Dedicated server (#871)

* My brain hurts, here is a broken dedicated server

* somewhat stablised the server

* Made it less shouty, and added channel

* Split the DS functionallity from the main.go file

* Split the DS functionallity from the main.go file, and remembered to add the server file

* My brain hurts, here is a broken dedicated server

* somewhat stablised the server

* Made it less shouty, and added channel

* Split the DS functionallity from the main.go file

* Split the DS functionallity from the main.go file, and remembered to add the server file

* Added Stable Dedicated Server Functionallity

Co-authored-by: gravestench <dknuth0101@gmail.com>

d2networking/dedicated_server.go

@@ -0,0 +1,74 @@
+package d2networking
+
+import (
+	"os"
+	"strconv"
+
+	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset"
+	"github.com/OpenDiablo2/OpenDiablo2/d2networking/d2server"
+)
+
+const (
+	stopServer = 0b1
+)
+
+/*
+StartDedicatedServer Checks whether or not we should start a server i.e the -listen parameter has been passed in, and if so launches a
+server hosted to the network, in theory. (this is still WIP)
+*/
+func StartDedicatedServer(manager *d2asset.AssetManager, in chan byte, log chan string) (started bool, e error) {
+	var listen bool
+
+	maxPlayers := 3
+
+	for argCount, arg := range os.Args {
+		if arg == "--listen" || arg == "-L" {
+			listen = true
+		}
+
+		if arg == "--maxplayers" || arg == "-p" {
+			max, _ := strconv.ParseInt(os.Args[argCount+1], 10, 32)
+			maxPlayers = int(max)
+		}
+	}
+
+	if !listen {
+		return false, nil
+	}
+
+	server, err := d2server.NewGameServer(manager, true, maxPlayers)
+
+	if err != nil {
+		return false, err
+	}
+
+	err = server.Start()
+
+	if err != nil {
+		return false, err
+	}
+
+	// I have done the messaging with a bitmask for memory efficiency, this can easily be translated to pretty error
+	// messages later, sue me.
+	go func() {
+		for {
+			msgIn := <-in
+			/* For those who do not know an AND operation denoted by & discards bits which do not line up so for instance:
+			01011001 & 00000001 = 00000001 or 1
+			00100101 & 00000010 = 00000000 or 0
+			01100110 & 01100000 = 01100000 or 96
+			these can be used to have multiple messages in just 8 bits, that's a quarter of a rune in go!
+			*/
+			if (msgIn & stopServer) == stopServer {
+				log <- "Stopping server"
+
+				server.Stop()
+				log <- "Exiting..."
+
+				os.Exit(0)
+			}
+		}
+	}()
+
+	return true, nil
+}

main.go

@@ -2,6 +2,11 @@ package main
 
 import (
 	"log"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/OpenDiablo2/OpenDiablo2/d2networking"
 
 	"github.com/OpenDiablo2/OpenDiablo2/d2app"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset"
@@ -47,6 +52,28 @@ func main() {
 		return
 	}
 
+	srvChanIn := make(chan byte)
+	srvChanLog := make(chan string)
+	started, srvErr := d2networking.StartDedicatedServer(asset, srvChanIn, srvChanLog)
+
+	if srvErr != nil {
+		panic(err)
+	}
+
+	c := make(chan os.Signal)
+	signal.Notify(c, os.Interrupt, syscall.SIGTERM) // This traps Control-c to safely shut down the server
+
+	go func() {
+		<-c
+		srvChanIn <- 0b1
+	}()
+
+	if started {
+		for data := range srvChanLog {
+			log.Println(data)
+		}
+	}
+
 	audio := ebiten2.CreateAudio(asset)
 
 	inputManager := d2input.NewInputManager()