Improved build script.

.gitignore

@@ -37,3 +37,4 @@ build/
 
 src/main/resources/app
 /build_system
+/log

build_system.d

@@ -1,6 +1,8 @@
 #!/usr/bin/env dub
 /+ dub.sdl:
     dependency "dsh" version="~>1.6.1"
+    dependency "dxml" version="~>0.4.3"
+    dependency "requests" version="~>2.0.8"
 +/
 
 /**
@@ -11,27 +13,107 @@
 module build_system;
 
 import dsh;
+import dxml.dom;
+import dxml.util;
+
 import std.stdio;
 import std.string;
+import std.algorithm;
+import std.uni;
 
 const DIST = "./src/main/resources/app";
 const DIST_ORIGIN = "./quasar-app/dist/spa";
+const APP_DIR = "./quasar-app";
 const APP_BUILD = "quasar build -m spa";
 const API_BUILD = "mvn clean package spring-boot:repackage -DskipTests=true";
 
-void main(string[] args) {
-    print("Building RailSignalAPI");
-    chdir("quasar-app");
+const LOG_DIR = "./log";
+const API_LOG = LOG_DIR ~ "/api_build.txt";
+const APP_LOG = LOG_DIR ~ "/app_build.txt";
+
+int main(string[] args) {
+    string ver = getVersion();
+    if (ver is null) {
+        error("Could not determine version.");
+        return 1;
+    }
+    removeIfExists(LOG_DIR);
+    mkdir(LOG_DIR);
+    print("Building Rail Signal v%s", ver);
+
+    if (args.length >= 2) {
+        string command = args[1].strip.toLower;
+        if (command == "app") {
+            buildApp();
+        } else if (command == "api") {
+            buildApi(ver);
+        } else if (command == "all") {
+            buildApp();
+            buildApi(ver);
+            if (args.length >= 3 && args[2].strip.toLower == "release") {
+                if (args.length >= 4) {
+                    string token = args[3].strip();
+                    print("Are you sure you want to create a GitHub release for version %s?", ver);
+                    string response = readln().strip.toLower;
+                    if (response == "yes" || response == "y") createRelease(token, ver);
+                } else {
+                    error("Missing required personal access token to create a GitHub release.");
+                    return 1;
+                }
+            }
+        }
+    } else {
+        buildApp();
+        buildApi(ver);
+    }
+
+    return 0;
+}
+
+/** 
+ * Builds the production version of the frontend app and injects it into the
+ * API's resources to serve statically.
+ */
+void buildApp() {
+    chdir(APP_DIR);
     print("Building app...");
-    runOrQuit(APP_BUILD);
+    runOrQuit(APP_BUILD, "." ~ APP_LOG); // Use an extra dot because we moved into app dir.
     print("Copying dist from %s to %s", DIST_ORIGIN, DIST);
     chdir("..");
     removeIfExists(DIST);
     mkdir(DIST);
     copyDir(DIST_ORIGIN, DIST);
-
-    print("Building API...");
-    runOrQuit(API_BUILD);
-    print("Build complete!");
 }
 
+/** 
+ * Builds the production version of the backend API.
+ */
+void buildApi(string ver) {
+    print("Building API...");
+    runOrQuit(API_BUILD, API_LOG);
+    string[] jars = findFilesByExtension("target", ".jar", false);
+    string jarFile = jars[0];
+    string finalJarFile = "./target/rail-signal-" ~ ver ~ ".jar";
+    // Clean up the jar file name.
+    copy(jarFile, finalJarFile);
+    print("Build complete. Created %s", finalJarFile);
+}
+
+/** 
+ * Parses the version of the system from the pom file.
+ * Returns: The version string, or null if it couldn't be found.
+ */
+string getVersion() {
+    auto data = parseDOM!simpleXML(readText("pom.xml"));
+    auto root = data.children[0];
+    foreach (child; root.children) {
+        if (child.name == "version") {
+            return child.children[0].text;
+        }
+    }
+    return null;
+}
+
+void createRelease(string token, string ver) {
+    
+}

src/main/java/nl/andrewl/railsignalapi/rest/dto/component/in/SwitchPayload.java

@@ -4,6 +4,11 @@ import javax.validation.constraints.NotEmpty;
 import javax.validation.constraints.NotNull;
 import javax.validation.constraints.Size;
 
+/**
+ * A switch has a set of possible configurations, each of which links two
+ * different nodes. Most conventional switches have two configurations, but for
+ * universal compatibility, as many as 10 may be allowed.
+ */
 public class SwitchPayload extends ComponentPayload {
 	@NotNull @Size(max = 10)
 	public SwitchConfigurationPayload[] possibleConfigurations;

src/main/java/nl/andrewl/railsignalapi/service/ComponentService.java

@@ -173,9 +173,11 @@ public class ComponentService {
 	}
 
 	private void updateConnectedNodes(PathNode owner, Set<PathNode> newNodes) {
+		// The set of all path nodes that will be disconnected from the owner.
 		Set<PathNode> disconnected = new HashSet<>(owner.getConnectedNodes());
 		disconnected.removeAll(newNodes);
 
+		// The set of all path nodes that will be connected to the owner.
 		Set<PathNode> connected = new HashSet<>(newNodes);
 		connected.removeAll(owner.getConnectedNodes());