import java.io.IOException;

import java.rmi.NotBoundException;

import java.rmi.RemoteException;

import java.rmi.registry.LocateRegistry;

import java.rmi.registry.Registry;

import java.util.List;

public class Client {

MasterServerClientInterface masterStub;

static Registry registry;

int regPort = Configurations.REG_PORT;

String regAddr = Configurations.REG_ADDR;

int chunkSize = Configurations.CHUNK_SIZE; // in bytes

public Client() {

try {

registry = LocateRegistry.getRegistry(regAddr, regPort);

masterStub = (MasterServerClientInterface) registry.lookup("MasterServerClientInterface");

System.out.println("[@client] Master Stub fetched successfuly");

} catch (RemoteException | NotBoundException e) {

// fatal error .. no registry could be linked

e.printStackTrace();

}

}

public byte[] read(String fileName) throws IOException, NotBoundException{

List<ReplicaLoc> locations = masterStub.read(fileName);

System.out.println("[@client] Master Granted read operation");

// TODO fetch from all and verify

ReplicaLoc replicaLoc = locations.get(0);

ReplicaServerClientInterface replicaStub = (ReplicaServerClientInterface) registry.lookup("ReplicaClient"+replicaLoc.getId());

FileContent fileContent = replicaStub.read(fileName);

System.out.println("[@client] read operation completed successfuly");

System.out.println("[@client] data:");

System.out.println(new String(fileContent.getData()));

return fileContent.getData();

}

public ReplicaServerClientInterface initWrite(String fileName, Long txnID) throws IOException, NotBoundException{

WriteAck ackMsg = masterStub.write(fileName);

txnID = new Long(ackMsg.getTransactionId());

return (ReplicaServerClientInterface) registry.lookup("ReplicaClient"+ackMsg.getLoc().getId());

}

public void writeChunk (long txnID, String fileName, byte[] chunk, long seqN, ReplicaServerClientInterface replicaStub) throws RemoteException, IOException{

FileContent fileContent = new FileContent(fileName, chunk);

ChunkAck chunkAck;

do {

chunkAck = replicaStub.write(txnID, seqN, fileContent);

} while(chunkAck.getSeqNo() != seqN);

}

public void write (String fileName, byte[] data) throws IOException, NotBoundException, MessageNotFoundException{

WriteAck ackMsg = masterStub.write(fileName);

ReplicaServerClientInterface replicaStub = (ReplicaServerClientInterface) registry.lookup("ReplicaClient"+ackMsg.getLoc().getId());

System.out.println("[@client] Master granted write operation");

int segN = (int) Math.ceil(1.0*data.length/chunkSize);

FileContent fileContent = new FileContent(fileName);

ChunkAck chunkAck;

byte[] chunk = new byte[chunkSize];

for (int i = 0; i < segN-1; i++) {

System.arraycopy(data, i*chunkSize, chunk, 0, chunkSize);

fileContent.setData(chunk);

do {

chunkAck = replicaStub.write(ackMsg.getTransactionId(), i, fileContent);

} while(chunkAck.getSeqNo() != i);

}

// Handling last chunk of the file < chunk size

int lastChunkLen = chunkSize;

if (data.length%chunkSize > 0)

lastChunkLen = data.length%chunkSize;

chunk = new byte[lastChunkLen];

System.arraycopy(data, segN-1, chunk, 0, lastChunkLen);

fileContent.setData(chunk);

do {

chunkAck = replicaStub.write(ackMsg.getTransactionId(), segN-1, fileContent);

} while(chunkAck.getSeqNo() != segN-1 );

System.out.println("[@client] write operation complete");

replicaStub.commit(ackMsg.getTransactionId(), segN);

System.out.println("[@client] commit operation complete");

}

public void commit(String fileName, long txnID, long seqN) throws MessageNotFoundException, IOException, NotBoundException{

ReplicaLoc primaryLoc = masterStub.locatePrimaryReplica(fileName);

ReplicaServerClientInterface primaryStub = (ReplicaServerClientInterface) registry.lookup("ReplicaClient"+primaryLoc.getId());

primaryStub.commit(txnID, seqN);

System.out.println("[@client] commit operation complete");

}

public void batchOperations(String[] cmds){

System.out.println("[@client] batch operations started");

String cmd ;

String[] tokens;

for (int i = 0; i < cmds.length; i++) {

cmd = cmds[i];

tokens = cmd.split(", ");

try {

if (tokens[0].trim().equals("read"))

this.read(tokens[1].trim());

else if (tokens[0].trim().equals("write"))

this.write(tokens[1].trim(), tokens[2].trim().getBytes());

else if (tokens[0].trim().equals("commit"))

this.commit(tokens[1].trim(), Long.parseLong(tokens[2].trim()), Long.parseLong(tokens[3].trim()));

}catch (IOException | NotBoundException | MessageNotFoundException e){

System.err.println("Operation "+i+" Failed");

}

}

System.out.println("[@client] batch operations completed");

}

}