/*
 * 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", the "GNU Affero General Public License v3.0 only", 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", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.rest.action.admin.indices;

import org.elasticsearch.action.admin.indices.template.get.GetComposableIndexTemplateAction;
import org.elasticsearch.client.internal.node.NodeClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.rest.BaseRestHandler;
import org.elasticsearch.rest.RestRequest;
import org.elasticsearch.rest.RestUtils;
import org.elasticsearch.rest.Scope;
import org.elasticsearch.rest.ServerlessScope;
import org.elasticsearch.rest.action.RestCancellableNodeClient;
import org.elasticsearch.rest.action.RestToXContentListener;

import java.io.IOException;
import java.util.List;
import java.util.Set;

import static org.elasticsearch.rest.RestRequest.Method.GET;
import static org.elasticsearch.rest.RestRequest.Method.HEAD;
import static org.elasticsearch.rest.RestStatus.NOT_FOUND;
import static org.elasticsearch.rest.RestStatus.OK;

@ServerlessScope(Scope.PUBLIC)
public class RestGetComposableIndexTemplateAction extends BaseRestHandler {

    @Override
    public List<Route> routes() {
        return List.of(
            new Route(GET, "/_index_template"),
            new Route(GET, "/_index_template/{name}"),
            new Route(HEAD, "/_index_template/{name}")
        );
    }

    @Override
    public String getName() {
        return "get_composable_index_template_action";
    }

    @Override
    public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client) throws IOException {
        final GetComposableIndexTemplateAction.Request getRequest = new GetComposableIndexTemplateAction.Request(
            RestUtils.getMasterNodeTimeout(request),
            request.param("name")
        );
        getRequest.includeDefaults(request.paramAsBoolean("include_defaults", false));
        RestUtils.consumeDeprecatedLocalParameter(request);

        final boolean implicitAll = getRequest.name() == null;

        return channel -> new RestCancellableNodeClient(client, request.getHttpChannel()).execute(
            GetComposableIndexTemplateAction.INSTANCE,
            getRequest,
            new RestToXContentListener<>(channel, r -> {
                final boolean templateExists = r.indexTemplates().isEmpty() == false;
                return (templateExists || implicitAll) ? OK : NOT_FOUND;
            })
        );
    }

    @Override
    protected Set<String> responseParams() {
        return Settings.FORMAT_PARAMS;
    }

}