Copyright (c) 2000, 2017 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.team.internal.core;

import java.io.DataInputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;

import org.eclipse.core.resources.IStorage;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.content.IContentType;
import org.eclipse.core.runtime.content.IContentTypeManager;
import org.eclipse.team.core.IFileContentManager;
import org.eclipse.team.core.IStringMapping;
import org.eclipse.team.core.Team;

TODO: implement extension point
/**
 * TODO: implement extension point
 */
public class FileContentManager implements IFileContentManager {

	private static final String PREF_TEAM_EXTENSION_TYPES= "file_types"; //$NON-NLS-1$
	private static final String PREF_TEAM_FILENAME_TYPES= "cvs_mode_for_file_without_extensions"; //$NON-NLS-1$

	private static class StringMapping implements IStringMapping {

		private final String fString;
		private final int fType;

		public StringMapping(String string, int type) {
			fString= string;
			fType= type;
		}

		@Override
		public String getString() {
			return fString;
		}

		@Override
		public int getType() {
			return fType;
		}
	}

	private static class UserExtensionMappings extends UserStringMappings {

		public UserExtensionMappings(String key) {
			super(key);
		}

		@Override
		protected Map<String, Integer> loadMappingsFromPreferences() {
			final Map<String, Integer> result= super.loadMappingsFromPreferences();
			if (loadMappingsFromOldWorkspace(result)) {
				TeamPlugin.getPlugin().savePluginPreferences();
			}
			return result;
		}

		
If the workspace is an old 2.0 one, read the old file and delete it.
Params:
A – map where the new mappings should be added.
Returns:
true if the workspace was a 2.0 one and the old mappings have
been added to the map, false otherwise./**
		 * If the workspace is an old 2.0 one, read the old file and delete it.
		 *
		 * @param A map where the new mappings should be added.
		 *
		 * @return true if the workspace was a 2.0 one and the old mappings have
		 * been added to the map, false otherwise.
		 *
		 */
		private boolean loadMappingsFromOldWorkspace(Map<String, Integer> map) {
			// File name of the persisted file type information
			String STATE_FILE = ".fileTypes"; //$NON-NLS-1$
			IPath pluginStateLocation = TeamPlugin.getPlugin().getStateLocation().append(STATE_FILE);
			File f = pluginStateLocation.toFile();

			if (!f.exists())
				return false;

			try {
				DataInputStream input = new DataInputStream(new FileInputStream(f));
				try {
					map.putAll(readOldFormatExtensionMappings(input));
				} finally {
					input.close();
					f.delete();
				}
			} catch (IOException ex) {
				TeamPlugin.log(IStatus.ERROR, ex.getMessage(), ex);
				return false;
			}
			return true;
		}

		
Read the saved file type state from the given input stream.
Params:
input – the input stream to read the saved state from
Throws:
IOException – if an I/O problem occurs/**
		 * Read the saved file type state from the given input stream.
		 *
		 * @param input the input stream to read the saved state from
		 * @throws IOException if an I/O problem occurs
		 */
		private Map<String, Integer> readOldFormatExtensionMappings(DataInputStream input) throws IOException {
			final Map<String, Integer> result= new TreeMap<>();
			int numberOfMappings = 0;
			try {
				numberOfMappings = input.readInt();
			} catch (EOFException e) {
				// Ignore the exception, it will occur if there are no
				// patterns stored in the state file.
				return Collections.emptyMap();
			}
			for (int i = 0; i < numberOfMappings; i++) {
				final String extension = input.readUTF();
				final int type = input.readInt();
				result.put(extension, Integer.valueOf(type));
			}
			return result;
		}
	}

	private final UserStringMappings fUserExtensionMappings, fUserNameMappings;
	private PluginStringMappings fPluginExtensionMappings;//, fPluginNameMappings;
	private IContentType textContentType;

	public FileContentManager() {
		fUserExtensionMappings= new UserExtensionMappings(PREF_TEAM_EXTENSION_TYPES);
		fUserNameMappings= new UserStringMappings(PREF_TEAM_FILENAME_TYPES);
		fPluginExtensionMappings= new PluginStringMappings(TeamPlugin.FILE_TYPES_EXTENSION, "extension"); //$NON-NLS-1$
	}

	@Override
	public int getTypeForName(String filename) {
		final int userType= fUserNameMappings.getType(filename);
//        final int pluginType= fPluginNameMappings.getType(filename);
//        return userType != Team.UNKNOWN ? userType : pluginType;
		return userType;
	}

	@Override
	public int getTypeForExtension(String extension) {
		final int userType= fUserExtensionMappings.getType(extension);
		final int pluginType= fPluginExtensionMappings.getType(extension);
		return userType != Team.UNKNOWN ? userType : pluginType;
	}

	@Override
	public void addNameMappings(String[] names, int [] types) {
		fUserNameMappings.addStringMappings(names, types);
	}

	@Override
	public void addExtensionMappings(String[] extensions, int [] types) {
		fUserExtensionMappings.addStringMappings(extensions, types);
	}

	@Override
	public void setNameMappings(String[] names, int [] types) {
		fUserNameMappings.setStringMappings(names, types);
	}

	@Override
	public void setExtensionMappings(String[] extensions, int [] types) {
		fUserExtensionMappings.setStringMappings(extensions, types);
	}

	@Override
	public IStringMapping[] getNameMappings() {
		return getMappings(fUserNameMappings, null);//fPluginNameMappings);
	}

	@Override
	public IStringMapping[] getExtensionMappings() {
		return getMappings(fUserExtensionMappings, fPluginExtensionMappings);
	}

	@Override
	public int getType(IStorage storage) {
		int type;

		final String name= storage.getName();
		if (name != null && (type= getTypeForName(name)) != Team.UNKNOWN)
			return type;

		final String extension= getFileExtension(name);
		if (extension != null && (type= getTypeForExtension(extension)) != Team.UNKNOWN)
			return type;

		IContentType contentType = Platform.getContentTypeManager().findContentTypeFor(name);
		if (contentType != null) {
			IContentType textType = getTextContentType();
			if (contentType.isKindOf(textType)) {
				return Team.TEXT;
			}
		}

		return Team.UNKNOWN;
	}

	private IContentType getTextContentType() {
		if (textContentType == null)
			textContentType = Platform.getContentTypeManager().getContentType(IContentTypeManager.CT_TEXT);
		return textContentType;
	}

	@Override
	public IStringMapping[] getDefaultNameMappings() {
		// TODO: There is currently no extension point for this
		return new IStringMapping[0];//getStringMappings(fPluginNameMappings.referenceMap());
	}

	@Override
	public IStringMapping[] getDefaultExtensionMappings() {
		return getStringMappings(fPluginExtensionMappings.referenceMap());
	}

	@Override
	public boolean isKnownExtension(String extension) {
		return fUserExtensionMappings.referenceMap().containsKey(extension)
		|| fPluginExtensionMappings.referenceMap().containsKey(extension);
	}

	@Override
	public boolean isKnownFilename(String filename) {
		return fUserNameMappings.referenceMap().containsKey(filename);
//        || fPluginNameMappings.referenceMap().containsKey(filename);
	}

	private static String getFileExtension(String name) {
		if (name == null)
			return null;
		int index = name.lastIndexOf('.');
		if (index == -1)
			return null;
		if (index == (name.length() - 1))
			return ""; //$NON-NLS-1$
		return name.substring(index + 1);
	}

	private static IStringMapping [] getStringMappings(Map map) {
		final IStringMapping [] result= new IStringMapping [map.size()];
		int index= 0;
		for (final Iterator iter = map.entrySet().iterator(); iter.hasNext();) {
			final Map.Entry entry= (Map.Entry)iter.next();
			result[index++]= new StringMapping((String)entry.getKey(), ((Integer)entry.getValue()).intValue());
		}
		return result;
	}

	private IStringMapping [] getMappings(UserStringMappings userMappings, PluginStringMappings pluginMappings) {
		final Map<String, Integer> mappings= new HashMap<>();
		if (pluginMappings != null)
			mappings.putAll(pluginMappings.referenceMap());
		mappings.putAll(userMappings.referenceMap());
		return getStringMappings(mappings);
	}
}