GH-48 Introduce simple update checker, using Modrinth api.

eternalcode-commons-updater-example/build.gradle.kts

@@ -0,0 +1,7 @@
+plugins {
+    `commons-java-17`
+}
+
+dependencies {
+    implementation(project(":eternalcode-commons-updater"))
+}

eternalcode-commons-updater-example/src/main/java/com/eternalcode/commons/updater/example/ExampleChecker.java

@@ -0,0 +1,17 @@
+package com.eternalcode.commons.updater.example;
+
+import com.eternalcode.commons.updater.UpdateResult;
+
+public class ExampleChecker {
+    public static void main(String[] args) {
+        ExampleUpdateService service = new ExampleUpdateService();
+
+        UpdateResult modrinthResult = service.checkModrinth("EternalCombat", "2.2.0");
+        System.out.println("Modrinth update available: " + modrinthResult.isUpdateAvailable());
+        if (modrinthResult.isUpdateAvailable()) {
+            System.out.println("Latest: " + modrinthResult.latestVersion());
+            System.out.println("Download: " + modrinthResult.downloadUrl());
+            System.out.println("Release page: " + modrinthResult.releaseUrl());
+        }
+    }
+}

eternalcode-commons-updater-example/src/main/java/com/eternalcode/commons/updater/example/ExampleUpdateService.java

@@ -0,0 +1,13 @@
+package com.eternalcode.commons.updater.example;
+
+import com.eternalcode.commons.updater.UpdateResult;
+import com.eternalcode.commons.updater.Version;
+import com.eternalcode.commons.updater.impl.ModrinthUpdateChecker;
+
+public final class ExampleUpdateService {
+    private final ModrinthUpdateChecker modrinthChecker = new ModrinthUpdateChecker();
+
+    public UpdateResult checkModrinth(String projectId, String currentVersion) {
+        return modrinthChecker.check(projectId, new Version(currentVersion));
+    }
+}

eternalcode-commons-updater/build.gradle.kts

@@ -0,0 +1,10 @@
+plugins {
+    `commons-java-17`
+    `commons-publish`
+    `commons-repositories`
+    `commons-java-unit-test`
+}
+
+tasks.test {
+    useJUnitPlatform()
+}

eternalcode-commons-updater/src/main/java/com/eternalcode/commons/updater/UpdateChecker.java

@@ -0,0 +1,6 @@
+package com.eternalcode.commons.updater;
+
+public interface UpdateChecker {
+
+    UpdateResult check(String projectId, Version currentVersion);
+}

eternalcode-commons-updater/src/main/java/com/eternalcode/commons/updater/UpdateResult.java

@@ -0,0 +1,8 @@
+package com.eternalcode.commons.updater;
+
+public record UpdateResult(Version currentVersion, Version latestVersion, String downloadUrl, String releaseUrl) {
+
+    public boolean isUpdateAvailable() {
+        return this.latestVersion.isNewerThan(this.currentVersion);
+    }
+}

eternalcode-commons-updater/src/main/java/com/eternalcode/commons/updater/Version.java

@@ -0,0 +1,34 @@
+package com.eternalcode.commons.updater;
+
+public class Version implements Comparable<Version> {
+
+    private final String value;
+
+    public Version(String version) {
+        this.value = version.trim();
+    }
+
+    @Override
+    public int compareTo(Version version) {
+        return this.value.compareTo(version.value);
+    }
+
+    public boolean isNewerThan(Version version) {
+        return this.value.compareTo(version.value) > 0;
+    }
+
+    @Override
+    public boolean equals(Object object) {
+        return object instanceof Version other && value.equals(other.value);
+    }
+
+    @Override
+    public int hashCode() {
+        return value.hashCode();
+    }
+
+    @Override
+    public String toString() {
+        return this.value;
+    }
+}

eternalcode-commons-updater/src/main/java/com/eternalcode/commons/updater/impl/ModrinthUpdateChecker.java

@@ -0,0 +1,92 @@
+package com.eternalcode.commons.updater.impl;
+
+import com.eternalcode.commons.updater.UpdateChecker;
+import com.eternalcode.commons.updater.UpdateResult;
+import com.eternalcode.commons.updater.Version;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
+import java.util.Optional;
+
+public final class ModrinthUpdateChecker implements UpdateChecker {
+
+    private static final String API_BASE_URL = "https://api.modrinth.com/v2";
+    private static final String MODRINTH_BASE_URL = "https://modrinth.com/mod";
+    private static final String USER_AGENT = "UpdateChecker/1.0";
+    private static final Duration TIMEOUT = Duration.ofSeconds(10);
+
+    private final HttpClient client;
+
+    public ModrinthUpdateChecker() {
+        this.client = HttpClient.newBuilder().connectTimeout(TIMEOUT).build();
+    }
+
+    @Override
+    public UpdateResult check(String projectId, Version currentVersion) {
+        if (projectId == null || projectId.trim().isEmpty()) {
+            throw new IllegalArgumentException("Project ID cannot be null or empty");
+        }
+
+        try {
+            String url = API_BASE_URL + "/project/" + projectId + "/version";
+
+            HttpRequest request =
+                HttpRequest.newBuilder().uri(URI.create(url)).header("User-Agent", USER_AGENT).timeout(TIMEOUT).build();
+
+            HttpResponse<String> response = this.client.send(request, HttpResponse.BodyHandlers.ofString());
+
+            if (response.statusCode() != 200) {
+                return createEmptyResult(currentVersion);
+            }
+
+            String json = response.body();
+            if (json == null || json.trim().isEmpty()) {
+                return createEmptyResult(currentVersion);
+            }
+
+            Optional<String> versionNumber = extractJsonValue(json, "version_number");
+            Optional<String> downloadUrl = extractJsonValue(json, "url");
+
+            if (versionNumber.isEmpty()) {
+                return createEmptyResult(currentVersion);
+            }
+
+            String releaseUrl = MODRINTH_BASE_URL + "/" + projectId + "/version/" + versionNumber.get();
+            Version latestVersion = new Version(versionNumber.get());
+
+            return new UpdateResult(currentVersion, latestVersion, downloadUrl.orElse(null), releaseUrl);
+        }
+        catch (Exception exception) {
+            throw new RuntimeException("Failed to check Modrinth updates for project: " + projectId, exception);
+        }
+    }
+
+    private UpdateResult createEmptyResult(Version currentVersion) {
+        return new UpdateResult(currentVersion, currentVersion, null, null);
+    }
+
+    private Optional<String> extractJsonValue(String json, String key) {
+        if (json == null || key == null) {
+            return Optional.empty();
+        }
+
+        String pattern = "\"" + key + "\":\"";
+        int start = json.indexOf(pattern);
+
+        if (start == -1) {
+            return Optional.empty();
+        }
+
+        start += pattern.length();
+        int end = json.indexOf("\"", start);
+
+        if (end == -1) {
+            return Optional.empty();
+        }
+
+        String value = json.substring(start, end);
+        return value.isEmpty() ? Optional.empty() : Optional.of(value);
+    }
+}

settings.gradle.kts

@@ -4,3 +4,5 @@ include(":eternalcode-commons-bukkit")
 include(":eternalcode-commons-adventure")
 include(":eternalcode-commons-shared")
 include("eternalcode-commons-folia")
+include("eternalcode-commons-updater")
+include("eternalcode-commons-updater-example")