package liquibase.database.core;
   
   import liquibase.database.AbstractDatabase;
   import liquibase.database.DatabaseConnection;
   import liquibase.exception.DatabaseException;
   import liquibase.executor.ExecutorService;
   import liquibase.statement.core.RawSqlStatement;
   
   /**
   * Encapsulates MySQL database support.
   */
  public class MySQLDatabase extends AbstractDatabase {
      public static final String PRODUCT_NAME = "MySQL";
  
      public String getTypeName() {
          return "mysql";
      }
  
      // todo: handle @Override
      // public String getConnectionUsername() throws DatabaseException {
      // return super.getConnection().getConnectionUserName().replaceAll("\\@.*", "");
      // }
  
      public int getPriority() {
          return PRIORITY_DEFAULT;
      }
  
      public boolean isCorrectDatabaseImplementation(DatabaseConnection conn) throws DatabaseException {
          return PRODUCT_NAME.equalsIgnoreCase(conn.getDatabaseProductName());
      }
  
      public String getDefaultDriver(String url) {
          if (url.startsWith("jdbc:mysql")) {
              return "com.mysql.jdbc.Driver";
          }
          return null;
      }
  
      @Override
      public boolean supportsSequences() {
          return false;
      }
  
      public boolean supportsInitiallyDeferrableColumns() {
          return false;
      }
  
      public String getCurrentDateTimeFunction() {
          if (currentDateTimeFunction != null) {
              return currentDateTimeFunction;
          }
  
          return "NOW()";
      }
  
      @Override
      public String getLineComment() {
          return "--";
      }
  
      @Override
      public String getConcatSql(String... values) {
          StringBuffer returnString = new StringBuffer();
          returnString.append("CONCAT_WS(");
          for (String value : values) {
              returnString.append(value).append(", ");
          }
  
          return returnString.toString().replaceFirst(", $", ")");
      }
  
      public boolean supportsTablespaces() {
          return false;
      }
  
      @Override
      protected String getDefaultDatabaseSchemaName() throws DatabaseException {
          // return super.getDefaultDatabaseSchemaName().replaceFirst("\\@.*","");
          return getConnection().getCatalog();
      }
  
      @Override
      public String convertRequestedSchemaToSchema(String requestedSchema) throws DatabaseException {
          if (requestedSchema == null) {
              return getDefaultDatabaseSchemaName();
          }
          return requestedSchema;
      }
  
      @Override
      public String convertRequestedSchemaToCatalog(String requestedSchema) throws DatabaseException {
          return requestedSchema;
      }
  
      @Override
      public String escapeDatabaseObject(String objectName) {
          return "`" + objectName + "`";
      }
  
     @Override
     public String escapeIndexName(String schemaName, String indexName) {
         return escapeDatabaseObject(indexName);
     }
 
     @Override
     public boolean supportsForeignKeyDisable() {
         return true;
     }
 
     @Override
     public boolean disableForeignKeyChecks() throws DatabaseException {
         boolean enabled = ExecutorService.getInstance().getExecutor(this)
                 .queryForInt(new RawSqlStatement("SELECT @@FOREIGN_KEY_CHECKS")) == 1;
         ExecutorService.getInstance().getExecutor(this).execute(new RawSqlStatement("SET FOREIGN_KEY_CHECKS=0"));
         return enabled;
     }
 
     @Override
     public void enableForeignKeyChecks() throws DatabaseException {
         ExecutorService.getInstance().getExecutor(this).execute(new RawSqlStatement("SET FOREIGN_KEY_CHECKS=1"));
     }
 }