/src/main/java/com/atlassian/jconnect/jira/customfields/LocationParser.java

package com.atlassian.jconnect.jira.customfields;

import com.atlassian.jira.util.I18nHelper;
import com.atlassian.jira.util.MessageSet;
import com.atlassian.jira.util.MessageSetImpl;
import com.google.common.collect.ImmutableMap;

import java.util.Map;

import static java.text.MessageFormat.format;

/**
 * Parses location string values.
 *
 */
public final class LocationParser {

    private static final Map<String,String> DEFAULT_MESSAGES = ImmutableMap.<String,String>builder()
            .put("customfields.locationsearcher.error.nothreefields", "Raw value '{0}' should contain 3 fields separated by comma")
            .put("customfields.location.lat", "Latitude")
            .put("customfields.location.lng", "Longitude")
            .put("customfields.locationsearcher.error.parselnglat", "Unable to parse value {0} of field {1}")
            .put("customfields.locationsearcher.error.latlngnotinrange", "{0} value {1} is not in expected range {2}")
            .put("customfields.locationsearcher.error.parsedistance", "Unable to parse distance value {0}")
            .put("customfields.locationsearcher.error.distancenegative", "Distance value {0} must not be negative")
            .build();

    private LocationParser() {
        throw new AssertionError("Don't instantiate me");
    }

    public static LocationQuery validateAndParseLocationQuery(String rawValue, I18nHelper i18n, MessageSet errors) {
        final String[] split = rawValue.split(",");
        if (split.length != 3) {
            errors.addErrorMessage(i18nizeOrNot(i18n, "customfields.locationsearcher.error.nothreefields", rawValue));
            return null;
        }
        final String latName = i18nizeOrNot(i18n, "customfields.location.lat");
        final double lat = checkLatLng(i18n, errors, split[0].trim(), latName);
        if (!GeoCalculator.LAT_RANGE.containsDouble(lat)) {
             i18nizeOrNot(i18n, "customfields.locationsearcher.error.latlngnotinrange", latName, lat, GeoCalculator.LAT_RANGE);
        }
        final String lngName = i18nizeOrNot(i18n, "customfields.location.lng");
        final double lng = checkLatLng(i18n, errors, split[1].trim(), lngName);
        if (!GeoCalculator.LNG_RANGE.containsDouble(lng)) {
             i18nizeOrNot(i18n, "customfields.locationsearcher.error.latlngnotinrange", lngName, lng, GeoCalculator.LNG_RANGE);
        }
        final long distance  = checkDistance(i18n, errors, split[2].trim());
        if (errors.hasAnyErrors()) {
            return null;
        }
        else return new LocationQuery(lat, lng, distance);
    }

    public static LocationQuery parseLocationQuery(String rawValue) {
        MessageSet errors = new MessageSetImpl();
        LocationQuery result = validateAndParseLocationQuery(rawValue, null, errors);
        if (errors.hasAnyErrors()) {
            throw new IllegalArgumentException("Unable to parse " + rawValue + ":\n" + errors.getErrorMessages());
        }
        return result;
    }

    private static double checkLatLng(I18nHelper i18n, MessageSet errors, String value, String name) {
        try {
            return Double.parseDouble(value);
        } catch(NumberFormatException nfe) {
            errors.addErrorMessage(i18nizeOrNot(i18n, "customfields.locationsearcher.error.parselnglat", value, name));
        }
        return -1;
    }

    private static long checkDistance(I18nHelper i18n, MessageSet errors, String value) {
        try {
            // TODO this has to be smarter if we allow users to define units
            final long distance = Long.parseLong(value);
            if (distance < 0) {
                errors.addErrorMessage(i18nizeOrNot(i18n, "customfields.locationsearcher.error.distancenegative", value));
                return -1;
            }
            return distance;
        } catch(NumberFormatException nfe) {
            errors.addErrorMessage(i18nizeOrNot(i18n, "customfields.locationsearcher.error.parsedistance", value));
        }
        return -1;
    }

    private static String i18nizeOrNot(I18nHelper i18n, String key, Object... params) {
        if (i18n != null) {
            return i18n.getText(key, params);
        } else {
            String rawMsg = DEFAULT_MESSAGES.get(key);
            if (rawMsg == null) {
                return "*** NO MESSAGE FOR <" + key + ">";
            } else {
                return format(rawMsg, params);
            }
        }
    }
}