/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.epam.dlab.backendapi.service.impl;

import com.epam.dlab.backendapi.ProvisioningServiceApplicationConfiguration;
import com.epam.dlab.backendapi.core.Directories;
import com.epam.dlab.backendapi.core.commands.DockerAction;
import com.epam.dlab.backendapi.core.commands.DockerCommands;
import com.epam.dlab.backendapi.core.commands.RunDockerCommand;
import com.epam.dlab.backendapi.core.response.handlers.ReuploadKeyCallbackHandler;
import com.epam.dlab.dto.reuploadkey.ReuploadKeyCallbackDTO;
import com.epam.dlab.dto.reuploadkey.ReuploadKeyDTO;
import com.epam.dlab.exceptions.DlabException;
import com.epam.dlab.model.ResourceData;
import com.epam.dlab.rest.contracts.ApiCallbacks;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import lombok.extern.slf4j.Slf4j;

import java.io.IOException;

import static java.lang.String.format;
import static java.nio.file.Files.readAllBytes;
import static java.nio.file.Paths.get;

@Slf4j
@Singleton
public class KeyService extends DockerService implements DockerCommands {

	private static final String REUPLOAD_KEY_ACTION = "reupload_key";

	private final ProvisioningServiceApplicationConfiguration conf;

	@Inject
	public KeyService(ProvisioningServiceApplicationConfiguration conf) {
		this.conf = conf;
	}


	public void reuploadKeyAction(String userName, ReuploadKeyDTO dto, DockerAction action) {
		log.debug("{} for edge user {}", action, dto.getEdgeUserName());

		long count = dto.getResources()
				.stream()
				.map(resourceData -> buildCallbackDTO(resourceData, getUuid(), dto))
				.peek(callbackDto -> startCallbackListener(userName, callbackDto))
				.peek(callbackDto ->
						runDockerCmd(userName, callbackDto.getId(), buildRunDockerCommand(callbackDto, action),
								buildDockerCommandDTO(callbackDto)))
				.count();
		log.debug("Executed {} Docker commands", count);
	}

	public String getAdminKey() {
		try {
			return new String(readAllBytes(get(format("%s/%s.pem", conf.getKeyDirectory(), conf.getAdminKey()))));
		} catch (IOException e) {
			log.error("Can not read admin key: {}", e.getMessage());
			throw new DlabException("Can not read admin key: " + e.getMessage(), e);
		}
	}

	private String getUuid() {
		return DockerCommands.generateUUID();
	}

	private void runDockerCmd(String userName, String uuid, RunDockerCommand runDockerCommand,
							  ReuploadKeyCallbackDTO callbackDto) {
		try {
			final String command = commandBuilder.buildCommand(runDockerCommand, callbackDto);
			log.trace("Docker command: {}", command);
			commandExecutor.executeAsync(userName, uuid, command);
		} catch (Exception e) {
			log.error("Exception occured during reuploading key: {} for command {}", e.getLocalizedMessage(),
					runDockerCommand.toCMD());
		}
	}

	private void startCallbackListener(String userName, ReuploadKeyCallbackDTO dto) {
		folderListenerExecutor.start(configuration.getKeyLoaderDirectory(),
				configuration.getKeyLoaderPollTimeout(),
				new ReuploadKeyCallbackHandler(selfService, ApiCallbacks.REUPLOAD_KEY_URI,
						userName, dto));
	}

	@Override
	public String getResourceType() {
		return Directories.EDGE_LOG_DIRECTORY;
	}

	private RunDockerCommand buildRunDockerCommand(ReuploadKeyCallbackDTO callbackDto, DockerAction action) {
		return new RunDockerCommand()
				.withInteractive()
				.withName(getContainerName(callbackDto))
				.withVolumeForRootKeys(configuration.getKeyDirectory())
				.withVolumeForResponse(configuration.getKeyLoaderDirectory())
				.withVolumeForLog(configuration.getDockerLogDirectory(), getResourceType())
				.withResource(callbackDto.getResource().getResourceType().toString())
				.withRequestId(callbackDto.getId())
				.withConfKeyName(configuration.getAdminKey())
				.withImage(configuration.getEdgeImage())
				.withAction(action);
	}

	private ReuploadKeyCallbackDTO buildCallbackDTO(ResourceData resource, String uuid, ReuploadKeyDTO dto) {
		return new ReuploadKeyCallbackDTO()
				.withId(uuid)
				.withEdgeUserName(dto.getEdgeUserName())
				.withServiceBaseName(dto.getServiceBaseName())
				.withConfOsFamily(dto.getConfOsFamily())
				.withResourceId(resource.getResourceId())
				.withResource(resource);
	}

	private ReuploadKeyCallbackDTO buildDockerCommandDTO(ReuploadKeyCallbackDTO dto) {
		return new ReuploadKeyCallbackDTO()
				.withEdgeUserName(dto.getEdgeUserName())
				.withServiceBaseName(dto.getServiceBaseName())
				.withConfOsFamily(dto.getConfOsFamily())
				.withResourceId(dto.getResourceId());
	}

	private String getContainerName(ReuploadKeyCallbackDTO callbackDto) {
		return nameContainer(callbackDto.getEdgeUserName(), REUPLOAD_KEY_ACTION,
				callbackDto.getResource().getResourceType().toString(),
				callbackDto.getResource().getResourceId());
	}

}