Mhlidd/config inversion

build.gradle

@@ -66,6 +66,7 @@ spotlessPredeclare {
   }
 }
 apply from: "$rootDir/gradle/spotless.gradle"
+apply from: "$rootDir/gradle/configInversionLinter.gradle"
 
 def compileTask = tasks.register("compile")
 

components/environment/build.gradle.kts

@@ -3,8 +3,45 @@ plugins {
   id("com.gradleup.shadow")
 }
 
+sourceSets {
+  create("generator") {
+    java.srcDir("src/generator/java")
+  }
+  val main by getting {
+    java {
+      srcDir("build/generated/sources/supported")
+    }
+  }
+}
+
+dependencies {
+  "generatorImplementation"("com.fasterxml.jackson.core:jackson-databind:2.15.2")
+  "generatorImplementation"("org.slf4j:slf4j-api:1.7.36")
+}
+
 apply(from = "$rootDir/gradle/java.gradle")
 
+val compileGeneratorJava = tasks.named("compileGeneratorJava")
+
+val generateSupportedConfigurations by tasks.registering(JavaExec::class) {
+  // We can run the generator with the main sourceSet runtimeClasspath
+  dependsOn(compileGeneratorJava)
+  mainClass.set("datadog.environment.ParseSupportedConfigurations")
+  classpath = sourceSets["generator"].runtimeClasspath
+
+  val outputFile = layout.buildDirectory.file("generated/sources/supported/GeneratedSupportedConfigurations.java")
+  args("supported-configurations.json", outputFile.get().asFile.absolutePath)
+
+  doFirst {
+    outputFile.get().asFile.parentFile.mkdirs()
+  }
+}
+// Ensure Java compilation depends on the generated sources
+sourceSets["main"].java.srcDir(layout.buildDirectory.dir("generated/sources/supported"))
+
+tasks.named("compileJava") {
+  dependsOn(generateSupportedConfigurations)
+}
 /*
  * Add an addition gradle configuration to be consumed by bootstrap only.
  * "datadog.trace." prefix is required to be excluded from Jacoco instrumentation.

components/environment/src/generator/java/datadog/environment/ParseSupportedConfigurations.java

@@ -0,0 +1,142 @@
+package datadog.environment;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.PrintWriter;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class ParseSupportedConfigurations {
+
+  public static void main(String[] args) {
+    String supportedConfigurationsFilename =
+        args[0]; // e.g., "resources/supported-configurations.json"
+    String generatedMappingPath = args[1]; // e.g.,
+    // "build/generated-sources/datadog/environment/GeneratedSupportedConfigurations.java"
+
+    String jsonString;
+    try {
+
+      InputStream in =
+          ParseSupportedConfigurations.class
+              .getClassLoader()
+              .getResourceAsStream(supportedConfigurationsFilename);
+      if (in == null) {
+        throw new IllegalArgumentException(
+            "Resource not found: " + supportedConfigurationsFilename);
+      }
+
+      ObjectMapper mapper = new ObjectMapper();
+      Map<String, Object> fileData = mapper.readValue(in, Map.class);
+
+      Map<String, List<String>> supported =
+          (Map<String, List<String>>) fileData.get("supportedConfigurations");
+      Map<String, List<String>> aliases = (Map<String, List<String>>) fileData.get("aliases");
+      Map<String, String> deprecated = (Map<String, String>) fileData.get("deprecations");
+
+      Map<String, String> aliasMapping = new HashMap<>();
+      for (Map.Entry<String, List<String>> entry : aliases.entrySet()) {
+        for (String alias : entry.getValue()) {
+          aliasMapping.put(alias, entry.getKey());
+        }
+      }
+      generateJavaFile(generatedMappingPath, supported.keySet(), aliases, aliasMapping, deprecated);
+    } catch (IOException e) {
+      throw new RuntimeException("Failed to read " + supportedConfigurationsFilename, e);
+    }
+  }
+
+  private static void generateJavaFile(
+      String outputPath,
+      Set<String> supported,
+      Map<String, List<String>> aliases,
+      Map<String, String> aliasMapping,
+      Map<String, String> deprecated)
+      throws IOException {
+    try (PrintWriter out = new PrintWriter(Files.newBufferedWriter(Paths.get(outputPath)))) {
+      out.println("package datadog.environment;");
+      out.println();
+      out.println("import java.util.*;");
+      out.println();
+      out.println("public final class GeneratedSupportedConfigurations {");
+
+      // Supported set using Arrays.asList and HashSet
+      out.println("  public static final Set<String> SUPPORTED;");
+      out.println();
+
+      // ALIASES map
+      out.println("  public static final Map<String, List<String>> ALIASES;");
+      out.println();
+
+      // ALIAS_MAPPING map
+      out.println("  public static final Map<String, String> ALIAS_MAPPING;");
+      out.println();
+
+      // DEPRECATED map
+      out.println("  public static final Map<String, String> DEPRECATED;");
+      out.println();
+
+      // Static initializer block
+      out.println("  static {");
+
+      // Initialize SUPPORTED
+      out.print("    Set<String> supportedSet = new HashSet<>(Arrays.asList(");
+      Iterator<String> supportedIter = supported.iterator();
+      while (supportedIter.hasNext()) {
+        String key = supportedIter.next();
+        out.print("\"" + key + "\"");
+        if (supportedIter.hasNext()) {
+          out.print(", ");
+        }
+      }
+      out.println("));");
+      out.println("    SUPPORTED = Collections.unmodifiableSet(supportedSet);");
+      out.println();
+
+      // Initialize ALIASES
+      out.println("    Map<String, List<String>> aliasesMap = new HashMap<>();");
+      for (Map.Entry<String, List<String>> entry : aliases.entrySet()) {
+        out.printf(
+            "    aliasesMap.put(\"%s\", Collections.unmodifiableList(Arrays.asList(%s)));\n",
+            entry.getKey(), quoteList(entry.getValue()));
+      }
+      out.println("    ALIASES = Collections.unmodifiableMap(aliasesMap);");
+      out.println();
+
+      // Initialize ALIAS_MAPPING
+      out.println("    Map<String, String> aliasMappingMap = new HashMap<>();");
+      for (Map.Entry<String, String> entry : aliasMapping.entrySet()) {
+        out.printf("    aliasMappingMap.put(\"%s\", \"%s\");\n", entry.getKey(), entry.getValue());
+      }
+      out.println("    ALIAS_MAPPING = Collections.unmodifiableMap(aliasMappingMap);");
+      out.println();
+
+      // Initialize DEPRECATED
+      out.println("    Map<String, String> deprecatedMap = new HashMap<>();");
+      for (Map.Entry<String, String> entry : deprecated.entrySet()) {
+        out.printf("    deprecatedMap.put(\"%s\", \"%s\");\n", entry.getKey(), entry.getValue());
+      }
+      out.println("    DEPRECATED = Collections.unmodifiableMap(deprecatedMap);");
+
+      out.println("  }"); // end static block
+      out.println("}"); // end class
+    }
+  }
+
+  private static String quoteList(List<String> list) {
+    StringBuilder sb = new StringBuilder();
+    for (int i = 0; i < list.size(); i++) {
+      sb.append("\"").append(list.get(i)).append("\"");
+      if (i < list.size() - 1) {
+        sb.append(", ");
+      }
+    }
+    return sb.toString();
+  }
+}