1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
package scalevalapokalypsi.Server
// TODO: TLS/SSL / import javax.net.ssl.SSLServerSocketFactory
import scalevalapokalypsi.Model.{Adventure, Event}
import scalevalapokalypsi.Model.Entities.Player
import scalevalapokalypsi.constants.*
import scalevalapokalypsi.utils.stringToByteArray
import java.io.IOException
import java.lang.System.currentTimeMillis
import java.lang.Thread.sleep
import java.net.{ServerSocket, Socket}
/** `Server` exists to initialize a server for the game
* and run it with its method `startServer`.
*
* @param port the TCP port the server should listen on
* @param maxClients the maximum number of clients that may be in the game
* simultaneously.
* @param timeLimit the time limit clients should have to execute their turns.
* @param joinAfterStart whether new clients are accepted after the game has
* been started
*/
class Server(
port: Int,
maxClients: Int,
val timeLimit: Int,
val joinAfterStart: Boolean
):
private val socket = ServerSocket(port)
private val clientGetter = ConnectionGetter(socket)
private val clients: Clients = Clients(maxClients)
private val buffer: Array[Byte] = Array.ofDim(1024)
private var bufferIndex = 0
private var adventure: Option[Adventure] = None
private var previousTurn = 0.0
/** Starts the server. Won't terminate under normal circumstances. */
def startServer(): Unit =
while true do
this.serverStep()
sleep(POLL_INTERVAL)
private def serverStep(): Unit =
this.clients.removeNonCompliant()
if this.adventure.isEmpty || this.joinAfterStart then
this.receiveNewClient()
this.readFromAll()
this.clients.foreach(_.interpretData())
this.makeClientsSing()
this.writeClientDataToClients()
this.writeObservations()
this.endGameForDeadClients()
if this.canExecuteTurns then
this.clients.foreach(_.giveTurn())
this.adventure.foreach(_.takeNpcTurns())
this.clients.foreach(c =>
this.writeToClient(this.turnStartInfo(c), c)
)
this.previousTurn = currentTimeMillis().toDouble / 1000.0
if this.adventure.isDefined && this.joinAfterStart then
this.clients.foreach( c => if c.isReadyForGameStart then
this.adventure.foreach(a =>
c.getName.foreach(n => a.addPlayer(n))
)
startGameForClient(c)
)
else if
this.adventure.isEmpty &&
!this.clients.isEmpty &&
this.clients.forall(_.isReadyForGameStart)
then
this.adventure = Some(Adventure(this.clients.names))
this.clients.foreach(startGameForClient(_))
this.previousTurn = currentTimeMillis().toDouble / 1000.0
/** Helper function to start the game for the specified client c.
* MAY ONLY BE USED IF `this.adventure` is Some!
* Apparently guard clauses are bad because they use return or something,
* but assertions should be fine, as long as they enforce the function
* contract?
*/
private def startGameForClient(c: Client): Unit =
assert(this.adventure.isDefined)
c.gameStart()
val name = c.getName
val playerEntity: Option[Player] = name match
case Some(n) => this.adventure match
case Some(a) => a.getPlayer(n)
case None => None
case None => None
playerEntity.foreach(c.givePlayer(_))
this.writeToClient(
s"$timeLimit\r\n${this.turnStartInfo(c)}", c
)
val joinEvent = c.player.map(p => Event(
Map.from(Vector((p, ""))),
s"${p.name} joins the game."
))
joinEvent.foreach(ev => this.clients.foreach(cl =>
if cl != c then
cl.player.foreach(_.observe(ev))
))
private def writeObservations(): Unit =
this.clients.foreach(c =>
val observations = c.player.map(_.readAndClearObservations())
observations.foreach(_.foreach((s: String) =>
this.writeToClient(s"$ACTION_NONBLOCKING_INDICATOR$s\r\n", c))
)
)
private def makeClientsSing(): Unit =
this.clients.foreach(c =>
c.startSongIfNeeded()
)
/** Helper function to determine if the next turn can be taken */
private def canExecuteTurns: Boolean =
val requirement1 = this.adventure.isDefined
val requirement2 = !this.clients.isEmpty // nice! you can just return
// to the game after everyone
// left and everything is just
// as before!
val allPlayersReady = this.clients.forall(_.hasActed)
val requirement3 = (allPlayersReady
|| currentTimeMillis() / 1000 >= previousTurn + timeLimit)
requirement1 && requirement2 && requirement3
/** Receives a new client and stores it in `clients`.
*
* @return describes if a client was added
*/
private def receiveNewClient(): Boolean =
this.clientGetter.newClient() match
case Some(c) =>
clients.addClient(Client(c))
true
case None =>
false
private def turnStartInfo(client: Client): String =
val clientArea = client.player.map(_.location)
val areaDesc = clientArea
.map(_.description)
.getOrElse("You are floating in the middle of a soothing void.")
val directions = clientArea
.map(_.getNeighborNames.mkString(LIST_SEPARATOR))
.getOrElse("")
val items = clientArea
.map(_.getItemNames.mkString(LIST_SEPARATOR))
.getOrElse("")
val entities = client.player.map(c =>
c.location
.getEntityNames
.filter(c.name != _)
.mkString(LIST_SEPARATOR)
).getOrElse("")
s"$TURN_INDICATOR\r\n$areaDesc\r\n$directions\r\n$items\r\n$entities\r\n"
/** Sends `message` to all clients
*
* @param message the message to send
*/
private def writeToAll(message: String): Unit =
this.clients.mapAndRemove(c =>
val output = c.socket.getOutputStream
output.write(stringToByteArray(message))
output.flush()
)
private def endGameForDeadClients(): Unit =
this.clients.removeNonSatisfying(c =>
c.player.forall((p: Player) =>
if !p.isAlive then
this.writeToClient(s"$GAME_END_INDICATOR\r\n", c)
false
else
true
)
)
private def writeToClient(message: String, client: Client): Unit =
try {
val output = client.socket.getOutputStream
output.write(stringToByteArray(message))
output.flush()
} catch {
case e: IOException => client.failedProtocol()
}
/** Sends every client's `dataToThisClient` to the client */
private def writeClientDataToClients(): Unit =
this.clients.mapAndRemove(c =>
val output = c.socket.getOutputStream
val data = c.dataToThisClient()
output.write(stringToByteArray(data))
output.flush()
)
/** Reads data sent by clients and stores it in the `Client`s of `clients` */
private def readFromAll(): Unit =
clients.mapAndRemove(c =>
val input = c.socket.getInputStream
while input.available() != 0 do
val bytesRead = input.read(buffer)
if bytesRead != -1 then
c.receiveData(buffer.take(bytesRead).toVector)
)
end Server
|
