/*
 * Encog(tm) Core v3.4 - Java Version
 * http://www.heatonresearch.com/encog/
 * https://github.com/encog/encog-java-core
 
 * Copyright 2008-2016 Heaton Research, Inc.
 *
 * 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.
 *   
 * For more information on Heaton Research copyrights, licenses 
 * and trademarks visit:
 * http://www.heatonresearch.com/copyright
 */
package org.encog.app.analyst.csv;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

import org.encog.app.analyst.AnalystError;
import org.encog.app.analyst.EncogAnalyst;
import org.encog.app.analyst.csv.basic.BasicFile;
import org.encog.app.analyst.csv.basic.LoadedRow;
import org.encog.app.analyst.script.normalize.AnalystField;
import org.encog.app.quant.QuantError;
import org.encog.ml.MLRegression;
import org.encog.ml.data.MLData;
import org.encog.ml.data.basic.BasicMLData;
import org.encog.util.csv.CSVFormat;
import org.encog.util.csv.ReadCSV;

/**
 * Used by the analyst to evaluate a CSV file.
 * 
 */
public class AnalystEvaluateRawCSV extends BasicFile {

	/**
	 * The analyst file to use.
	 */
	private EncogAnalyst analyst;
	
	/**
	 * The input count.
	 */
	private int inputCount;
	
	/**
	 * The output count.
	 */
	private int outputCount;
	
	/**
	 * The ideal count.
	 */
	private int idealCount;

	/**
	 * Analyze the data. This counts the records and prepares the data to be
	 * processed.
	 * @param theAnalyst The analyst to use.
	 * @param inputFile The input file.
	 * @param headers True if headers are present.
	 * @param format The format the file is in.
	 */
	public void analyze(final EncogAnalyst theAnalyst, 
			final File inputFile,
			final boolean headers, final CSVFormat format) {
		this.setInputFilename(inputFile);
		setExpectInputHeaders(headers);
		setInputFormat(format);
		this.analyst = theAnalyst;

		setAnalyzed(true);

		performBasicCounts();

		this.inputCount = this.analyst.determineInputCount();
		this.outputCount = this.analyst.determineOutputCount();
		this.idealCount = getInputHeadings().length - this.inputCount;

		if ((getInputHeadings().length != this.inputCount)
				&& (getInputHeadings().length 
						!= (this.inputCount + this.outputCount))) {
			throw new AnalystError("Invalid number of columns("
					+ getInputHeadings().length + "), must match input("
					+ this.inputCount + ") count or input+output("
					+ (this.inputCount + this.outputCount) + ") count.");
		}

	}

	/**
	 * Prepare the output file, write headers if needed.
	 * 
	 * @param outputFile
	 *            The name of the output file.
	 * @param method
	 * @return The output stream for the text file.
	 */
	private PrintWriter analystPrepareOutputFile(final File outputFile) {
		try {
			final PrintWriter tw = new PrintWriter(new FileWriter(outputFile));

			// write headers, if needed
			if (isProduceOutputHeaders()) {
				final StringBuilder line = new StringBuilder();

				// first handle the input fields
				for (final AnalystField field : this.analyst.getScript()
						.getNormalize().getNormalizedFields()) {
					if (field.isInput()) {
						field.addRawHeadings(line, null, getFormat());
					}
				}

				// now, handle any ideal fields
				if (this.idealCount > 0) {
					for (final AnalystField field : this.analyst.getScript()
							.getNormalize().getNormalizedFields()) {
						if (field.isOutput()) {
							field.addRawHeadings(line, "ideal:",
									getFormat());
						}
					}
				}

				// now, handle the output fields
				for (final AnalystField field : this.analyst.getScript()
						.getNormalize().getNormalizedFields()) {
					if (field.isOutput()) {
						field.addRawHeadings(line, "output:", 
								getFormat());
					}
				}

				tw.println(line.toString());
			}

			return tw;

		} catch (final IOException e) {
			throw new QuantError(e);
		}
	}

	/**
	 * Process the file.
	 * @param outputFile The output file.
	 * @param method The method to use.
	 */
	public void process(final File outputFile, 			
			final MLRegression method) {

		final ReadCSV csv = new ReadCSV(getInputFilename().toString(),
				isExpectInputHeaders(), getFormat());

		if (method.getInputCount() != this.inputCount) {
			throw new AnalystError("This machine learning method has "
					+ method.getInputCount()
					+ " inputs, however, the data has " + this.inputCount
					+ " inputs.");
		}

		MLData output = null;
		final MLData input = new BasicMLData(method.getInputCount());

		final PrintWriter tw = analystPrepareOutputFile(outputFile);

		resetStatus();
		while (csv.next()) {
			updateStatus(false);
			final LoadedRow row = new LoadedRow(csv, this.idealCount);

			int dataIndex = 0;
			// load the input data
			for (int i = 0; i < this.inputCount; i++) {
				final String str = row.getData()[i];
				final double d = getFormat().parse(str);
				input.setData(i, d);
				dataIndex++;
			}

			// do we need to skip the ideal values?
			dataIndex += this.idealCount;

			// compute the result
			output = method.compute(input);

			// display the computed result
			for (int i = 0; i < this.outputCount; i++) {
				final double d = output.getData(i);
				row.getData()[dataIndex++] = getFormat().format(d,
						getPrecision());
			}

			writeRow(tw, row);
		}
		reportDone(false);
		tw.close();
		csv.close();
	}
}