sdis1819-t7g05

import java.io.File;

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.InetAddress;

import java.security.NoSuchAlgorithmException;

/**

 * BackupTask

 */

public class RestoreTask implements Runnable {

    private static final int MAX_CHUNK_SIZE = 64000; // 64KBytes

    private static final String CRLF = Integer.toHexString(0xD) + Integer.toHexString(0xA);

    private String filePath;

    private InetAddress MCaddress;

    private int MCport;

    private Peer peer;

    private String version;

    RestoreTask(String pathname, String version, Peer peer) {

        this.filePath = pathname;

        this.MCaddress = peer.getMCaddress();

        this.MCport = peer.getMCport();

        this.version = version;

        this.peer = peer;

    }

    @Override

    public void run() {

        File file = new File(this.filePath);

        try {

            String fileId = BackupFile.generateFileId(this.filePath, file.lastModified());

            long interval;

            RestoreFile restoreFile = new RestoreFile(new File("Peer-" + this.peer.getSenderId() + File.separator + "Backups" + File.separator + this.filePath), fileId, file.length()/MAX_CHUNK_SIZE + 1);

            this.peer.restoreMap.put(fileId, restoreFile);

            DatagramSocket socket = new DatagramSocket();

            //GETCHUNK <Version> <SenderId> <FileId> <ChunkNo> <CRLF><CRLF>

            for (int i = 0; i <= file.length()/MAX_CHUNK_SIZE; i++) {

                interval = 1000;

                String message = "GETCHUNK " + this.version + " " + peer.getSenderId() + " " + fileId + " " + i + " " + CRLF + CRLF;

                DatagramPacket packet = new DatagramPacket(message.getBytes(), message.length(), this.MCaddress, this.MCport);

                while (interval <= 31000) { //31 = 1+2+4+8+16

                    this.peer.print("sending GETCHUNK message");

                    socket.send(packet);

                    Thread.sleep(interval);

                    if (this.peer.restoreMap.get(fileId).hasChunk(i)){

                        break;

                    }

                    interval *= 2;

                }

                                if(interval > 31000) {

                                        this.peer.print("Couldn't get all chunks");

                                        return;

                                }

            }

            if (!restoreFile.restoreFile(file)) {

                this.peer.print("The file couldn't be restored due to lack of chunks");

            } else {

                this.peer.print("The file was restored successfully");

            }

            socket.close();

            this.peer.print("RESTORE protocol finished");

        } catch (IOException | NoSuchAlgorithmException | InterruptedException e) {

            e.printStackTrace();

        }

    }

}