/*
 * Created on Apr 9, 2005
 *
 */
package aima.learning.framework;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;

import aima.util.Util;

public class DataSetFactory {
	
	public  DataSet fromFile(String filename,DataSetSpecification spec,String separator) throws Exception {
		// assumed file in data directory and ends in .csv
		DataSet ds = new DataSet(spec);
		BufferedReader reader = new BufferedReader(new InputStreamReader(
				this.getClass().getResourceAsStream("../data/" + filename + ".csv")));
		String line;
		while ((line = reader.readLine()) != null) {
			ds.add(exampleFromString(line,spec,separator));
		}
		
		return ds;

	}
	
	public static Example exampleFromString(String data,DataSetSpecification dataSetSpec,String separator){
		Hashtable<String,Attribute> attributes = new Hashtable<String,Attribute>();
		List<String> attributeValues = Arrays.asList(data.split(separator));
		if (dataSetSpec.isValid(attributeValues)){
			List<String> names = dataSetSpec.getAttributeNames();
			Iterator<String> nameiter = names.iterator();
			Iterator<String> valueiter = attributeValues.iterator();
			while(nameiter.hasNext() && valueiter.hasNext()){
				String name = nameiter.next();
				AttributeSpecification attributeSpec = dataSetSpec.getAttributeSpecFor(name);
				Attribute attribute =  attributeSpec.createAttribute(valueiter.next());
				attributes.put(name,attribute);
			}
			String targetAttributeName = dataSetSpec.getTarget();
			AttributeSpecification attributeSpec =dataSetSpec.getAttributeSpecFor(targetAttributeName );
			return new Example(attributes,attributes.get(targetAttributeName));
		}
		else{
			throw new RuntimeException("Unable to construct Example from " + data);
		}
	}
	
	public static DataSet getRestaurantDataSet() throws Exception{
		DataSetSpecification spec = createRestaurantDataSetSpec();
		return new DataSetFactory().fromFile("restaurant",spec,"\\s+");
	}
	
	
	
	public static DataSetSpecification createRestaurantDataSetSpec() {
		DataSetSpecification dss =  new DataSetSpecification();
		dss.defineStringAttribute("alternate",Util.yesno());
		dss.defineStringAttribute("bar",Util.yesno());
		dss.defineStringAttribute("fri/sat",Util.yesno());
		dss.defineStringAttribute("hungry",Util.yesno());
		dss.defineStringAttribute("patrons",new String[]{"None","Some","Full"});
		dss.defineStringAttribute("price",new String[]{"$","$$","$$$"});
		dss.defineStringAttribute("raining",Util.yesno());
		dss.defineStringAttribute("reservation",Util.yesno());
		dss.defineStringAttribute("type",new String[]{"French","Italian","Thai","Burger"});
		dss.defineStringAttribute("wait_estimate",new String[]{"0-10","10-30","30-60",">60"});
		dss.defineStringAttribute("will_wait",Util.yesno());
		//last attribute is the target attribute unless the target is explicitly reset with dss.setTarget(name)

		return dss;
	}
	
	public static DataSet getIrisDataSet() throws Exception{
		DataSetSpecification spec = createIrisDataSetSpec();
		return new DataSetFactory().fromFile("iris",spec,",");
	}
	public static DataSetSpecification createIrisDataSetSpec() {
		DataSetSpecification dss =  new DataSetSpecification();
		dss.defineNumericAttribute("sepal_length");
		dss.defineNumericAttribute("sepal_width");
		dss.defineNumericAttribute("petal_length");
		dss.defineNumericAttribute("petal_width");
		dss.defineStringAttribute("plant_category",new String[]{"setosa","versicolor","virginica"});
		return dss;
	}
	


}