/**
    * Copyright 2011 The Kuali Foundation Licensed under the
    * Educational Community 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.osedu.org/licenses/ECL-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 org.kuali.common.impex.data.impl;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.util.List;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.kuali.common.impex.data.MpxHeaderData;
  import org.kuali.common.impex.data.SqlProducer;
  import org.kuali.common.impex.model.Schema;
  import org.kuali.common.impex.model.Table;
  import org.kuali.common.jdbc.SqlMetaData;
  import org.kuali.common.jdbc.supplier.AbstractSupplier;
  import org.kuali.common.jdbc.supplier.LocationSupplier;
  import org.kuali.common.util.CollectionUtils;
  import org.kuali.common.util.LocationUtils;
  import org.kuali.common.util.TextMetaData;
  
  /**
   * This class provides an implementation of the SqlSupplier interface using an Mpx resource as the data source
   * 
   * @author andrewlubbers
   */
  public class MpxLocationSupplier extends AbstractSupplier implements LocationSupplier {
  
  	public static final String DEFAULT_MPX_EXTENSION = ".mpx";
  	public static final String UTF8 = "UTF-8";
  
  	protected BufferedReader reader;
  	protected Table table;
      protected MpxHeaderData headerData;
  
  	String extension = DEFAULT_MPX_EXTENSION;
  	String encoding = UTF8;
  	SqlProducer producer;
  	String location;
  
      /**
       * Data model provider
       */
      Schema schema;
  
  	@Override
  	public void open() throws IOException {
  		this.table = getTable();
  		this.reader = LocationUtils.getBufferedReader(location, encoding);
          this.headerData = getHeader(reader);
  	}
  
  	@Override
  	public List<String> getSql() throws IOException {
  		return producer.getSql(table, headerData, reader);
  	}
  
  	@Override
  	public void close() {
  		IOUtils.closeQuietly(reader);
  		this.table = null;
  	}
  
  	protected Table getTable() {
  		String filename = LocationUtils.getFilename(location);
  		if (!StringUtils.endsWithIgnoreCase(filename, extension)) {
  			throw new IllegalArgumentException(location + " does not end with " + extension);
  		}
  		int end = filename.length() - extension.length();
  		String tableName = StringUtils.substring(filename, 0, end);
  
          for (Table t : schema.getTables()) {
              if(t.getName().equalsIgnoreCase(tableName)) {
                  return t;
              }
          }
  
          throw new IllegalArgumentException("Unable to locate table [" + tableName + "]");
  	}
  
  	@Override
  	public void fillInMetaData() {
  		TextMetaData tmd = LocationUtils.getTextMetaData(location);
  		this.metaData = new SqlMetaData(tmd.getLines() - 1, tmd.getSize());
  	}
  
     /**
      * Parses the next line in the given reader and returns a MpxHeaderData built from header information
      *
      * This method assumes the given reader is at the beginning of an mpx file
      *
      * @param reader the mpx file reader
      * @return the next parsed header data
      * @throws IllegalArgumentException when the next non-blank line from the reader is not a header line
      *      IOException if a read error is thrown from the reader
      */
     protected MpxHeaderData getHeader(BufferedReader reader) throws IOException {
         String line = reader.readLine();
         while(org.codehaus.plexus.util.StringUtils.isBlank(line)) {
             line = reader.readLine();
         }
 
         if (ParseUtils.isHeaderLine(line)) {
             MpxHeaderData header = new MpxHeaderData();
             header.getColumnNames().addAll(CollectionUtils.getTrimmedListFromCSV(line));
 
             return header;
         }
         else {
             throw new IllegalArgumentException("Could not parse mpx header, next non-blank in given reader is not a header line.  Reached line was: " + line);
         }
     }
 
 	public String getEncoding() {
 		return encoding;
 	}
 
 	public void setEncoding(String encoding) {
 		this.encoding = encoding;
 	}
 
 	@Override
 	public String getLocation() {
 		return location;
 	}
 
 	@Override
 	public void setLocation(String location) {
 		this.location = location;
 	}
 
 	public SqlProducer getProducer() {
 		return producer;
 	}
 
 	public void setProducer(SqlProducer producer) {
 		this.producer = producer;
 	}
 
 	public String getExtension() {
 		return extension;
 	}
 
 	public void setExtension(String extension) {
 		this.extension = extension;
 	}
 
     public Schema getSchema() {
         return schema;
     }
 
     public void setSchema(Schema schema) {
         this.schema = schema;
     }
 }