/*
 * #%L
 * HAPI FHIR - Core Library
 * %%
 * Copyright (C) 2014 - 2024 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.context;

import ca.uhn.fhir.context.phonetic.IPhoneticEncoder;
import ca.uhn.fhir.rest.api.RestSearchParameterTypeEnum;
import jakarta.annotation.Nonnull;
import jakarta.annotation.Nullable;
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.IBaseExtension;
import org.hl7.fhir.instance.model.api.IIdType;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;

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

public class RuntimeSearchParam {
        private final IIdType myId;
        private final Set<String> myBase;
        private final String myDescription;
        private final String myName;
        private final RestSearchParameterTypeEnum myParamType;
        private final String myPath;
        private final Set<String> myTargets;
        private final Set<String> myProvidesMembershipInCompartments;
        private final RuntimeSearchParamStatusEnum myStatus;
        private final String myUri;
        private final Map<String, List<IBaseExtension<?, ?>>> myExtensions = new HashMap<>();
        private final Map<String, String> myUpliftRefchains = new HashMap<>();
        private final ComboSearchParamType myComboSearchParamType;
        private final List<Component> myComponents;
        private final IIdType myIdUnqualifiedVersionless;
        private IPhoneticEncoder myPhoneticEncoder;
        private boolean myEnabledForSearching = true;

        /**
         * Constructor
         */
        public RuntimeSearchParam(
                        IIdType theId,
                        String theUri,
                        String theName,
                        String theDescription,
                        String thePath,
                        RestSearchParameterTypeEnum theParamType,
                        Set<String> theProvidesMembershipInCompartments,
                        Set<String> theTargets,
                        RuntimeSearchParamStatusEnum theStatus,
                        Collection<String> theBase) {
                this(
                                theId,
                                theUri,
                                theName,
                                theDescription,
                                thePath,
                                theParamType,
                                theProvidesMembershipInCompartments,
                                theTargets,
                                theStatus,
                                null,
                                Collections.emptyList(),
                                theBase);
        }

        /**
         * Copy constructor
         */
        public RuntimeSearchParam(RuntimeSearchParam theSp) {
                this(
                                theSp.getId(),
                                theSp.getUri(),
                                theSp.getName(),
                                theSp.getDescription(),
                                theSp.getPath(),
                                theSp.getParamType(),
                                theSp.getProvidesMembershipInCompartments(),
                                theSp.getTargets(),
                                theSp.getStatus(),
                                theSp.getComboSearchParamType(),
                                theSp.getComponents(),
                                theSp.getBase());
        }

        /**
         * Constructor
         */
        public RuntimeSearchParam(
                        IIdType theId,
                        String theUri,
                        String theName,
                        String theDescription,
                        String thePath,
                        RestSearchParameterTypeEnum theParamType,
                        Set<String> theProvidesMembershipInCompartments,
                        Set<String> theTargets,
                        RuntimeSearchParamStatusEnum theStatus,
                        ComboSearchParamType theComboSearchParamType,
                        List<Component> theComponents,
                        Collection<String> theBase) {
                super();

                myId = theId;
                myIdUnqualifiedVersionless = theId != null ? theId.toUnqualifiedVersionless() : null;
                myUri = theUri;
                myName = theName;
                myDescription = theDescription;
                myPath = thePath;
                myParamType = theParamType;
                myStatus = theStatus;
                if (theProvidesMembershipInCompartments != null && !theProvidesMembershipInCompartments.isEmpty()) {
                        myProvidesMembershipInCompartments = Collections.unmodifiableSet(theProvidesMembershipInCompartments);
                } else {
                        myProvidesMembershipInCompartments = null;
                }
                if (theTargets != null && theTargets.isEmpty() == false) {
                        myTargets = Collections.unmodifiableSet(theTargets);
                } else {
                        myTargets = Collections.emptySet();
                }

                if (theBase == null || theBase.isEmpty()) {
                        HashSet<String> base = new HashSet<>();
                        if (isNotBlank(thePath)) {
                                int indexOf = thePath.indexOf('.');
                                if (indexOf != -1) {
                                        base.add(trim(thePath.substring(0, indexOf)));
                                }
                        }
                        myBase = Collections.unmodifiableSet(base);
                } else {
                        myBase = Collections.unmodifiableSet(new HashSet<>(theBase));
                }
                myComboSearchParamType = theComboSearchParamType;
                if (theComponents != null) {
                        myComponents = Collections.unmodifiableList(theComponents);
                } else {
                        myComponents = Collections.emptyList();
                }
        }

        /**
         * Is this search parameter actually enabled for being used in searches (as opposed to only being used for
         * generating indexes, which might be desired while the search parameter is still being indexed). This
         * setting defaults to {@literal true} if it isn't set otherwise.
         */
        public boolean isEnabledForSearching() {
                return myEnabledForSearching;
        }

        /**
         * Is this search parameter actually enabled for being used in searches (as opposed to only being used for
         * generating indexes, which might be desired while the search parameter is still being indexed). This
         * setting defaults to {@literal true} if it isn't set otherwise.
         */
        public void setEnabledForSearching(boolean theEnabledForSearching) {
                myEnabledForSearching = theEnabledForSearching;
        }

        public List<Component> getComponents() {
                return myComponents;
        }

        /**
         * Returns <code>null</code> if this is not a combo search param type
         */
        @Nullable
        public ComboSearchParamType getComboSearchParamType() {
                return myComboSearchParamType;
        }

        /**
         * Retrieve user data - This can be used to store any application-specific data
         */
        @Nonnull
        public List<IBaseExtension<?, ?>> getExtensions(String theKey) {
                List<IBaseExtension<?, ?>> retVal = myExtensions.get(theKey);
                if (retVal != null) {
                        retVal = Collections.unmodifiableList(retVal);
                } else {
                        retVal = Collections.emptyList();
                }
                return retVal;
        }

        /**
         * Sets user data - This can be used to store any application-specific data
         */
        public RuntimeSearchParam addExtension(String theKey, IBaseExtension<?, ?> theValue) {
                List<IBaseExtension<?, ?>> valuesList = myExtensions.computeIfAbsent(theKey, k -> new ArrayList<>());
                valuesList.add(theValue);
                return this;
        }

        @Override
        public String toString() {
                return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE)
                                .append("base", myBase)
                                .append("name", myName)
                                .append("path", myPath)
                                .append("id", myId)
                                .append("uri", myUri)
                                .toString();
        }

        public IIdType getId() {
                return myId;
        }

        public IIdType getIdUnqualifiedVersionless() {
                return myIdUnqualifiedVersionless;
        }

        public String getUri() {
                return myUri;
        }

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

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

                RuntimeSearchParam that = (RuntimeSearchParam) theO;

                return new EqualsBuilder()
                                .append(getId(), that.getId())
                                .append(getName(), that.getName())
                                .append(getPath(), that.getPath())
                                .append(getUri(), that.getUri())
                                .isEquals();
        }

        @Override
        public int hashCode() {
                return new HashCodeBuilder(17, 37)
                                .append(getId())
                                .append(getName())
                                .append(getPath())
                                .append(getUri())
                                .toHashCode();
        }

        public Set<String> getBase() {
                return myBase;
        }

        @Nonnull
        public Set<String> getTargets() {
                return myTargets;
        }

        public boolean hasTargets() {
                return !myTargets.isEmpty();
        }

        public RuntimeSearchParamStatusEnum getStatus() {
                return myStatus;
        }

        public String getDescription() {
                return myDescription;
        }

        public String getName() {
                return myName;
        }

        public RestSearchParameterTypeEnum getParamType() {
                return myParamType;
        }

        public String getPath() {
                return myPath;
        }

        public List<String> getPathsSplit() {
                return getPathsSplitForResourceType(null);
        }

        /**
         * Can return null
         */
        public Set<String> getProvidesMembershipInCompartments() {
                return myProvidesMembershipInCompartments;
        }

        public RuntimeSearchParam setPhoneticEncoder(IPhoneticEncoder thePhoneticEncoder) {
                myPhoneticEncoder = thePhoneticEncoder;
                return this;
        }

        public String encode(String theString) {
                if (myPhoneticEncoder == null || theString == null) {
                        return theString;
                }
                return myPhoneticEncoder.encode(theString);
        }

        public List<String> getPathsSplitForResourceType(@Nullable String theResourceName) {
                String path = getPath();
                if (path.indexOf('|') == -1) {
                        if (theResourceName != null && !pathMatchesResourceType(theResourceName, path)) {
                                return Collections.emptyList();
                        }
                        return Collections.singletonList(path);
                }

                List<String> retVal = new ArrayList<>();
                StringTokenizer tok = new StringTokenizer(path, "|");
                while (tok.hasMoreElements()) {
                        String nextPath = tok.nextToken().trim();
                        if (theResourceName != null && !pathMatchesResourceType(theResourceName, nextPath)) {
                                continue;
                        }
                        retVal.add(nextPath.trim());
                }
                return retVal;
        }

        public void addUpliftRefchain(@Nonnull String theCode, @Nonnull String theElementName) {
                myUpliftRefchains.put(theCode, theElementName);
        }

        /**
         * Does this search parameter have an uplift refchain definition for the given code?
         * See the HAPI FHIR documentation for a description of how uplift refchains work.
         *
         * @since 6.6.0
         */
        public boolean hasUpliftRefchain(String theCode) {
                return myUpliftRefchains.containsKey(theCode);
        }

        /**
         * Returns a set of all codes associated with uplift refchains for this search parameter.
         * See the HAPI FHIR documentation for a description of how uplift refchains work.
         *
         * @since 6.6.0
         */
        public Set<String> getUpliftRefchainCodes() {
                return Collections.unmodifiableSet(myUpliftRefchains.keySet());
        }

        /**
         * Does this search parameter have any uplift refchain definitions?
         * See the HAPI FHIR documentation for a description of how uplift refchains work.
         *
         * @since 6.6.0
         */
        public boolean hasUpliftRefchains() {
                return !myUpliftRefchains.isEmpty();
        }

        /**
         * This method tests whether a given FHIRPath expression <i>could</i>
         * possibly apply to the given resource type.
         *
         * @param theResourceName
         * @param thePath
         * @return
         */
        static boolean pathMatchesResourceType(String theResourceName, String thePath) {
                for (int i = 0; i < thePath.length() - 1; i++) {
                        char nextChar = thePath.charAt(i);
                        if (Character.isLowerCase(nextChar)) {
                                return true;
                        }
                        if (Character.isLetter(nextChar)) {
                                if (fhirPathExpressionStartsWith(theResourceName, thePath, i)) {
                                        return true;
                                }
                                if (fhirPathExpressionStartsWith("Resource", thePath, i)) {
                                        return true;
                                }
                                if (fhirPathExpressionStartsWith("DomainResource", thePath, i)) {
                                        return true;
                                }
                                return false;
                        }
                }

                return false;
        }

        private static boolean fhirPathExpressionStartsWith(String theResourceName, String thePath, int theStartingIndex) {
                if (thePath.startsWith(theResourceName, theStartingIndex) && thePath.length() > theResourceName.length()) {
                        for (int i = theResourceName.length() + theStartingIndex; i < thePath.length(); i++) {
                                char nextChar = thePath.charAt(i);
                                if (nextChar == '.') {
                                        return true;
                                } else if (nextChar != ' ') {
                                        return false;
                                }
                        }
                }
                return false;
        }

        public enum RuntimeSearchParamStatusEnum {
                ACTIVE,
                DRAFT,
                RETIRED,
                UNKNOWN
        }

        public static class Component {
                private final String myExpression;
                private final String myReference;

                /**
                 * Constructor
                 */
                public Component(String theExpression, String theReference) {
                        myExpression = theExpression;
                        myReference = theReference;
                }

                @Override
                public String toString() {
                        return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE)
                                        .append("expression", myExpression)
                                        .append("reference", myReference)
                                        .toString();
                }

                public String getExpression() {
                        return myExpression;
                }

                public String getReference() {
                        return myReference;
                }
        }
}