/*
 * Java Genetic Algorithm Library (jenetics-8.1.0).
 * Copyright (c) 2007-2024 Franz Wilhelmstötter
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Author:
 *    Franz Wilhelmstötter (franz.wilhelmstoetter@gmail.com)
 */
package io.jenetics.xml;

import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
import static io.jenetics.xml.stream.Reader.attr;
import static io.jenetics.xml.stream.Reader.elem;
import static io.jenetics.xml.stream.Reader.elems;
import static io.jenetics.xml.stream.Reader.text;

import java.io.InputStream;
import java.util.List;
import java.util.function.Function;
import java.util.function.IntFunction;
import java.util.stream.Stream;

import javax.xml.stream.XMLStreamException;

import io.jenetics.BoundedGene;
import io.jenetics.Chromosome;
import io.jenetics.DoubleGene;
import io.jenetics.EnumGene;
import io.jenetics.Gene;
import io.jenetics.IntegerGene;
import io.jenetics.LongGene;
import io.jenetics.util.CharSeq;
import io.jenetics.util.ISeq;
import io.jenetics.util.MSeq;
import io.jenetics.xml.stream.AutoCloseableXMLStreamReader;
import io.jenetics.xml.stream.Reader;
import io.jenetics.xml.stream.XML;

/**
 * This class contains static fields and methods, for creating chromosome- and
 * genotype readers for different gene types.
 *
 * {@snippet lang="java":
 * final Reader<Genotype<BitGene>> bgr =
 *     Readers.Genotype.reader(Readers.BitChromosome.reader());
 *
 * final Reader<Genotype<IntegerGene>> igr =
 *     Writers.Genotype.reader(Readers.IntegerChromosome.reader());
 *
 * final Reader<Genotype<DoubleGene>> dgr =
 *     Readers.Genotype.reader(Readers.DoubleChromosome.reader());
 * }
 *
 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
 * @version 3.9
 * @since 3.9
 */
public final class Readers {
        private Readers() {}

        /**
         * Bit chromosome reader methods, which reads XML-representations of
         * bit-chromosomes.
         * <p>
         * <b>XML</b>
         * <pre> {@code
         * <bit-chromosome length="20" ones-probability="0.5">11100011101011001010</bit-chromosome>
         * } </pre>
         */
        public static final class BitChromosome {
                private BitChromosome() {}

                /**
                 * Return a XML reader for {@link io.jenetics.BitChromosome} objects.
                 *
                 * @return a chromosome reader
                 */
                public static Reader<io.jenetics.BitChromosome> reader() {
                        return elem(
                                v -> io.jenetics.BitChromosome.of(
                                        (String)v[2], (int)v[0], (double)v[1]
                                ),
                                Writers.BitChromosome.ROOT_NAME,
                                attr(Writers.BitChromosome.LENGTH_NAME)
                                        .map(Integer::parseInt),
                                attr(Writers.BitChromosome.ONES_PROBABILITY_NAME)
                                        .map(Double::parseDouble),
                                text()
                        );
                }

                /**
                 * Read a new {@link io.jenetics.BitChromosome} from the given input
                 * stream.
                 *
                 * @param in the data source of the bit-chromosome
                 * @return the bit-chromosome read from the input stream
                 * @throws XMLStreamException if reading the chromosome fails
                 * @throws NullPointerException if the given input stream is {@code null}
                 */
                public static io.jenetics.BitChromosome read(final InputStream in)
                        throws XMLStreamException
                {
                        try (AutoCloseableXMLStreamReader xml = XML.reader(in)) {
                                xml.next();
                                return reader().read(xml);
                        }
                }
        }

        /**
         * Reader methods for {@link io.jenetics.CharacterChromosome} objects.
         * <p>
         * <b>XML format</b>
         * <pre> {@code
         * <character-chromosome length="4">
         *     <valid-alleles>ABCDEFGHIJKLMNOPQRSTUVWXYZ<valid-alleles>
         *     <alleles>ASDF</alleles>
         * </character-chromosome>
         * } </pre>
         */
        public static final class CharacterChromosome {
                private CharacterChromosome() {}

                /**
                 * Return a XML reader for {@link io.jenetics.CharacterChromosome}
                 * objects.
                 *
                 * @return a chromosome reader
                 */
                public static Reader<io.jenetics.CharacterChromosome> reader() {
                        return elem(
                                v -> io.jenetics.CharacterChromosome.of(
                                        (String)v[2], (CharSeq)v[1]
                                ),
                                Writers.CharacterChromosome.ROOT_NAME,
                                attr(Writers.CharacterChromosome.LENGTH_NAME)
                                        .map(Integer::parseInt),
                                elem(Writers.CharacterChromosome.VALID_ALLELES_NAME,
                                        text().map(CharSeq::new)),
                                elem(Writers.CharacterChromosome.ALLELES_NAME, text())
                        );
                }

                /**
                 * Read a new {@link io.jenetics.CharacterChromosome} from the given
                 * input stream.
                 *
                 * @param in the data source of the chromosome
                 * @return the bit-chromosome read from the input stream
                 * @throws XMLStreamException if reading the chromosome fails
                 * @throws NullPointerException if the given input stream is {@code null}
                 */
                public static io.jenetics.CharacterChromosome read(final InputStream in)
                        throws XMLStreamException
                {
                        try (AutoCloseableXMLStreamReader xml = XML.reader(in)) {
                                xml.next();
                                return reader().read(xml);
                        }
                }

        }

        /**
         * Reader methods for {@link io.jenetics.BoundedChromosome} objects.
         * <p>
         * <b>XML format</b>
         * <pre> {@code
         * <root-name length="3">
         *     <min>aaa</min>
         *     <max>zzz</max>
         *     <alleles>
         *         <allele>iii</allele>
         *         <allele>fff</allele>
         *         <allele>ggg</allele>
         *     </alleles>
         * </root-name>
         * } </pre>
         */
        public static final class BoundedChromosome {
                private BoundedChromosome() {}

                /**
                 * Create a bounded chromosome reader with the given configuration.
                 *
                 * @param name the root element name
                 * @param gene the gene creator
                 * @param genes the gene array creator
                 * @param chromosome the chromosome creator
                 * @param alleleReader the allele reader
                 * @param <A> the allele type
                 * @param <G> the gene type
                 * @param <C> the chromosome type
                 * @return a bounded chromosome reader
                 * @throws NullPointerException if one of the arguments is {@code null}
                 */
                public static <
                        A extends Comparable<? super A>,
                        G extends BoundedGene<A, G>,
                        C extends io.jenetics.BoundedChromosome<A, G>
                >
                Reader<C> reader(
                        final String name,
                        final BoundedGeneCreator<A, G> gene,
                        final IntFunction<G[]> genes,
                        final Function<G[], C> chromosome,
                        final Reader<? extends A> alleleReader
                ) {
                        return elem(v -> {
                                final int length = (int)v[0];
                                @SuppressWarnings("unchecked")
                                final A min = (A)v[1];
                                @SuppressWarnings("unchecked")
                                final A max = (A)v[2];
                                @SuppressWarnings("unchecked")
                                final List<A> alleles = (List<A>)v[3];

                                if (alleles.size() != length) {
                                        throw new IllegalArgumentException(format(
                                                "Expected %d alleles, but got %d,",
                                                length, alleles.size()
                                        ));
                                }

                                return chromosome.apply(
                                        alleles.stream()
                                                .map(value -> gene.create(value, min, max))
                                                .toArray(genes)
                                );
                        }, name,
                                attr(Writers.BoundedChromosome.LENGTH_NAME).map(Integer::parseInt),
                                elem(Writers.BoundedChromosome.MIN_NAME, alleleReader),
                                elem(Writers.BoundedChromosome.MAX_NAME, alleleReader),
                                elem(Writers.BoundedChromosome.ALLELES_NAME,
                                        elems(elem(Writers.BoundedChromosome.ALLELE_NAME, alleleReader))
                                )
                        );
                }

        }

        /**
         * Reader methods for {@link io.jenetics.IntegerChromosome} objects.
         * <p>
         * <b>XML format</b>
         * <pre> {@code
         * <int-chromosome length="3">
         *     <min>-2147483648</min>
         *     <max>2147483647</max>
         *     <alleles>
         *         <allele>-1878762439</allele>
         *         <allele>-957346595</allele>
         *         <allele>-88668137</allele>
         *     </alleles>
         * </int-chromosome>
         * } </pre>
         */
        public static final class IntegerChromosome {
                private IntegerChromosome() {}

                /**
                 * Return the default allele reader for the {@code IntegerChromosome}.
                 *
                 * @return the default allele reader
                 */
                public static Reader<Integer> alleleReader() {
                        return text().map(Integer::parseInt);
                }

                /**
                 * Return a {@link io.jenetics.IntegerChromosome} reader.
                 *
                 * @return a integer chromosome reader
                 */
                public static Reader<io.jenetics.IntegerChromosome> reader() {
                        return BoundedChromosome.reader(
                                Writers.IntegerChromosome.ROOT_NAME,
                                IntegerGene::of,
                                IntegerGene[]::new,
                                io.jenetics.IntegerChromosome::of,
                                alleleReader()
                        );
                }

                /**
                 * Read a new {@link io.jenetics.IntegerChromosome} from the given
                 * input stream.
                 *
                 * @param in the data source of the chromosome
                 * @return a new chromosome
                 * @throws XMLStreamException if reading the chromosome fails
                 * @throws NullPointerException if the given input stream is {@code null}
                 */
                public static io.jenetics.IntegerChromosome read(final InputStream in)
                        throws XMLStreamException
                {
                        try (AutoCloseableXMLStreamReader reader = XML.reader(in)) {
                                reader.next();
                                return reader().read(reader);
                        }
                }

        }

        /**
         * Reader methods for {@link io.jenetics.LongChromosome} objects.
         * <p>
         * <b>XML format</b>
         * <pre> {@code
         * <long-chromosome length="3">
         *     <min>-9223372036854775808</min>
         *     <max>9223372036854775807</max>
         *     <alleles>
         *         <allele>-1345217698116542402</allele>
         *         <allele>-7144755673073475303</allele>
         *         <allele>6053786736809578435</allele>
         *     </alleles>
         * </long-chromosome>
         * } </pre>
         */
        public static final class LongChromosome {
                private LongChromosome() {}

                /**
                 * Return the default allele reader for the {@code LongChromosome}.
                 *
                 * @return the default allele reader
                 */
                public static Reader<Long> alleleReader() {
                        return text().map(Long::parseLong);
                }

                /**
                 * Return a {@link io.jenetics.LongChromosome} reader.
                 *
                 * @return a long chromosome reader
                 */
                public static Reader<io.jenetics.LongChromosome> reader() {
                        return BoundedChromosome.reader(
                                Writers.LongChromosome.ROOT_NAME,
                                LongGene::of,
                                LongGene[]::new,
                                io.jenetics.LongChromosome::of,
                                alleleReader()
                        );
                }

                /**
                 * Read a new {@link io.jenetics.LongChromosome} from the given
                 * input stream.
                 *
                 * @param in the data source of the chromosome
                 * @return a new chromosome
                 * @throws XMLStreamException if reading the chromosome fails
                 * @throws NullPointerException if the given input stream is {@code null}
                 */
                public static io.jenetics.LongChromosome read(final InputStream in)
                        throws XMLStreamException
                {
                        try (var reader = XML.reader(in)) {
                                reader.next();
                                return reader().read(reader);
                        }
                }

        }

        /**
         * Reader methods for {@link io.jenetics.DoubleChromosome} objects.
         * <p>
         * <b>XML format</b>
         * <pre> {@code
         * <double-chromosome length="3">
         *     <min>0.0</min>
         *     <max>1.0</max>
         *     <alleles>
         *         <allele>0.27251556008507416</allele>
         *         <allele>0.003140816229067145</allele>
         *         <allele>0.43947528327497376</allele>
         *     </alleles>
         * </double-chromosome>
         * }</pre>
         */
        public static final class DoubleChromosome {
                private DoubleChromosome() {}

                /**
                 * Return the default allele reader for the {@code DoubleChromosome}.
                 *
                 * @return the default allele reader
                 */
                public static Reader<Double> alleleReader() {
                        return text().map(Double::parseDouble);
                }

                /**
                 * Return a {@link io.jenetics.DoubleChromosome} reader.
                 *
                 * @return a double chromosome reader
                 */
                public static Reader<io.jenetics.DoubleChromosome> reader() {
                        return BoundedChromosome.reader(
                                Writers.DoubleChromosome.ROOT_NAME,
                                DoubleGene::of,
                                DoubleGene[]::new,
                                io.jenetics.DoubleChromosome::of,
                                alleleReader()
                        );
                }

                /**
                 * Read a new {@link io.jenetics.DoubleChromosome} from the given
                 * input stream.
                 *
                 * @param in the data source of the chromosome
                 * @return a new chromosome
                 * @throws XMLStreamException if reading the chromosome fails
                 * @throws NullPointerException if the given input stream is {@code null}
                 */
                public static io.jenetics.DoubleChromosome read(final InputStream in)
                        throws XMLStreamException
                {
                        try (var reader = XML.reader(in)) {
                                reader.next();
                                return reader().read(reader);
                        }
                }

        }

        /**
         * Reader methods for {@link io.jenetics.PermutationChromosome} objects.
         * <p>
         * <b>XML format</b>
         * <pre> {@code
         * <permutation-chromosome length="5">
         *     <valid-alleles type="java.lang.Integer">
         *         <allele>0</allele>
         *         <allele>1</allele>
         *         <allele>2</allele>
         *         <allele>3</allele>
         *         <allele>4</allele>
         *     </valid-alleles>
         *     <order>2 1 3 5 4</order>
         * </permutation-chromosome>
         * } </pre>
         */
        public static final class PermutationChromosome {
                private PermutationChromosome() {}

                /**
                 * Return a reader for permutation chromosomes with the given allele
                 * reader.
                 *
                 * @param alleleReader the allele reader
                 * @param <A> the allele type
                 * @return a permutation chromosome reader
                 * @throws NullPointerException if the given allele reader is
                 *        {@code null}
                 */
                public static <A> Reader<io.jenetics.PermutationChromosome<A>>
                reader(final Reader<? extends A> alleleReader) {
                        requireNonNull(alleleReader);

                        return elem(v -> {
                                final int length = (int)v[0];
                                @SuppressWarnings("unchecked")
                                final ISeq<A> validAlleles = ISeq.of((List<A>)v[1]);

                                final int[] order = Stream.of(((String) v[2]).split("\\s"))
                                        .mapToInt(Integer::parseInt)
                                        .toArray();

                                final MSeq<EnumGene<A>> alleles = MSeq.ofLength(length);
                                for (int i = 0; i < length; ++i) {
                                        final EnumGene<A> gene = EnumGene.of(order[i], validAlleles);
                                        alleles.set(i, gene);
                                }

                                return new io.jenetics.PermutationChromosome<>(alleles.toISeq());
                        },
                                Writers.PermutationChromosome.ROOT_NAME,
                                attr(Writers.PermutationChromosome.LENGTH_NAME).map(Integer::parseInt),
                                elem(Writers.PermutationChromosome.VALID_ALLELES_NAME,
                                        elems(elem(Writers.PermutationChromosome.ALLELE_NAME, alleleReader))
                                ),
                                elem(Writers.PermutationChromosome.ORDER_NAME, text())
                        );
                }

                /**
                 * Reads a new {@link io.jenetics.PermutationChromosome} from the given
                 * input stream.
                 *
                 * @param <A> the allele type
                 * @param in the data source of the chromosome
                 * @param alleleReader the allele reader
                 * @return a new permutation chromosome
                 * @throws XMLStreamException if reading the chromosome fails
                 * @throws NullPointerException if one of the arguments is {@code null}
                 */
                public static <A> io.jenetics.PermutationChromosome<A>
                read(final InputStream in, final Reader<? extends A> alleleReader)
                        throws XMLStreamException
                {
                        requireNonNull(alleleReader);
                        requireNonNull(in);

                        try (var xml = XML.reader(in)) {
                                xml.next();
                                return PermutationChromosome.<A>reader(alleleReader).read(xml);
                        }
                }

        }

        /**
         * Writer methods for {@link io.jenetics.Genotype} objects.
         * <p>
         * <b>XML format</b>
         * <pre> {@code
         * <genotype length="2" ngenes="5">
         *     <double-chromosome length="3">
         *         <min>0.0</min>
         *         <max>1.0</max>
         *         <alleles>
         *             <allele>0.27251556008507416</allele>
         *             <allele>0.003140816229067145</allele>
         *             <allele>0.43947528327497376</allele>
         *         </alleles>
         *     </double-chromosome>
         *     <double-chromosome length="2">
         *         <min>0.0</min>
         *         <max>1.0</max>
         *         <alleles>
         *             <allele>0.4026521545744768</allele>
         *             <allele>0.36137605952663554</allele>
         *         <alleles>
         *     </double-chromosome>
         * </genotype>
         * } </pre>
         */
        public static final class Genotype {
                private Genotype() {}

                /**
                 * Create a genotype reader with the given chromosome reader.
                 *
                 * @param chromosomeReader the underlying chromosome reader
                 * @param <A> the allele type
                 * @param <G> the gene type
                 * @param <C> the chromosome type
                 * @return a genotype reader with the given chromosome reader
                 * @throws NullPointerException if the given {@code chromosomeReader} is
                 *         {@code null}
                 */
                public static <
                        A,
                        G extends Gene<A, G>,
                        C extends Chromosome<G>
                >
                Reader<io.jenetics.Genotype<G>>
                reader(final Reader<? extends C> chromosomeReader) {
                        requireNonNull(chromosomeReader);

                        return elem(v -> {
                                @SuppressWarnings("unchecked")
                                final List<C> chromosomes = (List<C>)v[2];
                                final io.jenetics.Genotype<G> genotype =
                                        io.jenetics.Genotype.of(chromosomes);

                                final int length = (int)v[0];
                                final int ngenes = (int)v[1];
                                if (length != genotype.length()) {
                                        throw new IllegalArgumentException(format(
                                                "Expected %d chromosome, but read %d.",
                                                length, genotype.length()
                                        ));
                                }
                                if (ngenes != genotype.geneCount()) {
                                        throw new IllegalArgumentException(format(
                                                "Expected %d genes, but read %d.",
                                                ngenes, genotype.geneCount()
                                        ));
                                }

                                return genotype;
                        },
                                Writers.Genotype.ROOT_NAME,
                                attr(Writers.Genotype.LENGTH_NAME).map(Integer::parseInt),
                                attr(Writers.Genotype.NGENES_NAME).map(Integer::parseInt),
                                elems(chromosomeReader)
                        );
                }

                /**
                 * Reads a genotype by using the given chromosome reader.
                 *
                 * @param <A> the allele type
                 * @param <G> the gene type
                 * @param <C> the chromosome type
                 * @param in the input stream to read the genotype from
                 * @param chromosomeReader the used chromosome reader
                 * @return a genotype by using the given chromosome reader
                 * @throws XMLStreamException if reading the genotype fails
                 * @throws NullPointerException if one of the arguments is {@code null}
                 */
                public static <
                        A,
                        G extends Gene<A, G>,
                        C extends Chromosome<G>
                >
                io.jenetics.Genotype<G>
                read(final InputStream in, final Reader<? extends C> chromosomeReader)
                        throws XMLStreamException
                {
                        requireNonNull(chromosomeReader);
                        requireNonNull(in);

                        try (var xml = XML.reader(in)) {
                                xml.next();
                                return reader(chromosomeReader).read(xml);
                        }
                }
        }

        /**
         * This class contains static reader methods for
         * {@link io.jenetics.Genotype} objects.
         * <p>
         * <b>XML format</b>
         * <pre> {@code
         * <genotypes length="1">
         *     <genotype length="2" ngenes="5">
         *         <double-chromosome length="3">
         *             <min>0.0</min>
         *             <max>1.0</max>
         *             <alleles>
         *                 <allele>0.27251556008507416</allele>
         *                 <allele>0.003140816229067145</allele>
         *                 <allele>0.43947528327497376</allele>
         *             </alleles>
         *         </double-chromosome>
         *         <double-chromosome length="2">
         *             <min>0.0</min>
         *             <max>1.0</max>
         *             <alleles>
         *                 <allele>0.4026521545744768</allele>
         *                 <allele>0.36137605952663554</allele>
         *             <alleles>
         *         </double-chromosome>
         *     </genotype>
         * </genotypes>
         * } </pre>
         */
        public static final class Genotypes {
                private Genotypes() {}

                /**
                 * Return a genotype reader using the given chromosome reader.
                 *
                 * @param chromosomeReader the underlying chromosome reader
                 * @param <A> the allele type
                 * @param <G> the gene type
                 * @param <C> the chromosome type
                 * @return a genotype reader using the given chromosome reader
                 * @throws NullPointerException if the given {@code chromosomeReader} is
                 *         {@code null}
                 */
                @SuppressWarnings("unchecked")
                public static <
                        A,
                        G extends Gene<A, G>,
                        C extends Chromosome<G>
                >
                Reader<List<io.jenetics.Genotype<G>>>
                reader(final Reader<C> chromosomeReader) {
                        return elem(
                                p -> (List<io.jenetics.Genotype<G>>)p[0],
                                Writers.Genotypes.ROOT_NAME,
                                elems(Genotype.reader(chromosomeReader))
                        );
                }

                /**
                 * Reads the genotypes by using the given chromosome reader.
                 *
                 * @param <A> the allele type
                 * @param <G> the gene type
                 * @param <C> the chromosome type
                 * @param in the input stream to read the genotype from
                 * @param chromosomeReader the used chromosome reader
                 * @return a genotype by using the given chromosome reader
                 * @throws XMLStreamException if reading the genotype fails
                 * @throws NullPointerException if one of the arguments is {@code null}
                 */
                public static <
                        A,
                        G extends Gene<A, G>,
                        C extends Chromosome<G>
                >
                List<io.jenetics.Genotype<G>>
                read(final InputStream in, final Reader<? extends C> chromosomeReader)
                        throws XMLStreamException
                {
                        requireNonNull(chromosomeReader);
                        requireNonNull(in);

                        try (var xml = XML.reader(in)) {
                                xml.next();
                                return reader(chromosomeReader).read(xml);
                        }
                }

        }

        /**
         * Reads the genotypes by using the given chromosome reader.
         *
         * @see Genotypes#read(InputStream, Reader)
         *
         * @param <A> the allele type
         * @param <G> the gene type
         * @param <C> the chromosome type
         * @param in the input stream to read the genotype from
         * @param chromosomeReader the used chromosome reader
         * @return a genotype by using the given chromosome reader
         * @throws XMLStreamException if reading the genotype fails
         * @throws NullPointerException if one of the arguments is {@code null}
         */
        public static <
                A,
                G extends Gene<A, G>,
                C extends Chromosome<G>
        >
        List<io.jenetics.Genotype<G>>
        read(final InputStream in, final Reader<? extends C> chromosomeReader)
                throws XMLStreamException
        {
                return Genotypes.read(in, chromosomeReader);
        }

}