/*
 * Portions of this software was developed by employees of the National Institute
 * of Standards and Technology (NIST), an agency of the Federal Government and is
 * being made available as a public service. Pursuant to title 17 United States
 * Code Section 105, works of NIST employees are not subject to copyright
 * protection in the United States. This software may be subject to foreign
 * copyright. Permission in the United States and in foreign countries, to the
 * extent that NIST may hold copyright, to use, copy, modify, create derivative
 * works, and distribute this software and its documentation without fee is hereby
 * granted on a non-exclusive basis, provided that this notice and disclaimer
 * of warranty appears in all copies.
 *
 * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
 * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
 * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
 * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
 * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
 * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
 * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
 * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
 * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
 * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
 * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
 */

package gov.nist.secauto.metaschema.core.model.constraint;

import gov.nist.secauto.metaschema.core.datatype.markup.MarkupLine;
import gov.nist.secauto.metaschema.core.datatype.markup.MarkupMultiline;
import gov.nist.secauto.metaschema.core.metapath.DynamicContext;
import gov.nist.secauto.metaschema.core.metapath.MetapathExpression;
import gov.nist.secauto.metaschema.core.metapath.item.atomic.IBooleanItem;
import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
import gov.nist.secauto.metaschema.core.util.ObjectUtils;
import gov.nist.secauto.metaschema.core.util.ReplacementScanner;

import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.regex.Pattern;

import javax.xml.namespace.QName;

import edu.umd.cs.findbugs.annotations.NonNull;
import edu.umd.cs.findbugs.annotations.Nullable;

public final class DefaultExpectConstraint
    extends AbstractConstraint
    implements IExpectConstraint {
  @SuppressWarnings("null")
  @NonNull
  private static final Pattern METAPATH_VALUE_TEMPLATE_PATTERN
      = Pattern.compile("(?<!\\\\)(\\{\\s*((?:(?:\\\\})|[^}])*)\\s*\\})");
  @NonNull
  private final MetapathExpression test;
  private final String message;

  /**
   * Construct a new expect constraint which requires that the associated test
   * evaluates to {@link IBooleanItem#TRUE} against the target.
   *
   * @param id
   *          the optional identifier for the constraint
   * @param formalName
   *          the constraint's formal name or {@code null} if not provided
   * @param description
   *          the constraint's semantic description or {@code null} if not
   *          provided
   * @param source
   *          information about the constraint source
   * @param level
   *          the significance of a violation of this constraint
   * @param target
   *          the Metapath expression identifying the nodes the constraint targets
   * @param properties
   *          a collection of associated properties
   * @param test
   *          a Metapath expression that is evaluated against the target node to
   *          determine if the constraint passes
   * @param message
   *          an optional message to emit when the constraint is violated
   * @param remarks
   *          optional remarks describing the intent of the constraint
   */
  private DefaultExpectConstraint(
      @Nullable String id,
      @Nullable String formalName,
      @Nullable MarkupLine description,
      @NonNull ISource source,
      @NonNull Level level,
      @NonNull MetapathExpression target,
      @NonNull Map<QName, Set<String>> properties,
      @NonNull MetapathExpression test,
      @Nullable String message,
      MarkupMultiline remarks) {
    super(id, formalName, description, source, level, target, properties, remarks);
    this.test = Objects.requireNonNull(test);
    this.message = message;
  }

  @Override
  public MetapathExpression getTest() {
    return test;
  }

  @Override
  public String getMessage() {
    return message;
  }

  @Override
  public CharSequence generateMessage(@NonNull INodeItem item, @NonNull DynamicContext context) {
    String message = getMessage();

    return message == null ? null
        : ReplacementScanner.replaceTokens(message, METAPATH_VALUE_TEMPLATE_PATTERN, match -> {
          @SuppressWarnings("null")
          @NonNull String metapath = match.group(2);
          MetapathExpression expr = MetapathExpression.compile(metapath);
          return expr.evaluateAs(item, MetapathExpression.ResultType.STRING, context);
        });
  }

  @Override
  public <T, R> R accept(IConstraintVisitor<T, R> visitor, T state) {
    return visitor.visitExpectConstraint(this, state);
  }

  @NonNull
  public static Builder builder() {
    return new Builder();
  }

  public static final class Builder
      extends AbstractConstraintBuilder<Builder, DefaultExpectConstraint> {
    private MetapathExpression test;
    private String message;

    private Builder() {
      // disable construction
    }

    public Builder test(@NonNull MetapathExpression test) {
      this.test = test;
      return this;
    }

    public Builder message(@NonNull String message) {
      this.message = message;
      return this;
    }

    @Override
    protected Builder getThis() {
      return this;
    }

    @Override
    protected void validate() {
      super.validate();

      ObjectUtils.requireNonNull(getTest());
    }

    protected MetapathExpression getTest() {
      return test;
    }

    protected String getMessage() {
      return message;
    }

    @Override
    protected DefaultExpectConstraint newInstance() {
      return new DefaultExpectConstraint(
          getId(),
          getFormalName(),
          getDescription(),
          ObjectUtils.notNull(getSource()),
          getLevel(),
          getTarget(),
          getProperties(),
          ObjectUtils.requireNonNull(getTest()),
          getMessage(),
          getRemarks());
    }
  }
}