/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.index.mapper;

import org.apache.lucene.search.BoostQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.util.BytesRef;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.Version;
import org.elasticsearch.common.Explicit;
import org.elasticsearch.common.collect.Tuple;
import org.elasticsearch.common.geo.ShapeRelation;
import org.elasticsearch.common.joda.Joda;
import org.elasticsearch.common.network.InetAddresses;
import org.elasticsearch.common.settings.Setting;
import org.elasticsearch.common.time.DateFormatter;
import org.elasticsearch.common.time.DateMathParser;
import org.elasticsearch.common.util.LocaleUtils;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.fielddata.IndexFieldData;
import org.elasticsearch.index.fielddata.plain.BinaryIndexFieldData;
import org.elasticsearch.index.query.SearchExecutionContext;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.support.CoreValuesSourceType;
import org.elasticsearch.search.lookup.SearchLookup;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.function.Supplier;

import static org.elasticsearch.index.query.RangeQueryBuilder.GTE_FIELD;
import static org.elasticsearch.index.query.RangeQueryBuilder.GT_FIELD;
import static org.elasticsearch.index.query.RangeQueryBuilder.LTE_FIELD;
import static org.elasticsearch.index.query.RangeQueryBuilder.LT_FIELD;

/** A {@link FieldMapper} for indexing numeric and date ranges, and creating queries */
public class RangeFieldMapper extends FieldMapper {
    public static final boolean DEFAULT_INCLUDE_UPPER = true;
    public static final boolean DEFAULT_INCLUDE_LOWER = true;

    public static class Defaults {
        public static final Explicit<Boolean> COERCE = new Explicit<>(true, false);
        public static final DateFormatter DATE_FORMATTER = DateFieldMapper.DEFAULT_DATE_TIME_FORMATTER;
    }

    // this is private since it has a different default
    static final Setting<Boolean> COERCE_SETTING =
        Setting.boolSetting("index.mapping.coerce", true, Setting.Property.IndexScope);

    private static RangeFieldMapper toType(FieldMapper in) {
        return (RangeFieldMapper) in;
    }

    public static class Builder extends FieldMapper.Builder {

        private final Parameter<Boolean> index = Parameter.indexParam(m -> toType(m).index, true);
        private final Parameter<Boolean> hasDocValues = Parameter.docValuesParam(m -> toType(m).hasDocValues, true);
        private final Parameter<Boolean> store = Parameter.storeParam(m -> toType(m).store, false);
        private final Parameter<Explicit<Boolean>> coerce;
        private final Parameter<String> format
            = Parameter.stringParam("format", false, m -> toType(m).format, Defaults.DATE_FORMATTER.pattern());
        private final Parameter<Locale> locale = new Parameter<>("locale", false, () -> Locale.ROOT,
            (n, c, o) -> LocaleUtils.parse(o.toString()), m -> toType(m).locale);
        private final Parameter<Float> boost = Parameter.boostParam();
        private final Parameter<Map<String, String>> meta = Parameter.metaParam();

        private final RangeType type;
        private final Version indexCreatedVersion;

        public Builder(String name, RangeType type, boolean coerceByDefault, Version indexCreatedVersion) {
            super(name);
            this.type = type;
            this.coerce = Parameter.explicitBoolParam("coerce", true, m -> toType(m).coerce, coerceByDefault);
            if (this.type != RangeType.DATE) {
                format.neverSerialize();
                locale.neverSerialize();
            }
            this.indexCreatedVersion = indexCreatedVersion;
        }

        public void docValues(boolean hasDocValues) {
            this.hasDocValues.setValue(hasDocValues);
        }

        Builder format(String format) {
            this.format.setValue(format);
            return this;
        }

        @Override
        protected List<Parameter<?>> getParameters() {
            return Arrays.asList(index, hasDocValues, store, coerce, format, locale, boost, meta);
        }

        protected RangeFieldType setupFieldType(ContentPath contentPath) {
            if (format.isConfigured()) {
                if (type != RangeType.DATE) {
                    throw new IllegalArgumentException("field [" + name() + "] of type [range]"
                        + " should not define a dateTimeFormatter unless it is a " + RangeType.DATE + " type");
                }
                DateFormatter dateTimeFormatter;
                if (Joda.isJodaPattern(indexCreatedVersion, format.getValue())) {
                    dateTimeFormatter = Joda.forPattern(format.getValue()).withLocale(locale.getValue());
                } else {
                    dateTimeFormatter = DateFormatter.forPattern(format.getValue()).withLocale(locale.getValue());
                }
                return new RangeFieldType(buildFullName(contentPath), index.getValue(), store.getValue(), hasDocValues.getValue(),
                    dateTimeFormatter, coerce.getValue().value(), meta.getValue());
            }
            if (type == RangeType.DATE) {
                return new RangeFieldType(buildFullName(contentPath), index.getValue(), store.getValue(), hasDocValues.getValue(),
                    Defaults.DATE_FORMATTER, coerce.getValue().value(), meta.getValue());
            }
            return new RangeFieldType(buildFullName(contentPath), type, index.getValue(), store.getValue(), hasDocValues.getValue(),
                coerce.getValue().value(), meta.getValue());
        }

        @Override
        public RangeFieldMapper build(ContentPath contentPath) {
            RangeFieldType ft = setupFieldType(contentPath);
            ft.setBoost(boost.getValue());
            return new RangeFieldMapper(name, ft, multiFieldsBuilder.build(this, contentPath), copyTo.build(), type, this);
        }
    }

    public static final class RangeFieldType extends MappedFieldType {
        protected final RangeType rangeType;
        protected final DateFormatter dateTimeFormatter;
        protected final DateMathParser dateMathParser;
        protected final boolean coerce;

        public RangeFieldType(String name, RangeType type, boolean indexed, boolean stored,
                              boolean hasDocValues, boolean coerce, Map<String, String> meta) {
            super(name, indexed, stored, hasDocValues, TextSearchInfo.SIMPLE_MATCH_WITHOUT_TERMS, meta);
            assert type != RangeType.DATE;
            this.rangeType = Objects.requireNonNull(type);
            dateTimeFormatter = null;
            dateMathParser = null;
            this.coerce = coerce;
        }

        public RangeFieldType(String name, RangeType type) {
            this(name, type, true, false, true, false, Collections.emptyMap());
        }

        public RangeFieldType(String name, boolean indexed, boolean stored,  boolean hasDocValues, DateFormatter formatter,
                              boolean coerce, Map<String, String> meta) {
            super(name, indexed, stored, hasDocValues, TextSearchInfo.SIMPLE_MATCH_WITHOUT_TERMS, meta);
            this.rangeType = RangeType.DATE;
            this.dateTimeFormatter = Objects.requireNonNull(formatter);
            this.dateMathParser = dateTimeFormatter.toDateMathParser();
            this.coerce = coerce;
        }

        public RangeFieldType(String name, DateFormatter formatter) {
            this(name, true, false, true, formatter, false, Collections.emptyMap());
        }

        public RangeType rangeType() { return rangeType; }

        @Override
        public IndexFieldData.Builder fielddataBuilder(String fullyQualifiedIndexName, Supplier<SearchLookup> searchLookup) {
            failIfNoDocValues();
            return new BinaryIndexFieldData.Builder(name(), CoreValuesSourceType.RANGE);
        }

        @Override
        public ValueFetcher valueFetcher(SearchExecutionContext context, String format) {
            DateFormatter defaultFormatter = dateTimeFormatter();
            DateFormatter formatter = format != null
                ? DateFormatter.forPattern(format).withLocale(defaultFormatter.locale())
                : defaultFormatter;

            return new SourceValueFetcher(name(), context) {

                @Override
                @SuppressWarnings("unchecked")
                protected Object parseSourceValue(Object value) {
                    RangeType rangeType = rangeType();
                    if ((value instanceof Map) == false) {
                        assert rangeType == RangeType.IP;
                        Tuple<InetAddress, Integer> ipRange = InetAddresses.parseCidr(value.toString());
                        return InetAddresses.toCidrString(ipRange.v1(), ipRange.v2());
                    }

                    Map<String, Object> range = (Map<String, Object>) value;
                    Map<String, Object> parsedRange = new HashMap<>();
                    for (Map.Entry<String, Object> entry : range.entrySet()) {
                        Object parsedValue = rangeType.parseValue(entry.getValue(), coerce, dateMathParser);
                        Object formattedValue = rangeType.formatValue(parsedValue, formatter);
                        parsedRange.put(entry.getKey(), formattedValue);
                    }
                    return parsedRange;
                }
            };
        }

        @Override
        public String typeName() {
            return rangeType.name;
        }

        public DateFormatter dateTimeFormatter() {
            return dateTimeFormatter;
        }

        protected DateMathParser dateMathParser() {
            return dateMathParser;
        }

        @Override
        public DocValueFormat docValueFormat(String format, ZoneId timeZone) {
            if (rangeType == RangeType.DATE) {
                DateFormatter dateTimeFormatter = this.dateTimeFormatter;
                if (format != null) {
                    dateTimeFormatter = DateFormatter.forPattern(format).withLocale(dateTimeFormatter.locale());
                }
                if (timeZone == null) {
                    timeZone = ZoneOffset.UTC;
                }
                // the resolution here is always set to milliseconds, as aggregations use this formatter mainly and those are always in
                // milliseconds. The only special case here is docvalue fields, which are handled somewhere else
                return new DocValueFormat.DateTime(dateTimeFormatter, timeZone, DateFieldMapper.Resolution.MILLISECONDS);
            }
            return super.docValueFormat(format, timeZone);
        }

        @Override
        public Query termQuery(Object value, SearchExecutionContext context) {
            Query query = rangeQuery(value, value, true, true, ShapeRelation.INTERSECTS, null, null, context);
            if (boost() != 1f) {
                query = new BoostQuery(query, boost());
            }
            return query;
        }

        @Override
        public Query rangeQuery(Object lowerTerm, Object upperTerm, boolean includeLower, boolean includeUpper,
                                ShapeRelation relation, ZoneId timeZone, DateMathParser parser, SearchExecutionContext context) {
            failIfNotIndexed();
            if (parser == null) {
                parser = dateMathParser();
            }
            return rangeType.rangeQuery(name(), hasDocValues(), lowerTerm, upperTerm, includeLower, includeUpper, relation,
                timeZone, parser, context);
        }
    }

    private final RangeType type;
    private final boolean index;
    private final boolean hasDocValues;
    private final boolean store;
    private final Explicit<Boolean> coerce;
    private final String format;
    private final Locale locale;

    private final boolean coerceByDefault;
    private final Version indexCreatedVersion;

    private RangeFieldMapper(
        String simpleName,
        MappedFieldType mappedFieldType,
        MultiFields multiFields,
        CopyTo copyTo,
        RangeType type,
        Builder builder) {
        super(simpleName, mappedFieldType, multiFields, copyTo);
        this.type = type;
        this.index = builder.index.getValue();
        this.hasDocValues = builder.hasDocValues.getValue();
        this.store = builder.store.getValue();
        this.coerce = builder.coerce.getValue();
        this.format = builder.format.getValue();
        this.locale = builder.locale.getValue();
        this.coerceByDefault = builder.coerce.getDefaultValue().value();
        this.indexCreatedVersion = builder.indexCreatedVersion;
    }

    boolean coerce() {
        return coerce.value();
    }

    @Override
    public FieldMapper.Builder getMergeBuilder() {
        return new Builder(simpleName(), type, coerceByDefault, indexCreatedVersion).init(this);
    }

    @Override
    public RangeFieldType fieldType() {
        return (RangeFieldType) super.fieldType();
    }

    @Override
    protected String contentType() {
        return fieldType().typeName();
    }

    @Override
    protected void parseCreateField(ParseContext context) throws IOException {
        Range range;
        if (context.externalValueSet()) {
            range = context.parseExternalValue(Range.class);
        } else {
            XContentParser parser = context.parser();
            final XContentParser.Token start = parser.currentToken();
            if (start == XContentParser.Token.VALUE_NULL) {
                return;
            } else if (start == XContentParser.Token.START_OBJECT) {
                RangeFieldType fieldType = fieldType();
                RangeType rangeType = fieldType.rangeType;
                String fieldName = null;
                Object from = rangeType.minValue();
                Object to = rangeType.maxValue();
                boolean includeFrom = DEFAULT_INCLUDE_LOWER;
                boolean includeTo = DEFAULT_INCLUDE_UPPER;
                XContentParser.Token token;
                while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                    if (token == XContentParser.Token.FIELD_NAME) {
                        fieldName = parser.currentName();
                    } else {
                        if (fieldName.equals(GT_FIELD.getPreferredName())) {
                            includeFrom = false;
                            if (parser.currentToken() != XContentParser.Token.VALUE_NULL) {
                                from = rangeType.parseFrom(fieldType, parser, coerce.value(), includeFrom);
                            }
                        } else if (fieldName.equals(GTE_FIELD.getPreferredName())) {
                            includeFrom = true;
                            if (parser.currentToken() != XContentParser.Token.VALUE_NULL) {
                                from = rangeType.parseFrom(fieldType, parser, coerce.value(), includeFrom);
                            }
                        } else if (fieldName.equals(LT_FIELD.getPreferredName())) {
                            includeTo = false;
                            if (parser.currentToken() != XContentParser.Token.VALUE_NULL) {
                                to = rangeType.parseTo(fieldType, parser, coerce.value(), includeTo);
                            }
                        } else if (fieldName.equals(LTE_FIELD.getPreferredName())) {
                            includeTo = true;
                            if (parser.currentToken() != XContentParser.Token.VALUE_NULL) {
                                to = rangeType.parseTo(fieldType, parser, coerce.value(), includeTo);
                            }
                        } else {
                            throw new MapperParsingException("error parsing field [" +
                                name() + "], with unknown parameter [" + fieldName + "]");
                        }
                    }
                }
                range = new Range(rangeType, from, to, includeFrom, includeTo);
            } else if (fieldType().rangeType == RangeType.IP && start == XContentParser.Token.VALUE_STRING) {
                range = parseIpRangeFromCidr(parser);
            } else {
                throw new MapperParsingException("error parsing field ["
                    + name() + "], expected an object but got " + parser.currentName());
            }
        }
        context.doc().addAll(fieldType().rangeType.createFields(context, name(), range, index, hasDocValues, store));

        if (hasDocValues == false && (index || store)) {
            createFieldNamesField(context);
        }
    }

    private static Range parseIpRangeFromCidr(final XContentParser parser) throws IOException {
        final Tuple<InetAddress, Integer> cidr = InetAddresses.parseCidr(parser.text());
        // create the lower value by zeroing out the host portion, upper value by filling it with all ones.
        byte[] lower = cidr.v1().getAddress();
        byte[] upper = lower.clone();
        for (int i = cidr.v2(); i < 8 * lower.length; i++) {
            int m = 1 << 7 - (i & 7);
            lower[i >> 3] &= ~m;
            upper[i >> 3] |= m;
        }
        try {
            return new Range(RangeType.IP, InetAddress.getByAddress(lower), InetAddress.getByAddress(upper), true, true);
        } catch (UnknownHostException bogus) {
            throw new AssertionError(bogus);
        }
    }

    /** Class defining a range */
    public static class Range {
        RangeType type;
        Object from;
        Object to;
        private final boolean includeFrom;
        private final boolean includeTo;

        public Range(RangeType type, Object from, Object to, boolean includeFrom, boolean includeTo) {
            this.type = type;
            this.from = from;
            this.to = to;
            this.includeFrom = includeFrom;
            this.includeTo = includeTo;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }
            Range range = (Range) o;
            return includeFrom == range.includeFrom &&
                includeTo == range.includeTo &&
                type == range.type &&
                from.equals(range.from) &&
                to.equals(range.to);
        }

        @Override
        public int hashCode() {
            return Objects.hash(type, from, to, includeFrom, includeTo);
        }

        @Override
        public String toString() {
            StringBuilder sb = new StringBuilder();
            sb.append(includeFrom ? '[' : '(');
            Object f = includeFrom || from.equals(type.minValue()) ? from : type.nextDown(from);
            Object t = includeTo || to.equals(type.maxValue()) ? to : type.nextUp(to);
            sb.append(type == RangeType.IP ? InetAddresses.toAddrString((InetAddress)f) : f.toString());
            sb.append(" : ");
            sb.append(type == RangeType.IP ? InetAddresses.toAddrString((InetAddress)t) : t.toString());
            sb.append(includeTo ? ']' : ')');
            return sb.toString();
        }

        public Object getFrom() {
            return from;
        }

        public Object getTo() {
            return to;
        }
    }

    static class BinaryRangesDocValuesField extends CustomDocValuesField {

        private final Set<Range> ranges;
        private final RangeType rangeType;

        BinaryRangesDocValuesField(String name, Range range, RangeType rangeType) {
            super(name);
            this.rangeType = rangeType;
            ranges = new HashSet<>();
            add(range);
        }

        void add(Range range) {
            ranges.add(range);
        }

        @Override
        public BytesRef binaryValue() {
            try {
                return rangeType.encodeRanges(ranges);
            } catch (IOException e) {
                throw new ElasticsearchException("failed to encode ranges", e);
            }
        }
    }
}
