/*
 * Copyright 2008-present MongoDB, 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.
 */

package com.mongodb.client.model.changestream;

import com.mongodb.MongoNamespace;
import com.mongodb.assertions.Assertions;
import com.mongodb.lang.Nullable;
import org.bson.BsonDocument;
import org.bson.BsonInt64;
import org.bson.BsonString;
import org.bson.BsonTimestamp;
import org.bson.codecs.Codec;
import org.bson.codecs.configuration.CodecRegistry;
import org.bson.codecs.pojo.annotations.BsonCreator;
import org.bson.codecs.pojo.annotations.BsonId;
import org.bson.codecs.pojo.annotations.BsonIgnore;
import org.bson.codecs.pojo.annotations.BsonProperty;

Represents the $changeStream aggregation output document. 
Note: this class will not be applicable for all change stream outputs. If using custom pipelines that radically change the
change stream result, then an alternative document format should be used.
Type parameters:
<TDocument> – The type that this collection will encode the fullDocument field into.
Since:
3.6/**
 * Represents the {@code $changeStream} aggregation output document.
 *
 * <p>Note: this class will not be applicable for all change stream outputs. If using custom pipelines that radically change the
 * change stream result, then an alternative document format should be used.</p>
 *
 * @param <TDocument> The type that this collection will encode the {@code fullDocument} field into.
 * @since 3.6
 */
public final class ChangeStreamDocument<TDocument> {

    @BsonId()
    private final BsonDocument resumeToken;
    private final BsonDocument namespaceDocument;
    private final BsonDocument destinationNamespaceDocument;
    private final TDocument fullDocument;
    private final BsonDocument documentKey;
    private final BsonTimestamp clusterTime;
    private final OperationType operationType;
    private final UpdateDescription updateDescription;
    private final BsonInt64 txnNumber;
    private final BsonDocument lsid;

    
Creates a new instance
Params:
operationType – the operation type
resumeToken – the resume token
namespaceDocument – the BsonDocument representing the namespace
destinationNamespaceDocument – the BsonDocument representing the destinatation namespace
fullDocument – the full document
documentKey – a document containing the _id of the changed document
clusterTime – the cluster time at which the change occured
updateDescription – the update description
txnNumber – the transaction number
lsid – the identifier for the session associated with the transaction
Since:
3.11/**
     * Creates a new instance
     *
     * @param operationType the operation type
     * @param resumeToken the resume token
     * @param namespaceDocument the BsonDocument representing the namespace
     * @param destinationNamespaceDocument the BsonDocument representing the destinatation namespace
     * @param fullDocument the full document
     * @param documentKey a document containing the _id of the changed document
     * @param clusterTime the cluster time at which the change occured
     * @param updateDescription the update description
     * @param txnNumber the transaction number
     * @param lsid the identifier for the session associated with the transaction
     *
     * @since 3.11
     */
    @BsonCreator
    public ChangeStreamDocument(@BsonProperty("operationType") final OperationType operationType,
                                @BsonProperty("resumeToken") final BsonDocument resumeToken,
                                @Nullable @BsonProperty("ns") final BsonDocument namespaceDocument,
                                @Nullable @BsonProperty("to") final BsonDocument destinationNamespaceDocument,
                                @Nullable @BsonProperty("fullDocument") final TDocument fullDocument,
                                @Nullable @BsonProperty("documentKey") final BsonDocument documentKey,
                                @Nullable @BsonProperty("clusterTime") final BsonTimestamp clusterTime,
                                @Nullable @BsonProperty("updateDescription") final UpdateDescription updateDescription,
                                @Nullable @BsonProperty("txnNumber") final BsonInt64 txnNumber,
                                @Nullable @BsonProperty("lsid") final BsonDocument lsid) {
        this.resumeToken = resumeToken;
        this.namespaceDocument = namespaceDocument;
        this.destinationNamespaceDocument = destinationNamespaceDocument;
        this.documentKey = documentKey;
        this.fullDocument = fullDocument;
        this.clusterTime = clusterTime;
        this.operationType = operationType;
        this.updateDescription = updateDescription;
        this.txnNumber = txnNumber;
        this.lsid = lsid;
    }

    private static BsonDocument namespaceToDocument(final MongoNamespace namespace) {
        Assertions.notNull("namespace", namespace);
        return new BsonDocument("db", new BsonString(namespace.getDatabaseName()))
                .append("coll", new BsonString(namespace.getCollectionName()));
    }

    
Returns the resumeToken
Returns:
the resumeToken/**
     * Returns the resumeToken
     *
     * @return the resumeToken
     */
    public BsonDocument getResumeToken() {
        return resumeToken;
    }

    
Returns the namespace, derived from the "ns" field in a change stream document.
The invalidate operation type does include a MongoNamespace in the ChangeStreamDocument response. The
dropDatabase operation type includes a MongoNamespace, but does not include a collection name as part
of the namespace.
Returns:
the namespace. If the namespaceDocument is null or if it is missing either the 'db' or 'coll' keys,
then this will return null./**
     * Returns the namespace, derived from the "ns" field in a change stream document.
     *
     * The invalidate operation type does include a MongoNamespace in the ChangeStreamDocument response. The
     * dropDatabase operation type includes a MongoNamespace, but does not include a collection name as part
     * of the namespace.
     *
     * @return the namespace. If the namespaceDocument is null or if it is missing either the 'db' or 'coll' keys,
     * then this will return null.
     */
    @BsonIgnore
    @Nullable
    public MongoNamespace getNamespace() {
        if (namespaceDocument == null) {
            return null;
        }
        if (!namespaceDocument.containsKey("db") || !namespaceDocument.containsKey("coll")) {
            return null;
        }

        return new MongoNamespace(namespaceDocument.getString("db").getValue(), namespaceDocument.getString("coll").getValue());
    }

    
Returns the namespace cocument, derived from the "ns" field in a change stream document.
The namespace document is a BsonDocument containing the values associated with a MongoNamespace. The
'db' key refers to the database name and the 'coll' key refers to the collection name.
Returns:
the namespaceDocument
Since:
3.8/**
     * Returns the namespace cocument, derived from the "ns" field in a change stream document.
     *
     * The namespace document is a BsonDocument containing the values associated with a MongoNamespace. The
     * 'db' key refers to the database name and the 'coll' key refers to the collection name.
     *
     * @return the namespaceDocument
     * @since 3.8
     */
    @BsonProperty("ns")
    @Nullable
    public BsonDocument getNamespaceDocument() {
        return namespaceDocument;
    }

    
Returns the destination namespace, derived from the "to" field in a change stream document.

The destination namespace is used to indicate the destination of a collection rename event.

See Also:
OperationType.RENAME
Returns:
the namespace. If the "to" document is null or absent, then this will return null.
Since:
3.11/**
     * Returns the destination namespace, derived from the "to" field in a change stream document.
     *
     * <p>
     * The destination namespace is used to indicate the destination of a collection rename event.
     * </p>
     *
     * @return the namespace. If the "to" document is null or absent, then this will return null.
     * @see OperationType#RENAME
     * @since 3.11
     */
    @BsonIgnore
    @Nullable
    public MongoNamespace getDestinationNamespace() {
        if (destinationNamespaceDocument == null) {
            return null;
        }

        return new MongoNamespace(destinationNamespaceDocument.getString("db").getValue(),
                destinationNamespaceDocument.getString("coll").getValue());
    }

    
Returns the destination namespace document, derived from the "to" field in a change stream document.

The destination namespace document is a BsonDocument containing the values associated with a MongoNamespace. The
'db' key refers to the database name and the 'coll' key refers to the collection name.

Returns:
the destinationNamespaceDocument
Since:
3.11/**
     * Returns the destination namespace document, derived from the "to" field in a change stream document.
     *
     * <p>
     * The destination namespace document is a BsonDocument containing the values associated with a MongoNamespace. The
     * 'db' key refers to the database name and the 'coll' key refers to the collection name.
     * </p>
     * @return the destinationNamespaceDocument
     * @since 3.11
     */
    @BsonProperty("to")
    @Nullable
    public BsonDocument getDestinationNamespaceDocument() {
        return destinationNamespaceDocument;
    }

    
Returns the database name
Returns:
the databaseName. If the namespaceDocument is null or if it is missing the 'db' key, then this will
return null.
Since:
3.8/**
     * Returns the database name
     *
     * @return the databaseName. If the namespaceDocument is null or if it is missing the 'db' key, then this will
     * return null.
     * @since 3.8
     */
    @BsonIgnore
    @Nullable
    public String getDatabaseName() {
        if (namespaceDocument == null) {
            return null;
        }
        if (!namespaceDocument.containsKey("db")) {
            return null;
        }
        return namespaceDocument.getString("db").getValue();
    }

    
Returns the fullDocument
Returns:
the fullDocument/**
     * Returns the fullDocument
     *
     * @return the fullDocument
     */
    @Nullable
    public TDocument getFullDocument() {
        return fullDocument;
    }

    
Returns a document containing just the _id of the changed document.

For unsharded collections this contains a single field, _id, with the
value of the _id of the document updated.  For sharded collections,
this will contain all the components of the shard key in order,
followed by the _id if the _id isn’t part of the shard key.

Returns:
the document key, or null if the event is not associated with a single document (e.g. a collection rename event)/**
     * Returns a document containing just the _id of the changed document.
     * <p>
     * For unsharded collections this contains a single field, _id, with the
     * value of the _id of the document updated.  For sharded collections,
     * this will contain all the components of the shard key in order,
     * followed by the _id if the _id isn’t part of the shard key.
     * </p>
     *
     * @return the document key, or null if the event is not associated with a single document (e.g. a collection rename event)
     */
    @Nullable
    public BsonDocument getDocumentKey() {
        return documentKey;
    }

    
Gets the cluster time at which the change occurred.
Returns:
the cluster time at which the change occurred
Since:
3.8
@mongodb.server.release
4.0/**
     * Gets the cluster time at which the change occurred.
     *
     * @return the cluster time at which the change occurred
     * @since 3.8
     * @mongodb.server.release 4.0
     */
    @Nullable
    public BsonTimestamp getClusterTime() {
        return clusterTime;
    }

    
Returns the operationType
Returns:
the operationType/**
     * Returns the operationType
     *
     * @return the operationType
     */
    public OperationType getOperationType() {
        return operationType;
    }

    
Returns the updateDescription
Returns:
the updateDescription, or null if the event is not associated with a single document (e.g. a collection rename event)/**
     * Returns the updateDescription
     *
     * @return the updateDescription, or null if the event is not associated with a single document (e.g. a collection rename event)
     */
    @Nullable
    public UpdateDescription getUpdateDescription() {
        return updateDescription;
    }

    
Returns the transaction number
Returns:
the transaction number, or null if not part of a multi-document transaction
Since:
3.11
@mongodb.server.release
4.0/**
     * Returns the transaction number
     *
     * @return the transaction number, or null if not part of a multi-document transaction
     * @since 3.11
     * @mongodb.server.release 4.0
     */
    @Nullable
    public BsonInt64 getTxnNumber() {
        return txnNumber;
    }

    
Returns the identifier for the session associated with the transaction
Returns:
the lsid, or null if not part of a multi-document transaction
Since:
3.11
@mongodb.server.release
4.0/**
     * Returns the identifier for the session associated with the transaction
     *
     * @return the lsid, or null if not part of a multi-document transaction
     * @since 3.11
     * @mongodb.server.release 4.0
     */
    @Nullable
    public BsonDocument getLsid() {
        return lsid;
    }

    
Creates the codec for the specific ChangeStreamOutput type
Params:
fullDocumentClass – the class to use to represent the fullDocument
codecRegistry – the codec registry
Type parameters:
<TFullDocument> – the fullDocument type
Returns:
the codec/**
     * Creates the codec for the specific ChangeStreamOutput type
     *
     * @param fullDocumentClass the class to use to represent the fullDocument
     * @param codecRegistry the codec registry
     * @param <TFullDocument> the fullDocument type
     * @return the codec
     */
    public static <TFullDocument> Codec<ChangeStreamDocument<TFullDocument>> createCodec(final Class<TFullDocument> fullDocumentClass,
                                                                                         final CodecRegistry codecRegistry) {
        return new ChangeStreamDocumentCodec<TFullDocument>(fullDocumentClass, codecRegistry);
    }

    @Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        ChangeStreamDocument<?> that = (ChangeStreamDocument<?>) o;

        if (resumeToken != null ? !resumeToken.equals(that.resumeToken) : that.resumeToken != null) {
            return false;
        }
        if (namespaceDocument != null ? !namespaceDocument.equals(that.namespaceDocument) : that.namespaceDocument != null) {
            return false;
        }
        if (destinationNamespaceDocument != null
                ? !destinationNamespaceDocument.equals(that.destinationNamespaceDocument)
                : that.destinationNamespaceDocument != null) {
            return false;
        }
        if (fullDocument != null ? !fullDocument.equals(that.fullDocument) : that.fullDocument != null) {
            return false;
        }
        if (documentKey != null ? !documentKey.equals(that.documentKey) : that.documentKey != null) {
            return false;
        }
        if (clusterTime != null ? !clusterTime.equals(that.clusterTime) : that.clusterTime != null) {
            return false;
        }
        if (operationType != that.operationType) {
            return false;
        }
        if (updateDescription != null ? !updateDescription.equals(that.updateDescription) : that.updateDescription != null) {
            return false;
        }
        if (txnNumber != null ? !txnNumber.equals(that.txnNumber) : that.txnNumber != null) {
            return false;
        }
        if (lsid != null ? !lsid.equals(that.lsid) : that.lsid != null) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode() {
        int result = resumeToken != null ? resumeToken.hashCode() : 0;
        result = 31 * result + (namespaceDocument != null ? namespaceDocument.hashCode() : 0);
        result = 31 * result + (destinationNamespaceDocument != null ? destinationNamespaceDocument.hashCode() : 0);
        result = 31 * result + (fullDocument != null ? fullDocument.hashCode() : 0);
        result = 31 * result + (documentKey != null ? documentKey.hashCode() : 0);
        result = 31 * result + (clusterTime != null ? clusterTime.hashCode() : 0);
        result = 31 * result + (operationType != null ? operationType.hashCode() : 0);
        result = 31 * result + (updateDescription != null ? updateDescription.hashCode() : 0);
        result = 31 * result + (txnNumber != null ? txnNumber.hashCode() : 0);
        result = 31 * result + (lsid != null ? lsid.hashCode() : 0);
        return result;
    }

    @Override
    public String toString() {
        return "ChangeStreamDocument{"
                + " operationType=" + operationType
                + ", resumeToken=" + resumeToken
                + ", namespace=" + getNamespace()
                + ", destinationNamespace=" + getDestinationNamespace()
                + ", fullDocument=" + fullDocument
                + ", documentKey=" + documentKey
                + ", clusterTime=" + clusterTime
                + ", updateDescription=" + updateDescription
                + ", txnNumber=" + txnNumber
                + ", lsid=" + lsid
                + "}";
    }
}