package liquibase.precondition.core;

 import liquibase.exception.ValidationErrors;

 import liquibase.exception.Warnings;

 import liquibase.precondition.Precondition;

 import liquibase.database.Database;

 import liquibase.changelog.DatabaseChangeLog;

 import liquibase.changelog.ChangeSet;

 import liquibase.changelog.ChangeLogParameters;

 import liquibase.exception.PreconditionFailedException;

 import liquibase.exception.PreconditionErrorException;

 public class ChangeLogPropertyDefinedPrecondition implements Precondition {

     private String property;

     private String value;

     public String getName() {

         return "changeLogPropertyDefined";

     }

     public String getProperty() {

         return property;

     }

     public void setProperty(String property) {

         this.property = property;

     }

     public String getValue() {

         return value;

     }

     public void setValue(String value) {

         this.value = value;

     }

     public Warnings warn(Database database) {

         return new Warnings();

     }

     public ValidationErrors validate(Database database) {

         return new ValidationErrors();

     }

     public void check(Database database, DatabaseChangeLog changeLog, ChangeSet changeSet)

             throws PreconditionFailedException, PreconditionErrorException {

         ChangeLogParameters changeLogParameters = changeLog.getChangeLogParameters();

         if (changeLogParameters == null) {

             throw new PreconditionFailedException("No Changelog properties were set", changeLog, this);

         }

         Object propertyValue = changeLogParameters.getValue(property);

         if (propertyValue == null) {

             throw new PreconditionFailedException("Changelog property '" + property + "' was not set", changeLog, this);

         }

         if (value != null && !propertyValue.toString().equals(value)) {

             throw new PreconditionFailedException("Expected changelog property '" + property + "' to have a value of '"

                     + value + "'.  Got '" + propertyValue + "'", changeLog, this);

         }

     }

 }