Class ServerModel

java.lang.Object

ServerModel

All Implemented Interfaces:

ServerModelApi

public final class ServerModel
extends Object
implements ServerModelApi

The ServerModel is the class responsible for tracking the state of the server, including its current users and the channels they are in. This class is used by subclasses of Command to handle commands from clients, as well as the ServerBackend to coordinate client connection and disconnection.

Constructor Summary

Constructors

Constructor and Description
ServerModel() Constructs a ServerModel and initializes any collections needed for modeling the server state.

Method Summary

Modifier and Type	Method and Description
Broadcast	deregisterUser(int userId) Informs the model that the client with the given user ID has disconnected from the server.
Collection<String>	getChannels() Returns a collection of the names of all the channels that are present on the server.
String	getNickname(int userId) Returns the nickname currently associated with the given user ID.
String	getOwner(String channelName) Returns the nickname of the owner of the current channel.
Collection<String>	getRegisteredUsers() Returns a collection of the nicknames of all users that are registered with the server.
int	getUserId(String nickname) Returns the user ID currently associated with the given nickname.
Collection<String>	getUsers(String channelName) Returns a collection of the nicknames of all the users in a given channel.
static boolean	isValidName(String name) Determines if a given nickname is valid or invalid (contains at least one alphanumeric character, and no non-alphanumeric characters).
Broadcast	registerUser(int userId) Informs the model that a client has connected to the server with the given user ID.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ServerModel

public ServerModel()

Constructs a ServerModel and initializes any collections needed for modeling the server state.

Method Detail

registerUser

public Broadcast registerUser(int userId)

Informs the model that a client has connected to the server with the given user ID. The model should update its state so that it can identify this user during later interactions with the model. Any user that is registered with the server (without being later deregistered) should appear in the output of getRegisteredUsers().

Specified by:

registerUser in interface ServerModelApi

Parameters:

userId - the unique ID created by the backend to represent this user

Returns:

a Broadcast informing the user of their new nickname

isValidName

public static boolean isValidName(String name)

Determines if a given nickname is valid or invalid (contains at least one alphanumeric character, and no non-alphanumeric characters).

Parameters:

name - The channel or nickname string to validate

Returns:

true if the string is a valid name

deregisterUser

public Broadcast deregisterUser(int userId)

Informs the model that the client with the given user ID has disconnected from the server. After a user ID is deregistered, the server backend is free to reassign this user ID to an entirely different client. As such, the model should take care to expunge any state pertaining to a user who has been deregistered. Any user that is deregistered (without later being registered) should not appear in the output of getRegisteredUsers(). The behavior of this method if the given user ID is not registered with the model is undefined.

Specified by:

deregisterUser in interface ServerModelApi

Parameters:

userId - the unique ID created by the backend to represent this user

Returns:

A Broadcast informing other clients in the disconnected user's channels that they have disconnected

getUserId

public int getUserId(String nickname)

Returns the user ID currently associated with the given nickname. The returned ID is -1 if the nickname is not currently in use.

Specified by:

getUserId in interface ServerModelApi

Parameters:

nickname - The user's nickname

Returns:

the id of said user

getNickname

public String getNickname(int userId)

Returns the nickname currently associated with the given user ID. The returned string is null if the user ID is not currently in use.

Specified by:

getNickname in interface ServerModelApi

Parameters:

userId - The ID whose nickname to return.

Returns:

The nickname associated with the current ID.

getRegisteredUsers

public Collection<String> getRegisteredUsers()

Returns a collection of the nicknames of all users that are registered with the server. Provided for testing; modifications to the returned collection should not affect the server state.

Specified by:

getRegisteredUsers in interface ServerModelApi

Returns:

the collection of registered user nicknames

getChannels

public Collection<String> getChannels()

Returns a collection of the names of all the channels that are present on the server. Provided for testing; modifications to the returned collection should not affect the server state.

Specified by:

getChannels in interface ServerModelApi

Returns:

the collection of channel names

getUsers

public Collection<String> getUsers(String channelName)

Returns a collection of the nicknames of all the users in a given channel. The returned collection is empty if no channel with the given name exists. Provided for testing; modifications to the returned collection should not affect the server state.

Specified by:

getUsers in interface ServerModelApi

Parameters:

channelName - The channel whose member nicknames should be returned

Returns:

the collection of user nicknames in the current channel

getOwner

public String getOwner(String channelName)

Returns the nickname of the owner of the current channel. The result is null if no channel with the given name exists. Provided for testing.

Specified by:

getOwner in interface ServerModelApi

Parameters:

channelName - The channel whose owner nickname should be returned

Returns:

the nickname of the channel owner