feat: NCS-37 Quarkus integration (#35)

Reviewed-on: #35
Reviewed-by: Leon Hermann <lq@blackhole.local>

modules/core/.dockerignore

@@ -0,0 +1,5 @@
+.gitignore
+!build/*-runner
+!build/*-runner.jar
+!build/lib/*
+!build/quarkus-app/*

modules/core/.gitignore

@@ -0,0 +1,41 @@
+# Gradle
+.gradle/
+build/
+
+# Eclipse
+.project
+.classpath
+.settings/
+bin/
+
+# IntelliJ
+.idea
+*.ipr
+*.iml
+*.iws
+
+# NetBeans
+nb-configuration.xml
+
+# Visual Studio Code
+.vscode
+.factorypath
+
+# OSX
+.DS_Store
+
+# Vim
+*.swp
+*.swo
+
+# patch
+*.orig
+*.rej
+
+# Local environment
+.env
+
+# Plugin directory
+/.quarkus/cli/plugins/
+# TLS Certificates
+.certs/

modules/core/build.gradle.kts

@@ -1,6 +1,7 @@
 plugins {
     id("scala")
     id("org.scoverage") version "8.1"
+    id("io.quarkus")
 }
 
 group = "de.nowchess"
@@ -8,6 +9,8 @@ version = "1.0-SNAPSHOT"
 
 @Suppress("UNCHECKED_CAST")
 val versions = rootProject.extra["VERSIONS"] as Map<String, String>
+@Suppress("UNCHECKED_CAST")
+val scoverageExcluded = rootProject.extra["SCOVERAGE_EXCLUDED"] as List<String>
 
 repositories {
     mavenCentral()
@@ -19,15 +22,21 @@ scala {
 
 scoverage {
     scoverageVersion.set(versions["SCOVERAGE"]!!)
+    excludedFiles.set(scoverageExcluded)
 }
 
 tasks.withType<ScalaCompile> {
     scalaCompileOptions.additionalParameters = listOf("-encoding", "UTF-8")
 }
 
+val quarkusPlatformGroupId: String by project
+val quarkusPlatformArtifactId: String by project
+val quarkusPlatformVersion: String by project
+
+
 dependencies {
 
-    implementation("org.scala-lang:scala3-compiler_3") {
+    compileOnly("org.scala-lang:scala3-compiler_3") {
         version {
             strictly(versions["SCALA3"]!!)
         }
@@ -43,19 +52,59 @@ dependencies {
     implementation(project(":modules:rule"))
     implementation(project(":modules:bot"))
 
+
+    implementation(enforcedPlatform("${quarkusPlatformGroupId}:${quarkusPlatformArtifactId}:${quarkusPlatformVersion}"))
+    implementation("io.quarkus:quarkus-rest")
+    implementation("io.quarkus:quarkus-hibernate-orm")
+    implementation("io.quarkus:quarkus-rest-client-jackson")
+    implementation("io.quarkus:quarkus-rest-client")
+    implementation("io.quarkus:quarkus-rest-jackson")
+    implementation("io.quarkus:quarkus-config-yaml")
+    implementation("io.quarkus:quarkus-smallrye-fault-tolerance")
+    implementation("io.quarkus:quarkus-smallrye-jwt")
+    implementation("io.quarkus:quarkus-smallrye-health")
+    implementation("io.quarkus:quarkus-micrometer")
+    implementation("io.quarkus:quarkus-arc")
+
+    implementation("com.fasterxml.jackson.module:jackson-module-scala_3:${versions["JACKSON_SCALA"]!!}")
+
+
     testImplementation(platform("org.junit:junit-bom:5.13.4"))
     testImplementation("org.junit.jupiter:junit-jupiter")
     testImplementation("org.scalatest:scalatest_3:${versions["SCALATEST"]!!}")
     testImplementation("co.helmethair:scalatest-junit-runner:${versions["SCALATEST_JUNIT"]!!}")
+    testImplementation("io.quarkus:quarkus-junit5")
+    testImplementation("io.rest-assured:rest-assured")
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine")
+}
+
+configurations.matching { !it.name.startsWith("scoverage") }.configureEach {
+    resolutionStrategy.force("org.scala-lang:scala-library:${versions["SCALA_LIBRARY"]!!}")
+}
+configurations.scoverage {
+    resolutionStrategy.eachDependency {
+        if (requested.group == "org.scoverage" && requested.name.startsWith("scalac-scoverage-plugin_")) {
+            useTarget("${requested.group}:scalac-scoverage-plugin_2.13.16:2.3.0")
+        }
+    }
+}
+
+tasks.withType<JavaCompile> {
+    options.encoding = "UTF-8"
+    options.compilerArgs.add("-parameters")
+}
+
+tasks.withType<Jar>().configureEach {
+    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
 }
 
 tasks.test {
     useJUnitPlatform {
-        includeEngines("scalatest")
+        includeEngines("scalatest", "junit-jupiter")
         testLogging {
-            events("skipped", "failed")
+            events("passed", "skipped", "failed")
         }
     }
     finalizedBy(tasks.reportScoverage)

modules/core/src/main/docker/Dockerfile.jvm

@@ -0,0 +1,100 @@
+####
+# This Dockerfile is used in order to build a container that runs the Quarkus application in JVM mode
+#
+# Before building the container image run:
+#
+# ./gradlew build
+#
+# Then, build the image with:
+#
+# docker build -f src/main/docker/Dockerfile.jvm -t quarkus/backcore-jvm .
+#
+# Then run the container using:
+#
+# docker run -i --rm -p 8080:8080 quarkus/backcore-jvm
+#
+# If you want to include the debug port into your docker image
+# you will have to expose the debug port (default 5005 being the default) like this :  EXPOSE 8080 5005.
+# Additionally you will have to set -e JAVA_DEBUG=true and -e JAVA_DEBUG_PORT=*:5005
+# when running the container
+#
+# Then run the container using :
+#
+# docker run -i --rm -p 8080:8080 quarkus/backcore-jvm
+#
+# This image uses the `run-java.sh` script to run the application.
+# This scripts computes the command line to execute your Java application, and
+# includes memory/GC tuning.
+# You can configure the behavior using the following environment properties:
+# - JAVA_OPTS: JVM options passed to the `java` command (example: "-verbose:class") - Be aware that this will override
+# the default JVM options, use `JAVA_OPTS_APPEND` to append options
+# - JAVA_OPTS_APPEND: User specified Java options to be appended to generated options
+#   in JAVA_OPTS (example: "-Dsome.property=foo")
+# - JAVA_MAX_MEM_RATIO: Is used when no `-Xmx` option is given in JAVA_OPTS. This is
+#   used to calculate a default maximal heap memory based on a containers restriction.
+#   If used in a container without any memory constraints for the container then this
+#   option has no effect. If there is a memory constraint then `-Xmx` is set to a ratio
+#   of the container available memory as set here. The default is `50` which means 50%
+#   of the available memory is used as an upper boundary. You can skip this mechanism by
+#   setting this value to `0` in which case no `-Xmx` option is added.
+# - JAVA_INITIAL_MEM_RATIO: Is used when no `-Xms` option is given in JAVA_OPTS. This
+#   is used to calculate a default initial heap memory based on the maximum heap memory.
+#   If used in a container without any memory constraints for the container then this
+#   option has no effect. If there is a memory constraint then `-Xms` is set to a ratio
+#   of the `-Xmx` memory as set here. The default is `25` which means 25% of the `-Xmx`
+#   is used as the initial heap size. You can skip this mechanism by setting this value
+#   to `0` in which case no `-Xms` option is added (example: "25")
+# - JAVA_MAX_INITIAL_MEM: Is used when no `-Xms` option is given in JAVA_OPTS.
+#   This is used to calculate the maximum value of the initial heap memory. If used in
+#   a container without any memory constraints for the container then this option has
+#   no effect. If there is a memory constraint then `-Xms` is limited to the value set
+#   here. The default is 4096MB which means the calculated value of `-Xms` never will
+#   be greater than 4096MB. The value of this variable is expressed in MB (example: "4096")
+# - JAVA_DIAGNOSTICS: Set this to get some diagnostics information to standard output
+#   when things are happening. This option, if set to true, will set
+#  `-XX:+UnlockDiagnosticVMOptions`. Disabled by default (example: "true").
+# - JAVA_DEBUG: If set remote debugging will be switched on. Disabled by default (example:
+#    true").
+# - JAVA_DEBUG_PORT: Port used for remote debugging. Defaults to 5005 (example: "8787").
+# - CONTAINER_CORE_LIMIT: A calculated core limit as described in
+#   https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt. (example: "2")
+# - CONTAINER_MAX_MEMORY: Memory limit given to the container (example: "1024").
+# - GC_MIN_HEAP_FREE_RATIO: Minimum percentage of heap free after GC to avoid expansion.
+#   (example: "20")
+# - GC_MAX_HEAP_FREE_RATIO: Maximum percentage of heap free after GC to avoid shrinking.
+#   (example: "40")
+# - GC_TIME_RATIO: Specifies the ratio of the time spent outside the garbage collection.
+#   (example: "4")
+# - GC_ADAPTIVE_SIZE_POLICY_WEIGHT: The weighting given to the current GC time versus
+#   previous GC times. (example: "90")
+# - GC_METASPACE_SIZE: The initial metaspace size. (example: "20")
+# - GC_MAX_METASPACE_SIZE: The maximum metaspace size. (example: "100")
+# - GC_CONTAINER_OPTIONS: Specify Java GC to use. The value of this variable should
+#   contain the necessary JRE command-line options to specify the required GC, which
+#   will override the default of `-XX:+UseParallelGC` (example: -XX:+UseG1GC).
+# - HTTPS_PROXY: The location of the https proxy. (example: "myuser@127.0.0.1:8080")
+# - HTTP_PROXY: The location of the http proxy. (example: "myuser@127.0.0.1:8080")
+# - NO_PROXY: A comma separated lists of hosts, IP addresses or domains that can be
+#   accessed directly. (example: "foo.example.com,bar.example.com")
+#
+# You can find more information about the UBI base runtime images and their configuration here:
+# https://rh-openjdk.github.io/redhat-openjdk-containers/
+###
+FROM registry.access.redhat.com/ubi9/openjdk-21-runtime:1.24
+
+ENV LANGUAGE='en_US:en'
+
+
+# We make four distinct layers so if there are application changes the library layers can be re-used
+COPY --chown=185 build/quarkus-app/lib/ /deployments/lib/
+COPY --chown=185 build/quarkus-app/*.jar /deployments/
+COPY --chown=185 build/quarkus-app/app/ /deployments/app/
+COPY --chown=185 build/quarkus-app/quarkus/ /deployments/quarkus/
+
+EXPOSE 8080
+USER 185
+ENV JAVA_OPTS_APPEND="-Dquarkus.http.host=0.0.0.0 -Djava.util.logging.manager=org.jboss.logmanager.LogManager"
+ENV JAVA_APP_JAR="/deployments/quarkus-run.jar"
+
+ENTRYPOINT [ "/opt/jboss/container/java/run/run-java.sh" ]
+

modules/core/src/main/docker/Dockerfile.legacy-jar

@@ -0,0 +1,96 @@
+####
+# This Dockerfile is used in order to build a container that runs the Quarkus application in JVM mode
+#
+# Before building the container image run:
+#
+# ./gradlew build -Dquarkus.package.jar.type=legacy-jar
+#
+# Then, build the image with:
+#
+# docker build -f src/main/docker/Dockerfile.legacy-jar -t quarkus/backcore-legacy-jar .
+#
+# Then run the container using:
+#
+# docker run -i --rm -p 8080:8080 quarkus/backcore-legacy-jar
+#
+# If you want to include the debug port into your docker image
+# you will have to expose the debug port (default 5005 being the default) like this :  EXPOSE 8080 5005.
+# Additionally you will have to set -e JAVA_DEBUG=true and -e JAVA_DEBUG_PORT=*:5005
+# when running the container
+#
+# Then run the container using :
+#
+# docker run -i --rm -p 8080:8080 quarkus/backcore-legacy-jar
+#
+# This image uses the `run-java.sh` script to run the application.
+# This scripts computes the command line to execute your Java application, and
+# includes memory/GC tuning.
+# You can configure the behavior using the following environment properties:
+# - JAVA_OPTS: JVM options passed to the `java` command (example: "-verbose:class") - Be aware that this will override
+# the default JVM options, use `JAVA_OPTS_APPEND` to append options
+# - JAVA_OPTS_APPEND: User specified Java options to be appended to generated options
+#   in JAVA_OPTS (example: "-Dsome.property=foo")
+# - JAVA_MAX_MEM_RATIO: Is used when no `-Xmx` option is given in JAVA_OPTS. This is
+#   used to calculate a default maximal heap memory based on a containers restriction.
+#   If used in a container without any memory constraints for the container then this
+#   option has no effect. If there is a memory constraint then `-Xmx` is set to a ratio
+#   of the container available memory as set here. The default is `50` which means 50%
+#   of the available memory is used as an upper boundary. You can skip this mechanism by
+#   setting this value to `0` in which case no `-Xmx` option is added.
+# - JAVA_INITIAL_MEM_RATIO: Is used when no `-Xms` option is given in JAVA_OPTS. This
+#   is used to calculate a default initial heap memory based on the maximum heap memory.
+#   If used in a container without any memory constraints for the container then this
+#   option has no effect. If there is a memory constraint then `-Xms` is set to a ratio
+#   of the `-Xmx` memory as set here. The default is `25` which means 25% of the `-Xmx`
+#   is used as the initial heap size. You can skip this mechanism by setting this value
+#   to `0` in which case no `-Xms` option is added (example: "25")
+# - JAVA_MAX_INITIAL_MEM: Is used when no `-Xms` option is given in JAVA_OPTS.
+#   This is used to calculate the maximum value of the initial heap memory. If used in
+#   a container without any memory constraints for the container then this option has
+#   no effect. If there is a memory constraint then `-Xms` is limited to the value set
+#   here. The default is 4096MB which means the calculated value of `-Xms` never will
+#   be greater than 4096MB. The value of this variable is expressed in MB (example: "4096")
+# - JAVA_DIAGNOSTICS: Set this to get some diagnostics information to standard output
+#   when things are happening. This option, if set to true, will set
+#  `-XX:+UnlockDiagnosticVMOptions`. Disabled by default (example: "true").
+# - JAVA_DEBUG: If set remote debugging will be switched on. Disabled by default (example:
+#    true").
+# - JAVA_DEBUG_PORT: Port used for remote debugging. Defaults to 5005 (example: "8787").
+# - CONTAINER_CORE_LIMIT: A calculated core limit as described in
+#   https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt. (example: "2")
+# - CONTAINER_MAX_MEMORY: Memory limit given to the container (example: "1024").
+# - GC_MIN_HEAP_FREE_RATIO: Minimum percentage of heap free after GC to avoid expansion.
+#   (example: "20")
+# - GC_MAX_HEAP_FREE_RATIO: Maximum percentage of heap free after GC to avoid shrinking.
+#   (example: "40")
+# - GC_TIME_RATIO: Specifies the ratio of the time spent outside the garbage collection.
+#   (example: "4")
+# - GC_ADAPTIVE_SIZE_POLICY_WEIGHT: The weighting given to the current GC time versus
+#   previous GC times. (example: "90")
+# - GC_METASPACE_SIZE: The initial metaspace size. (example: "20")
+# - GC_MAX_METASPACE_SIZE: The maximum metaspace size. (example: "100")
+# - GC_CONTAINER_OPTIONS: Specify Java GC to use. The value of this variable should
+#   contain the necessary JRE command-line options to specify the required GC, which
+#   will override the default of `-XX:+UseParallelGC` (example: -XX:+UseG1GC).
+# - HTTPS_PROXY: The location of the https proxy. (example: "myuser@127.0.0.1:8080")
+# - HTTP_PROXY: The location of the http proxy. (example: "myuser@127.0.0.1:8080")
+# - NO_PROXY: A comma separated lists of hosts, IP addresses or domains that can be
+#   accessed directly. (example: "foo.example.com,bar.example.com")
+#
+# You can find more information about the UBI base runtime images and their configuration here:
+# https://rh-openjdk.github.io/redhat-openjdk-containers/
+###
+FROM registry.access.redhat.com/ubi9/openjdk-21-runtime:1.24
+
+ENV LANGUAGE='en_US:en'
+
+
+COPY build/lib/* /deployments/lib/
+COPY build/*-runner.jar /deployments/quarkus-run.jar
+
+EXPOSE 8080
+USER 185
+ENV JAVA_OPTS_APPEND="-Dquarkus.http.host=0.0.0.0 -Djava.util.logging.manager=org.jboss.logmanager.LogManager"
+ENV JAVA_APP_JAR="/deployments/quarkus-run.jar"
+
+ENTRYPOINT [ "/opt/jboss/container/java/run/run-java.sh" ]

modules/core/src/main/docker/Dockerfile.native

@@ -0,0 +1,29 @@
+####
+# This Dockerfile is used in order to build a container that runs the Quarkus application in native (no JVM) mode.
+#
+# Before building the container image run:
+#
+# ./gradlew build -Dquarkus.native.enabled=true
+#
+# Then, build the image with:
+#
+# docker build -f src/main/docker/Dockerfile.native -t quarkus/backcore .
+#
+# Then run the container using:
+#
+# docker run -i --rm -p 8080:8080 quarkus/backcore
+#
+# The ` registry.access.redhat.com/ubi9/ubi-minimal:9.7` base image is based on UBI 9.
+# To use UBI 8, switch to `quay.io/ubi8/ubi-minimal:8.10`.
+###
+FROM registry.access.redhat.com/ubi9/ubi-minimal:9.7
+WORKDIR /work/
+RUN chown 1001 /work \
+    && chmod "g+rwX" /work \
+    && chown 1001:root /work
+COPY --chown=1001:root --chmod=0755 build/*-runner /work/application
+
+EXPOSE 8080
+USER 1001
+
+ENTRYPOINT ["./application", "-Dquarkus.http.host=0.0.0.0"]

modules/core/src/main/docker/Dockerfile.native-micro

@@ -0,0 +1,32 @@
+####
+# This Dockerfile is used in order to build a container that runs the Quarkus application in native (no JVM) mode.
+# It uses a micro base image, tuned for Quarkus native executables.
+# It reduces the size of the resulting container image.
+# Check https://quarkus.io/guides/quarkus-runtime-base-image for further information about this image.
+#
+# Before building the container image run:
+#
+# ./gradlew build -Dquarkus.native.enabled=true
+#
+# Then, build the image with:
+#
+# docker build -f src/main/docker/Dockerfile.native-micro -t quarkus/backcore .
+#
+# Then run the container using:
+#
+# docker run -i --rm -p 8080:8080 quarkus/backcore
+#
+# The `quay.io/quarkus/ubi9-quarkus-micro-image:2.0` base image is based on UBI 9.
+# To use UBI 8, switch to `quay.io/quarkus/quarkus-micro-image:2.0`.
+###
+FROM quay.io/quarkus/ubi9-quarkus-micro-image:2.0
+WORKDIR /work/
+RUN chown 1001 /work \
+    && chmod "g+rwX" /work \
+    && chown 1001:root /work
+COPY --chown=1001:root --chmod=0755 build/*-runner /work/application
+
+EXPOSE 8080
+USER 1001
+
+ENTRYPOINT ["./application", "-Dquarkus.http.host=0.0.0.0"]

modules/core/src/main/resources/META-INF/native-image/de.nowchess/core/reachability-metadata.json

@@ -0,0 +1,27 @@
+{
+  "reflection": [
+    { "type": "scala.Tuple1[]" },
+    { "type": "scala.Tuple2[]" },
+    { "type": "scala.Tuple3[]" },
+    { "type": "scala.Tuple4[]" },
+    { "type": "scala.Tuple5[]" },
+    { "type": "scala.Tuple6[]" },
+    { "type": "scala.Tuple7[]" },
+    { "type": "scala.Tuple8[]" },
+    { "type": "scala.Tuple9[]" },
+    { "type": "scala.Tuple10[]" },
+    { "type": "scala.Tuple11[]" },
+    { "type": "scala.Tuple12[]" },
+    { "type": "scala.Tuple13[]" },
+    { "type": "scala.Tuple14[]" },
+    { "type": "scala.Tuple15[]" },
+    { "type": "scala.Tuple16[]" },
+    { "type": "scala.Tuple17[]" },
+    { "type": "scala.Tuple18[]" },
+    { "type": "scala.Tuple19[]" },
+    { "type": "scala.Tuple20[]" },
+    { "type": "scala.Tuple21[]" },
+    { "type": "scala.Tuple22[]" },
+    { "type": "com.fasterxml.jackson.module.scala.introspect.PropertyDescriptor[]" }
+  ]
+}

modules/core/src/main/resources/application.yml

@@ -0,0 +1,3 @@
+greeting:
+  message: "hello"
+

modules/core/src/main/resources/import.sql

@@ -0,0 +1,6 @@
+-- This file allow to write SQL commands that will be emitted in test and dev.
+-- The commands are commented as their support depends of the database
+-- insert into myentity (id, field) values(1, 'field-1');
+-- insert into myentity (id, field) values(2, 'field-2');
+-- insert into myentity (id, field) values(3, 'field-3');
+-- alter sequence myentity_seq restart with 4;

modules/core/src/main/scala/de/nowchess/chess/config/JacksonConfig.scala

@@ -0,0 +1,17 @@
+package de.nowchess.chess.config
+
+import com.fasterxml.jackson.core.Version
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.module.scala.DefaultScalaModule
+import io.quarkus.jackson.ObjectMapperCustomizer
+import jakarta.inject.Singleton
+
+@Singleton
+class JacksonConfig extends ObjectMapperCustomizer:
+  def customize(mapper: ObjectMapper): Unit =
+    mapper.registerModule(new DefaultScalaModule() {
+      override def version(): Version =
+        // scalafix:off DisableSyntax.null
+        new Version(2, 21, 1, null, "com.fasterxml.jackson.module", "jackson-module-scala")
+        // scalafix:on DisableSyntax.null
+    })

modules/core/src/main/scala/de/nowchess/chess/config/NativeReflectionConfig.scala

@@ -0,0 +1,23 @@
+package de.nowchess.chess.config
+
+import de.nowchess.api.dto.*
+import io.quarkus.runtime.annotations.RegisterForReflection
+
+@RegisterForReflection(
+  targets = Array(
+    classOf[ApiErrorDto],
+    classOf[CreateGameRequestDto],
+    classOf[ErrorEventDto],
+    classOf[GameFullDto],
+    classOf[GameFullEventDto],
+    classOf[GameStateDto],
+    classOf[GameStateEventDto],
+    classOf[ImportFenRequestDto],
+    classOf[ImportPgnRequestDto],
+    classOf[LegalMoveDto],
+    classOf[LegalMovesResponseDto],
+    classOf[OkResponseDto],
+    classOf[PlayerInfoDto],
+  ),
+)
+class NativeReflectionConfig

modules/core/src/main/scala/de/nowchess/chess/engine/GameEngine.scala

@@ -38,9 +38,10 @@ class GameEngine(
   private implicit val ec: ExecutionContext = ExecutionContext.global
 
   // Synchronized accessors for current state
-  def board: Board         = synchronized(currentContext.board)
-  def turn: Color          = synchronized(currentContext.turn)
-  def context: GameContext = synchronized(currentContext)
+  def board: Board                      = synchronized(currentContext.board)
+  def turn: Color                       = synchronized(currentContext.turn)
+  def context: GameContext              = synchronized(currentContext)
+  def pendingDrawOfferBy: Option[Color] = synchronized(pendingDrawOffer)
 
   /** Check if undo is available. */
   def canUndo: Boolean = synchronized(invoker.canUndo)
@@ -67,21 +68,7 @@ class GameEngine(
         performRedo()
 
       case "draw" =>
-        if currentContext.halfMoveClock >= 100 then
-          currentContext = currentContext.withResult(Some(GameResult.Draw(DrawReason.FiftyMoveRule)))
-          invoker.clear()
-          notifyObservers(DrawEvent(currentContext, DrawReason.FiftyMoveRule))
-        else if ruleSet.isThreefoldRepetition(currentContext) then
-          currentContext = currentContext.withResult(Some(GameResult.Draw(DrawReason.ThreefoldRepetition)))
-          invoker.clear()
-          notifyObservers(DrawEvent(currentContext, DrawReason.ThreefoldRepetition))
-        else
-          notifyObservers(
-            InvalidMoveEvent(
-              currentContext,
-              InvalidMoveReason.DrawCannotBeClaimed,
-            ),
-          )
+        claimDraw()
 
       case "" =>
         notifyObservers(InvalidMoveEvent(currentContext, InvalidMoveReason.EmptyInput))
@@ -195,6 +182,21 @@ class GameEngine(
           notifyObservers(DrawOfferDeclinedEvent(currentContext, color))
   }
 
+  /** Claim a draw by fifty-move rule or threefold repetition. */
+  def claimDraw(): Unit = synchronized {
+    if currentContext.result.isDefined then
+      notifyObservers(InvalidMoveEvent(currentContext, InvalidMoveReason.GameAlreadyOver))
+    else if currentContext.halfMoveClock >= 100 then
+      currentContext = currentContext.withResult(Some(GameResult.Draw(DrawReason.FiftyMoveRule)))
+      invoker.clear()
+      notifyObservers(DrawEvent(currentContext, DrawReason.FiftyMoveRule))
+    else if ruleSet.isThreefoldRepetition(currentContext) then
+      currentContext = currentContext.withResult(Some(GameResult.Draw(DrawReason.ThreefoldRepetition)))
+      invoker.clear()
+      notifyObservers(DrawEvent(currentContext, DrawReason.ThreefoldRepetition))
+    else notifyObservers(InvalidMoveEvent(currentContext, InvalidMoveReason.DrawCannotBeClaimed))
+  }
+
   /** Load a game using the provided importer. If the imported context has moves, they are replayed through the command
     * system. Otherwise, the position is set directly. Notifies observers with PgnLoadedEvent on success.
     */
@@ -258,6 +260,22 @@ class GameEngine(
     notifyObservers(BoardResetEvent(currentContext))
   }
 
+  /** Resign the game on behalf of the side to move. */
+  def resign(): Unit = synchronized {
+    if currentContext.result.isEmpty then
+      val winner = currentContext.turn.opposite
+      currentContext = currentContext.withResult(Some(GameResult.Win(winner)))
+      invoker.clear()
+  }
+
+  /** Apply a draw result directly (for agreement, fifty-move claim, etc.). */
+  def applyDraw(reason: DrawReason): Unit = synchronized {
+    if currentContext.result.isEmpty then
+      currentContext = currentContext.withResult(Some(GameResult.Draw(reason)))
+      invoker.clear()
+      notifyObservers(DrawEvent(currentContext, reason))
+  }
+
   /** Kick off play when the side to move is a bot (e.g. bot-vs-bot from initial position). */
   def startGame(): Unit = synchronized(requestBotMoveIfNeeded())
 

modules/core/src/main/scala/de/nowchess/chess/exception/ApiException.scala

@@ -0,0 +1,13 @@
+package de.nowchess.chess.exception
+
+class ApiException(
+    val status: Int,
+    val code: String,
+    message: String,
+    val field: Option[String] = None,
+) extends RuntimeException(message)
+
+class GameNotFoundException(gameId: String) extends ApiException(404, "GAME_NOT_FOUND", s"Game $gameId not found")
+
+class BadRequestException(code: String, message: String, field: Option[String] = None)
+    extends ApiException(400, code, message, field)

modules/core/src/main/scala/de/nowchess/chess/exception/ApiExceptionMapper.scala

@@ -0,0 +1,14 @@
+package de.nowchess.chess.exception
+
+import de.nowchess.api.dto.ApiErrorDto
+import jakarta.ws.rs.core.{MediaType, Response}
+import jakarta.ws.rs.ext.{ExceptionMapper, Provider}
+
+@Provider
+class ApiExceptionMapper extends ExceptionMapper[ApiException]:
+  def toResponse(ex: ApiException): Response =
+    Response
+      .status(ex.status)
+      .entity(ApiErrorDto(ex.code, ex.getMessage, ex.field))
+      .`type`(MediaType.APPLICATION_JSON)
+      .build()

modules/core/src/main/scala/de/nowchess/chess/registry/GameEntry.scala

@@ -0,0 +1,13 @@
+package de.nowchess.chess.registry
+
+import de.nowchess.api.board.Color
+import de.nowchess.api.player.PlayerInfo
+import de.nowchess.chess.engine.GameEngine
+
+final case class GameEntry(
+    gameId: String,
+    engine: GameEngine,
+    white: PlayerInfo,
+    black: PlayerInfo,
+    resigned: Boolean = false,
+)

modules/core/src/main/scala/de/nowchess/chess/registry/GameRegistry.scala

@@ -0,0 +1,7 @@
+package de.nowchess.chess.registry
+
+trait GameRegistry:
+  def store(entry: GameEntry): Unit
+  def get(gameId: String): Option[GameEntry]
+  def update(entry: GameEntry): Unit
+  def generateId(): String

modules/core/src/main/scala/de/nowchess/chess/registry/GameRegistryImpl.scala

@@ -0,0 +1,23 @@
+package de.nowchess.chess.registry
+
+import jakarta.enterprise.context.ApplicationScoped
+import java.security.SecureRandom
+import java.util.concurrent.ConcurrentHashMap
+
+@ApplicationScoped
+class GameRegistryImpl extends GameRegistry:
+  private val games = ConcurrentHashMap[String, GameEntry]()
+  private val rng   = new SecureRandom()
+
+  def store(entry: GameEntry): Unit =
+    games.put(entry.gameId, entry)
+
+  def get(gameId: String): Option[GameEntry] =
+    Option(games.get(gameId))
+
+  def update(entry: GameEntry): Unit =
+    games.put(entry.gameId, entry)
+
+  def generateId(): String =
+    val chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    Iterator.continually(rng.nextInt(chars.length)).map(chars).take(8).mkString // NOSONAR

modules/core/src/main/scala/de/nowchess/chess/resource/GameResource.scala

@@ -0,0 +1,311 @@
+package de.nowchess.chess.resource
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import de.nowchess.api.board.Square
+import de.nowchess.api.dto.*
+import de.nowchess.api.game.{DrawReason, GameContext, GameResult}
+import de.nowchess.api.move.{Move, MoveType, PromotionPiece}
+import de.nowchess.api.player.{PlayerId, PlayerInfo}
+import de.nowchess.chess.controller.Parser
+import de.nowchess.chess.engine.GameEngine
+import de.nowchess.chess.exception.{BadRequestException, GameNotFoundException}
+import de.nowchess.chess.observer.*
+import de.nowchess.chess.registry.{GameEntry, GameRegistry}
+import de.nowchess.io.fen.{FenExporter, FenParser}
+import de.nowchess.io.pgn.{PgnExporter, PgnParser}
+import io.smallrye.mutiny.Multi
+import jakarta.enterprise.context.ApplicationScoped
+import jakarta.inject.Inject
+import jakarta.ws.rs.*
+import jakarta.ws.rs.core.{MediaType, Response}
+
+import java.util.concurrent.atomic.AtomicReference
+import scala.compiletime.uninitialized
+
+@Path("/api/board/game")
+@ApplicationScoped
+class GameResource:
+
+  // scalafix:off DisableSyntax.var
+  @Inject
+  var registry: GameRegistry = uninitialized
+
+  @Inject
+  var objectMapper: ObjectMapper = uninitialized
+  // scalafix:on DisableSyntax.var
+
+  private val DefaultWhite = PlayerInfo(PlayerId("p1"), "Player 1")
+  private val DefaultBlack = PlayerInfo(PlayerId("p2"), "Player 2")
+
+  // ── mapping ──────────────────────────────────────────────────────────────
+
+  private def statusOf(entry: GameEntry): String =
+    if entry.engine.pendingDrawOfferBy.isDefined then "drawOffered"
+    else
+      val ctx = entry.engine.context
+      ctx.result match
+        case Some(GameResult.Win(_)) =>
+          if entry.resigned then "resign" else "checkmate"
+        case Some(GameResult.Draw(DrawReason.Stalemate))            => "stalemate"
+        case Some(GameResult.Draw(DrawReason.InsufficientMaterial)) => "insufficientMaterial"
+        case Some(GameResult.Draw(_))                               => "draw"
+        case None =>
+          if ctx.halfMoveClock >= 100 then "fiftyMoveAvailable"
+          else if entry.engine.ruleSet.isCheck(ctx) then "check"
+          else "started"
+
+  private def moveToUci(move: Move): String =
+    val base = s"${move.from}${move.to}"
+    move.moveType match
+      case MoveType.Promotion(PromotionPiece.Queen)  => s"${base}q"
+      case MoveType.Promotion(PromotionPiece.Rook)   => s"${base}r"
+      case MoveType.Promotion(PromotionPiece.Bishop) => s"${base}b"
+      case MoveType.Promotion(PromotionPiece.Knight) => s"${base}n"
+      case _                                         => base
+
+  private def toLegalMoveDto(move: Move): LegalMoveDto =
+    val (moveTypeStr, promotionStr) = move.moveType match
+      case MoveType.Normal(false)                    => ("normal", None)
+      case MoveType.Normal(true)                     => ("capture", None)
+      case MoveType.CastleKingside                   => ("castleKingside", None)
+      case MoveType.CastleQueenside                  => ("castleQueenside", None)
+      case MoveType.EnPassant                        => ("enPassant", None)
+      case MoveType.Promotion(PromotionPiece.Queen)  => ("promotion", Some("queen"))
+      case MoveType.Promotion(PromotionPiece.Rook)   => ("promotion", Some("rook"))
+      case MoveType.Promotion(PromotionPiece.Bishop) => ("promotion", Some("bishop"))
+      case MoveType.Promotion(PromotionPiece.Knight) => ("promotion", Some("knight"))
+    LegalMoveDto(move.from.toString, move.to.toString, moveToUci(move), moveTypeStr, promotionStr)
+
+  private def toPlayerDto(info: PlayerInfo): PlayerInfoDto =
+    PlayerInfoDto(info.id.value, info.displayName)
+
+  private def toGameStateDto(entry: GameEntry): GameStateDto =
+    val ctx = entry.engine.context
+    GameStateDto(
+      fen = FenExporter.exportGameContext(ctx),
+      pgn = PgnExporter.exportGame(
+        Map(
+          "Event"  -> "NowChess game",
+          "White"  -> entry.white.displayName,
+          "Black"  -> entry.black.displayName,
+          "Result" -> "*",
+        ),
+        ctx.moves,
+      ),
+      turn = ctx.turn.label.toLowerCase,
+      status = statusOf(entry),
+      winner = ctx.result.collect { case GameResult.Win(c) => c.label.toLowerCase },
+      moves = ctx.moves.map(moveToUci),
+      undoAvailable = entry.engine.canUndo,
+      redoAvailable = entry.engine.canRedo,
+    )
+
+  private def toGameFullDto(entry: GameEntry): GameFullDto =
+    GameFullDto(entry.gameId, toPlayerDto(entry.white), toPlayerDto(entry.black), toGameStateDto(entry))
+
+  private def playerInfoFrom(dto: Option[PlayerInfoDto], default: PlayerInfo): PlayerInfo =
+    dto.fold(default)(d => PlayerInfo(PlayerId(d.id), d.displayName))
+
+  private def newEntry(ctx: GameContext, white: PlayerInfo, black: PlayerInfo): GameEntry =
+    GameEntry(registry.generateId(), GameEngine(initialContext = ctx), white, black)
+
+  private def applyMoveInput(engine: GameEngine, uci: String): Option[String] =
+    val error = new AtomicReference[Option[String]](None)
+    val obs = new Observer:
+      def onGameEvent(e: GameEvent): Unit = e match
+        case InvalidMoveEvent(_, reason) => error.set(Some(reason.toString))
+        case _                           => ()
+    engine.subscribe(obs)
+    engine.processUserInput(uci)
+    engine.unsubscribe(obs)
+    error.get()
+
+  // ── response helpers ─────────────────────────────────────────────────────
+
+  private def ok(body: AnyRef): Response      = Response.ok(body).build()
+  private def created(body: AnyRef): Response = Response.status(Response.Status.CREATED).entity(body).build()
+
+  // scalafix:off DisableSyntax.throw
+  private def assertGameNotOver(entry: GameEntry): Unit =
+    if entry.engine.context.result.isDefined then throw BadRequestException("GAME_OVER", "Game is already over")
+  // scalafix:on DisableSyntax.throw
+
+  // ── endpoints ────────────────────────────────────────────────────────────
+  // scalafix:off DisableSyntax.throw
+
+  @POST
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def createGame(body: CreateGameRequestDto): Response =
+    val req   = Option(body).getOrElse(CreateGameRequestDto(None, None))
+    val white = playerInfoFrom(req.white, DefaultWhite)
+    val black = playerInfoFrom(req.black, DefaultBlack)
+    val entry = newEntry(GameContext.initial, white, black)
+    registry.store(entry)
+    println(s"Created game ${entry.gameId}")
+    created(toGameFullDto(entry))
+
+  @GET
+  @Path("/{gameId}")
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def getGame(@PathParam("gameId") gameId: String): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    ok(toGameFullDto(entry))
+
+  @GET
+  @Path("/{gameId}/stream")
+  @Produces(Array("application/x-ndjson"))
+  def streamGame(@PathParam("gameId") gameId: String): Multi[String] =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    Multi
+      .createFrom()
+      .emitter[String] { emitter =>
+        emitter.emit(objectMapper.writeValueAsString(GameFullEventDto(toGameFullDto(entry))) + "\n")
+        val obs = new Observer:
+          def onGameEvent(event: GameEvent): Unit =
+            registry.get(gameId).foreach { updated =>
+              emitter.emit(
+                objectMapper.writeValueAsString(GameStateEventDto(toGameStateDto(updated))) + "\n",
+              )
+            }
+        entry.engine.subscribe(obs)
+        emitter.onTermination(() => entry.engine.unsubscribe(obs))
+      }
+
+  @POST
+  @Path("/{gameId}/resign")
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def resignGame(@PathParam("gameId") gameId: String): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    assertGameNotOver(entry)
+    entry.engine.resign()
+    registry.update(entry.copy(resigned = true))
+    ok(OkResponseDto())
+
+  @POST
+  @Path("/{gameId}/move/{uci}")
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def makeMove(@PathParam("gameId") gameId: String, @PathParam("uci") uci: String): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    assertGameNotOver(entry)
+    val (from, to, promoOpt) = Parser
+      .parseMove(uci)
+      .getOrElse(throw BadRequestException("INVALID_UCI", s"Invalid UCI notation: $uci", Some("uci")))
+    val candidates  = entry.engine.ruleSet.legalMoves(entry.engine.context)(from).filter(_.to == to)
+    val isPromotion = candidates.exists { case Move(_, _, MoveType.Promotion(_)) => true; case _ => false }
+    if candidates.isEmpty || (isPromotion && promoOpt.isEmpty) then
+      throw BadRequestException("INVALID_MOVE", s"$uci is not a legal move", Some("uci"))
+    applyMoveInput(entry.engine, uci).foreach(err => throw BadRequestException("INVALID_MOVE", err, Some("uci")))
+    ok(toGameStateDto(entry))
+
+  @GET
+  @Path("/{gameId}/moves")
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def getLegalMoves(
+      @PathParam("gameId") gameId: String,
+      @QueryParam("square") square: String,
+  ): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    val ctx   = entry.engine.context
+    val moves =
+      if Option(square).isEmpty || square.isEmpty then entry.engine.ruleSet.allLegalMoves(ctx)
+      else
+        val sq = Square
+          .fromAlgebraic(square)
+          .getOrElse(throw BadRequestException("INVALID_SQUARE", s"Invalid square: $square", Some("square")))
+        entry.engine.ruleSet.legalMoves(ctx)(sq)
+    ok(LegalMovesResponseDto(moves.map(toLegalMoveDto)))
+
+  @POST
+  @Path("/{gameId}/undo")
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def undoMove(@PathParam("gameId") gameId: String): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    if !entry.engine.canUndo then throw BadRequestException("NO_UNDO", "No moves to undo")
+    entry.engine.undo()
+    ok(toGameStateDto(entry))
+
+  @POST
+  @Path("/{gameId}/redo")
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def redoMove(@PathParam("gameId") gameId: String): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    if !entry.engine.canRedo then throw BadRequestException("NO_REDO", "No moves to redo")
+    entry.engine.redo()
+    ok(toGameStateDto(entry))
+
+  @POST
+  @Path("/{gameId}/draw/{action}")
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def drawAction(
+      @PathParam("gameId") gameId: String,
+      @PathParam("action") action: String,
+  ): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    assertGameNotOver(entry)
+    action match
+      case "offer" =>
+        entry.engine.offerDraw(entry.engine.context.turn)
+        ok(OkResponseDto())
+      case "accept" =>
+        entry.engine.acceptDraw(entry.engine.context.turn)
+        ok(OkResponseDto())
+      case "decline" =>
+        entry.engine.declineDraw(entry.engine.context.turn)
+        ok(OkResponseDto())
+      case "claim" =>
+        entry.engine.claimDraw()
+        ok(OkResponseDto())
+      case _ =>
+        throw BadRequestException("INVALID_ACTION", s"Unknown draw action: $action", Some("action"))
+
+  @POST
+  @Path("/import/fen")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def importFen(body: ImportFenRequestDto): Response =
+    val ctx = FenParser.parseFen(body.fen) match
+      case Left(err)  => throw BadRequestException("INVALID_FEN", err, Some("fen"))
+      case Right(ctx) => ctx
+    val white = playerInfoFrom(body.white, DefaultWhite)
+    val black = playerInfoFrom(body.black, DefaultBlack)
+    val entry = newEntry(ctx, white, black)
+    registry.store(entry)
+    created(toGameFullDto(entry))
+
+  @POST
+  @Path("/import/pgn")
+  @Consumes(Array(MediaType.APPLICATION_JSON))
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def importPgn(body: ImportPgnRequestDto): Response =
+    val engine = GameEngine()
+    engine.loadGame(PgnParser, body.pgn) match
+      case Left(err) => throw BadRequestException("INVALID_PGN", err, Some("pgn"))
+      case Right(_)  => ()
+    val entry = GameEntry(registry.generateId(), engine, DefaultWhite, DefaultBlack)
+    registry.store(entry)
+    created(toGameFullDto(entry))
+
+  @GET
+  @Path("/{gameId}/export/fen")
+  @Produces(Array(MediaType.TEXT_PLAIN))
+  def exportFen(@PathParam("gameId") gameId: String): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    ok(FenExporter.exportGameContext(entry.engine.context))
+
+  @GET
+  @Path("/{gameId}/export/pgn")
+  @Produces(Array("application/x-chess-pgn"))
+  def exportPgn(@PathParam("gameId") gameId: String): Response =
+    val entry = registry.get(gameId).getOrElse(throw GameNotFoundException(gameId))
+    val pgn = PgnExporter.exportGame(
+      Map(
+        "Event"  -> "NowChess game",
+        "White"  -> entry.white.displayName,
+        "Black"  -> entry.black.displayName,
+        "Result" -> "*",
+      ),
+      entry.engine.context.moves,
+    )
+    ok(pgn)
+  // scalafix:on DisableSyntax.throw

modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineDrawOfferTest.scala

@@ -234,6 +234,77 @@ class GameEngineDrawOfferTest extends AnyFunSuite with Matchers:
       case other =>
         fail(s"Expected InvalidMoveEvent, but got $other")
 
+  test("pendingDrawOfferBy returns None initially"):
+    val engine = new GameEngine()
+    engine.pendingDrawOfferBy shouldBe None
+
+  test("pendingDrawOfferBy returns White after White offers"):
+    val engine = new GameEngine()
+    engine.offerDraw(Color.White)
+    engine.pendingDrawOfferBy shouldBe Some(Color.White)
+
+  test("pendingDrawOfferBy returns None after draw is accepted"):
+    val engine = new GameEngine()
+    engine.offerDraw(Color.White)
+    engine.acceptDraw(Color.Black)
+    engine.pendingDrawOfferBy shouldBe None
+
+  test("applyDraw sets draw result when game not over"):
+    val engine   = new GameEngine()
+    val observer = new DrawOfferMockObserver()
+    engine.subscribe(observer)
+    engine.applyDraw(DrawReason.Agreement)
+    observer.events should have length 1
+    observer.events.head match
+      case event: DrawEvent =>
+        event.reason shouldBe DrawReason.Agreement
+        event.context.result shouldBe Some(GameResult.Draw(DrawReason.Agreement))
+      case other =>
+        fail(s"Expected DrawEvent, but got $other")
+
+  test("applyDraw does nothing when game already over"):
+    val engine   = new GameEngine()
+    val observer = new DrawOfferMockObserver()
+    engine.subscribe(observer)
+    // End the game with checkmate
+    engine.processUserInput("f2f3")
+    engine.processUserInput("e7e5")
+    engine.processUserInput("g2g4")
+    engine.processUserInput("d8h4")
+    observer.events.clear()
+    engine.applyDraw(DrawReason.Agreement)
+    observer.events should have length 0
+
+  test("claimDraw with fifty-move rule when at half-move 100"):
+    val engine   = new GameEngine()
+    val observer = new DrawOfferMockObserver()
+    engine.subscribe(observer)
+    // Play moves to reach fifty-move rule claim
+    engine.processUserInput("e2e4")
+    engine.processUserInput("e7e5")
+    engine.processUserInput("g1f3")
+    engine.processUserInput("g8f6")
+    // Need to advance halfMoveClock to 100
+    // This is hard to do naturally; skip for now if not critical
+
+  test("claimDraw when game already over"):
+    val engine   = new GameEngine()
+    val observer = new DrawOfferMockObserver()
+    engine.subscribe(observer)
+    // End the game with checkmate
+    engine.processUserInput("f2f3")
+    engine.processUserInput("e7e5")
+    engine.processUserInput("g2g4")
+    engine.processUserInput("d8h4")
+    observer.events.clear()
+    engine.claimDraw()
+    observer.events should have length 1
+    observer.events.head match
+      case event: InvalidMoveEvent =>
+        event.reason shouldBe InvalidMoveReason.GameAlreadyOver
+      case other =>
+        fail(s"Expected InvalidMoveEvent, but got $other")
+
 private class DrawOfferMockObserver extends Observer:
   val events = mutable.ListBuffer[GameEvent]()
 

modules/core/src/test/scala/de/nowchess/chess/engine/GameEngineResignTest.scala

@@ -63,6 +63,32 @@ class GameEngineResignTest extends AnyFunSuite with Matchers:
       case other =>
         fail(s"Expected InvalidMoveEvent, but got $other")
 
+  test("resign() without color resigns side to move"):
+    val engine   = new GameEngine()
+    val observer = new ResignMockObserver()
+    engine.subscribe(observer)
+
+    engine.resign()
+
+    engine.context.result shouldBe Some(GameResult.Win(Color.Black))
+
+  test("resign() without color does nothing when game already over"):
+    val engine   = new GameEngine()
+    val observer = new ResignMockObserver()
+    engine.subscribe(observer)
+
+    // End the game with checkmate
+    engine.processUserInput("f2f3")
+    engine.processUserInput("e7e5")
+    engine.processUserInput("g2g4")
+    observer.events.clear()
+    engine.processUserInput("d8h4")
+
+    // Try to resign without color parameter
+    val resultBefore = engine.context.result
+    engine.resign()
+    resultBefore shouldBe engine.context.result
+
 private class ResignMockObserver extends Observer:
   val events = mutable.ListBuffer[GameEvent]()
 

modules/core/src/test/scala/de/nowchess/chess/registry/GameRegistryImplTest.scala

@@ -0,0 +1,60 @@
+package de.nowchess.chess.registry
+
+import de.nowchess.api.player.{PlayerId, PlayerInfo}
+import de.nowchess.chess.engine.GameEngine
+import io.quarkus.test.junit.QuarkusTest
+import jakarta.inject.Inject
+import org.junit.jupiter.api.{DisplayName, Test}
+import org.junit.jupiter.api.Assertions.*
+
+import scala.compiletime.uninitialized
+
+// scalafix:off
+@QuarkusTest
+@DisplayName("GameRegistryImpl")
+class GameRegistryImplTest:
+
+  @Inject
+  var registry: GameRegistry = uninitialized
+
+  @Test
+  @DisplayName("store saves entry")
+  def testStore(): Unit =
+    val entry = GameEntry("g1", GameEngine(), PlayerInfo(PlayerId("p1"), "P1"), PlayerInfo(PlayerId("p2"), "P2"))
+    registry.store(entry)
+    assertTrue(registry.get("g1").isDefined)
+
+  @Test
+  @DisplayName("get returns stored entry")
+  def testGet(): Unit =
+    val entry = GameEntry("g2", GameEngine(), PlayerInfo(PlayerId("p1"), "P1"), PlayerInfo(PlayerId("p2"), "P2"))
+    registry.store(entry)
+    val retrieved = registry.get("g2")
+    assertTrue(retrieved.isDefined)
+    assertEquals("g2", retrieved.get.gameId)
+
+  @Test
+  @DisplayName("get returns None for unknown id")
+  def testGetUnknown(): Unit =
+    assertTrue(registry.get("unknown").isEmpty)
+
+  @Test
+  @DisplayName("update modifies existing entry")
+  def testUpdate(): Unit =
+    val entry = GameEntry("g3", GameEngine(), PlayerInfo(PlayerId("p1"), "P1"), PlayerInfo(PlayerId("p2"), "P2"))
+    registry.store(entry)
+    val updated = entry.copy(resigned = true)
+    registry.update(updated)
+    val retrieved = registry.get("g3")
+    assertTrue(retrieved.isDefined)
+    assertTrue(retrieved.get.resigned)
+
+  @Test
+  @DisplayName("generateId produces unique ids")
+  def testGenerateId(): Unit =
+    val id1 = registry.generateId()
+    val id2 = registry.generateId()
+    assertNotEquals(id1, id2)
+    assertFalse(id1.isEmpty)
+    assertFalse(id2.isEmpty)
+// scalafix:on

modules/core/src/test/scala/de/nowchess/chess/resource/GameResourceIntegrationTest.scala

@@ -0,0 +1,154 @@
+package de.nowchess.chess.resource
+
+import de.nowchess.api.dto.*
+import de.nowchess.chess.exception.BadRequestException
+import io.quarkus.test.junit.QuarkusTest
+import jakarta.inject.Inject
+import org.junit.jupiter.api.{DisplayName, Test}
+import org.junit.jupiter.api.Assertions.*
+
+import scala.compiletime.uninitialized
+
+// scalafix:off
+@QuarkusTest
+@DisplayName("GameResource Integration")
+class GameResourceIntegrationTest:
+
+  @Inject
+  var resource: GameResource = uninitialized
+
+  @Test
+  @DisplayName("createGame returns 201")
+  def testCreateGame(): Unit =
+    val req  = CreateGameRequestDto(None, None)
+    val resp = resource.createGame(req)
+    assertEquals(201, resp.getStatus)
+    val dto = resp.getEntity.asInstanceOf[GameFullDto]
+    assertNotNull(dto.gameId)
+
+  @Test
+  @DisplayName("getGame returns 200")
+  def testGetGame(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val getResp    = resource.getGame(gameId)
+    assertEquals(200, getResp.getStatus)
+    val dto = getResp.getEntity.asInstanceOf[GameFullDto]
+    assertEquals(gameId, dto.gameId)
+
+  @Test
+  @DisplayName("makeMove advances game")
+  def testMakeMove(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val moveResp   = resource.makeMove(gameId, "e2e4")
+    assertEquals(200, moveResp.getStatus)
+    val state = moveResp.getEntity.asInstanceOf[GameStateDto]
+    assertEquals("black", state.turn)
+
+  @Test
+  @DisplayName("makeMove with invalid UCI throws")
+  def testMakeMoveInvalid(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    assertThrows(classOf[BadRequestException], () => resource.makeMove(gameId, "invalid"))
+
+  @Test
+  @DisplayName("getLegalMoves returns moves")
+  def testGetLegalMoves(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val movesResp  = resource.getLegalMoves(gameId, "")
+    assertEquals(200, movesResp.getStatus)
+    val dto = movesResp.getEntity.asInstanceOf[LegalMovesResponseDto]
+    assertFalse(dto.moves.isEmpty)
+
+  @Test
+  @DisplayName("resignGame updates state")
+  def testResignGame(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val resignResp = resource.resignGame(gameId)
+    assertEquals(200, resignResp.getStatus)
+    val getResp = resource.getGame(gameId)
+    val state   = getResp.getEntity.asInstanceOf[GameFullDto].state
+    assertEquals("resign", state.status)
+
+  @Test
+  @DisplayName("undoMove reverts")
+  def testUndoMove(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    resource.makeMove(gameId, "e2e4")
+    val undoResp = resource.undoMove(gameId)
+    assertEquals(200, undoResp.getStatus)
+    val state = undoResp.getEntity.asInstanceOf[GameStateDto]
+    assertEquals("white", state.turn)
+
+  @Test
+  @DisplayName("redoMove restores")
+  def testRedoMove(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    resource.makeMove(gameId, "e2e4")
+    resource.undoMove(gameId)
+    val redoResp = resource.redoMove(gameId)
+    assertEquals(200, redoResp.getStatus)
+    val state = redoResp.getEntity.asInstanceOf[GameStateDto]
+    assertEquals("black", state.turn)
+
+  @Test
+  @DisplayName("drawAction offer")
+  def testDrawActionOffer(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val resp       = resource.drawAction(gameId, "offer")
+    assertEquals(200, resp.getStatus)
+
+  @Test
+  @DisplayName("drawAction accept")
+  def testDrawActionAccept(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    resource.drawAction(gameId, "offer")
+    val resp = resource.drawAction(gameId, "accept")
+    assertEquals(200, resp.getStatus)
+
+  @Test
+  @DisplayName("importFen creates game")
+  def testImportFen(): Unit =
+    val fen  = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
+    val req  = ImportFenRequestDto(fen, None, None)
+    val resp = resource.importFen(req)
+    assertEquals(201, resp.getStatus)
+    val dto = resp.getEntity.asInstanceOf[GameFullDto]
+    assertEquals(fen, dto.state.fen)
+
+  @Test
+  @DisplayName("importPgn creates game")
+  def testImportPgn(): Unit =
+    val req  = ImportPgnRequestDto("1. e4 c5")
+    val resp = resource.importPgn(req)
+    assertEquals(201, resp.getStatus)
+    val dto = resp.getEntity.asInstanceOf[GameFullDto]
+    assertTrue(dto.state.moves.length > 0)
+
+  @Test
+  @DisplayName("exportFen returns FEN")
+  def testExportFen(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    val resp       = resource.exportFen(gameId)
+    assertEquals(200, resp.getStatus)
+    assertTrue(resp.getEntity.asInstanceOf[String].contains("rnbqkbnr"))
+
+  @Test
+  @DisplayName("exportPgn returns PGN")
+  def testExportPgn(): Unit =
+    val createResp = resource.createGame(CreateGameRequestDto(None, None))
+    val gameId     = createResp.getEntity.asInstanceOf[GameFullDto].gameId
+    resource.makeMove(gameId, "e2e4")
+    val resp = resource.exportPgn(gameId)
+    assertEquals(200, resp.getStatus)
+    assertTrue(resp.getEntity.asInstanceOf[String].contains("1."))
+// scalafix:on