import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.NoSuchElementException;
import java.util.StringTokenizer;
import java.util.Vector;

import org.shodor.util11.StrLib;

/**
 * Handles File input/ouput.
 */
public class FileIO {

	public static final String FILE_EXTENSION = "txt";

	private static final String DELIMITERS = "\t, ";

	/**
	 * Accepts a data file as input and returns a vector, each element
	 * representing an experimental condition.
	 */
	public static Vector loadExperimentalConditionFile(File datafile) {
		Vector retValue = new Vector();

		String[] header = new String[0]; // Human descriptions of property
		// fields.
		boolean headerRead = false;

		BufferedReader in;
		try {
			in = new BufferedReader(new InputStreamReader(
					new BufferedInputStream(new FileInputStream(datafile))));
		} catch (FileNotFoundException fnfe) {
			System.out
					.println("The file: "
							+ datafile.getName()
							+ " cannot be found.  Returning empty experimental conditions.");
			return retValue;
		}

		String input;
		int lineNumber = 0;
		int ignorefields = 2; // participant ID and experimental condition ID
		try {
			while ((input = in.readLine()) != null) {
				lineNumber++;
				StringTokenizer st = new StringTokenizer(input, DELIMITERS,
						true); // Include Delimeter in token to detect blank
				// cells.

				if (!headerRead) { // Read and store the property descriptions.
					/**
					 * Ignore the first 4 tokens (2 tabs and participant ID
					 * header and experimental ID header). Then divide the
					 * remaining tokens by two and round up to ignore tokens and
					 * get the length of the header array.
					 */
					int ignoretokens = 2 * ignorefields; // Ignore tabs
					if (st.countTokens() % 2 == 0) {
						header = new String[(st.countTokens() - ignoretokens) / 2];
					} else {
						header = new String[((st.countTokens() - ignoretokens) / 2) + 1];
					}
					// Do not need participant ID header text or experimental
					// condition ID header or included tabs.
					for (int i = 0; i < ignoretokens; i++) {
						st.nextToken();
					}
					for (int i = 0; i < header.length; i++) {
						try {
							header[i] = st.nextToken().trim();
							if (st.hasMoreTokens()) {
								st.nextToken();
							}
						} catch (NoSuchElementException nsee) {
							System.out.println("No such element for header "
									+ i + ", header.length: " + header.length
									+ ", tokens: " + st.countTokens());
						}
					}
					headerRead = true;
				} else {
					int participantID = (Integer
							.parseInt(st.nextToken().trim()));
					st.nextToken(); // Ignore delimeter. Assume all participant
					// and experimental condition IDs are
					// entered.
					int conditionID = (Integer.parseInt(st.nextToken().trim()));
					st.nextToken(); // Ignore delimeter. Assume all participant
					// and experimental condition IDs are
					// entered.
					double[] fields = new double[header.length];
					for (int i = 0; i < fields.length; i++) {
						String nextToken = "";
						try {
							nextToken = st.nextToken().trim();
						} catch (NoSuchElementException nsee) {
							// The line has no more tokens and the remaining
							// cells are blank.
							if (TimeSeries.DEBUG) {
								System.out
										.println("No remaining tokens.  Returning Double.NaN.  "+"line number: " + lineNumber
												+ ", column number "
												+ (i + 1 + ignorefields)+"");
							}
							fields[i] = Double.NaN;
							continue;
						}

						if (nextToken.length() == 0) {
							// The cell is blank. No data is in the cell.
							if (TimeSeries.DEBUG) {
								System.out.println("Blank Cell!!!");
								System.out.println("line number: " + lineNumber
										+ ", column number "
										+ (i + 1 + ignorefields));
							}
							fields[i] = Double.NaN;
						} else {
							try {
								fields[i] = (new Double(nextToken))
										.doubleValue();
							} catch (NumberFormatException nfe) { // XXX May
								// want
								// to throw
								// exception and
								// display a
								// pop-up
								System.out
										.println("Error reading numerical value from data set.");
								nfe.printStackTrace();
								return null;
							}
							// Advance tokenizer passed delimeter if not at the
							// end.
							if (st.hasMoreTokens()) {
								st.nextToken();
							}
						}
					}
					// Is there already an element in the retValue vector
					// corresponding to the experimental condition ID?
					int previousConditionIndex = -1;
					for (int i = 0; i < retValue.size(); i++) {
						if (conditionID == ((ExperimentalCondition) retValue
								.elementAt(i)).getExperimentalConditionID()) {
							previousConditionIndex = i;
						}
					}
					// If yes, add the trial to the experimental condition
					// vector.
					if (previousConditionIndex != -1) {
						ExperimentalCondition ec = (ExperimentalCondition) retValue
								.elementAt(previousConditionIndex);
						ec.addTrial(participantID, fields);
					} else { // If no, add a new ExperimentalCondition object
						// to the experimental condition vector and then
						// add the data fields to the experimental
						// condition object.
						retValue.addElement(new ExperimentalCondition(
								conditionID, header));
						ExperimentalCondition ec = (ExperimentalCondition) retValue
								.lastElement();
						ec.addTrial(participantID, fields);
					}
				}
			}
		} catch (IOException ioe) {
			System.out
					.println("ERROR: Parsing data file " + datafile.getName());
			System.out.println(ioe.getMessage());
			ioe.printStackTrace();
		} catch (Exception e) {
			System.out.println(e.getMessage());
			e.printStackTrace();
		}

		try {
			in.close();
		} catch (IOException ioe) {
			System.out.println("Error closing datafile.");
			System.out.println(ioe.getMessage());
			ioe.printStackTrace();
		}

		return retValue;

	}
}