {

    private final String fDefaultType;

    /** Default ctor for instantiation by the extension point. */
    public NameResolver() {
        this("java.lang.Object"); //$NON-NLS-1$
    }

    NameResolver(String defaultType) {
        fDefaultType = defaultType;
    }

    /*
     * @see org.eclipse.jface.text.templates.TemplateVariableResolver#resolve(org.eclipse.jface.text.templates.TemplateVariable,
     * org.eclipse.jface.text.templates.TemplateContext)
     */
    @Override
    public void resolve(TemplateVariable variable, TemplateContext context) {
        List<String> params = variable.getVariableType().getParams();
        String param;
        if (params.size() == 0)
            param = fDefaultType;
        else
            param = params.get(0);
        JavaContext jc = (JavaContext)context;
        TemplateVariable ref = jc.getTemplateVariable(param);
        MultiVariable mv = (MultiVariable)variable;
        if (ref instanceof MultiVariable) {
            // reference is another variable
            MultiVariable refVar = (MultiVariable)ref;
            jc.addDependency(refVar, mv);

            refVar.getAllChoices();
            Object[] types = flatten(refVar.getAllChoices());
            for (int i = 0; i < types.length; i++) {
                String[] names = jc.suggestVariableNames(mv.toString(types[i]));
                mv.setChoices(types[i], names);
            }

            mv.setKey(refVar.getCurrentChoice());
            jc.markAsUsed(mv.getDefaultValue());
        } else {
            // reference is a Java type name
            jc.addImport(param);
            String[] names = jc.suggestVariableNames(param);
            mv.setChoices(names);
            jc.markAsUsed(names[0]);
        }
    }

    private Object[] flatten(Object[][] allValues) {
        List<Object> flattened = new ArrayList<Object>(allValues.length);
        for (int i = 0; i < allValues.length; i++) {
            flattened.addAll(Arrays.asList(allValues[i]));
        }
        return flattened.toArray(new Object[flattened.size()]);
    }
}