/*
 * Copyright (c) 2018-2019. Developed by Hedgecode.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.hedgecode.chess.img;

/**
 * Utilities for path, file name and extension manipulation.
 *
 * @author Dmitry Samoshin aka gotty
 */
public final class FilenameUtils {

    private static final String EMPTY_STRING = "";

    private static final char EXTENSION_SEPARATOR = '.';

    private static final char UNIX_SEPARATOR = '/';
    private static final char WINDOWS_SEPARATOR = '\\';

    private static final String PATH_COLON = ":";

    private static final String JAR_SEPARATOR = ".jar!";

    private static final String OS = System.getProperty("os.name").toLowerCase();

    private static final String WIN_OS_TEMPLATE = "win";

    public static String getName(final String fileName) {
        if (fileName == null) {
            return null;
        }
        final int endPathIndex = Math.max(
                fileName.lastIndexOf(UNIX_SEPARATOR),
                fileName.lastIndexOf(WINDOWS_SEPARATOR)
        );
        return fileName.substring(endPathIndex + 1);
    }

    public static String getBaseName(final String fileName) {
        return removeExtension(
                getName(fileName)
        );
    }

    public static String getExtension(final String fileName) {
        if (fileName == null) {
            return null;
        }
        final int extensionPos = fileName.lastIndexOf(EXTENSION_SEPARATOR);
        return extensionPos < 0
                ? EMPTY_STRING
                : fileName.substring(extensionPos + 1);
    }

    public static String getFullPath(final String parentDir, final String... childDirs) {
        StringBuilder sb = new StringBuilder();
        sb.append(parentDir);
        if (childDirs.length > 0) {
            for (String childDir : childDirs) {
                sb.append(isWindows() ? WINDOWS_SEPARATOR : UNIX_SEPARATOR).append(childDir);
            }
        }
        return sb.toString();
    }

    public static String fixPath(final String path) {
        if (isWindows()) {
            return path.startsWith(String.valueOf(UNIX_SEPARATOR))
                    && path.contains(PATH_COLON)
                    ? path.substring(1)
                    : path;
        }
        return path;
    }

    public static String getPathFromJar(final String jarPath) {
        final int jarEndPos = jarPath.lastIndexOf(JAR_SEPARATOR);
        return jarEndPos < 0
                ? EMPTY_STRING
                : jarPath.substring(jarEndPos + JAR_SEPARATOR.length());
    }

    private static String removeExtension(final String fileName) {
        if (fileName == null) {
            return null;
        }
        final int extensionPos = fileName.lastIndexOf(EXTENSION_SEPARATOR);
        return extensionPos < 0
                ? fileName
                : fileName.substring(0, extensionPos);
    }

    private static boolean isWindows() {
        return (OS.contains(WIN_OS_TEMPLATE));
    }

    private FilenameUtils() {
        throw new AssertionError(
                "No org.hedgecode.chess.img.FilenameUtils instances!"
        );
    }

}