/*
 * Copyright (c) 2010 by Intevation GmbH
 *
 * This program is free software under the LGPL (>=v2.1)
 * Read the file LGPL.txt coming with the software for details
 * or visit http://www.gnu.org/licenses/ if it does not exist.
 */

package de.intevation.gnv.utils;

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Point;

import com.vividsolutions.jts.io.ParseException;
import com.vividsolutions.jts.io.WKTReader;

import de.intevation.gnv.geobackend.util.DateUtils;

import de.intevation.gnv.utils.exception.ValidationException;

import java.util.Date;

import org.apache.commons.validator.GenericValidator;

import org.apache.log4j.Logger;

/**
 * @author <a href="mailto:tim.englich@intevation.de">Tim Englich</a>
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 *
 */
public class InputValidator {
    /**
     * the logger, used to log exceptions and additonaly information
     */
    private static Logger log = Logger.getLogger(InputValidator.class);


    public final static String NODATASELECTEDVALUE = "n/n";

    /**
     * Constructor
     */
    public InputValidator() {
        super();
    }

    /**
     * Validates the input of a range of double or date values. The input values
     * need to be valid double or date values. <i>minInput</i> needs to be
     * smaller or equal <i>maxInput</i>.
     *
     * @param minInput The lower bound.
     * @param maxInput The upper bound.
     * @param type One of 'Date' or 'Double'.
     * @return true, if the input is valid, otherwise false.
     */
    public static boolean isInputValid(String minInput, String maxInput, String type) {
        log.debug("InputValidator.isInputValid " + minInput + " " + maxInput + " " +type);
        boolean returnValue = false;
        if ("Date".equalsIgnoreCase(type)) {
            try {
                Date min = DateUtils.getDateFromString(minInput,DateUtils.DATE_PATTERN);
                Date max = DateUtils.getDateFromString(maxInput,DateUtils.DATE_PATTERN);
                int value = max.compareTo(min);
                returnValue = value >= 0;
            } catch (Exception e) {
                log.error(e,e);
            }
        } else if ("Double".equalsIgnoreCase(type)) {
            try {
                double min = Double.parseDouble(minInput);
                double max = Double.parseDouble(maxInput);
                returnValue = max >= min;
            } catch (Exception e) {
                log.error(e,e);
            }
        }
        log.debug("Is valid? " + returnValue);
        return returnValue;
    }

    /**
     * Validates an input.
     *
     * @param input The input value.
     * @param type The input value type.
     * @return true if the input is valid, otherwise false.
     */
    public static boolean isInputValid(String input, String type) {
        if (input.length() == 0 || input.equals("")) {
            return false;
        }

        log.debug("InputValidator.isInputValid " + input + " " + type);

        // Let's check polygons and linestrings first, because they might
        // contain comma. A splitting at comma characters wouldn't be good here.
        if ("Polygon".equalsIgnoreCase(type) || "Linestring".equalsIgnoreCase(type))
        {
            try {
                WKTReader reader = new WKTReader();
                reader.read(input);

                return true;
            }
            catch (ParseException pe) {
                log.warn(pe, pe);
                return false;
            }
        }

        // Check all the other input here
        boolean returnValue = false;
        String[] values = input.split(",");

        for (int i = 0; i < values.length; i++) {
            boolean valid;

            if (NODATASELECTEDVALUE.equals(values[i].trim())){
                valid = true;
            } else if ("Integer".equalsIgnoreCase(type)) {
                valid = GenericValidator.isInt(values[i].trim());
            } else if ("Double".equalsIgnoreCase(type)) {
                valid = GenericValidator.isDouble(values[i].trim());
            } else if ("String".equalsIgnoreCase(type)) {
                valid = GenericValidator.matchRegexp(values[i], "[a-zA-Z0-9]"); // TODO:
                                                                                // FIXME:
                                                                                // VALIDATE
                                                                                // REGEXP
            } else if ("Date".equalsIgnoreCase(type)) {
                valid = GenericValidator.isDate(values[i].trim(),
                        DateUtils.DATE_PATTERN, true);
            } else if ("Point".equalsIgnoreCase(type) || "Geometry".equals(type)) {
                valid = GenericValidator.matchRegexp(values[i], "[0-9]"); // TODO:
                                                                          // FIXME:
                                                                          // VALIDATE
                                                                          // REGEXP
            } else if ("AttributeName".equalsIgnoreCase(type)) {
                valid = org.apache.commons.validator.GenericValidator
                        .matchRegexp(values[i], "[a-zA-Z0-9]"); // TODO: FIXME:
                                                                // VALIDATE
                                                                // REGEXP
            } else if ("Coordinate".equalsIgnoreCase(type)) {
                    try {
                        valid = getPointValue(values[i]) != null;
                    } catch (ValidationException e) {
                        log.debug(e.getMessage());
                        valid = false;
                    }
            } else {
                valid = false;
            }
            if (!valid) {
                returnValue = false;
                break;
            } else {
                returnValue = true;
            }
        }
        log.debug("Is valid? " + returnValue);
        return returnValue;
    }


    /**
     * Returns a point from wkt string.
     *
     * @param value The wkt string.
     * @return a point.
     * @throws ValidationException if <i>value</i> is not valid.
     */
    public static Point getPointValue(String value) throws ValidationException{
        log.debug("InputValidator.getPointValue " + value);

        if (value.toLowerCase().startsWith("point")){
            try {
                return (Point)new WKTReader().read(value);
            } catch (ParseException e) {
                log.error(e,e);
                throw new ValidationException(e);
            }
        }else{
            String[] s, p;

            double x=0,y=0;
            log.info("Position :"+value);
            s = value.split(" ");
            if (s.length != 2) {
                  throw new ValidationException("Kein Blank separiert Breite und Länge");
            }
            p = s[0].split("[nNsS]");
            try {
                if (p.length == 1)
                    y = new Double(p[0]);
                else
                    y = new Double(p[0]) +   new Double(p[1]) / new Double(60.);
                if (s[0].toLowerCase().contains("s"))
                    y = -y;
            }
            catch (Exception e) {
                throw new ValidationException("Kein N|S oder nicht im ersten Substring, zB 56n42");

            }
            p = s[1].split("[eEwW]");
            try {
                if (p.length ==1)
                    x = new Double(p[0]);
                else
                    x = new Double(p[0]) +  new Double(p[1]) / new Double(60.) ;
                if (s[1].toLowerCase().contains("w"))
                    x = -x;
            }
            catch (Exception e) {
                throw new ValidationException("Kein E|W oder nicht im zweiten Substring");
            }
            return new GeometryFactory().createPoint(new Coordinate(x,y));
        }
    }


    /**
     * Makes sure that <i>tmp</i> is between <i>lo</i> and <i>up</i>.
     *
     * @param tmp The value to validate.
     * @param lo The lower range bound.
     * @param up The upper range bound.
     * @return true, if tmp is valid, otherwise false.
     */
    public static boolean isDateValid(Date tmp, Date lo, Date up) {
        // take the time in seconds to compare
        long tmpTime = tmp.getTime() / 1000;
        long tmpLow  = lo.getTime() / 1000;
        long tmpUp   = up.getTime() / 1000;

        if (log.isDebugEnabled()) {
            log.debug("Date validation...");
            log.debug("-> lower bound [sec]: " + tmpLow);
            log.debug("-> upper bound [sec]: " + tmpUp);
            log.debug("-> input data  [sec]: " + tmpTime);
        }

        // XXX There is a buffer of 1 second for the valid range of the time.
        if (tmpTime < (tmpLow-1) || tmpTime > (tmpUp+1)) {
            log.warn(
                "Date [" + tmp.toString() + "] is out of range ["
                + lo.toString() + " to "+ up.toString() + "].");
            return false;
        }

        return true;
    }
}
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