/*******************************************************************************
 * Copyright (c) 2006 Sybase, Inc. 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:
 *     Sybase, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.jsf.core.internal.tld;

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

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IStorage;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.jdt.core.IClasspathContainer;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IPackageFragment;
import org.eclipse.jdt.core.IPackageFragmentRoot;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;

/**
 * @author mengbo
 */
public class LoadBundleUtil {

	private LoadBundleUtil() {
	    // no external instantiation
	}


	/**
	 * @param project
	 * @param baseName
	 * @return an IStorage pointing to the request bundle or null if not found
	 * @throws CoreException if the search for the file encounters a problem
	 */
	public static IStorage getLoadBundleResource(final IProject project,
			final String baseName) throws CoreException {
		if (project == null || baseName == null) {
			return null;
		}
		IStorage loadBundleResource = null;
		if (project.hasNature(JavaCore.NATURE_ID)) {
			IJavaProject javaProject = JavaCore.create(project);
			IFile sourceFile = getSourceFile(javaProject, baseName);
			if (sourceFile == null || !sourceFile.exists()) {
				loadBundleResource = getJarFile(javaProject, baseName);
			} else {
				loadBundleResource = sourceFile;
			}
		}

		return loadBundleResource;
	}

	private static IFile getSourceFile(IJavaProject javaProject, String baseName)
			throws JavaModelException {
		IClasspathEntry[] classpathEntries = javaProject.getRawClasspath();
		for (int i = 0; i < classpathEntries.length; i++) {
			if (classpathEntries[i].getEntryKind() == IClasspathEntry.CPE_SOURCE) {
				final IFile file = getFile(javaProject, baseName,
						classpathEntries, i);
				if (file.exists()) {
					return file;
				}
			} else if (classpathEntries[i].getEntryKind() == IClasspathEntry.CPE_PROJECT) {
				IProject project = ResourcesPlugin.getWorkspace().getRoot()
						.getProject(classpathEntries[i].getPath().toString());
				IJavaProject javaProject3 = JavaCore.create(project);
				final IFile file = getSourceFile(javaProject3, baseName);
				if (file != null && file.exists()) {
					return file;
				}
			}
			else if (classpathEntries[i].getEntryKind() == IClasspathEntry.CPE_CONTAINER && classpathEntries[i].getPath().equals(new Path("org.eclipse.jst.j2ee.internal.module.container")))  //$NON-NLS-1$
			{ 
				IClasspathContainer container = JavaCore.getClasspathContainer(classpathEntries[i].getPath(), javaProject);
				IClasspathEntry[] classpathEntries2 = container.getClasspathEntries();
				for (int j = 0; j < classpathEntries2.length; j++) 
				{
					if (classpathEntries2[j].getEntryKind() == IClasspathEntry.CPE_PROJECT) 
					{
						IProject project = ResourcesPlugin.getWorkspace().getRoot().getProject(classpathEntries2[j].getPath().toString());
						IJavaProject javaProject3 = JavaCore.create(project);
						final IFile file = getSourceFile(javaProject3, baseName);
						if (file != null && file.exists())
						{
							return file;
						}
					}
				}
			}
		}
		return null;
	}


	private static IFile getFile(IJavaProject javaProject, String baseName,
			IClasspathEntry[] classpathEntries, int i) {
		IPath path = classpathEntries[i].getPath()
				.append(getFilePath(baseName)).removeFirstSegments(1);
		path = javaProject.getProject().getFullPath().append(path);
		return ResourcesPlugin.getWorkspace().getRoot().getFile(path);
	}

	private static IPath getFilePath(String baseName) {
		IPath path = new Path(baseName.replace('.', '/'));
		path = path.addFileExtension("properties");//$NON-NLS-1$
		return path;
	}

	private static IStorage getJarFile(IJavaProject javaProject, String baseName)
			throws JavaModelException {
		IClasspathEntry[] roots = javaProject.getRawClasspath();
		return getJarFile(javaProject, baseName, roots);
	}

	private static IStorage getJarFile(IJavaProject javaProject, String baseName,
			IClasspathEntry[] roots) throws JavaModelException
	{
		for (int i = 0; i < roots.length; i++) {
			if (roots[i].getEntryKind() == IClasspathEntry.CPE_LIBRARY ||
					roots[i].getEntryKind() == IClasspathEntry.CPE_CONTAINER)
			{
				IStorage storage = getResourceFromLibrary(
						javaProject, baseName, roots[i]);
				if (storage != null)
				{
					return storage;
				}
			}
//			else if ( roots[i].getEntryKind() == IClasspathEntry.CPE_CONTAINER) 
//			{
//				IClasspathContainer classpathContainer = JavaCore.getClasspathContainer(roots[i].getPath(), javaProject);
//				final IClasspathEntry[] classpathEntries = 
//					classpathContainer.getClasspathEntries();
//				IStorage storage = getJarFile(javaProject, baseName, classpathEntries);
//				if (storage != null)
//				{
//					return storage;
//				}
//			}
		}
		return null;
	}

	private static IStorage getResourceFromLibrary(
			IJavaProject javaProject, String baseName, IClasspathEntry entry) throws JavaModelException 
	{
		IPackageFragmentRoot[] packageFragmentRoots = javaProject
				.findPackageFragmentRoots(entry);
		for (int j = 0; j < packageFragmentRoots.length; j++) {
			String packageName = getPackageName(baseName);
			Object[] resources = null;
			if (packageName.length() == 0) {
				resources = packageFragmentRoots[j].getNonJavaResources();
			} else {
				IPackageFragment fragment = packageFragmentRoots[j]
						.getPackageFragment(getPackageName(baseName));
				if (fragment != null && fragment.exists()) {
					resources = fragment.getNonJavaResources();
				}
			}

			if (resources != null && resources.length > 0) {
				for (int k = 0; k < resources.length; k++) {
					if (resources[k] instanceof IStorage) {
						IStorage storage = (IStorage) resources[k];
						if (getFileName(baseName).equalsIgnoreCase(
								storage.getName())) {
							return storage;
						}
					}
				}
			}
		}
		return null;
	}

	private static String getPackageName(String baseName) {
		int index = baseName.lastIndexOf('.');
		if (index == -1) {
			return "";//$NON-NLS-1$
		}
        return baseName.substring(0, index);
	}

	private static String getFileName(String baseName) {
		int index = baseName.lastIndexOf('.');
		if (index == -1) {
			return baseName + ".properties"; //$NON-NLS-1$
		}
        return baseName.substring(index + 1).concat(".properties");//$NON-NLS-1$
	}

    /**
     * Encapsulates the hiearchy of bundle data sources in the hierarchy
     * for a ResourceBundle base name.  In practice this is often simply
     * a single IFile for a 
     * @author cbateman
     *
     */
//    public static class BundleHierarchy
//    {
//        // list in order from most specific (first queried) to least,
//        // front to back
//        //private final List        _hierarchy; 
//    
//        /**
//         * Takes the list *by reference*.  Does not take a copy.
//         * @param hierarchy
//         */
//        public BundleHierarchy(List hierarchy)
//        {
//            _hierarchy = hierarchy;
//        }
//        
//        public BundleHierarchy()
//        {
//            _hierarchy = new ArrayList();
//        }
//    }
    
    /**
     * Used to describe the design time approximation of the locale lookup precendence
     * that will be used by ResourceBundle to find a localized resource bundle.
     * 
     * See the official JavaDoc for java.util.ResourceBundle.getBundle for docs on search
     * order.  
     * 
     * @author cbateman
     *
     */
    public static class LocaleDescriptor
    {
        private Locale            _locale;
        private List              _possibleSuffices;
        
        /**
         * @param language -- must not be null
         */
        public LocaleDescriptor(String language)
        {
            _locale = new Locale(language);
        }
        
        /**
         * All arguments must be non-null.  To set a language only descriptor,
         * see others.
         * 
         * @param language -- must not be null
         * @param country -- must not be null
         */
        public LocaleDescriptor(String language,
                String country)
        {
            _locale = new Locale(language, country);
        }
        
        /**
         * All arguments must be non-null. Null arguments will cause an exception.
         * To create descriptor without variant and/or country set, see other constructors
         * @param language -- must not be null
         * @param country -- must not be null
         * @param variant -- must not be null
         */
        public LocaleDescriptor(String language,
                String country, String variant) 
        {
            _locale = new Locale(language, country, variant);
        }
        
        /**
         * @param baseName
         * @return an iterator through all possible bundle names starting with the most
         * specific and becoming more general for base name based on this locale.
         * 
         * i.e. if baseName is "bundle" and the local is en_US_1 then in order the 
         * iterator will produce:
         * 
         * bundle_en_US_1
         * bundle_en_US
         * bundle_en
         * bundle
         * 
         * per the ResourceBundle API
         * 
         */
        public Iterator getBundleNameIterator(final String baseName)
        {
            
            return new Iterator()
            {
                final Iterator  it = getPossibleBaseNameSuffices().iterator();
                
                public boolean hasNext() {
                   return it.hasNext();
                }

                public Object next() {
                    return baseName+it.next(); 
                }

                public void remove() {
                    // delegate; should throw exception
                    it.remove();
                }
            };
        }

        private synchronized List getPossibleBaseNameSuffices()
        {
            if (_possibleSuffices == null)
            {
                List possibleSuffices = new ArrayList(3);

                final String language = _locale.getLanguage();
                final String country = _locale.getCountry();
                final String variant = _locale.getVariant();

                possibleSuffices.add(""); //$NON-NLS-1$
                possibleSuffices.add("_"+language); //$NON-NLS-1$
                if (country != null)
                {
                    possibleSuffices.add(0, "_"+language + "_" + country); //$NON-NLS-1$ //$NON-NLS-2$
                    if (variant != null)
                    {
                        possibleSuffices.add(0, "_"+language+"_"+country+"_"+variant); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
                    }
                }
                _possibleSuffices = Collections.unmodifiableList(possibleSuffices);
            }

            return _possibleSuffices;
       }

        /**
         * @return the local information as a standard locale object
         */
        public Locale getLocale()
        {
            return _locale;
        }
    }
}