/*******************************************************************************
 * Copyright (c) 2000, 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
 *******************************************************************************/
package org.eclipse.che.ide.ext.java.jdt.templates;


import org.eclipse.che.ide.ext.java.jdt.CUVariables;
import org.eclipse.che.ide.ext.java.jdt.templates.api.Template;
import org.eclipse.che.ide.ext.java.jdt.templates.api.TemplateBuffer;
import org.eclipse.che.ide.ext.java.jdt.templates.api.TemplateContext;
import org.eclipse.che.ide.ext.java.jdt.templates.api.TemplateException;
import org.eclipse.che.ide.ext.java.jdt.templates.api.TemplateTranslator;
import org.eclipse.che.ide.ext.java.jdt.templates.api.TemplateVariableResolver;
import org.eclipse.che.ide.ext.java.worker.WorkerMessageHandler;
import org.eclipse.che.ide.ext.java.jdt.text.LineTracker;
import org.eclipse.che.ide.ext.java.jdt.text.DefaultLineTracker;
import org.eclipse.che.ide.runtime.Assert;
import org.eclipse.che.ide.api.text.BadLocationException;
import org.eclipse.che.ide.api.text.Region;

import java.util.Iterator;

public class CodeTemplateContext extends TemplateContext {

    private String fLineDelimiter;

    public CodeTemplateContext(String contextTypeName, String lineDelim) {
        super(WorkerMessageHandler.get().getTemplateContextRegistry().getContextType(contextTypeName));
        fLineDelimiter = lineDelim;
    }

    /*
     * @see org.eclipse.jdt.internal.corext.template.TemplateContext#evaluate(org.eclipse.jdt.internal.corext.template.Template)
     */
    @Override
    public TemplateBuffer evaluate(Template template) throws BadLocationException, TemplateException {
        // test that all variables are defined
        Iterator<TemplateVariableResolver> iterator = getContextType().resolvers();
        while (iterator.hasNext()) {
            TemplateVariableResolver var = iterator.next();
            if (var instanceof CodeTemplateContextType.CodeTemplateVariableResolver) {
                Assert.isNotNull(getVariable(var.getType()), "Variable " + var.getType() + "not defined"); //$NON-NLS-1$ //$NON-NLS-2$
            }
        }

        if (!canEvaluate(template))
            return null;

        String pattern = changeLineDelimiter(template.getPattern(), fLineDelimiter);

        TemplateTranslator translator = new TemplateTranslator();
        TemplateBuffer buffer = translator.translate(pattern);
        getContextType().resolve(buffer, this);
        return buffer;
    }

    private static String changeLineDelimiter(String code, String lineDelim) {
        try {
            LineTracker tracker = new DefaultLineTracker();
            tracker.set(code);
            int nLines = tracker.getNumberOfLines();
            if (nLines == 1) {
                return code;
            }

            StringBuffer buf = new StringBuffer();
            for (int i = 0; i < nLines; i++) {
                if (i != 0) {
                    buf.append(lineDelim);
                }
                Region region = tracker.getLineInformation(i);
                String line = code.substring(region.getOffset(), region.getOffset() + region.getLength());
                buf.append(line);
            }
            return buf.toString();
        } catch (BadLocationException e) {
            // can not happen
            return code;
        }
    }

    /* (non-Javadoc)
     * @see org.eclipse.jdt.internal.corext.template.TemplateContext#canEvaluate(org.eclipse.jdt.internal.corext.template.Template)
     */
    @Override
    public boolean canEvaluate(Template template) {
        return true;
    }

    public void setCompilationUnitVariables(CUVariables var) {

        setVariable(CodeTemplateContextType.FILENAME, var.getFileName());
        setVariable(CodeTemplateContextType.PACKAGENAME, var.getPackageName());
        setVariable(CodeTemplateContextType.PROJECTNAME, var.getProjectName());
    }

//    private String getPackage(File file) {
//        Project project = file.getProject();
//        //TODO magic constants
//        String sourcePath =
//                project.hasProperty("sourceFolder") ? (String)project.getPropertyValue("sourceFolder")
//                                                    : "src/main/java";
//        String parentPath = file.getPath();
//        String packageText = parentPath.substring((project.getPath() + "/" + sourcePath + "/").length());
//        if (packageText.isEmpty())
//            return "";
//        if (packageText.endsWith("/"))
//            packageText = packageText.substring(0, packageText.length() - 1);
//        return packageText.replaceAll("/", ".");
//    }
}