// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.actions.search;

import static org.openstreetmap.josm.tools.I18n.marktr;
import static org.openstreetmap.josm.tools.I18n.tr;

import java.io.PushbackReader;
import java.io.StringReader;
import java.text.Normalizer;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.actions.search.PushbackTokenizer.Range;
import org.openstreetmap.josm.actions.search.PushbackTokenizer.Token;
import org.openstreetmap.josm.data.Bounds;
import org.openstreetmap.josm.data.osm.Node;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
import org.openstreetmap.josm.data.osm.OsmUtils;
import org.openstreetmap.josm.data.osm.Relation;
import org.openstreetmap.josm.data.osm.RelationMember;
import org.openstreetmap.josm.data.osm.Way;
import org.openstreetmap.josm.tools.Geometry;
import org.openstreetmap.josm.tools.Predicate;
import org.openstreetmap.josm.tools.Utils;
import org.openstreetmap.josm.tools.date.DateUtils;

/**
 Implements a google-like search.
 <br>
 Grammar:
<pre>
expression =
  fact | expression
  fact expression
  fact

fact =
 ( expression )
 -fact
 term?
 term=term
 term:term
 term
 </pre>

 @author Imi
 */
public class SearchCompiler {

    private boolean caseSensitive = false;
    private boolean regexSearch = false;
    private static String  rxErrorMsg = marktr("The regex \"{0}\" had a parse error at offset {1}, full error:\n\n{2}");
    private static String  rxErrorMsgNoPos = marktr("The regex \"{0}\" had a parse error, full error:\n\n{1}");
    private PushbackTokenizer tokenizer;
    private static Map<String, SimpleMatchFactory> simpleMatchFactoryMap = new HashMap<>();
    private static Map<String, UnaryMatchFactory> unaryMatchFactoryMap = new HashMap<>();
    private static Map<String, BinaryMatchFactory> binaryMatchFactoryMap = new HashMap<>();

    public SearchCompiler(boolean caseSensitive, boolean regexSearch, PushbackTokenizer tokenizer) {
        this.caseSensitive = caseSensitive;
        this.regexSearch = regexSearch;
        this.tokenizer = tokenizer;

        /* register core match factories at first instance, so plugins should
         * never be able to generate a NPE
         */
        if (simpleMatchFactoryMap.isEmpty()) {
            addMatchFactory(new CoreSimpleMatchFactory());
        }
        if (unaryMatchFactoryMap.isEmpty()) {
            addMatchFactory(new CoreUnaryMatchFactory());
        }
    }

    /**
     * Add (register) MatchFactory with SearchCompiler
     * @param factory
     */
    public static void addMatchFactory(MatchFactory factory) {
        for (String keyword : factory.getKeywords()) {
            // TODO: check for keyword collisions
            if (factory instanceof SimpleMatchFactory) {
                simpleMatchFactoryMap.put(keyword, (SimpleMatchFactory)factory);
            } else if (factory instanceof UnaryMatchFactory) {
                unaryMatchFactoryMap.put(keyword, (UnaryMatchFactory)factory);
            } else if (factory instanceof BinaryMatchFactory) {
                binaryMatchFactoryMap.put(keyword, (BinaryMatchFactory)factory);
            } else
                throw new AssertionError("Unknown match factory");
        }
    }

    public class CoreSimpleMatchFactory implements SimpleMatchFactory {
        private Collection<String> keywords = Arrays.asList("id", "version",
                "changeset", "nodes", "ways", "tags", "areasize", "waylength", "modified", "selected",
                "incomplete", "untagged", "closed", "new", "indownloadedarea",
                "allindownloadedarea", "inview", "allinview", "timestamp", "nth", "nth%");

        @Override
        public Match get(String keyword, PushbackTokenizer tokenizer) throws ParseError {
            switch(keyword) {
            case "modified":
                return new Modified();
            case "selected":
                return new Selected();
            case "incomplete":
                return new Incomplete();
            case "untagged":
                return new Untagged();
            case "closed":
                return new Closed();
            case "new":
                return new New();
            case "indownloadedarea":
                return new InDataSourceArea(false);
            case "allindownloadedarea":
                return new InDataSourceArea(true);
            case "inview":
                return new InView(false);
            case "allinview":
                return new InView(true);
            default:
                if (tokenizer != null) {
                    switch (keyword) {
                    case "id":
                        return new Id(tokenizer);
                    case "version":
                        return new Version(tokenizer);
                    case "changeset":
                        return new ChangesetId(tokenizer);
                    case "nodes":
                        return new NodeCountRange(tokenizer);
                    case "ways":
                        return new WayCountRange(tokenizer);
                    case "tags":
                        return new TagCountRange(tokenizer);
                    case "areasize":
                        return new AreaSize(tokenizer);
                    case "waylength":
                        return new WayLength(tokenizer);
                    case "nth":
                        return new Nth(tokenizer, false);
                    case "nth%":
                        return new Nth(tokenizer, true);
                    case "timestamp":
                        // add leading/trailing space in order to get expected split (e.g. "a--" => {"a", ""})
                        String rangeS = " " + tokenizer.readTextOrNumber() + " ";
                        String[] rangeA = rangeS.split("/");
                        if (rangeA.length == 1) {
                            return new KeyValue(keyword, rangeS.trim(), regexSearch, caseSensitive);
                        } else if (rangeA.length == 2) {
                            String rangeA1 = rangeA[0].trim();
                            String rangeA2 = rangeA[1].trim();
                            // if min timestap is empty: use lowest possible date
                            long minDate = DateUtils.fromString(rangeA1.isEmpty() ? "1980" : rangeA1).getTime();
                            // if max timestamp is empty: use "now"
                            long maxDate = rangeA2.isEmpty() ? System.currentTimeMillis() : DateUtils.fromString(rangeA2).getTime();
                            return new TimestampRange(minDate, maxDate);
                        } else {
                            // I18n: Don't translate timestamp keyword
                            throw new ParseError(tr("Expecting <i>min</i>/<i>max</i> after ''timestamp''"));
                        }
                    }
                }
            }
            return null;
        }

        @Override
        public Collection<String> getKeywords() {
            return keywords;
        }
    }

    public static class CoreUnaryMatchFactory implements UnaryMatchFactory {
        private static Collection<String> keywords = Arrays.asList("parent", "child");

        @Override
        public UnaryMatch get(String keyword, Match matchOperand, PushbackTokenizer tokenizer) {
            if ("parent".equals(keyword))
                return new Parent(matchOperand);
            else if ("child".equals(keyword))
                return new Child(matchOperand);
            return null;
        }

        @Override
        public Collection<String> getKeywords() {
            return keywords;
        }
    }

    /**
     * Classes implementing this interface can provide Match operators.
     */
    private interface MatchFactory {
        public Collection<String> getKeywords();
    }

    public interface SimpleMatchFactory extends MatchFactory {
        public Match get(String keyword, PushbackTokenizer tokenizer) throws ParseError;
    }

    public interface UnaryMatchFactory extends MatchFactory {
        public UnaryMatch get(String keyword, Match matchOperand, PushbackTokenizer tokenizer) throws ParseError;
    }

    public interface BinaryMatchFactory extends MatchFactory {
        public BinaryMatch get(String keyword, Match lhs, Match rhs, PushbackTokenizer tokenizer) throws ParseError;
    }

    /**
     * Base class for all search operators.
     */
    public abstract static class Match implements Predicate<OsmPrimitive> {

        public abstract boolean match(OsmPrimitive osm);

        /**
         * Tests whether one of the primitives matches.
         */
        protected boolean existsMatch(Collection<? extends OsmPrimitive> primitives) {
            for (OsmPrimitive p : primitives) {
                if (match(p))
                    return true;
            }
            return false;
        }

        /**
         * Tests whether all primitives match.
         */
        protected boolean forallMatch(Collection<? extends OsmPrimitive> primitives) {
            for (OsmPrimitive p : primitives) {
                if (!match(p))
                    return false;
            }
            return true;
        }

        @Override
        public final boolean evaluate(OsmPrimitive object) {
            return match(object);
        }
    }

    /**
     * A unary search operator which may take data parameters.
     */
    public abstract static class UnaryMatch extends Match {

        protected final Match match;

        public UnaryMatch(Match match) {
            if (match == null) {
                // "operator" (null) should mean the same as "operator()"
                // (Always). I.e. match everything
                this.match = new Always();
            } else {
                this.match = match;
            }
        }

        public Match getOperand() {
            return match;
        }
    }

    /**
     * A binary search operator which may take data parameters.
     */
    public abstract static class BinaryMatch extends Match {

        protected final Match lhs;
        protected final Match rhs;

        public BinaryMatch(Match lhs, Match rhs) {
            this.lhs = lhs;
            this.rhs = rhs;
        }

        public Match getLhs() {
            return lhs;
        }

        public Match getRhs() {
            return rhs;
        }
    }

    /**
     * Matches every OsmPrimitive.
     */
    public static class Always extends Match {
        /** The unique instance/ */
        public static final Always INSTANCE = new Always();
        @Override public boolean match(OsmPrimitive osm) {
            return true;
        }
    }

    /**
     * Never matches any OsmPrimitive.
     */
    public static class Never extends Match {
        @Override
        public boolean match(OsmPrimitive osm) {
            return false;
        }
    }

    /**
     * Inverts the match.
     */
    public static class Not extends UnaryMatch {
        public Not(Match match) {super(match);}
        @Override public boolean match(OsmPrimitive osm) {
            return !match.match(osm);
        }
        @Override public String toString() {return "!"+match;}
        public Match getMatch() {
            return match;
        }
    }

    /**
     * Matches if the value of the corresponding key is ''yes'', ''true'', ''1'' or ''on''.
     */
    private static class BooleanMatch extends Match {
        private final String key;
        private final boolean defaultValue;

        public BooleanMatch(String key, boolean defaultValue) {
            this.key = key;
            this.defaultValue = defaultValue;
        }
        @Override
        public boolean match(OsmPrimitive osm) {
            Boolean ret = OsmUtils.getOsmBoolean(osm.get(key));
            if (ret == null)
                return defaultValue;
            else
                return ret;
        }
    }

    /**
     * Matches if both left and right expressions match.
     */
    public static class And extends BinaryMatch {
    public And(Match lhs, Match rhs) {super(lhs, rhs);}
        @Override public boolean match(OsmPrimitive osm) {
            return lhs.match(osm) && rhs.match(osm);
        }
        @Override public String toString() {
            return lhs + " && " + rhs;
        }
    }

    /**
     * Matches if the left OR the right expression match.
     */
    public static class Or extends BinaryMatch {
    public Or(Match lhs, Match rhs) {super(lhs, rhs);}
        @Override public boolean match(OsmPrimitive osm) {
            return lhs.match(osm) || rhs.match(osm);
        }
        @Override public String toString() {
            return lhs + " || " + rhs;
        }
    }

    /**
     * Matches if the left OR the right expression match, but not both.
     */
    public static class Xor extends BinaryMatch {
    public Xor(Match lhs, Match rhs) {super(lhs, rhs);}
        @Override public boolean match(OsmPrimitive osm) {
            return lhs.match(osm) ^ rhs.match(osm);
        }
        @Override public String toString() {
            return lhs + " ^ " + rhs;
        }
    }

    /**
     * Matches objects with ID in the given range.
     */
    private static class Id extends RangeMatch {
        public Id(Range range) {super(range);}
        public Id(PushbackTokenizer tokenizer) throws ParseError {
            this(tokenizer.readRange(tr("Range of primitive ids expected")));
        }
        @Override protected Long getNumber(OsmPrimitive osm) {
            return osm.isNew() ? 0 : osm.getUniqueId();
        }
        @Override protected String getString() {
            return "id";
        }
    }

    /**
     * Matches objects with a changeset ID in the given range.
     */
    private static class ChangesetId extends RangeMatch {
        public ChangesetId(Range range) {super(range);}
        public ChangesetId(PushbackTokenizer tokenizer) throws ParseError {
            this(tokenizer.readRange(tr("Range of changeset ids expected")));
        }
        @Override protected Long getNumber(OsmPrimitive osm) {
            return (long) osm.getChangesetId();
        }
        @Override protected String getString() {
            return "changeset";
        }
    }

    /**
     * Matches objects with a version number in the given range.
     */
    private static class Version extends RangeMatch {
        public Version(Range range) {super(range);}
        public Version(PushbackTokenizer tokenizer) throws ParseError {
            this(tokenizer.readRange(tr("Range of versions expected")));
        }
        @Override protected Long getNumber(OsmPrimitive osm) {
            return (long) osm.getVersion();
        }
        @Override protected String getString() {
            return "version";
        }
    }

    /**
     * Matches objects with the given key-value pair.
     */
    private static class KeyValue extends Match {
        private final String key;
        private final Pattern keyPattern;
        private final String value;
        private final Pattern valuePattern;
        private final boolean caseSensitive;

        public KeyValue(String key, String value, boolean regexSearch, boolean caseSensitive) throws ParseError {
            this.caseSensitive = caseSensitive;
            if (regexSearch) {
                int searchFlags = regexFlags(caseSensitive);

                try {
                    this.keyPattern = Pattern.compile(key, searchFlags);
                } catch (PatternSyntaxException e) {
                    throw new ParseError(tr(rxErrorMsg, e.getPattern(), e.getIndex(), e.getMessage()), e);
                } catch (Exception e) {
                    throw new ParseError(tr(rxErrorMsgNoPos, key, e.getMessage()), e);
                }
                try {
                    this.valuePattern = Pattern.compile(value, searchFlags);
                } catch (PatternSyntaxException e) {
                    throw new ParseError(tr(rxErrorMsg, e.getPattern(), e.getIndex(), e.getMessage()), e);
                } catch (Exception e) {
                    throw new ParseError(tr(rxErrorMsgNoPos, value, e.getMessage()), e);
                }
                this.key = key;
                this.value = value;

            } else if (caseSensitive) {
                this.key = key;
                this.value = value;
                this.keyPattern = null;
                this.valuePattern = null;
            } else {
                this.key = key.toLowerCase();
                this.value = value;
                this.keyPattern = null;
                this.valuePattern = null;
            }
        }

        @Override public boolean match(OsmPrimitive osm) {

            if (keyPattern != null) {
                if (!osm.hasKeys())
                    return false;

                /* The string search will just get a key like
                 * 'highway' and look that up as osm.get(key). But
                 * since we're doing a regex match we'll have to loop
                 * over all the keys to see if they match our regex,
                 * and only then try to match against the value
                 */

                for (String k: osm.keySet()) {
                    String v = osm.get(k);

                    Matcher matcherKey = keyPattern.matcher(k);
                    boolean matchedKey = matcherKey.find();

                    if (matchedKey) {
                        Matcher matcherValue = valuePattern.matcher(v);
                        boolean matchedValue = matcherValue.find();

                        if (matchedValue)
                            return true;
                    }
                }
            } else {
                String mv = null;

                if ("timestamp".equals(key)) {
                    mv = DateUtils.fromDate(osm.getTimestamp());
                } else {
                    mv = osm.get(key);
                }

                if (mv == null)
                    return false;

                String v1 = caseSensitive ? mv : mv.toLowerCase();
                String v2 = caseSensitive ? value : value.toLowerCase();

                v1 = Normalizer.normalize(v1, Normalizer.Form.NFC);
                v2 = Normalizer.normalize(v2, Normalizer.Form.NFC);
                return v1.indexOf(v2) != -1;
            }

            return false;
        }
        @Override public String toString() {return key+"="+value;}
    }

    public static class ValueComparison extends Match {
        private final String key;
        private final String referenceValue;
        private final int compareMode;

        public ValueComparison(String key, String referenceValue, int compareMode) {
            this.key = key;
            this.referenceValue = referenceValue;
            this.compareMode = compareMode;
        }

        @Override
        public boolean match(OsmPrimitive osm) {
            int compareResult;
            String currentValue = osm.get(key);
            if (currentValue == null) return false;
            try {
                compareResult = Double.compare(
                        Double.parseDouble(currentValue),
                        Double.parseDouble(referenceValue)
                );
            } catch (NumberFormatException ignore) {
                compareResult = osm.get(key).compareTo(referenceValue);
            }
            return compareMode < 0 ? compareResult < 0 : compareMode > 0 ? compareResult > 0 : compareResult == 0;
        }
    }

    /**
     * Matches objects with the exact given key-value pair.
     */
    public static class ExactKeyValue extends Match {

        private enum Mode {
            ANY, ANY_KEY, ANY_VALUE, EXACT, NONE, MISSING_KEY,
            ANY_KEY_REGEXP, ANY_VALUE_REGEXP, EXACT_REGEXP, MISSING_KEY_REGEXP;
        }

        private final String key;
        private final String value;
        private final Pattern keyPattern;
        private final Pattern valuePattern;
        private final Mode mode;

        public ExactKeyValue(boolean regexp, String key, String value) throws ParseError {
            if ("".equals(key))
                throw new ParseError(tr("Key cannot be empty when tag operator is used. Sample use: key=value"));
            this.key = key;
            this.value = value == null?"":value;
            if ("".equals(this.value) && "*".equals(key)) {
                mode = Mode.NONE;
            } else if ("".equals(this.value)) {
                if (regexp) {
                    mode = Mode.MISSING_KEY_REGEXP;
                } else {
                    mode = Mode.MISSING_KEY;
                }
            } else if ("*".equals(key) && "*".equals(this.value)) {
                mode = Mode.ANY;
            } else if ("*".equals(key)) {
                if (regexp) {
                    mode = Mode.ANY_KEY_REGEXP;
                } else {
                    mode = Mode.ANY_KEY;
                }
            } else if ("*".equals(this.value)) {
                if (regexp) {
                    mode = Mode.ANY_VALUE_REGEXP;
                } else {
                    mode = Mode.ANY_VALUE;
                }
            } else {
                if (regexp) {
                    mode = Mode.EXACT_REGEXP;
                } else {
                    mode = Mode.EXACT;
                }
            }

            if (regexp && key.length() > 0 && !"*".equals(key)) {
                try {
                    keyPattern = Pattern.compile(key, regexFlags(false));
                } catch (PatternSyntaxException e) {
                    throw new ParseError(tr(rxErrorMsg, e.getPattern(), e.getIndex(), e.getMessage()));
                } catch (Exception e) {
                    throw new ParseError(tr(rxErrorMsgNoPos, key, e.getMessage()));
                }
            } else {
                keyPattern = null;
            }
            if (regexp && this.value.length() > 0 && !"*".equals(this.value)) {
                try {
                    valuePattern = Pattern.compile(this.value, regexFlags(false));
                } catch (PatternSyntaxException e) {
                    throw new ParseError(tr(rxErrorMsg, e.getPattern(), e.getIndex(), e.getMessage()));
                } catch (Exception e) {
                    throw new ParseError(tr(rxErrorMsgNoPos, value, e.getMessage()));
                }
            } else {
                valuePattern = null;
            }
        }

        @Override
        public boolean match(OsmPrimitive osm) {

            if (!osm.hasKeys())
                return mode == Mode.NONE;

            switch (mode) {
            case NONE:
                return false;
            case MISSING_KEY:
                return osm.get(key) == null;
            case ANY:
                return true;
            case ANY_VALUE:
                return osm.get(key) != null;
            case ANY_KEY:
                for (String v:osm.getKeys().values()) {
                    if (v.equals(value))
                        return true;
                }
                return false;
            case EXACT:
                return value.equals(osm.get(key));
            case ANY_KEY_REGEXP:
                for (String v:osm.getKeys().values()) {
                    if (valuePattern.matcher(v).matches())
                        return true;
                }
                return false;
            case ANY_VALUE_REGEXP:
            case EXACT_REGEXP:
                for (String key: osm.keySet()) {
                    if (keyPattern.matcher(key).matches()) {
                        if (mode == Mode.ANY_VALUE_REGEXP
                                || valuePattern.matcher(osm.get(key)).matches())
                            return true;
                    }
                }
                return false;
            case MISSING_KEY_REGEXP:
                for (String k:osm.keySet()) {
                    if (keyPattern.matcher(k).matches())
                        return false;
                }
                return true;
            }
            throw new AssertionError("Missed state");
        }

        @Override
        public String toString() {
            return key + '=' + value;
        }

    }

    /**
     * Match a string in any tags (key or value), with optional regex and case insensitivity.
     */
    private static class Any extends Match {
        private final String search;
        private final Pattern searchRegex;
        private final boolean caseSensitive;

        public Any(String s, boolean regexSearch, boolean caseSensitive) throws ParseError {
            s = Normalizer.normalize(s, Normalizer.Form.NFC);
            this.caseSensitive = caseSensitive;
            if (regexSearch) {
                try {
                    this.searchRegex = Pattern.compile(s, regexFlags(caseSensitive));
                } catch (PatternSyntaxException e) {
                    throw new ParseError(tr(rxErrorMsg, e.getPattern(), e.getIndex(), e.getMessage()), e);
                } catch (Exception e) {
                    throw new ParseError(tr(rxErrorMsgNoPos, s, e.getMessage()), e);
                }
                this.search = s;
            } else if (caseSensitive) {
                this.search = s;
                this.searchRegex = null;
            } else {
                this.search = s.toLowerCase();
                this.searchRegex = null;
            }
        }

        @Override public boolean match(OsmPrimitive osm) {
            if (!osm.hasKeys() && osm.getUser() == null)
                return search.isEmpty();

            for (String key: osm.keySet()) {
                String value = osm.get(key);
                if (searchRegex != null) {

                    value = Normalizer.normalize(value, Normalizer.Form.NFC);

                    Matcher keyMatcher = searchRegex.matcher(key);
                    Matcher valMatcher = searchRegex.matcher(value);

                    boolean keyMatchFound = keyMatcher.find();
                    boolean valMatchFound = valMatcher.find();

                    if (keyMatchFound || valMatchFound)
                        return true;
                } else {
                    if (!caseSensitive) {
                        key = key.toLowerCase();
                        value = value.toLowerCase();
                    }

                    value = Normalizer.normalize(value, Normalizer.Form.NFC);

                    if (key.indexOf(search) != -1 || value.indexOf(search) != -1)
                        return true;
                }
            }
            return false;
        }
        @Override public String toString() {
            return search;
        }
    }

    private static class ExactType extends Match {
        private final OsmPrimitiveType type;
        public ExactType(String type) throws ParseError {
            this.type = OsmPrimitiveType.from(type);
            if (this.type == null)
                throw new ParseError(tr("Unknown primitive type: {0}. Allowed values are node, way or relation",
                        type));
        }
        @Override public boolean match(OsmPrimitive osm) {
            return type.equals(osm.getType());
        }
        @Override public String toString() {return "type="+type;}
    }

    /**
     * Matches objects last changed by the given username.
     */
    private static class UserMatch extends Match {
        private String user;
        public UserMatch(String user) {
            if ("anonymous".equals(user)) {
                this.user = null;
            } else {
                this.user = user;
            }
        }

        @Override public boolean match(OsmPrimitive osm) {
            if (osm.getUser() == null)
                return user == null;
            else
                return osm.getUser().hasName(user);
        }

        @Override public String toString() {
            return "user=" + (user == null ? "" : user);
        }
    }

    /**
     * Matches objects with the given relation role (i.e. "outer").
     */
    private static class RoleMatch extends Match {
        private String role;
        public RoleMatch(String role) {
            if (role == null) {
                this.role = "";
            } else {
                this.role = role;
            }
        }

        @Override public boolean match(OsmPrimitive osm) {
            for (OsmPrimitive ref: osm.getReferrers()) {
                if (ref instanceof Relation && !ref.isIncomplete() && !ref.isDeleted()) {
                    for (RelationMember m : ((Relation) ref).getMembers()) {
                        if (m.getMember() == osm) {
                            String testRole = m.getRole();
                            if(role.equals(testRole == null ? "" : testRole))
                                return true;
                        }
                    }
                }
            }
            return false;
        }

        @Override public String toString() {
            return "role=" + role;
        }
    }

    /**
     * Matches the n-th object of a relation and/or the n-th node of a way.
     */
    private static class Nth extends Match {

        private final int nth;
        private final boolean modulo;

        public Nth(PushbackTokenizer tokenizer, boolean modulo) throws ParseError {
            this((int) tokenizer.readNumber(tr("Positive integer expected")), modulo);
        }

        private Nth(int nth, boolean modulo) throws ParseError {
            if (nth <= 0) {
                throw new ParseError(tr("Positive integer expected"));
            }
            this.nth = nth;
            this.modulo = modulo;
        }

        @Override
        public boolean match(OsmPrimitive osm) {
            for (OsmPrimitive p : osm.getReferrers()) {
                Integer idx = null;
                if (p instanceof Way) {
                    Way w = (Way) p;
                    idx = w.getNodes().indexOf(osm);
                } else if (p instanceof Relation) {
                    Relation r = (Relation) p;
                    idx = r.getMemberPrimitivesList().indexOf(osm);
                }
                if (idx != null) {
                    if (idx.intValue() == nth || (modulo && idx.intValue() % nth == 0)) {
                        return true;
                    }
                }
            }
            return false;
        }
    }

    /**
     * Matches objects with properties in a certain range.
     */
    private abstract static class RangeMatch extends Match {

        private final long min;
        private final long max;

        public RangeMatch(long min, long max) {
            this.min = Math.min(min, max);
            this.max = Math.max(min, max);
        }

        public RangeMatch(Range range) {
            this(range.getStart(), range.getEnd());
        }

        protected abstract Long getNumber(OsmPrimitive osm);

        protected abstract String getString();

        @Override
        public boolean match(OsmPrimitive osm) {
            Long num = getNumber(osm);
            if (num == null)
                return false;
            else
                return (num >= min) && (num <= max);
        }

        @Override
        public String toString() {
            return getString() + "=" + min + "-" + max;
        }
    }


    /**
     * Matches ways with a number of nodes in given range
     */
    private static class NodeCountRange extends RangeMatch {
        public NodeCountRange(Range range) {
            super(range);
        }

        public NodeCountRange(PushbackTokenizer tokenizer) throws ParseError {
            this(tokenizer.readRange(tr("Range of numbers expected")));
        }

        @Override
        protected Long getNumber(OsmPrimitive osm) {
            if (osm instanceof Way) {
                return (long) ((Way) osm).getRealNodesCount();
            } else if (osm instanceof Relation) {
                return (long) ((Relation) osm).getMemberPrimitives(Node.class).size();
            } else {
                return null;
            }
        }

        @Override
        protected String getString() {
            return "nodes";
        }
    }

    /**
     * Matches objects with the number of referring/contained ways in the given range
     */
    private static class WayCountRange extends RangeMatch {
        public WayCountRange(Range range) {
            super(range);
        }

        public WayCountRange(PushbackTokenizer tokenizer) throws ParseError {
            this(tokenizer.readRange(tr("Range of numbers expected")));
        }

        @Override
        protected Long getNumber(OsmPrimitive osm) {
            if (osm instanceof Node) {
                return (long) Utils.filteredCollection(osm.getReferrers(), Way.class).size();
            } else if (osm instanceof Relation) {
                return (long) ((Relation) osm).getMemberPrimitives(Way.class).size();
            } else {
                return null;
            }
        }

        @Override
        protected String getString() {
            return "ways";
        }
    }

    /**
     * Matches objects with a number of tags in given range
     */
    private static class TagCountRange extends RangeMatch {
        public TagCountRange(Range range) {
            super(range);
        }

        public TagCountRange(PushbackTokenizer tokenizer) throws ParseError {
            this(tokenizer.readRange(tr("Range of numbers expected")));
        }

        @Override
        protected Long getNumber(OsmPrimitive osm) {
            return (long) osm.getKeys().size();
        }

        @Override
        protected String getString() {
            return "tags";
        }
    }

    /**
     * Matches objects with a timestamp in given range
     */
    private static class TimestampRange extends RangeMatch {

        public TimestampRange(long minCount, long maxCount) {
            super(minCount, maxCount);
        }

        @Override
        protected Long getNumber(OsmPrimitive osm) {
            return osm.getTimestamp().getTime();
        }

        @Override
        protected String getString() {
            return "timestamp";
        }

    }

    /**
     * Matches objects that are new (i.e. have not been uploaded to the server)
     */
    private static class New extends Match {
        @Override public boolean match(OsmPrimitive osm) {
            return osm.isNew();
        }
        @Override public String toString() {
            return "new";
        }
    }

    /**
     * Matches all objects that have been modified, created, or undeleted
     */
    private static class Modified extends Match {
        @Override public boolean match(OsmPrimitive osm) {
            return osm.isModified() || osm.isNewOrUndeleted();
        }
        @Override public String toString() {return "modified";}
    }

    /**
     * Matches all objects currently selected
     */
    private static class Selected extends Match {
        @Override public boolean match(OsmPrimitive osm) {
            return Main.main.getCurrentDataSet().isSelected(osm);
        }
        @Override public String toString() {return "selected";}
    }

    /**
     * Match objects that are incomplete, where only id and type are known.
     * Typically some members of a relation are incomplete until they are
     * fetched from the server.
     */
    private static class Incomplete extends Match {
        @Override public boolean match(OsmPrimitive osm) {
            return osm.isIncomplete();
        }
        @Override public String toString() {return "incomplete";}
    }

    /**
     * Matches objects that don't have any interesting tags (i.e. only has source,
     * FIXME, etc.). The complete list of uninteresting tags can be found here:
     * org.openstreetmap.josm.data.osm.OsmPrimitive.getUninterestingKeys()
     */
    private static class Untagged extends Match {
        @Override public boolean match(OsmPrimitive osm) {
            return !osm.isTagged() && !osm.isIncomplete();
        }
        @Override public String toString() {return "untagged";}
    }

    /**
     * Matches ways which are closed (i.e. first and last node are the same)
     */
    private static class Closed extends Match {
        @Override public boolean match(OsmPrimitive osm) {
            return osm instanceof Way && ((Way) osm).isClosed();
        }
        @Override public String toString() {return "closed";}
    }

    /**
     * Matches objects if they are parents of the expression
     */
    public static class Parent extends UnaryMatch {
        public Parent(Match m) {
            super(m);
        }
        @Override public boolean match(OsmPrimitive osm) {
            boolean isParent = false;

            if (osm instanceof Way) {
                for (Node n : ((Way)osm).getNodes()) {
                    isParent |= match.match(n);
                }
            } else if (osm instanceof Relation) {
                for (RelationMember member : ((Relation)osm).getMembers()) {
                    isParent |= match.match(member.getMember());
                }
            }
            return isParent;
        }
        @Override public String toString() {return "parent(" + match + ")";}
    }

    /**
     * Matches objects if they are children of the expression
     */
    public static class Child extends UnaryMatch {

        public Child(Match m) {
            super(m);
        }

        @Override public boolean match(OsmPrimitive osm) {
            boolean isChild = false;
            for (OsmPrimitive p : osm.getReferrers()) {
                isChild |= match.match(p);
            }
            return isChild;
        }
        @Override public String toString() {return "child(" + match + ")";}
    }

    /**
     * Matches if the size of the area is within the given range
     *
     * @author Ole Jørgen Brønner
     */
    private static class AreaSize extends RangeMatch {

        public AreaSize(Range range) {
            super(range);
        }

        public AreaSize(PushbackTokenizer tokenizer) throws ParseError {
            this(tokenizer.readRange(tr("Range of numbers expected")));
        }

        @Override
        protected Long getNumber(OsmPrimitive osm) {
            if (!(osm instanceof Way && ((Way) osm).isClosed()))
                return null;
            Way way = (Way) osm;
            return (long) Geometry.closedWayArea(way);
        }

        @Override
        protected String getString() {
            return "areasize";
        }
    }

    /**
     * Matches if the length of a way is within the given range
     */
    private static class WayLength extends RangeMatch {

        public WayLength(Range range) {
            super(range);
        }

        public WayLength(PushbackTokenizer tokenizer) throws ParseError {
            this(tokenizer.readRange(tr("Range of numbers expected")));
        }

        @Override
        protected Long getNumber(OsmPrimitive osm) {
            if (!(osm instanceof Way))
                return null;
            Way way = (Way) osm;
            return (long) way.getLength();
        }

        @Override
        protected String getString() {
            return "waylength";
        }
    }

    /**
     * Matches objects within the given bounds.
     */
    private abstract static class InArea extends Match {

        protected abstract Bounds getBounds();
        protected final boolean all;

        /**
         * @param all if true, all way nodes or relation members have to be within source area;if false, one suffices.
         */
        public InArea(boolean all) {
            this.all = all;
        }

        @Override
        public boolean match(OsmPrimitive osm) {
            if (!osm.isUsable())
                return false;
            else if (osm instanceof Node) {
                Bounds bounds = getBounds();
                return bounds != null && bounds.contains(((Node) osm).getCoor());
            } else if (osm instanceof Way) {
                Collection<Node> nodes = ((Way) osm).getNodes();
                return all ? forallMatch(nodes) : existsMatch(nodes);
            } else if (osm instanceof Relation) {
                Collection<OsmPrimitive> primitives = ((Relation) osm).getMemberPrimitives();
                return all ? forallMatch(primitives) : existsMatch(primitives);
            } else
                return false;
        }
    }

    /**
     * Matches objects within source area ("downloaded area").
     */
    private static class InDataSourceArea extends InArea {

        public InDataSourceArea(boolean all) {
            super(all);
        }

        @Override
        protected Bounds getBounds() {
            return new Bounds(Main.main.getCurrentDataSet().getDataSourceArea().getBounds2D());
        }
    }

    /**
     * Matches objects within current map view.
     */
    private static class InView extends InArea {

        public InView(boolean all) {
            super(all);
        }

        @Override
        protected Bounds getBounds() {
            if (!Main.isDisplayingMapView()) {
                return null;
            }
            return Main.map.mapView.getRealBounds();
        }
    }

    public static class ParseError extends Exception {
        public ParseError(String msg) {
            super(msg);
        }
        public ParseError(String msg, Throwable cause) {
            super(msg, cause);
        }
        public ParseError(Token expected, Token found) {
            this(tr("Unexpected token. Expected {0}, found {1}", expected, found));
        }
    }

    public static Match compile(String searchStr, boolean caseSensitive, boolean regexSearch) throws ParseError {
        return new SearchCompiler(caseSensitive, regexSearch,
                new PushbackTokenizer(
                        new PushbackReader(new StringReader(searchStr))))
        .parse();
    }

    /**
     * Parse search string.
     *
     * @return match determined by search string
     * @throws org.openstreetmap.josm.actions.search.SearchCompiler.ParseError
     */
    public Match parse() throws ParseError {
        Match m = parseExpression();
        if (!tokenizer.readIfEqual(Token.EOF))
            throw new ParseError(tr("Unexpected token: {0}", tokenizer.nextToken()));
        if (m == null)
            return new Always();
        return m;
    }

    /**
     * Parse expression. This is a recursive method.
     *
     * @return match determined by parsing expression
     * @throws org.openstreetmap.josm.actions.search.SearchCompiler.ParseError
     */
    private Match parseExpression() throws ParseError {
        Match factor = parseFactor();
        if (factor == null)
            // empty search string
            return null;
        if (tokenizer.readIfEqual(Token.OR))
            return new Or(factor, parseExpression(tr("Missing parameter for OR")));
        else if (tokenizer.readIfEqual(Token.XOR))
            return new Xor(factor, parseExpression(tr("Missing parameter for XOR")));
        else {
            Match expression = parseExpression();
            if (expression == null)
                // reached end of search string, no more recursive calls
                return factor;
            else
                // the default operator is AND
                return new And(factor, expression);
        }
    }

    /**
     * Parse expression, showing the specified error message if parsing fails.
     *
     * @param errorMessage to display if parsing error occurs
     * @return match determined by parsing expression
     * @throws org.openstreetmap.josm.actions.search.SearchCompiler.ParseError
     * @see #parseExpression()
     */
    private Match parseExpression(String errorMessage) throws ParseError {
        Match expression = parseExpression();
        if (expression == null)
            throw new ParseError(errorMessage);
        else
            return expression;
    }

    /**
     * Parse next factor (a search operator or search term).
     *
     * @return match determined by parsing factor string
     * @throws org.openstreetmap.josm.actions.search.SearchCompiler.ParseError
     */
    private Match parseFactor() throws ParseError {
        if (tokenizer.readIfEqual(Token.LEFT_PARENT)) {
            Match expression = parseExpression();
            if (!tokenizer.readIfEqual(Token.RIGHT_PARENT))
                throw new ParseError(Token.RIGHT_PARENT, tokenizer.nextToken());
            return expression;
        } else if (tokenizer.readIfEqual(Token.NOT)) {
            return new Not(parseFactor(tr("Missing operator for NOT")));
        } else if (tokenizer.readIfEqual(Token.KEY)) {
            // factor consists of key:value or key=value
            String key = tokenizer.getText();
            if (tokenizer.readIfEqual(Token.EQUALS)) {
                return new ExactKeyValue(regexSearch, key, tokenizer.readTextOrNumber());
            } else if (tokenizer.readIfEqual(Token.LESS_THAN)) {
                return new ValueComparison(key, tokenizer.readTextOrNumber(), -1);
            } else if (tokenizer.readIfEqual(Token.GREATER_THAN)) {
                return new ValueComparison(key, tokenizer.readTextOrNumber(), +1);
            } else if (tokenizer.readIfEqual(Token.COLON)) {
                // see if we have a Match that takes a data parameter
                SimpleMatchFactory factory = simpleMatchFactoryMap.get(key);
                if (factory != null)
                    return factory.get(key, tokenizer);

                UnaryMatchFactory unaryFactory = unaryMatchFactoryMap.get(key);
                if (unaryFactory != null)
                    return unaryFactory.get(key, parseFactor(), tokenizer);

                // key:value form where value is a string (may be OSM key search)
                return parseKV(key, tokenizer.readTextOrNumber());
            } else if (tokenizer.readIfEqual(Token.QUESTION_MARK))
                return new BooleanMatch(key, false);
            else {
                SimpleMatchFactory factory = simpleMatchFactoryMap.get(key);
                if (factory != null)
                    return factory.get(key, null);

                UnaryMatchFactory unaryFactory = unaryMatchFactoryMap.get(key);
                if (unaryFactory != null)
                    return unaryFactory.get(key, parseFactor(), null);

                // match string in any key or value
                return new Any(key, regexSearch, caseSensitive);
            }
        } else
            return null;
    }

    private Match parseFactor(String errorMessage) throws ParseError {
        Match fact = parseFactor();
        if (fact == null)
            throw new ParseError(errorMessage);
        else
            return fact;
    }

    private Match parseKV(String key, String value) throws ParseError {
        if (value == null) {
            value = "";
        }
        switch(key) {
        case "type":
            return new ExactType(value);
        case "user":
            return new UserMatch(value);
        case "role":
            return new RoleMatch(value);
        default:
            return new KeyValue(key, value, regexSearch, caseSensitive);
        }
    }

    private static int regexFlags(boolean caseSensitive) {
        int searchFlags = 0;

        // Enables canonical Unicode equivalence so that e.g. the two
        // forms of "\u00e9gal" and "e\u0301gal" will match.
        //
        // It makes sense to match no matter how the character
        // happened to be constructed.
        searchFlags |= Pattern.CANON_EQ;

        // Make "." match any character including newline (/s in Perl)
        searchFlags |= Pattern.DOTALL;

        // CASE_INSENSITIVE by itself only matches US-ASCII case
        // insensitively, but the OSM data is in Unicode. With
        // UNICODE_CASE casefolding is made Unicode-aware.
        if (!caseSensitive) {
            searchFlags |= (Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE);
        }

        return searchFlags;
    }
}