/*
 *
 *  Copyright 2016 Netflix, 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.netflix.genie.web.controllers;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
import com.netflix.genie.web.hateoas.assemblers.RootResourceAssembler;
import com.netflix.genie.web.hateoas.resources.RootResource;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.hateoas.MediaTypes;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;

/**
 * Rest controller for the V3 API root.
 *
 * @author tgianos
 * @since 3.0.0
 */
@RestController
@RequestMapping(value = "/api/v3")
@Slf4j
public class RootRestController {

    private final RootResourceAssembler rootResourceAssembler;

    /**
     * Constructor.
     *
     * @param rootResourceAssembler The assembler to use to construct resources.
     */
    @Autowired
    public RootRestController(final RootResourceAssembler rootResourceAssembler) {
        this.rootResourceAssembler = rootResourceAssembler;
    }

    /**
     * Get a simple HAL+JSON object which represents the various links available in Genie REST API as an entry point.
     *
     * @return the root resource containing various links to the real APIs
     */
    @RequestMapping(method = RequestMethod.GET, produces = MediaTypes.HAL_JSON_VALUE)
    @ResponseStatus(HttpStatus.OK)
    public RootResource getRoot() {
        final JsonNodeFactory factory = JsonNodeFactory.instance;
        final JsonNode node = factory
            .objectNode()
            .set(
                "description",
                factory.textNode("Genie V3 API")
            );
        return this.rootResourceAssembler.toResource(node);
    }
}