content: /**
   * Copyright (C) 2012 the original author or authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package co.jirm.orm.builder;
  
  import co.jirm.core.sql.Parameters;
  import co.jirm.core.util.SafeAppendable;
  
  import com.google.common.collect.ImmutableList;
  
  
  public class ConditionVisitors {
  	public static ConditionVisitor conditionVisitor(final Appendable appendable) {
  		
  		final SafeAppendable sb = new SafeAppendable(appendable);
  		
  		ConditionVisitor v = new ConditionVisitor() {
  			private int depth = 0;
  			
  			@Override
  			public void visitAnd(ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
  				depth++;
  				doCondition(" AND ", conditions, parameters);
  				
  			}
  			@Override
  			public void visitOr(ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
  				depth++;
  				doCondition(" OR ", conditions, parameters);
  			}
  			
  			private void doCondition(String op, ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
  				if (conditions.size() == 1) {
  					sb.append(op);
  					conditions.get(0).accept(this);
  					
  				}
  				else {
  					boolean top = depth == 1;
  					if (! top)
  						sb.append("( ");
  					boolean first = true;
  					for (ImmutableCondition c : conditions) {
  						if (first) { 
  							first = false; 
  							c.accept(this);
  						}
  						else {
  							sb.append(op);
  							c.accept(this);
  						}
  						
  					}
  					if (! top)
  						sb.append(" )");
  				}
  			}
  
  			@Override
  			public void visitSql(String sql, Parameters parameters) {
  				sb.append(sql);
  			}
  		};
  		return v;
  	}
  	
  	public static abstract class ParametersConditionVisitor extends ConditionVisitor {
  
  		@Override
  		public void visitAnd(ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
  			super.visitAnd(conditions, parameters);
  			doParameters(parameters);
  		}
  
  		@Override
  		public void visitOr(ImmutableList<ImmutableCondition> conditions, Parameters parameters) {
  			super.visitOr(conditions, parameters);
  			doParameters(parameters);
  		}
  
  		@Override
  		public void visitSql(String sql, Parameters parameters) {
  			doParameters(parameters);
  		}
  		
  		public abstract void doParameters(Parameters p);
  		
  	}
  }
  