/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.action.delete;

import org.apache.lucene.util.RamUsageEstimator;
import org.elasticsearch.TransportVersion;
import org.elasticsearch.action.ActionRequestValidationException;
import org.elasticsearch.action.CompositeIndicesRequest;
import org.elasticsearch.action.DocWriteRequest;
import org.elasticsearch.action.support.replication.ReplicatedWriteRequest;
import org.elasticsearch.cluster.routing.IndexRouting;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.lucene.uid.Versions;
import org.elasticsearch.core.Nullable;
import org.elasticsearch.index.VersionType;
import org.elasticsearch.index.mapper.MapperService;
import org.elasticsearch.index.shard.ShardId;

import java.io.IOException;

import static org.elasticsearch.action.ValidateActions.addValidationError;
import static org.elasticsearch.index.seqno.SequenceNumbers.UNASSIGNED_PRIMARY_TERM;
import static org.elasticsearch.index.seqno.SequenceNumbers.UNASSIGNED_SEQ_NO;

/**
 * A request to delete a document from an index based on its type and id.
 * <p>
 * The operation requires the {@link #index()} and {@link #id(String)} to
 * be set.
 *
 * @see DeleteResponse
 * @see org.elasticsearch.client.internal.Client#delete(DeleteRequest)
 */
public class DeleteRequest extends ReplicatedWriteRequest<DeleteRequest>
    implements
        DocWriteRequest<DeleteRequest>,
        CompositeIndicesRequest {

    private static final long SHALLOW_SIZE = RamUsageEstimator.shallowSizeOfInstance(DeleteRequest.class);

    private static final ShardId NO_SHARD_ID = null;

    private String id;
    @Nullable
    private String routing;
    private long version = Versions.MATCH_ANY;
    private VersionType versionType = VersionType.INTERNAL;
    private long ifSeqNo = UNASSIGNED_SEQ_NO;
    private long ifPrimaryTerm = UNASSIGNED_PRIMARY_TERM;

    public DeleteRequest(StreamInput in) throws IOException {
        this(null, in);
    }

    public DeleteRequest(@Nullable ShardId shardId, StreamInput in) throws IOException {
        super(shardId, in);
        if (in.getTransportVersion().before(TransportVersion.V_8_0_0)) {
            String type = in.readString();
            assert MapperService.SINGLE_MAPPING_NAME.equals(type) : "Expected [_doc] but received [" + type + "]";
        }
        id = in.readString();
        routing = in.readOptionalString();
        version = in.readLong();
        versionType = VersionType.fromValue(in.readByte());
        ifSeqNo = in.readZLong();
        ifPrimaryTerm = in.readVLong();
    }

    public DeleteRequest() {
        super(NO_SHARD_ID);
    }

    /**
     * Constructs a new delete request against the specified index. The {@link #id(String)}
     * must be set.
     */
    public DeleteRequest(String index) {
        super(NO_SHARD_ID);
        this.index = index;
    }

    /**
     * Constructs a new delete request against the specified index and id.
     *
     * @param index The index to get the document from
     * @param id    The id of the document
     */
    public DeleteRequest(String index, String id) {
        super(NO_SHARD_ID);
        this.index = index;
        this.id = id;
    }

    @Override
    public ActionRequestValidationException validate() {
        ActionRequestValidationException validationException = super.validate();
        if (Strings.isEmpty(id)) {
            validationException = addValidationError("id is missing", validationException);
        }

        validationException = DocWriteRequest.validateSeqNoBasedCASParams(this, validationException);

        return validationException;
    }

    /**
     * The id of the document to delete.
     */
    @Override
    public String id() {
        return id;
    }

    /**
     * Sets the id of the document to delete.
     */
    public DeleteRequest id(String id) {
        this.id = id;
        return this;
    }

    /**
     * Controls the shard routing of the request. Using this value to hash the shard
     * and not the id.
     */
    @Override
    public DeleteRequest routing(String routing) {
        if (routing != null && routing.length() == 0) {
            this.routing = null;
        } else {
            this.routing = routing;
        }
        return this;
    }

    /**
     * Controls the shard routing of the delete request. Using this value to hash the shard
     * and not the id.
     */
    @Override
    public String routing() {
        return this.routing;
    }

    @Override
    public DeleteRequest version(long version) {
        this.version = version;
        return this;
    }

    @Override
    public long version() {
        return this.version;
    }

    @Override
    public DeleteRequest versionType(VersionType versionType) {
        this.versionType = versionType;
        return this;
    }

    /**
     * If set, only perform this delete request if the document was last modification was assigned this sequence number.
     * If the document last modification was assigned a different sequence number a
     * {@link org.elasticsearch.index.engine.VersionConflictEngineException} will be thrown.
     */
    public long ifSeqNo() {
        return ifSeqNo;
    }

    /**
     * If set, only perform this delete request if the document was last modification was assigned this primary term.
     *
     * If the document last modification was assigned a different term a
     * {@link org.elasticsearch.index.engine.VersionConflictEngineException} will be thrown.
     */
    public long ifPrimaryTerm() {
        return ifPrimaryTerm;
    }

    /**
     * only perform this delete request if the document was last modification was assigned the given
     * sequence number. Must be used in combination with {@link #setIfPrimaryTerm(long)}
     *
     * If the document last modification was assigned a different sequence number a
     * {@link org.elasticsearch.index.engine.VersionConflictEngineException} will be thrown.
     */
    public DeleteRequest setIfSeqNo(long seqNo) {
        if (seqNo < 0 && seqNo != UNASSIGNED_SEQ_NO) {
            throw new IllegalArgumentException("sequence numbers must be non negative. got [" + seqNo + "].");
        }
        ifSeqNo = seqNo;
        return this;
    }

    /**
     * only perform this delete request if the document was last modification was assigned the given
     * primary term. Must be used in combination with {@link #setIfSeqNo(long)}
     *
     * If the document last modification was assigned a different primary term a
     * {@link org.elasticsearch.index.engine.VersionConflictEngineException} will be thrown.
     */
    public DeleteRequest setIfPrimaryTerm(long term) {
        if (term < 0) {
            throw new IllegalArgumentException("primary term must be non negative. got [" + term + "]");
        }
        ifPrimaryTerm = term;
        return this;
    }

    @Override
    public VersionType versionType() {
        return this.versionType;
    }

    @Override
    public OpType opType() {
        return OpType.DELETE;
    }

    @Override
    public boolean isRequireAlias() {
        return false;
    }

    @Override
    public void process(IndexRouting indexRouting) {
        // Nothing to do
    }

    @Override
    public int route(IndexRouting indexRouting) {
        return indexRouting.deleteShard(id, routing);
    }

    @Override
    public void writeTo(StreamOutput out) throws IOException {
        super.writeTo(out);
        writeBody(out);
    }

    @Override
    public void writeThin(StreamOutput out) throws IOException {
        super.writeThin(out);
        writeBody(out);
    }

    private void writeBody(StreamOutput out) throws IOException {
        if (out.getTransportVersion().before(TransportVersion.V_8_0_0)) {
            out.writeString(MapperService.SINGLE_MAPPING_NAME);
        }
        out.writeString(id);
        out.writeOptionalString(routing());
        out.writeLong(version);
        out.writeByte(versionType.getValue());
        out.writeZLong(ifSeqNo);
        out.writeVLong(ifPrimaryTerm);
    }

    @Override
    public String toString() {
        return "delete {[" + index + "][" + id + "]}";
    }

    @Override
    public long ramBytesUsed() {
        return SHALLOW_SIZE + RamUsageEstimator.sizeOf(id);
    }
}
