Inner `enum` does not `implement Serializable` when `serializableModel=true`

[Chrimle]

Discovered in #579, inner enums do not implement Serializable. Stems from openapi-generator.

[Chrimle]

Looks to be inherited by openapi-generator 🤔

[Chrimle]

Confirmed to be inherited from openapi-generator.

/*
 * Example OpenAPI Spec.
 * An example OpenAPI-spec to generate example Java records.
 *
 * The version of the OpenAPI document: 0.0.1
 *
 * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
 * https://openapi-generator.tech
 * Do not edit the class manually.
 *
 * This class was generated using custom mustache templates from
 * openapi-to-java-records-mustache-templates. For further information,
 * questions, requesting features or reporting issues, please visit:
 * https://github.com/Chrimle/openapi-to-java-records-mustache-templates.
 * Generated with Version: 3.4.0
 *
 */

package io.github.chrimle.o2jrm.serializableModel;

import java.util.Objects;
import com.google.gson.TypeAdapter;
import com.google.gson.annotations.JsonAdapter;
import com.google.gson.annotations.SerializedName;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;
import java.io.IOException;
import java.net.URI;
import java.util.Arrays;
import java.io.Serializable;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonArray;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.reflect.TypeToken;
import com.google.gson.TypeAdapter;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;
import java.io.IOException;

import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import io.github.chrimle.o2jrm.JSON;

/**
 * Example of a Record with inner enum classes
 */
@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", date = "2026-03-01T20:34:38.264714200+01:00[Europe/Stockholm]", comments = "Generator version: 7.20.0")
public class RecordWithInnerEnums implements Serializable {
  private static final long serialVersionUID = 1L;

  /**
   * Example of an inner enum class
   */
  @JsonAdapter(ExampleInnerEnum.Adapter.class)
  public enum ExampleInnerEnum {
    /**
     * Some description of ENUM1
     */
    ENUM1("ENUM1"),
    
    /**
     * Some description of ENUM2
     */
    ENUM2("ENUM2"),
    
    /**
     * Some description of ENUM3
     */
    ENUM3("ENUM3");

    private String value;

    ExampleInnerEnum(String value) {
      this.value = value;
    }

    public String getValue() {
      return value;
    }

    @Override
    public String toString() {
      return String.valueOf(value);
    }

    public static ExampleInnerEnum fromValue(String value) {
      for (ExampleInnerEnum b : ExampleInnerEnum.values()) {
        if (b.value.equals(value)) {
          return b;
        }
      }
      throw new IllegalArgumentException("Unexpected value '" + value + "'");
    }

    public static class Adapter extends TypeAdapter<ExampleInnerEnum> {
      @Override
      public void write(final JsonWriter jsonWriter, final ExampleInnerEnum enumeration) throws IOException {
        jsonWriter.value(enumeration.getValue());
      }

      @Override
      public ExampleInnerEnum read(final JsonReader jsonReader) throws IOException {
        String value =  jsonReader.nextString();
        return ExampleInnerEnum.fromValue(value);
      }
    }

    public static void validateJsonElement(JsonElement jsonElement) throws IOException {
      String value = jsonElement.getAsString();
      ExampleInnerEnum.fromValue(value);
    }
  }

  public static final String SERIALIZED_NAME_EXAMPLE_INNER = "exampleInner";
  @SerializedName(SERIALIZED_NAME_EXAMPLE_INNER)
  @javax.annotation.Nullable
  private ExampleInnerEnum exampleInner;

  /**
   * Example of another inner enum class with integer values
   */
  @JsonAdapter(ExampleInnerTwoEnum.Adapter.class)
  public enum ExampleInnerTwoEnum {
    NUMBER_404(404),
    
    NUMBER_501(501),
    
    NUMBER_503(503);

    private Integer value;

    ExampleInnerTwoEnum(Integer value) {
      this.value = value;
    }

    public Integer getValue() {
      return value;
    }

    @Override
    public String toString() {
      return String.valueOf(value);
    }

    public static ExampleInnerTwoEnum fromValue(Integer value) {
      for (ExampleInnerTwoEnum b : ExampleInnerTwoEnum.values()) {
        if (b.value.equals(value)) {
          return b;
        }
      }
      throw new IllegalArgumentException("Unexpected value '" + value + "'");
    }

    public static class Adapter extends TypeAdapter<ExampleInnerTwoEnum> {
      @Override
      public void write(final JsonWriter jsonWriter, final ExampleInnerTwoEnum enumeration) throws IOException {
        jsonWriter.value(enumeration.getValue());
      }

      @Override
      public ExampleInnerTwoEnum read(final JsonReader jsonReader) throws IOException {
        Integer value =  jsonReader.nextInt();
        return ExampleInnerTwoEnum.fromValue(value);
      }
    }

    public static void validateJsonElement(JsonElement jsonElement) throws IOException {
      Integer value = jsonElement.getAsInt();
      ExampleInnerTwoEnum.fromValue(value);
    }
  }

  public static final String SERIALIZED_NAME_EXAMPLE_INNER_TWO = "exampleInnerTwo";
  @SerializedName(SERIALIZED_NAME_EXAMPLE_INNER_TWO)
  @javax.annotation.Nullable
  private ExampleInnerTwoEnum exampleInnerTwo;

  /**
   * Example of another inner enum class with URI values
   */
  @JsonAdapter(ExampleInnerThreeEnum.Adapter.class)
  public enum ExampleInnerThreeEnum {
    HTTPS_GITHUB_COM_CHRIMLE_OPENAPI_TO_JAVA_RECORDS_MUSTACHE_TEMPLATES(URI.create("https://github.com/Chrimle/openapi-to-java-records-mustache-templates")),
    
    HTTPS_CHRIMLE_GITHUB_IO_OPENAPI_TO_JAVA_RECORDS_MUSTACHE_TEMPLATES_(URI.create("https://chrimle.github.io/openapi-to-java-records-mustache-templates/"));

    private URI value;

    ExampleInnerThreeEnum(URI value) {
      this.value = value;
    }

    public URI getValue() {
      return value;
    }

    @Override
    public String toString() {
      return String.valueOf(value);
    }

    public static ExampleInnerThreeEnum fromValue(URI value) {
      for (ExampleInnerThreeEnum b : ExampleInnerThreeEnum.values()) {
        if (b.value.equals(value)) {
          return b;
        }
      }
      throw new IllegalArgumentException("Unexpected value '" + value + "'");
    }

    public static class Adapter extends TypeAdapter<ExampleInnerThreeEnum> {
      @Override
      public void write(final JsonWriter jsonWriter, final ExampleInnerThreeEnum enumeration) throws IOException {
        jsonWriter.value(enumeration.getValue().toASCIIString());
      }

      @Override
      public ExampleInnerThreeEnum read(final JsonReader jsonReader) throws IOException {
        URI value =  URI.create(jsonReader.nextString());
        return ExampleInnerThreeEnum.fromValue(value);
      }
    }

    public static void validateJsonElement(JsonElement jsonElement) throws IOException {
      URI value = URI.create(jsonElement.getAsString());
      ExampleInnerThreeEnum.fromValue(value);
    }
  }

  public static final String SERIALIZED_NAME_EXAMPLE_INNER_THREE = "exampleInnerThree";
  @SerializedName(SERIALIZED_NAME_EXAMPLE_INNER_THREE)
  @javax.annotation.Nullable
  private ExampleInnerThreeEnum exampleInnerThree;

  public RecordWithInnerEnums() {
  }

  public RecordWithInnerEnums exampleInner(@javax.annotation.Nullable ExampleInnerEnum exampleInner) {
    this.exampleInner = exampleInner;
    return this;
  }

  /**
   * Example of an inner enum class
   * @return exampleInner
   */
  @javax.annotation.Nullable
  public ExampleInnerEnum getExampleInner() {
    return exampleInner;
  }

  public void setExampleInner(@javax.annotation.Nullable ExampleInnerEnum exampleInner) {
    this.exampleInner = exampleInner;
  }


  public RecordWithInnerEnums exampleInnerTwo(@javax.annotation.Nullable ExampleInnerTwoEnum exampleInnerTwo) {
    this.exampleInnerTwo = exampleInnerTwo;
    return this;
  }

  /**
   * Example of another inner enum class with integer values
   * @return exampleInnerTwo
   */
  @javax.annotation.Nullable
  public ExampleInnerTwoEnum getExampleInnerTwo() {
    return exampleInnerTwo;
  }

  public void setExampleInnerTwo(@javax.annotation.Nullable ExampleInnerTwoEnum exampleInnerTwo) {
    this.exampleInnerTwo = exampleInnerTwo;
  }


  public RecordWithInnerEnums exampleInnerThree(@javax.annotation.Nullable ExampleInnerThreeEnum exampleInnerThree) {
    this.exampleInnerThree = exampleInnerThree;
    return this;
  }

  /**
   * Example of another inner enum class with URI values
   * @return exampleInnerThree
   */
  @javax.annotation.Nullable
  public ExampleInnerThreeEnum getExampleInnerThree() {
    return exampleInnerThree;
  }

  public void setExampleInnerThree(@javax.annotation.Nullable ExampleInnerThreeEnum exampleInnerThree) {
    this.exampleInnerThree = exampleInnerThree;
  }



  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    RecordWithInnerEnums recordWithInnerEnums = (RecordWithInnerEnums) o;
    return Objects.equals(this.exampleInner, recordWithInnerEnums.exampleInner) &&
        Objects.equals(this.exampleInnerTwo, recordWithInnerEnums.exampleInnerTwo) &&
        Objects.equals(this.exampleInnerThree, recordWithInnerEnums.exampleInnerThree);
  }

  @Override
  public int hashCode() {
    return Objects.hash(exampleInner, exampleInnerTwo, exampleInnerThree);
  }

  @Override
  public String toString() {
    StringBuilder sb = new StringBuilder();
    sb.append("class RecordWithInnerEnums {\n");
    sb.append("    exampleInner: ").append(toIndentedString(exampleInner)).append("\n");
    sb.append("    exampleInnerTwo: ").append(toIndentedString(exampleInnerTwo)).append("\n");
    sb.append("    exampleInnerThree: ").append(toIndentedString(exampleInnerThree)).append("\n");
    sb.append("}");
    return sb.toString();
  }

  /**
   * Convert the given object to string with each line indented by 4 spaces
   * (except the first line).
   */
  private String toIndentedString(Object o) {
    if (o == null) {
      return "null";
    }
    return o.toString().replace("\n", "\n    ");
  }


  public static HashSet<String> openapiFields;
  public static HashSet<String> openapiRequiredFields;

  static {
    // a set of all properties/fields (JSON key names)
    openapiFields = new HashSet<String>(Arrays.asList("exampleInner", "exampleInnerTwo", "exampleInnerThree"));

    // a set of required properties/fields (JSON key names)
    openapiRequiredFields = new HashSet<String>(0);
  }

  /**
   * Validates the JSON Element and throws an exception if issues found
   *
   * @param jsonElement JSON Element
   * @throws IOException if the JSON Element is invalid with respect to RecordWithInnerEnums
   */
  public static void validateJsonElement(JsonElement jsonElement) throws IOException {
      if (jsonElement == null) {
        if (!RecordWithInnerEnums.openapiRequiredFields.isEmpty()) { // has required fields but JSON element is null
          throw new IllegalArgumentException(String.format(java.util.Locale.ROOT, "The required field(s) %s in RecordWithInnerEnums is not found in the empty JSON string", RecordWithInnerEnums.openapiRequiredFields.toString()));
        }
      }

      Set<Map.Entry<String, JsonElement>> entries = jsonElement.getAsJsonObject().entrySet();
      // check to see if the JSON string contains additional fields
      for (Map.Entry<String, JsonElement> entry : entries) {
        if (!RecordWithInnerEnums.openapiFields.contains(entry.getKey())) {
          throw new IllegalArgumentException(String.format(java.util.Locale.ROOT, "The field `%s` in the JSON string is not defined in the `RecordWithInnerEnums` properties. JSON: %s", entry.getKey(), jsonElement.toString()));
        }
      }
        JsonObject jsonObj = jsonElement.getAsJsonObject();
      if ((jsonObj.get("exampleInner") != null && !jsonObj.get("exampleInner").isJsonNull()) && !jsonObj.get("exampleInner").isJsonPrimitive()) {
        throw new IllegalArgumentException(String.format(java.util.Locale.ROOT, "Expected the field `exampleInner` to be a primitive type in the JSON string but got `%s`", jsonObj.get("exampleInner").toString()));
      }
      // validate the optional field `exampleInner`
      if (jsonObj.get("exampleInner") != null && !jsonObj.get("exampleInner").isJsonNull()) {
        ExampleInnerEnum.validateJsonElement(jsonObj.get("exampleInner"));
      }
      // validate the optional field `exampleInnerTwo`
      if (jsonObj.get("exampleInnerTwo") != null && !jsonObj.get("exampleInnerTwo").isJsonNull()) {
        ExampleInnerTwoEnum.validateJsonElement(jsonObj.get("exampleInnerTwo"));
      }
      if ((jsonObj.get("exampleInnerThree") != null && !jsonObj.get("exampleInnerThree").isJsonNull()) && !jsonObj.get("exampleInnerThree").isJsonPrimitive()) {
        throw new IllegalArgumentException(String.format(java.util.Locale.ROOT, "Expected the field `exampleInnerThree` to be a primitive type in the JSON string but got `%s`", jsonObj.get("exampleInnerThree").toString()));
      }
      // validate the optional field `exampleInnerThree`
      if (jsonObj.get("exampleInnerThree") != null && !jsonObj.get("exampleInnerThree").isJsonNull()) {
        ExampleInnerThreeEnum.validateJsonElement(jsonObj.get("exampleInnerThree"));
      }
  }

  public static class CustomTypeAdapterFactory implements TypeAdapterFactory {
    @SuppressWarnings("unchecked")
    @Override
    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
       if (!RecordWithInnerEnums.class.isAssignableFrom(type.getRawType())) {
         return null; // this class only serializes 'RecordWithInnerEnums' and its subtypes
       }
       final TypeAdapter<JsonElement> elementAdapter = gson.getAdapter(JsonElement.class);
       final TypeAdapter<RecordWithInnerEnums> thisAdapter
                        = gson.getDelegateAdapter(this, TypeToken.get(RecordWithInnerEnums.class));

       return (TypeAdapter<T>) new TypeAdapter<RecordWithInnerEnums>() {
           @Override
           public void write(JsonWriter out, RecordWithInnerEnums value) throws IOException {
             JsonObject obj = thisAdapter.toJsonTree(value).getAsJsonObject();
             elementAdapter.write(out, obj);
           }

           @Override
           public RecordWithInnerEnums read(JsonReader in) throws IOException {
             JsonElement jsonElement = elementAdapter.read(in);
             validateJsonElement(jsonElement);
             return thisAdapter.fromJsonTree(jsonElement);
           }

       }.nullSafe();
    }
  }

  /**
   * Create an instance of RecordWithInnerEnums given an JSON string
   *
   * @param jsonString JSON string
   * @return An instance of RecordWithInnerEnums
   * @throws IOException if the JSON string is invalid with respect to RecordWithInnerEnums
   */
  public static RecordWithInnerEnums fromJson(String jsonString) throws IOException {
    return JSON.getGson().fromJson(jsonString, RecordWithInnerEnums.class);
  }

  /**
   * Convert an instance of RecordWithInnerEnums to an JSON string
   *
   * @return JSON string
   */
  public String toJson() {
    return JSON.getGson().toJson(this);
  }
}