/*-
 * #%L
 * HAPI FHIR - Core Library
 * %%
 * Copyright (C) 2014 - 2025 Smile CDR, Inc.
 * %%
 * 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.
 * #L%
 */
package ca.uhn.fhir.interceptor.model;

import ca.uhn.fhir.model.api.IModelJson;
import ca.uhn.fhir.rest.api.Constants;
import ca.uhn.fhir.util.JsonUtil;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import jakarta.annotation.Nonnull;
import jakarta.annotation.Nullable;
import org.apache.commons.lang3.Validate;
import org.apache.commons.lang3.builder.EqualsBuilder;
import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;
import org.hl7.fhir.instance.model.api.IBaseResource;

import java.time.LocalDate;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import static org.apache.commons.lang3.ObjectUtils.defaultIfNull;

/**
 * @since 5.0.0
 */
public class RequestPartitionId implements IModelJson {
        private static final RequestPartitionId ALL_PARTITIONS = new RequestPartitionId();
        private static final ObjectMapper ourObjectMapper =
                        new ObjectMapper().registerModule(new com.fasterxml.jackson.datatype.jsr310.JavaTimeModule());

        @JsonProperty("partitionDate")
        private final LocalDate myPartitionDate;

        @JsonProperty("allPartitions")
        private final boolean myAllPartitions;

        @JsonProperty("partitionIds")
        private final List<Integer> myPartitionIds;

        @JsonProperty("partitionNames")
        private final List<String> myPartitionNames;

        /**
         * Constructor for a single partition
         */
        private RequestPartitionId(
                        @Nullable String thePartitionName, @Nullable Integer thePartitionId, @Nullable LocalDate thePartitionDate) {
                myPartitionIds = toListOrNull(thePartitionId);
                myPartitionNames = toListOrNull(thePartitionName);
                myPartitionDate = thePartitionDate;
                myAllPartitions = false;
        }

        /**
         * Constructor for a multiple partition
         */
        private RequestPartitionId(
                        @Nullable List<String> thePartitionName,
                        @Nullable List<Integer> thePartitionId,
                        @Nullable LocalDate thePartitionDate) {
                myPartitionIds = toListOrNull(thePartitionId);
                myPartitionNames = toListOrNull(thePartitionName);
                myPartitionDate = thePartitionDate;
                myAllPartitions = false;
        }

        /**
         * Constructor for all partitions
         */
        private RequestPartitionId() {
                super();
                myPartitionDate = null;
                myPartitionNames = null;
                myPartitionIds = null;
                myAllPartitions = true;
        }

        @Nonnull
        public static Optional<RequestPartitionId> getPartitionIfAssigned(IBaseResource theFromResource) {
                return Optional.ofNullable((RequestPartitionId) theFromResource.getUserData(Constants.RESOURCE_PARTITION_ID));
        }

        /**
         * Creates a new RequestPartitionId which includes all partition IDs from
         * this {@link RequestPartitionId} but also includes all IDs from the given
         * {@link RequestPartitionId}. Any duplicates are only included once, and
         * partition names and dates are ignored and not returned. This {@link RequestPartitionId}
         * and {@literal theOther} are not modified.
         *
         * @since 7.4.0
         */
        public RequestPartitionId mergeIds(RequestPartitionId theOther) {
                if (isAllPartitions() || theOther.isAllPartitions()) {
                        return RequestPartitionId.allPartitions();
                }

                // don't know why this is required - otherwise PartitionedStrictTransactionR4Test fails
                if (this.equals(theOther)) {
                        return this;
                }

                List<Integer> thisPartitionIds = getPartitionIds();
                List<Integer> otherPartitionIds = theOther.getPartitionIds();
                List<Integer> newPartitionIds = Stream.concat(thisPartitionIds.stream(), otherPartitionIds.stream())
                                .distinct()
                                .collect(Collectors.toList());
                return RequestPartitionId.fromPartitionIds(newPartitionIds);
        }

        public static RequestPartitionId fromJson(String theJson) throws JsonProcessingException {
                return ourObjectMapper.readValue(theJson, RequestPartitionId.class);
        }

        public boolean isAllPartitions() {
                return myAllPartitions;
        }

        public boolean isPartitionCovered(Integer thePartitionId) {
                return isAllPartitions() || getPartitionIds().contains(thePartitionId);
        }

        @Nullable
        public LocalDate getPartitionDate() {
                return myPartitionDate;
        }

        @Nullable
        public List<String> getPartitionNames() {
                return myPartitionNames;
        }

        @Nonnull
        public List<Integer> getPartitionIds() {
                Validate.notNull(myPartitionIds, "Partition IDs have not been set");
                return myPartitionIds;
        }

        @Override
        public String toString() {
                ToStringBuilder b = new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE);
                if (hasPartitionIds()) {
                        b.append("ids", getPartitionIds());
                }
                if (hasPartitionNames()) {
                        b.append("names", getPartitionNames());
                }
                if (myAllPartitions) {
                        b.append("allPartitions", myAllPartitions);
                }
                return b.build();
        }

        /**
         * Returns true if this partition definition contains the other.
         * Compatible with equals: {@code a.contains(b) && b.contains(a) ==> a.equals(b)}.
         * We can't implement Comparable because this is only a partial order.
         */
        public boolean contains(RequestPartitionId theOther) {
                if (this.isAllPartitions()) {
                        return true;
                } else if (theOther.isAllPartitions()) {
                        return false;
                }
                return this.myPartitionIds.containsAll(theOther.myPartitionIds);
        }

        @Override
        public boolean equals(Object theO) {
                if (this == theO) {
                        return true;
                }

                if (theO == null || getClass() != theO.getClass()) {
                        return false;
                }

                RequestPartitionId that = (RequestPartitionId) theO;

                EqualsBuilder b = new EqualsBuilder();
                b.append(myAllPartitions, that.myAllPartitions);
                b.append(myPartitionDate, that.myPartitionDate);
                b.append(myPartitionIds, that.myPartitionIds);
                b.append(myPartitionNames, that.myPartitionNames);
                return b.isEquals();
        }

        @Override
        public int hashCode() {
                return new HashCodeBuilder(17, 37)
                                .append(myPartitionDate)
                                .append(myAllPartitions)
                                .append(myPartitionIds)
                                .append(myPartitionNames)
                                .toHashCode();
        }

        public String toJson() {
                return JsonUtil.serializeOrInvalidRequest(this);
        }

        @Nullable
        public Integer getFirstPartitionIdOrNull() {
                if (myPartitionIds != null) {
                        return myPartitionIds.get(0);
                }
                return null;
        }

        public String getFirstPartitionNameOrNull() {
                if (myPartitionNames != null) {
                        return myPartitionNames.get(0);
                }
                return null;
        }

        /**
         * Returns true if this request partition contains only one partition ID and it is the DEFAULT partition ID (null)
         *
         * @deprecated use {@link #isPartition(Integer)} or {@link IDefaultPartitionSettings#isDefaultPartition(RequestPartitionId)}
         * instead
         * .
         */
        @Deprecated(since = "2025.02.R01")
        public boolean isDefaultPartition() {
                return isPartition(null);
        }

        /**
         * Test whether this request partition is for the given partition ID.
         *
         * @param thePartitionId is the partition id to be tested against
         * @return <code>true</code> if the request partition contains exactly one partition ID and the partition ID is
         *         <code>thePartitionId</code>.
         */
        public boolean isPartition(@Nullable Integer thePartitionId) {
                if (isAllPartitions()) {
                        return false;
                }
                return hasPartitionIds()
                                && getPartitionIds().size() == 1
                                && Objects.equals(getPartitionIds().get(0), thePartitionId);
        }

        public boolean hasPartitionId(Integer thePartitionId) {
                Validate.notNull(myPartitionIds, "Partition IDs not set");
                return myPartitionIds.contains(thePartitionId);
        }

        public boolean hasPartitionIds() {
                return myPartitionIds != null;
        }

        public boolean hasPartitionNames() {
                return myPartitionNames != null;
        }

        /**
         * Verifies that one of the requested partition is the default partition which is assumed to have a default value of
         * null.
         *
         * @return true if one of the requested partition is the default partition(null).
         *
         * @deprecated use {@link #hasDefaultPartitionId(Integer)} or {@link IDefaultPartitionSettings#hasDefaultPartitionId}
         * instead
         */
        @Deprecated(since = "2025.02.R01")
        public boolean hasDefaultPartitionId() {
                return hasDefaultPartitionId(null);
        }

        /**
         * Test whether this request partition has the default partition as one of its targeted partitions.
         *
         * This method can be directly invoked on a requestPartition object providing that <code>theDefaultPartitionId</code>
         * is known or through {@link IDefaultPartitionSettings#hasDefaultPartitionId} where the implementer of the interface
         * will provide the default partition id (see {@link IDefaultPartitionSettings#getDefaultPartitionId}).
         *
         * @param theDefaultPartitionId is the ID that was given to the default partition.  The default partition ID can be
         *                              NULL as per default or specifically assigned another value.
         *                              See PartitionSettings#setDefaultPartitionId.
         * @return <code>true</code> if the request partition has the default partition as one of the targeted partition.
         */
        public boolean hasDefaultPartitionId(@Nullable Integer theDefaultPartitionId) {
                return getPartitionIds().contains(theDefaultPartitionId);
        }

        public List<Integer> getPartitionIdsWithoutDefault() {
                return getPartitionIds().stream().filter(Objects::nonNull).collect(Collectors.toList());
        }

        @Nullable
        private static <T> List<T> toListOrNull(@Nullable Collection<T> theList) {
                if (theList != null) {
                        if (theList.size() == 1) {
                                return Collections.singletonList(theList.iterator().next());
                        }
                        return Collections.unmodifiableList(new ArrayList<>(theList));
                }
                return null;
        }

        @Nullable
        private static <T> List<T> toListOrNull(@Nullable T theObject) {
                if (theObject != null) {
                        return Collections.singletonList(theObject);
                }
                return null;
        }

        @SafeVarargs
        @Nullable
        private static <T> List<T> toListOrNull(@Nullable T... theObject) {
                if (theObject != null) {
                        return Arrays.asList(theObject);
                }
                return null;
        }

        @Nonnull
        public static RequestPartitionId allPartitions() {
                return ALL_PARTITIONS;
        }

        /**
         * @deprecated use {@link RequestPartitionId#defaultPartition(IDefaultPartitionSettings)} instead
         */
        @Deprecated
        @Nonnull
        //      TODO GGG: This is a now-bad usage and we should remove it. we cannot assume null means default.
        public static RequestPartitionId defaultPartition() {
                return fromPartitionIds(Collections.singletonList(null));
        }

        /**
         * Creates a RequestPartitionId for the default partition using the provided partition settings.
         * This method uses the default partition ID from the given settings to create the RequestPartitionId.
         *
         * @param theDefaultPartitionSettings the partition settings containing the default partition ID
         * @return a RequestPartitionId for the default partition
         */
        @Nonnull
        public static RequestPartitionId defaultPartition(IDefaultPartitionSettings theDefaultPartitionSettings) {
                return fromPartitionId(theDefaultPartitionSettings.getDefaultPartitionId());
        }

        @Deprecated
        @Nonnull
        //      TODO GGG: This is a now-bad usage and we should remove it. we cannot assume null means default.
        public static RequestPartitionId defaultPartition(@Nullable LocalDate thePartitionDate) {
                return fromPartitionIds(Collections.singletonList(null), thePartitionDate);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionId(@Nullable Integer thePartitionId) {
                return fromPartitionIds(Collections.singletonList(thePartitionId));
        }

        @Nonnull
        public static RequestPartitionId fromPartitionId(
                        @Nullable Integer thePartitionId, @Nullable LocalDate thePartitionDate) {
                return new RequestPartitionId(null, Collections.singletonList(thePartitionId), thePartitionDate);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionIds(@Nonnull Collection<Integer> thePartitionIds) {
                return fromPartitionIds(thePartitionIds, null);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionIds(
                        @Nonnull Collection<Integer> thePartitionIds, @Nullable LocalDate thePartitionDate) {
                return new RequestPartitionId(null, toListOrNull(thePartitionIds), thePartitionDate);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionIds(Integer... thePartitionIds) {
                return new RequestPartitionId(null, toListOrNull(thePartitionIds), null);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionName(@Nullable String thePartitionName) {
                return fromPartitionName(thePartitionName, null);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionName(
                        @Nullable String thePartitionName, @Nullable LocalDate thePartitionDate) {
                return new RequestPartitionId(thePartitionName, null, thePartitionDate);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionNames(@Nullable List<String> thePartitionNames) {
                return new RequestPartitionId(toListOrNull(thePartitionNames), null, null);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionNames(String... thePartitionNames) {
                return new RequestPartitionId(toListOrNull(thePartitionNames), null, null);
        }

        @Nonnull
        public static RequestPartitionId fromPartitionIdAndName(
                        @Nullable Integer thePartitionId, @Nullable String thePartitionName) {
                return new RequestPartitionId(thePartitionName, thePartitionId, null);
        }

        @Nonnull
        public static RequestPartitionId forPartitionIdAndName(
                        @Nullable Integer thePartitionId, @Nullable String thePartitionName, @Nullable LocalDate thePartitionDate) {
                return new RequestPartitionId(thePartitionName, thePartitionId, thePartitionDate);
        }

        @Nonnull
        public static RequestPartitionId forPartitionIdsAndNames(
                        List<String> thePartitionNames, List<Integer> thePartitionIds, LocalDate thePartitionDate) {
                return new RequestPartitionId(thePartitionNames, thePartitionIds, thePartitionDate);
        }

        /**
         * Create a string representation suitable for use as a cache key. Null aware.
         * <p>
         * Returns the partition IDs (numeric) as a joined string with a space between, using the string "null" for any null values
         */
        public static String stringifyForKey(@Nonnull RequestPartitionId theRequestPartitionId) {
                String retVal = "(all)";
                if (!theRequestPartitionId.isAllPartitions()) {
                        assert theRequestPartitionId.hasPartitionIds();
                        retVal = theRequestPartitionId.getPartitionIds().stream()
                                        .map(t -> defaultIfNull(t, "null").toString())
                                        .collect(Collectors.joining(" "));
                }
                return retVal;
        }

        public String asJson() throws JsonProcessingException {
                return ourObjectMapper.writeValueAsString(this);
        }
}