/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.maven.cling.invoker.mvnup.goals;
  
  import org.jdom2.Document;
  import org.jdom2.Element;
  import org.jdom2.Namespace;
  
  import static org.apache.maven.cling.invoker.mvnup.goals.UpgradeConstants.ModelVersions.MODEL_VERSION_4_0_0;
  import static org.apache.maven.cling.invoker.mvnup.goals.UpgradeConstants.ModelVersions.MODEL_VERSION_4_1_0;
  import static org.apache.maven.cling.invoker.mvnup.goals.UpgradeConstants.Namespaces.MAVEN_4_0_0_NAMESPACE;
  import static org.apache.maven.cling.invoker.mvnup.goals.UpgradeConstants.Namespaces.MAVEN_4_1_0_NAMESPACE;
  import static org.apache.maven.cling.invoker.mvnup.goals.UpgradeConstants.SchemaLocations.MAVEN_4_1_0_SCHEMA_LOCATION;
  import static org.apache.maven.cling.invoker.mvnup.goals.UpgradeConstants.XmlElements.MODEL_VERSION;
  
  /**
   * Utility class for handling Maven model version operations during upgrades.
   */
  public final class ModelVersionUtils {
  
      private ModelVersionUtils() {
          // Utility class
      }
  
      /**
       * Detects the model version from a POM document.
       * Uses both the modelVersion element and namespace URI for detection.
       *
       * @param pomDocument the POM document
       * @return the detected model version
       */
      public static String detectModelVersion(Document pomDocument) {
          Element root = pomDocument.getRootElement();
          Namespace namespace = root.getNamespace();
  
          // First try to get from modelVersion element
          Element modelVersionElement = root.getChild(MODEL_VERSION, namespace);
          if (modelVersionElement != null) {
              String modelVersion = modelVersionElement.getTextTrim();
              if (!modelVersion.isEmpty()) {
                  return modelVersion;
              }
          }
  
          // Fallback to namespace URI detection
          String namespaceUri = namespace.getURI();
          if (MAVEN_4_1_0_NAMESPACE.equals(namespaceUri)) {
              return MODEL_VERSION_4_1_0;
          } else if (MAVEN_4_0_0_NAMESPACE.equals(namespaceUri)) {
              return MODEL_VERSION_4_0_0;
          }
  
          // Default fallback
          return MODEL_VERSION_4_0_0;
      }
  
      /**
       * Checks if a model version is valid for upgrade operations.
       * Currently only supports 4.0.0 and 4.1.0.
       *
       * @param modelVersion the model version to validate
       * @return true if the model version is valid
       */
      public static boolean isValidModelVersion(String modelVersion) {
          return MODEL_VERSION_4_0_0.equals(modelVersion) || MODEL_VERSION_4_1_0.equals(modelVersion);
      }
  
      /**
       * Checks if an upgrade from one version to another is possible.
       *
       * @param fromVersion the source version
       * @param toVersion the target version
       * @return true if the upgrade is possible
       */
      public static boolean canUpgrade(String fromVersion, String toVersion) {
          if (fromVersion == null || toVersion == null) {
              return false;
          }
  
          // Currently only support 4.0.0 → 4.1.0 upgrade
          return MODEL_VERSION_4_0_0.equals(fromVersion) && MODEL_VERSION_4_1_0.equals(toVersion);
      }
  
     /**
      * Checks if a model version is eligible for inference optimizations.
      * Models 4.0.0+ are eligible (4.0.0 has limited inference, 4.1.0+ has full inference).
      *
      * @param modelVersion the model version to check
      * @return true if eligible for inference
      */
     public static boolean isEligibleForInference(String modelVersion) {
         return MODEL_VERSION_4_0_0.equals(modelVersion) || MODEL_VERSION_4_1_0.equals(modelVersion);
     }
 
     /**
      * Checks if a model version is newer than 4.1.0.
      *
      * @param modelVersion the model version to check
      * @return true if newer than 4.1.0
      */
     public static boolean isNewerThan410(String modelVersion) {
         if (modelVersion == null) {
             return false;
         }
 
         // Simple version comparison for now
         // This could be enhanced with proper version parsing if needed
         try {
             String[] parts = modelVersion.split("\\.");
             if (parts.length >= 2) {
                 int major = Integer.parseInt(parts[0]);
                 int minor = Integer.parseInt(parts[1]);
 
                 if (major > 4) {
                     return true;
                 }
                 if (major == 4 && minor > 1) {
                     return true;
                 }
                 if (major == 4 && minor == 1 && parts.length > 2) {
                     int patch = Integer.parseInt(parts[2]);
                     return patch > 0;
                 }
             }
         } catch (NumberFormatException e) {
             // If we can't parse it, assume it's not newer
             return false;
         }
 
         return false;
     }
 
     /**
      * Checks if a model version is greater than or equal to a target version.
      *
      * @param modelVersion the model version to check
      * @param targetVersion the target version to compare against
      * @return true if modelVersion >= targetVersion
      */
     public static boolean isVersionGreaterOrEqual(String modelVersion, String targetVersion) {
         if (modelVersion == null || targetVersion == null) {
             return false;
         }
 
         // Handle exact equality first
         if (modelVersion.equals(targetVersion)) {
             return true;
         }
 
         // For now, handle the specific cases we need
         if (MODEL_VERSION_4_1_0.equals(targetVersion)) {
             return MODEL_VERSION_4_1_0.equals(modelVersion) || isNewerThan410(modelVersion);
         }
 
         // Default to false for unknown comparisons
         return false;
     }
 
     /**
      * Updates the model version element in a POM document.
      *
      * @param pomDocument the POM document
      * @param newVersion the new model version
      */
     public static void updateModelVersion(Document pomDocument, String newVersion) {
         Element root = pomDocument.getRootElement();
         Namespace namespace = root.getNamespace();
 
         Element modelVersionElement = root.getChild(MODEL_VERSION, namespace);
         if (modelVersionElement != null) {
             modelVersionElement.setText(newVersion);
         } else {
             // Create new modelVersion element if it doesn't exist
             Element newModelVersionElement = new Element(MODEL_VERSION, namespace);
             newModelVersionElement.setText(newVersion);
 
             // Insert at the beginning of the document
             root.addContent(0, newModelVersionElement);
         }
     }
 
     /**
      * Removes the model version element from a POM document.
      * This is used during inference when the model version can be inferred.
      *
      * @param pomDocument the POM document
      * @return true if the element was removed, false if it didn't exist
      */
     public static boolean removeModelVersion(Document pomDocument) {
         Element root = pomDocument.getRootElement();
         Namespace namespace = root.getNamespace();
 
         Element modelVersionElement = root.getChild(MODEL_VERSION, namespace);
         if (modelVersionElement != null) {
             return root.removeContent(modelVersionElement);
         }
         return false;
     }
 
     /**
      * Gets the schema location for a model version.
      *
      * @param modelVersion the model version
      * @return the schema location
      */
     public static String getSchemaLocationForModelVersion(String modelVersion) {
         if (MODEL_VERSION_4_1_0.equals(modelVersion) || isNewerThan410(modelVersion)) {
             return MAVEN_4_1_0_SCHEMA_LOCATION;
         }
         return UpgradeConstants.SchemaLocations.MAVEN_4_0_0_SCHEMA_LOCATION;
     }
 }