/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package gov.nist.secauto.metaschema.core.model.constraint;
   
   import gov.nist.secauto.metaschema.core.datatype.markup.MarkupMultiline;
   import gov.nist.secauto.metaschema.core.metapath.MetapathException;
  import gov.nist.secauto.metaschema.core.metapath.MetapathExpression;
  import gov.nist.secauto.metaschema.core.model.ISource;
  import gov.nist.secauto.metaschema.core.model.constraint.impl.DefaultLet;
  
  import javax.xml.namespace.QName;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  /**
   * Represents a variable assignment for use in Metaschema module constraints.
   */
  @SuppressWarnings("PMD.ShortClassName")
  public interface ILet {
    /**
     * Create a new Let expression by compiling the provided Metapath expression
     * string.
     *
     * @param name
     *          the let expression variable name
     * @param valueExpression
     *          a Metapath expression string representing the variable value
     * @param source
     *          the source descriptor for the resource containing the constraint
     * @param remarks
     *          remarks about the let statement
     * @return the original let statement with the same name or {@code null}
     */
    @SuppressWarnings("PMD.ShortMethodName")
    @NonNull
    static ILet of(
        @NonNull QName name,
        @NonNull String valueExpression,
        @NonNull ISource source,
        @Nullable MarkupMultiline remarks) {
      try {
        return of(
            name,
            MetapathExpression.compile(valueExpression, source.getStaticContext()),
            source,
            remarks);
      } catch (MetapathException ex) {
        throw new MetapathException(
            String.format("Unable to compile the let expression '%s=%s'%s. %s",
                name,
                valueExpression,
                source.getSource() == null ? "" : " in " + source.getSource(),
                ex.getMessage()),
            ex);
      }
    }
  
    /**
     * Create a new Let expression.
     *
     * @param name
     *          the let expression variable name
     * @param valueExpression
     *          a Metapath expression representing the variable value
     * @param source
     *          the source descriptor for the resource containing the constraint
     * @param remarks
     *          remarks about the let statement
     * @return the original let statement with the same name or {@code null}
     */
    @SuppressWarnings("PMD.ShortMethodName")
    @NonNull
    static ILet of(
        @NonNull QName name,
        @NonNull MetapathExpression valueExpression,
        @NonNull ISource source,
        @Nullable MarkupMultiline remarks) {
      return new DefaultLet(name, valueExpression, source, remarks);
    }
  
    /**
     * Get the name of the let variable.
     *
     * @return the name
     */
    @NonNull
    QName getName();
  
    /**
     * Get the Metapath expression to use to query the value.
     *
     * @return the Metapath expression to use to query the value
     */
    @NonNull
    MetapathExpression getValueExpression();
 
   /**
    * Information about the source resource containing the let statement.
    *
    * @return the source information
    */
   @NonNull
   ISource getSource();
 
   /**
    * Get the remarks associated with the let statement.
    *
    * @return the remark or {@code null} if no remarks are defined
    */
   @Nullable
   MarkupMultiline getRemarks();
 }