/*

 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jnlp.converter;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URI;

import java.net.URL;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import jnlp.converter.parser.GeneralUtil;

public class HTTPHelper {

    public static final int BUFFER_SIZE = 4096;

    public static String downloadFile(String url, String destFolder, String destFileName) throws MalformedURLException, IOException {

        HttpURLConnection connection = null;

        String destFile = null;

        try {

            if (url.contains(" ")) {

                url = url.replace(" ", "%20");

            }

            if (url.contains("\\")) {

                url = url.replace("\\", "/");

            }

            URL resource = new URL(url);

            connection = (HttpURLConnection) resource.openConnection();

            int responseCode = connection.getResponseCode();

            if (responseCode == HttpURLConnection.HTTP_OK) {

                destFile = destFolder + File.separator + destFileName;

                Log.verbose("Downloading " + url + " to " + destFile);

                try (InputStream inputStream = connection.getInputStream();

                     OutputStream outputStream = new FileOutputStream(destFile)) {

                    byte[] buffer = new byte[BUFFER_SIZE];

                    int length;

                    do {

                        length = inputStream.read(buffer);

                        if (length > 0) {

                            outputStream.write(buffer, 0, length);

                        }

                    } while (length > 0);

                }

            } else {

                HTTPHelperException e = new HTTPHelperException("Error: Cannot download " + url + ". Server response code: " + responseCode);

                e.setResponseCode(responseCode);

                throw e;

            }

        } catch (IOException e) {

            if (e instanceof HTTPHelperException) {

                throw e;

            } else {

                throw new HTTPHelperException("Error: Cannot download " + url + ". " + e.getClass().getSimpleName() + ": " + e.getMessage());

            }

        } finally {

            if (connection != null) {

                connection.disconnect();

            }

        }

        return destFile;

    }

    public static String copyFile(String url, String destFolder, String destFileName) throws Exception {

        if (url.contains(" ")) {

            url = url.replace(" ", "%20");

        }

        URI sourceURI = new URI(url);

        String sourceFile = sourceURI.getPath();

        File file = new File(sourceFile);

        if (!file.exists()) {

            throw new FileNotFoundException("Error: " + sourceFile + " does not exist.");

        }

        String destFile = destFolder + File.separator + destFileName;

        file = new File(destFile);

        if (file.exists()) {

            file.delete();

        }

        Path sourcePath = Paths.get(sourceURI);

        Path destPath = Paths.get(destFile);

        Log.verbose("Copying " + url + " to " + destFile);

        Files.copy(sourcePath, destPath);

        return destFile;

    }

    public static boolean isHTTPUrl(String url) {

        return (url.startsWith("http://") || url.startsWith("https://"));

    }

    public static byte[] getJNLPBits(String versionedJNLP, String jnlp) throws Exception {

        String jnlpFilePath = null;

        byte[] bits = null;

        if (isHTTPUrl(jnlp)) {

            try {

                jnlpFilePath = downloadFile(versionedJNLP, JNLPConverter.getJnlpDownloadFolderStatic(), getFileNameFromURL(jnlp));

            } catch (HTTPHelperException ex) {

                if (ex.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND &&

                       !versionedJNLP.equals(jnlp)) {

                    Log.warning("Downloading versioned JNLP from " + versionedJNLP + " failed.");

                    Log.warning(ex.getMessage());

                    Log.warning("Downloading " + jnlp + " instead.");

                    jnlpFilePath = downloadFile(jnlp, JNLPConverter.getJnlpDownloadFolderStatic(), getFileNameFromURL(jnlp));

                } else {

                    throw ex;

                }

            }

            JNLPConverter.markFileToDelete(jnlpFilePath);

        } else {

            try {

                jnlpFilePath = copyFile(versionedJNLP, JNLPConverter.getJnlpDownloadFolderStatic(), getFileNameFromURL(jnlp));

            } catch (FileNotFoundException ex) {

                System.out.println("Error copying versioned JNLP from " + versionedJNLP);

                System.out.println(ex.getMessage());

                System.out.println("Copying " + jnlp + " instead.");

                jnlpFilePath = HTTPHelper.copyFile(jnlp, JNLPConverter.getJnlpDownloadFolderStatic(), getFileNameFromURL(jnlp));

            }

            JNLPConverter.markFileToDelete(jnlpFilePath);

        }

        File jnlpFile = new File(jnlpFilePath);

        if (jnlpFile.exists()) {

            bits = GeneralUtil.readBytes(new FileInputStream(jnlpFile), jnlpFile.length());

        }

        return bits;

    }

    public static String getFileNameFromURL(String url) throws IOException {

        int index;

        int index1 = url.lastIndexOf('/');

        int index2 = url.lastIndexOf('\\');

        if (index1 >= index2) {

            index = index1;

        } else {

            index = index2;

        }

        if (index != -1) {

            String name = url.substring(index + 1, url.length());

            name = name.replace("%20", " ");

            if (name.endsWith(".jnlp") || name.endsWith(".jar")) { // JNLP or JAR

                return name;

            } else if (name.endsWith(".ico")) { // Icons

                return name;

            } else {

                throw new IOException("Error: Unsupported file extension for " + url);

            }

        } else {

            throw new IOException("Error: URL (" + url + ") should end with file name.");

        }

    }

}