/*
 * 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; you may not use this file except in compliance with the Elastic License
 * 2.0.
 */
package org.elasticsearch.xpack.core.ccr.action;

import org.elasticsearch.action.ActionType;
import org.elasticsearch.action.ActionRequestValidationException;
import org.elasticsearch.action.ActionResponse;
import org.elasticsearch.action.support.master.MasterNodeReadRequest;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.common.xcontent.ToXContentObject;
import org.elasticsearch.common.xcontent.XContentBuilder;

import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;

public class FollowInfoAction extends ActionType<FollowInfoAction.Response> {

    public static final String NAME = "cluster:monitor/ccr/follow_info";

    public static final FollowInfoAction INSTANCE = new FollowInfoAction();

    private FollowInfoAction() {
        super(NAME, FollowInfoAction.Response::new);
    }

    public static class Request extends MasterNodeReadRequest<Request> {

        private String[] followerIndices;

        public Request() {
        }

        public String[] getFollowerIndices() {
            return followerIndices;
        }

        public void setFollowerIndices(String... followerIndices) {
            this.followerIndices = followerIndices;
        }

        @Override
        public ActionRequestValidationException validate() {
            return null;
        }

        public Request(StreamInput in) throws IOException {
            super(in);
            followerIndices = in.readOptionalStringArray();
        }

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

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Request request = (Request) o;
            return Arrays.equals(followerIndices, request.followerIndices);
        }

        @Override
        public int hashCode() {
            return Arrays.hashCode(followerIndices);
        }
    }

    public static class Response extends ActionResponse implements ToXContentObject {

        public static final ParseField FOLLOWER_INDICES_FIELD = new ParseField("follower_indices");

        private final List<FollowerInfo> followInfos;

        public Response(List<FollowerInfo> followInfos) {
            this.followInfos = followInfos;
        }

        public List<FollowerInfo> getFollowInfos() {
            return followInfos;
        }

        public Response(StreamInput in) throws IOException {
            super(in);
            followInfos = in.readList(FollowerInfo::new);
        }

        @Override
        public void writeTo(StreamOutput out) throws IOException {
            out.writeList(followInfos);
        }

        @Override
        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
            builder.startObject();
            builder.startArray(FOLLOWER_INDICES_FIELD.getPreferredName());
            for (FollowerInfo followInfo : followInfos) {
                followInfo.toXContent(builder, params);
            }
            builder.endArray();
            builder.endObject();
            return builder;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Response response = (Response) o;
            return Objects.equals(followInfos, response.followInfos);
        }

        @Override
        public int hashCode() {
            return Objects.hash(followInfos);
        }

        public String toString() {
            return Strings.toString(this);
        }

        public static class FollowerInfo implements Writeable, ToXContentObject {

            public static final ParseField FOLLOWER_INDEX_FIELD = new ParseField("follower_index");
            public static final ParseField REMOTE_CLUSTER_FIELD = new ParseField("remote_cluster");
            public static final ParseField LEADER_INDEX_FIELD = new ParseField("leader_index");
            public static final ParseField STATUS_FIELD = new ParseField("status");
            public static final ParseField PARAMETERS_FIELD = new ParseField("parameters");

            private final String followerIndex;
            private final String remoteCluster;
            private final String leaderIndex;
            private final Status status;
            private final FollowParameters parameters;

            public FollowerInfo(String followerIndex, String remoteCluster, String leaderIndex, Status status,
                                FollowParameters parameters) {
                this.followerIndex = followerIndex;
                this.remoteCluster = remoteCluster;
                this.leaderIndex = leaderIndex;
                this.status = status;
                this.parameters = parameters;
            }

            public String getFollowerIndex() {
                return followerIndex;
            }

            public String getRemoteCluster() {
                return remoteCluster;
            }

            public String getLeaderIndex() {
                return leaderIndex;
            }

            public Status getStatus() {
                return status;
            }

            public FollowParameters getParameters() {
                return parameters;
            }

            FollowerInfo(StreamInput in) throws IOException {
                followerIndex = in.readString();
                remoteCluster = in.readString();
                leaderIndex = in.readString();
                status = Status.fromString(in.readString());
                parameters = in.readOptionalWriteable(FollowParameters::new);
            }

            @Override
            public void writeTo(StreamOutput out) throws IOException {
                out.writeString(followerIndex);
                out.writeString(remoteCluster);
                out.writeString(leaderIndex);
                out.writeString(status.name);
                out.writeOptionalWriteable(parameters);
            }

            @Override
            public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
                builder.startObject();
                builder.field(FOLLOWER_INDEX_FIELD.getPreferredName(), followerIndex);
                builder.field(REMOTE_CLUSTER_FIELD.getPreferredName(), remoteCluster);
                builder.field(LEADER_INDEX_FIELD.getPreferredName(), leaderIndex);
                builder.field(STATUS_FIELD.getPreferredName(), status.name);
                if (parameters != null) {
                    builder.startObject(PARAMETERS_FIELD.getPreferredName());
                    {
                        parameters.toXContentFragment(builder);
                    }
                    builder.endObject();
                }
                builder.endObject();
                return builder;
            }

            @Override
            public boolean equals(Object o) {
                if (this == o) return true;
                if (o == null || getClass() != o.getClass()) return false;
                FollowerInfo that = (FollowerInfo) o;
                return Objects.equals(followerIndex, that.followerIndex) &&
                    Objects.equals(remoteCluster, that.remoteCluster) &&
                    Objects.equals(leaderIndex, that.leaderIndex) &&
                    status == that.status &&
                    Objects.equals(parameters, that.parameters);
            }

            @Override
            public int hashCode() {
                return Objects.hash(followerIndex, remoteCluster, leaderIndex, status, parameters);
            }

            public String toString() {
                return Strings.toString(this);
            }
        }

        public enum Status {

            ACTIVE("active"),
            PAUSED("paused");

            private final String name;

            Status(String name) {
                this.name = name;
            }

            public static Status fromString(String value) {
                switch (value) {
                    case "active":
                        return Status.ACTIVE;
                    case "paused":
                        return Status.PAUSED;
                    default:
                        throw new IllegalArgumentException("unexpected status value [" + value + "]");
                }
            }
        }
    }

}
