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 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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,

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package jdk.jfr.internal.tool;

import java.io.BufferedInputStream;

import java.io.DataInputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.PrintStream;

import java.nio.file.Files;

import java.nio.file.InvalidPathException;

import java.nio.file.Path;

import java.util.ArrayList;

import java.util.Deque;

import java.util.List;

import jdk.jfr.internal.consumer.ChunkHeader;

import jdk.jfr.internal.consumer.RecordingInput;

final class Disassemble extends Command {

    @Override

    public String getName() {

        return "disassemble";

    }

    @Override

    public List<String> getOptionSyntax() {

        List<String> list = new ArrayList<>();

        list.add("[--output <directory>]");

        list.add("[--max-chunks <chunks>]");

        list.add("[--max-size <size>]");

        list.add("<file>");

        return list;

    }

    @Override

    public void displayOptionUsage(PrintStream stream) {

        stream.println(" --output <directory>    The location to write the disassembled file,");

        stream.println("                         by default the current directory");

        stream.println("");

        stream.println(" --max-chunks <chunks>   Maximum number of chunks per disassembled file,");

        stream.println("                         by default 5. The chunk size varies, but is ");

        stream.println("                         typically around 15 MB.");

        stream.println("");

        stream.println(" --max-size <size>       Maximum number of bytes per file.");

        stream.println("");

        stream.println("  <file>                 Location of the recording file (.jfr)");

    }

    @Override

    public String getDescription() {

        return "Disassamble a recording file into smaller files/chunks";

    }

    @Override

    public void execute(Deque<String> options) throws UserSyntaxException, UserDataException {

        if (options.isEmpty()) {

            throw new UserSyntaxException("missing file");

        }

        Path file = getJFRInputFile(options);

        int maxChunks = Integer.MAX_VALUE;

        int maxsize = Integer.MAX_VALUE;

        String output = System.getProperty("user.dir");

        int optionCount = options.size();

        while (optionCount > 0) {

            if (acceptOption(options, "--output")) {

                output = options.pop();

            }

            if (acceptOption(options, "--max-size")) {

                String value = options.pop();

                try {

                    maxsize = Integer.parseInt(value);

                    if (maxsize < 1) {

                        throw new UserDataException("max size must be at least 1");

                    }

                } catch (NumberFormatException nfe) {

                    throw new UserDataException("not a valid value for --max-size.");

                }

            }

            if (acceptOption(options, "--max-chunks")) {

                String value = options.pop();

                try {

                    maxChunks = Integer.parseInt(value);

                    if (maxChunks < 1) {

                        throw new UserDataException("max chunks must be at least 1.");

                    }

                } catch (NumberFormatException nfe) {

                    throw new UserDataException("not a valid value for --max-size.");

                }

            }

            if (optionCount == options.size()) {

                // No progress made

                throw new UserSyntaxException("unknown option " + options.peek());

            }

            optionCount = options.size();

        }

        Path outputPath = getDirectory(output);

        println();

        println("Examining recording " + file + " ...");

        List<Long> sizes;

        if (maxsize != Integer.MAX_VALUE && maxChunks == Integer.MAX_VALUE) {

            try {

                long fileSize = Files.size(file);

                if (maxsize >=fileSize) {

                    println();

                    println("File size (" + fileSize +") does not exceed max size (" + maxsize + ")");

                    return;

                }

            } catch (IOException e) {

                throw new UserDataException("unexpected i/o error when determining file size" + e.getMessage());

            }

        }

        if (maxsize == Integer.MAX_VALUE && maxChunks == Integer.MAX_VALUE) {

            maxChunks = 5;

        }

        try {

            sizes = findChunkSizes(file);

        } catch (IOException e) {

            throw new UserDataException("unexpected i/o error. " + e.getMessage());

        }

        if (maxsize == Integer.MAX_VALUE == sizes.size() <= maxChunks) {

            throw new UserDataException("number of chunks in recording (" + sizes.size() + ") doesn't exceed max chunks (" + maxChunks + ")");

        }

        println();

        if (sizes.size() > 0) {

            List<Long> combinedSizes = combineChunkSizes(sizes, maxChunks, maxsize);

            print("File consists of " + sizes.size() + " chunks. The recording will be split into ");

            println(combinedSizes.size() + " files");

            println();

            splitFile(outputPath, file, combinedSizes);

        } else {

            throw new UserDataException("no JFR chunks found in file.");

        }

    }

    private List<Long> findChunkSizes(Path p) throws IOException {

            List<Long> sizes = new ArrayList<>();

            ChunkHeader ch = new ChunkHeader(input);

            sizes.add(ch.getSize());

            while (!ch.isLastChunk()) {

                ch = ch.nextHeader();

                sizes.add(ch.getSize());

            }

            return sizes;

        }

    }

    private List<Long> combineChunkSizes(List<Long> sizes, int maxChunks, long maxSize) {

        List<Long> reduced = new ArrayList<Long>();

        int chunks = 1;

        long fileSize = sizes.get(0);

        for (int i = 1; i < sizes.size(); i++) {

            long size = sizes.get(i);

            if (fileSize + size > maxSize) {

                reduced.add(fileSize);

                chunks = 1;

                fileSize = size;

                continue;

            }

            fileSize += size;

            if (chunks == maxChunks) {

                reduced.add(fileSize);

                fileSize = 0;

                chunks = 1;

                continue;

            }

            chunks++;

        }

        if (fileSize != 0) {

            reduced.add(fileSize);

        }

        return reduced;

    }

    private void splitFile(Path directory, Path file, List<Long> splitPositions) throws UserDataException {

        int padAmountZeros = String.valueOf(splitPositions.size() - 1).length();

        String fileName = file.getFileName().toString();

        String fileFormatter = fileName.subSequence(0, fileName.length() - 4) + "_%0" + padAmountZeros + "d.jfr";

        for (int i = 0; i < splitPositions.size(); i++) {

            String formattedFilename = String.format(fileFormatter, i);

            try {

                Path p = directory.resolve(formattedFilename);

                if (Files.exists(p)) {

                    throw new UserDataException("can't create disassembled file " + p + ", a file with that name already exist");

                }

            } catch (InvalidPathException ipe) {

                throw new UserDataException("can't construct path with filename" + formattedFilename);

            }

        }

        try (DataInputStream stream = new DataInputStream(new BufferedInputStream(new FileInputStream(file.toFile())))) {

            for (int i = 0; i < splitPositions.size(); i++) {

                Long l = splitPositions.get(i);

                byte[] bytes = readBytes(stream, l.intValue());

                String formattedFilename = String.format(fileFormatter, i);

                Path p = directory.resolve(formattedFilename);

                File splittedFile = p.toFile();

                println("Writing " + splittedFile + " ... " + bytes.length);

                FileOutputStream fos = new FileOutputStream(splittedFile);

                fos.write(bytes);

                fos.close();

            }

        } catch (IOException ioe) {

            throw new UserDataException("i/o error writing file " + file);

        }

    }

    private byte[] readBytes(InputStream stream, int count) throws UserDataException, IOException {

        byte[] data = new byte[count];

        int totalRead = 0;

        while (totalRead < data.length) {

            int read = stream.read(data, totalRead, data.length - totalRead);

            if (read == -1) {

                throw new UserDataException("unexpected end of data");

            }

            totalRead += read;

        }

        return data;

    }

}