package org.kuali.common.jdbc.supplier;
   
   import java.io.BufferedReader;
   import java.io.IOException;
   import java.util.List;
   
   import org.apache.commons.io.IOUtils;
   import org.kuali.common.jdbc.DefaultSqlReader;
   import org.kuali.common.jdbc.JdbcUtils;
  import org.kuali.common.jdbc.SqlMetaData;
  import org.kuali.common.jdbc.SqlReader;
  import org.kuali.common.util.LocationUtils;
  import org.springframework.util.Assert;
  
  /**
   * Supply SQL from strings that may have more than one SQL statement each
   */
  public class ComplexStringSupplier extends AbstractSupplier {
  
  	protected int index = 0;
  	protected BufferedReader in;
  
  	List<String> strings;
  	SqlReader reader = new DefaultSqlReader();
  
  	public ComplexStringSupplier() {
  		this(null);
  	}
  
  	public ComplexStringSupplier(List<String> strings) {
  		super();
  		this.strings = strings;
  	}
  
  	@Override
  	public void open() {
  
  		// Make sure we've got something to work with
  		Assert.notNull(strings, "strings is null");
  
  		// Reset index to zero
  		index = 0;
  
  		// Open a reader to the first string in the list
  		in = getBufferedReader(strings, index);
  	}
  
  	@Override
  	public List<String> getSql() {
  		try {
  			// Have the reader produce a SQL statement
  			List<String> sql = reader.getSql(in);
  
  			if (sql != null) {
  				// We got a SQL statement we are done
  				return sql;
  			} else {
  				// We've exhausted the current string, move to the next one
  				index++;
  			}
  
  			// We've exhausted all of the strings, we are done
  			if (index == strings.size()) {
  				return null;
  			}
  
  			// Open a reader to the new string
  			in = getBufferedReader(strings, index);
  
  			// Get a SQL statement from the new string
  			return getSql();
  		} catch (IOException e) {
  			throw new IllegalStateException(e);
  		}
  	}
  
  	/**
  	 * Extract a String from the list and open a BufferedReader that can read from it
  	 */
  	protected BufferedReader getBufferedReader(List<String> strings, int index) {
  		String string = strings.get(index);
  		return LocationUtils.getBufferedReaderFromString(string);
  	}
  
  	@Override
  	public void close() {
  		// Reset index to zero
  		index = 0;
  
  		// Make sure the BufferedReader is closed
  		IOUtils.closeQuietly(in);
  	}
  
  	@Override
  	public void fillInMetaData() {
  		long count = 0;
  		long size = 0;
  		for (String string : strings) {
  			SqlMetaData smd = getMetaData(string);
 			count += smd.getCount();
 			size += smd.getSize();
 		}
 		this.metaData = new SqlMetaData(count, size);
 	}
 
 	protected SqlMetaData getMetaData(String sql) {
 		BufferedReader in = null;
 		try {
 			in = LocationUtils.getBufferedReaderFromString(sql);
 			return JdbcUtils.getSqlMetaData(in, reader);
 		} catch (IOException e) {
 			throw new IllegalStateException(e);
 		} finally {
 			IOUtils.closeQuietly(in);
 		}
 	}
 
 	public List<String> getStrings() {
 		return strings;
 	}
 
 	public void setStrings(List<String> strings) {
 		this.strings = strings;
 	}
 
 	public SqlReader getReader() {
 		return reader;
 	}
 
 	public void setReader(SqlReader reader) {
 		this.reader = reader;
 	}
 
 }