package ca.uhn.fhir.model.api;

/*
 * #%L
 * HAPI FHIR - Core Library
 * %%
 * Copyright (C) 2014 - 2021 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%
 */

import ca.uhn.fhir.model.base.composite.BaseCodingDt;
import ca.uhn.fhir.model.primitive.IdDt;
import ca.uhn.fhir.model.primitive.InstantDt;
import ca.uhn.fhir.model.valueset.BundleEntrySearchModeEnum;
import ca.uhn.fhir.model.valueset.BundleEntryTransactionMethodEnum;
import ca.uhn.fhir.rest.server.exceptions.InternalErrorException;
import org.apache.commons.lang3.StringUtils;
import org.hl7.fhir.instance.model.api.IAnyResource;
import org.hl7.fhir.instance.model.api.IPrimitiveType;

import java.io.Serializable;
import java.util.*;

import static org.apache.commons.lang3.StringUtils.isNotBlank;

/**
 * Keys in this map refer to <b>resource metadata keys</b>, which are keys used to access information about specific resource instances that live outside of the resource body. Typically, these are
 * data elements which are sent/receieved in HTTP Headers along with read/create resource requests, or properties which can be found in bundle entries.
 * <p>
 * To access or set resource metadata values, every resource has a metadata map, and this class provides convenient getters/setters for interacting with that map. For example, to get a resource's
 * {@link #UPDATED} value, which is the "last updated" time for that resource, use the following code:
 * </p>
 * <p>
 * <code>InstantDt updated = ResourceMetadataKeyEnum.UPDATED.get(resource);</code>
 * <p>
 * <p>
 * To set this value, use the following:
 * </p>
 * <p>
 * <code>InstantDt update = new InstantDt("2011-01-02T11:22:33.0000Z"); // populate with the actual time<br>
 * ResourceMetadataKeyEnum.UPDATED.put(resource, update);</code>
 * </p>
 * <p>
 * Note that this class is not a Java Enum, and can therefore be extended (this is why it is not actually an Enum). Users of HAPI-FHIR are able to create their own classes extending this class to
 * define their own keys for storage in resource metadata if needed.
 * </p>
 */
public abstract class ResourceMetadataKeyEnum<T> implements Serializable {

        /**
         * If present and populated with a date/time (as an instance of {@link InstantDt}), this value is an indication that the resource is in the deleted state. This key is only used in a limited number
         * of scenarios, such as POSTing transaction bundles to a server, or returning resource history.
         * <p>
         * Values for this key are of type <b>{@link InstantDt}</b>
         * </p>
         */
        public static final ResourceMetadataKeySupportingAnyResource<InstantDt, IPrimitiveType<Date>> DELETED_AT = new ResourceMetadataKeySupportingAnyResource<InstantDt, IPrimitiveType<Date>>("DELETED_AT") {
                private static final long serialVersionUID = 1L;

                @Override
                public InstantDt get(IResource theResource) {
                        return getInstantFromMetadataOrNullIfNone(theResource.getResourceMetadata(), DELETED_AT);
                }

                @SuppressWarnings("unchecked")
                @Override
                public IPrimitiveType<Date> get(IAnyResource theResource) {
                        return (IPrimitiveType<Date>) theResource.getUserData(DELETED_AT.name());
                }

                @Override
                public void put(IResource theResource, InstantDt theObject) {
                        theResource.getResourceMetadata().put(DELETED_AT, theObject);
                }

                @Override
                public void put(IAnyResource theResource, IPrimitiveType<Date> theObject) {
                        theResource.setUserData(DELETED_AT.name(), theObject);
                }
        };

        /**
         * If present and populated with a {@link BundleEntrySearchModeEnum}, contains the "bundle entry search mode", which is the value of the status field in the Bundle entry containing this resource.
         * The value for this key corresponds to field <code>Bundle.entry.search.mode</code>. This value can be set to provide a status value of "include" for included resources being returned by a
         * server, or to "match" to indicate that the resource was returned because it matched the given search criteria.
         * <p>
         * Note that status is only used in FHIR DSTU2 and later.
         * </p>
         * <p>
         * Values for this key are of type <b>{@link BundleEntrySearchModeEnum}</b>
         * </p>
         */
        public static final ResourceMetadataKeySupportingAnyResource<BundleEntrySearchModeEnum, String> ENTRY_SEARCH_MODE = new ResourceMetadataKeySupportingAnyResource<BundleEntrySearchModeEnum, String>("ENTRY_SEARCH_MODE") {
                private static final long serialVersionUID = 1L;

                @Override
                public BundleEntrySearchModeEnum get(IResource theResource) {
                        return getEnumFromMetadataOrNullIfNone(theResource.getResourceMetadata(), ENTRY_SEARCH_MODE, BundleEntrySearchModeEnum.class, BundleEntrySearchModeEnum.VALUESET_BINDER);
                }

                @Override
                public String get(IAnyResource theResource) {
                        return (String) theResource.getUserData(ENTRY_SEARCH_MODE.name());
                }

                @Override
                public void put(IResource theResource, BundleEntrySearchModeEnum theObject) {
                        theResource.getResourceMetadata().put(ENTRY_SEARCH_MODE, theObject);
                }

                @Override
                public void put(IAnyResource theResource, String theObject) {
                        theResource.setUserData(ENTRY_SEARCH_MODE.name(), theObject);
                }
        };
        /**
         * If present and populated with a {@link BundleEntryTransactionMethodEnum}, contains the "bundle entry transaction operation", which is the value of the status field in the Bundle entry
         * containing this resource. The value for this key corresponds to field <code>Bundle.entry.transaction.operation</code>. This value can be set in resources being transmitted to a server to
         * provide a status value of "create" or "update" to indicate behaviour the server should observe. It may also be set to similar values (or to "noop") in resources being returned by a server as a
         * result of a transaction to indicate to the client what operation was actually performed.
         * <p>
         * Note that status is only used in FHIR DSTU2 and later.
         * </p>
         * <p>
         * Values for this key are of type <b>{@link BundleEntryTransactionMethodEnum}</b>
         * </p>
         */
        public static final ResourceMetadataKeySupportingAnyResource<BundleEntryTransactionMethodEnum, String> ENTRY_TRANSACTION_METHOD = new ResourceMetadataKeySupportingAnyResource<BundleEntryTransactionMethodEnum, String>(
                "ENTRY_TRANSACTION_OPERATION") {
                private static final long serialVersionUID = 1L;

                @Override
                public BundleEntryTransactionMethodEnum get(IResource theResource) {
                        return getEnumFromMetadataOrNullIfNone(theResource.getResourceMetadata(), ENTRY_TRANSACTION_METHOD, BundleEntryTransactionMethodEnum.class,
                                BundleEntryTransactionMethodEnum.VALUESET_BINDER);
                }

                @Override
                public String get(IAnyResource theResource) {
                        return (String) theResource.getUserData(ENTRY_TRANSACTION_METHOD.name());
                }

                @Override
                public void put(IResource theResource, BundleEntryTransactionMethodEnum theObject) {
                        theResource.getResourceMetadata().put(ENTRY_TRANSACTION_METHOD, theObject);
                }

                @Override
                public void put(IAnyResource theResource, String theObject) {
                        theResource.setUserData(ENTRY_TRANSACTION_METHOD.name(), theObject);
                }

        };

        /**
         * The value for this key represents a {@link List} of profile IDs that this resource claims to conform to.
         * <p>
         * <p>
         * Values for this key are of type <b>List&lt;IdDt&gt;</b>. Note that the returned list is <i>unmodifiable</i>, so you need to create a new list and call <code>put</code> to change its value.
         * </p>
         */
        public static final ResourceMetadataKeyEnum<List<IdDt>> PROFILES = new ResourceMetadataKeyEnum<List<IdDt>>("PROFILES") {
                private static final long serialVersionUID = 1L;

                @Override
                public List<IdDt> get(IResource theResource) {
                        return getIdListFromMetadataOrNullIfNone(theResource.getResourceMetadata(), PROFILES);
                }

                @Override
                public void put(IResource theResource, List<IdDt> theObject) {
                        theResource.getResourceMetadata().put(PROFILES, theObject);
                }
        };
        /**
         * The value for this key is the bundle entry <b>Published</b> time. This is defined by FHIR as "Time resource copied into the feed", which is generally best left to the current time.
         * <p>
         * Values for this key are of type <b>{@link InstantDt}</b>
         * </p>
         * <p>
         * <b>Server Note</b>: In servers, it is generally advisable to leave this value <code>null</code>, in which case the server will substitute the current time automatically.
         * </p>
         *
         * @see InstantDt
         */
        public static final ResourceMetadataKeyEnum<InstantDt> PUBLISHED = new ResourceMetadataKeyEnum<InstantDt>("PUBLISHED") {
                private static final long serialVersionUID = 1L;

                @Override
                public InstantDt get(IResource theResource) {
                        return getInstantFromMetadataOrNullIfNone(theResource.getResourceMetadata(), PUBLISHED);
                }

                @Override
                public void put(IResource theResource, InstantDt theObject) {
                        theResource.getResourceMetadata().put(PUBLISHED, theObject);
                }
        };
        public static final ResourceMetadataKeyEnum<List<BaseCodingDt>> SECURITY_LABELS = new ResourceMetadataKeyEnum<List<BaseCodingDt>>("SECURITY_LABELS") {
                private static final long serialVersionUID = 1L;

                @Override
                public List<BaseCodingDt> get(IResource resource) {
                        Object obj = resource.getResourceMetadata().get(SECURITY_LABELS);
                        if (obj == null) {
                                return null;
                        }
                        //noinspection unchecked
                        return (List<BaseCodingDt>) obj;
                }

                @Override
                public void put(IResource iResource, List<BaseCodingDt> labels) {
                        iResource.getResourceMetadata().put(SECURITY_LABELS, labels);
                }

        };
        /**
         * The value for this key is the list of tags associated with this resource
         * <p>
         * Values for this key are of type <b>{@link TagList}</b>
         * </p>
         *
         * @see TagList
         */
        public static final ResourceMetadataKeyEnum<TagList> TAG_LIST = new ResourceMetadataKeyEnum<TagList>("TAG_LIST") {
                private static final long serialVersionUID = 1L;

                @Override
                public TagList get(IResource theResource) {
                        Object retValObj = theResource.getResourceMetadata().get(TAG_LIST);
                        if (retValObj == null) {
                                return null;
                        } else {
                                return (TagList) retValObj;
                        }
                }

                @Override
                public void put(IResource theResource, TagList theObject) {
                        theResource.getResourceMetadata().put(TAG_LIST, theObject);
                }
        };
        /**
         * The value for this key is the bundle entry <b>Updated</b> time. This is defined by FHIR as "Last Updated for resource". This value is also used for populating the "Last-Modified" header in the
         * case of methods that return a single resource (read, vread, etc.)
         * <p>
         * Values for this key are of type <b>{@link InstantDt}</b>
         * </p>
         *
         * @see InstantDt
         */
        public static final ResourceMetadataKeyEnum<InstantDt> UPDATED = new ResourceMetadataKeyEnum<InstantDt>("UPDATED") {
                private static final long serialVersionUID = 1L;

                @Override
                public InstantDt get(IResource theResource) {
                        return getInstantFromMetadataOrNullIfNone(theResource.getResourceMetadata(), UPDATED);
                }

                @Override
                public void put(IResource theResource, InstantDt theObject) {
                        theResource.getResourceMetadata().put(UPDATED, theObject);
                }
        };
        /**
         * The value for this key is the version ID of the resource object.
         * <p>
         * Values for this key are of type <b>{@link String}</b>
         * </p>
         *
         * @deprecated The {@link IResource#getId()} resource ID will now be populated with the version ID via the {@link IdDt#getVersionIdPart()} method
         */
        @Deprecated
        public static final ResourceMetadataKeyEnum<String> VERSION = new ResourceMetadataKeyEnum<String>("VERSION") {
                private static final long serialVersionUID = 1L;

                @Override
                public String get(IResource theResource) {
                        return getStringFromMetadataOrNullIfNone(theResource.getResourceMetadata(), VERSION);
                }

                @Override
                public void put(IResource theResource, String theObject) {
                        theResource.getResourceMetadata().put(VERSION, theObject);
                }
        };
        /**
         * The value for this key is the version ID of the resource object.
         * <p>
         * Values for this key are of type <b>{@link IdDt}</b>
         * </p>
         *
         * @deprecated The {@link IResource#getId()} resource ID will now be populated with the version ID via the {@link IdDt#getVersionIdPart()} method
         */
        @Deprecated
        public static final ResourceMetadataKeyEnum<IdDt> VERSION_ID = new ResourceMetadataKeyEnum<IdDt>("VERSION_ID") {
                private static final long serialVersionUID = 1L;

                @Override
                public IdDt get(IResource theResource) {
                        return getIdFromMetadataOrNullIfNone(theResource.getResourceMetadata());
                }

                @Override
                public void put(IResource theResource, IdDt theObject) {
                        theResource.getResourceMetadata().put(VERSION_ID, theObject);
                }
        };
        private static final long serialVersionUID = 1L;
        private final String myValue;

        public ResourceMetadataKeyEnum(String theValue) {
                myValue = theValue;
        }

        @Override
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                ResourceMetadataKeyEnum<?> other = (ResourceMetadataKeyEnum<?>) obj;
                if (myValue == null) {
                        if (other.myValue != null)
                                return false;
                } else if (!myValue.equals(other.myValue))
                        return false;
                return true;
        }

        public abstract T get(IResource theResource);

        @Override
        public int hashCode() {
                final int prime = 31;
                int result = 1;
                result = prime * result + ((myValue == null) ? 0 : myValue.hashCode());
                return result;
        }

        public String name() {
                return myValue;
        }

        public abstract void put(IResource theResource, T theObject);

        public static abstract class ResourceMetadataKeySupportingAnyResource<T, T2> extends ResourceMetadataKeyEnum<T> {

                private static final long serialVersionUID = 1L;

                public ResourceMetadataKeySupportingAnyResource(String theValue) {
                        super(theValue);
                }

                public abstract T2 get(IAnyResource theResource);

                public abstract void put(IAnyResource theResource, T2 theObject);

        }

        public static final class ExtensionResourceMetadataKey extends ResourceMetadataKeyEnum<ExtensionDt> {
                public ExtensionResourceMetadataKey(String theUrl) {
                        super(theUrl);
                }

                @Override
                public ExtensionDt get(IResource theResource) {
                        Object retValObj = theResource.getResourceMetadata().get(this);
                        if (retValObj == null) {
                                return null;
                        } else if (retValObj instanceof ExtensionDt) {
                                return (ExtensionDt) retValObj;
                        }
                        throw new InternalErrorException("Found an object of type '" + retValObj.getClass().getCanonicalName()
                                + "' in resource metadata for key " + this.name() + " - Expected "
                                + ExtensionDt.class.getCanonicalName());
                }

                @Override
                public void put(IResource theResource, ExtensionDt theObject) {
                        theResource.getResourceMetadata().put(this, theObject);
                }
        }


        @SuppressWarnings("unchecked")
        private static <T extends Enum<?>> T getEnumFromMetadataOrNullIfNone(Map<ResourceMetadataKeyEnum<?>, Object> theResourceMetadata, ResourceMetadataKeyEnum<T> theKey, Class<T> theEnumType,
                                                                                                                                                                                                IValueSetEnumBinder<T> theBinder) {
                Object retValObj = theResourceMetadata.get(theKey);
                if (retValObj == null) {
                        return null;
                } else if (theEnumType.equals(retValObj.getClass())) {
                        return (T) retValObj;
                } else if (retValObj instanceof String) {
                        return theBinder.fromCodeString((String) retValObj);
                }
                throw new InternalErrorException("Found an object of type '" + retValObj.getClass().getCanonicalName() + "' in resource metadata for key " + theKey.name() + " - Expected "
                        + InstantDt.class.getCanonicalName());
        }

        private static IdDt getIdFromMetadataOrNullIfNone(Map<ResourceMetadataKeyEnum<?>, Object> theResourceMetadata) {
                return toId(ResourceMetadataKeyEnum.VERSION_ID, theResourceMetadata.get(ResourceMetadataKeyEnum.VERSION_ID));
        }

        private static List<IdDt> getIdListFromMetadataOrNullIfNone(Map<ResourceMetadataKeyEnum<?>, Object> theResourceMetadata, ResourceMetadataKeyEnum<?> theKey) {
                Object retValObj = theResourceMetadata.get(theKey);
                if (retValObj == null) {
                        return null;
                } else if (retValObj instanceof List) {
                        List<?> retValList = (List<?>) retValObj;
                        for (Object next : retValList) {
                                if (!(next instanceof IdDt)) {
                                        List<IdDt> retVal = new ArrayList<IdDt>();
                                        for (Object nextVal : retValList) {
                                                retVal.add(toId(theKey, nextVal));
                                        }
                                        return Collections.unmodifiableList(retVal);
                                }
                        }
                        @SuppressWarnings("unchecked")
                        List<IdDt> retVal = (List<IdDt>) retValList;
                        return Collections.unmodifiableList(retVal);
                } else {
                        return Collections.singletonList(toId(theKey, retValObj));
                }
        }

        private static InstantDt getInstantFromMetadataOrNullIfNone(Map<ResourceMetadataKeyEnum<?>, Object> theResourceMetadata, ResourceMetadataKeyEnum<InstantDt> theKey) {
                Object retValObj = theResourceMetadata.get(theKey);
                if (retValObj == null) {
                        return null;
                } else if (retValObj instanceof Date) {
                        return new InstantDt((Date) retValObj);
                } else if (retValObj instanceof InstantDt) {
                        if (((InstantDt) retValObj).isEmpty()) {
                                return null;
                        }
                        return (InstantDt) retValObj;
                }
                throw new InternalErrorException("Found an object of type '" + retValObj.getClass().getCanonicalName() + "' in resource metadata for key " + theKey.name() + " - Expected "
                        + InstantDt.class.getCanonicalName());
        }

        private static String getStringFromMetadataOrNullIfNone(Map<ResourceMetadataKeyEnum<?>, Object> theResourceMetadata, ResourceMetadataKeyEnum<String> theKey) {
                Object retValObj = theResourceMetadata.get(theKey);
                if (retValObj == null) {
                        return null;
                } else if (retValObj instanceof String) {
                        if (StringUtils.isBlank(((String) retValObj))) {
                                return null;
                        }
                        return (String) retValObj;
                }
                throw new InternalErrorException("Found an object of type '" + retValObj.getClass().getCanonicalName() + "' in resource metadata for key " + theKey.name() + " - Expected "
                        + String.class.getCanonicalName());
        }

        private static IdDt toId(ResourceMetadataKeyEnum<?> theKey, Object retValObj) {
                if (retValObj == null) {
                        return null;
                } else if (retValObj instanceof String) {
                        if (isNotBlank((String) retValObj)) {
                                return new IdDt((String) retValObj);
                        }
                        return null;
                } else if (retValObj instanceof IdDt) {
                        if (((IdDt) retValObj).isEmpty()) {
                                return null;
                        }
                        return (IdDt) retValObj;
                } else if (retValObj instanceof Number) {
                        return new IdDt(retValObj.toString());
                }
                throw new InternalErrorException("Found an object of type '" + retValObj.getClass().getCanonicalName() + "' in resource metadata for key " + theKey.name() + " - Expected "
                        + IdDt.class.getCanonicalName());
        }


}