package com.atlassian.sal.api.validate;
   
   import com.atlassian.annotations.PublicApi;
   import com.google.common.collect.ImmutableSet;
   
   import javax.annotation.Nonnull;
   import java.util.Collections;
   
   import static com.google.common.base.Preconditions.checkNotNull;
  
  @SuppressWarnings("UnusedDeclaration")
  @PublicApi
  /**
   * The outcome of a validation check.
   * @since 3.0
   */
  public class ValidationResult {
      private static final ValidationResult VALID = new ValidationResult(Collections.<String>emptySet());
  
      private final ImmutableSet<String> errorMessages;
  
      private final ImmutableSet<String> warningMessages;
  
      private ValidationResult(@Nonnull final Iterable<String> errorMessages) {
          this(errorMessages, Collections.<String>emptySet());
      }
  
      private ValidationResult(@Nonnull final Iterable<String> errorMessages, @Nonnull final Iterable<String> warningMessages) {
          checkNotNull(errorMessages, "errorMessages");
          checkNotNull(warningMessages, "warningMessages");
          this.errorMessages = ImmutableSet.copyOf(errorMessages);
          this.warningMessages = ImmutableSet.copyOf(warningMessages);
      }
  
      public static ValidationResult valid() {
          return VALID;
      }
  
      public static ValidationResult withErrorMessages(@Nonnull final Iterable<String> errorMessages) {
          return new ValidationResult(errorMessages);
      }
  
      public static ValidationResult withWarningMessages(@Nonnull final Iterable<String> warningMessages) {
          return new ValidationResult(Collections.<String>emptySet(), warningMessages);
      }
  
      public static ValidationResult withErrorAndWarningMessages(@Nonnull final Iterable<String> errorMessages, @Nonnull final Iterable<String> warningMessages) {
          return new ValidationResult(errorMessages, warningMessages);
      }
  
      /**
       * Return true if the validation passed, false if there were errors. (Note warnings do not cause this method to
       * return false).
       *
       * @return true if the validation passed, false if there were errors.
       * @see #hasWarnings()
       */
      public boolean isValid() {
          return errorMessages.isEmpty();
      }
  
      /**
       * Return true if the validation added error messages.
       *
       * @return true if the validation failed with error messages.
       */
      public boolean hasErrors() {
          return !errorMessages.isEmpty();
      }
  
      /**
       * Return true if the validation added warning messages.
       *
       * @return true if the validation failed with warning messages.
       */
      public boolean hasWarnings() {
          return !warningMessages.isEmpty();
      }
  
      /**
       * Returns error messages.
       * <p/>
       * These should normally be localised to the end user's locale. This will never be null, but may be empty.
       *
       * @return validation error messages, could be empty but not null.
       */
      @Nonnull
      public Iterable<String> getErrorMessages() {
          return errorMessages;
      }
  
      /**
       * Returns warnings messages.
       * <p/>
       * These should normally be localised to the end user's locale. This will never be null, but may be empty.
       *
       * @return validation warning messages, could be empty but not null.
       */
      @Nonnull
     public Iterable<String> getWarningMessages() {
         return warningMessages;
     }
 }