/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package dev.metaschema.core.model;
   
   import java.util.Map;
   import java.util.Objects;
  import java.util.Set;
  
  import dev.metaschema.core.MetaschemaConstants;
  import dev.metaschema.core.util.CollectionUtil;
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  /**
   * A marker interface for implementations that supports the mapping of a
   * namespace valued key to a set of values.
   */
  @FunctionalInterface
  public interface IAttributable {
    /**
     * The default key namespace for a property.
     */
    @NonNull
    String DEFAULT_PROPERY_NAMESPACE = MetaschemaConstants.METASCHEMA_NAMESPACE;
  
    /**
     * Get the mapping of property key to values.
     *
     * @return the mapping
     */
    @NonNull
    Map<Key, Set<String>> getProperties();
  
    /**
     * Determine if a property is defined.
     *
     * @param key
     *          the key of the property
     * @return {@code true} if the property is defined or {@code false} otherwise
     */
    default boolean hasProperty(@NonNull Key key) {
      return getProperties().containsKey(key);
    }
  
    /**
     * Get the values associated with a given property key.
     *
     * @param key
     *          the key of the property
     * @return the values or an empty set
     */
    @NonNull
    default Set<String> getPropertyValues(@NonNull Key key) {
      Set<String> retval = getProperties().get(key);
      if (retval == null) {
        retval = CollectionUtil.emptySet();
      }
      return retval;
    }
  
    /**
     * Determine if a given property, with a given {@code key}, has the identified
     * {@code value}.
     *
     * @param key
     *          the key of the property
     * @param value
     *          the expected property value
     * @return {@code true} if the property value is defined or {@code false}
     *         otherwise
     */
    default boolean hasPropertyValue(@NonNull Key key, @NonNull String value) {
      Set<String> values = getProperties().get(key);
      return values != null && values.contains(value);
    }
  
    /**
     * Get a property key based on the provided name and namespace.
     *
     * @param name
     *          the name portion of a property key
     * @param namespace
     *          the namespace portion of a property key
     * @return the property key
     */
    @NonNull
    static Key key(@NonNull String name, @NonNull String namespace) {
      return new Key(name, namespace);
    }
  
    /**
     * Get a property key based on the provided name and the default namespace.
     *
     * @param name
     *          the name portion of a property key
     * @return the property key
     * @see #DEFAULT_PROPERY_NAMESPACE
    */
   @NonNull
   static Key key(@NonNull String name) {
     return new Key(name);
   }
 
   /**
    * Represents a property key based on a name and a namespace.
    */
   // FIXME: use IEnhancedQName instead of name and namespace, or replace key
   // altogether with an integer value
   final class Key {
     @NonNull
     private final String name;
     @NonNull
     private final String namespace;
 
     private Key(@NonNull String name) {
       this(name, DEFAULT_PROPERY_NAMESPACE);
     }
 
     private Key(@NonNull String name, @NonNull String namespace) {
       this.name = name;
       this.namespace = namespace;
     }
 
     /**
      * Get the property key's name portion.
      *
      * @return the name
      */
     @NonNull
     public String getName() {
       return name;
     }
 
     /**
      * Get the property key's namespace portion.
      *
      * @return the name
      */
     @NonNull
     public String getNamespace() {
       return namespace;
     }
 
     @Override
     public int hashCode() {
       return Objects.hash(name, namespace);
     }
 
     @Override
     public boolean equals(Object obj) {
       if (this == obj) {
         return true;
       }
       if (!(obj instanceof Key)) {
         return false;
       }
       Key other = (Key) obj;
       return Objects.equals(name, other.name) && Objects.equals(namespace, other.namespace);
     }
   }
 }