/*-
 * ============LICENSE_START=======================================================
 * ONAP - SO
 * ================================================================================
 * Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * 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.
 * ============LICENSE_END=========================================================
 */

package org.onap.so.adapters.vdu;

/**
 * This interface defines a common API for template-based cloud deployments. The methods here should be adaptable for
 * Openstack (Heat), Cloudify (TOSCA), Aria (TOSCA), Multi-VIM (TBD), and others (e.g. Azure Resource Manager).
 * 
 * The deployed instances are referred to here as Virtual Deployment Units (VDUs). The package of templates that define
 * a give VDU is referred to as its blueprint.
 * 
 * Template-based orchestrators all follow a similar template/blueprint model. - One main template that is the top level
 * definition - Optional nested templates referenced/included by the main template - Optional files attached to the
 * template package, typically containing configuration files, install scripts, orchestration scripts, etc.
 * 
 * The main template also defines the required inputs for creating a new instance, and output values exposed by
 * successfully deployed instances. Inputs and outputs may include simple or complex (JSON) data types.
 * 
 * Each implementation of this interface is expected to understand the MSO CloudConfig to obtain the credentials for its
 * sub-orchestrator and the targeted cloud. The sub-orchestrator may have different credentials from the cloud (e.g. an
 * Aria instance in front of an Openstack cloud) or they may be the same (e.g. Heat)
 */
import java.util.Map;

public interface VduPlugin {

    /**
     * The instantiateVdu interface deploys a new VDU instance from a vdu model package.
     * 
     * For some VIMs, this may be a single command (e.g. Heat -> create stack) or may require a series of API calls
     * (e.g. Cloudify -> upload blueprint, create deployment, execute install workflow). These details are hidden within
     * the plug-in implementation. The instantiation should be fully completed before returning. On failures, this
     * method is expected to back out the attempt, leaving the cloud in its previous state.
     * 
     * It is expected that parameters have been validated and contain at minimum the required parameters for the given
     * template with no extra parameters.
     *
     * The VDU name supplied by the caller will be globally unique, and identify the artifact in A&AI. Inventory is
     * managed by the higher levels invoking this function.
     *
     * @param cloudInfo The target cloud + tenant identifiers for the VDU.
     * @param instanceName A unique name for the VDU instance to update.
     * @param inputs A map of key/value inputs. Values may be strings, numbers, or JSON objects. Will completely replace
     *        any inputs provided on the original instantiation.
     * @param vduModel Object containing the collection of templates and files that comprise the blueprint for this VDU.
     * @param rollbackOnFailure Flag to preserve or roll back the update on Failure. Should normally be True except in
     *        troubleshooting/debug cases. Might not be supported in all plug-ins.
     * 
     * @return A VduInstance object
     * @throws VduException Thrown if the sub-orchestrator API calls fail or if a timeout occurs. Various subclasses of
     *         VduException may be thrown.
     */
    public VduInstance instantiateVdu(CloudInfo cloudInfo, String instanceName, Map<String, Object> inputs,
            VduModelInfo vduModel, boolean rollbackOnFailure) throws VduException;

    /**
     * Query a deployed VDU instance. This call will return a VduInstance object, or null if the deployment does not
     * exist.
     * 
     * Some VIM orchestrators identify deployment instances by string UUIDs, and others by integers. In the latter case,
     * the ID will be passed in as a numeric string.
     *
     * The returned VduInstance object contains the input and output parameter maps, as well as other properties of the
     * deployment (name, status, last action, etc.).
     * 
     * @param cloudInfo The target cloud + tenant identifiers for the VDU.
     * @param vduInstanceId The ID of the deployment to query
     * 
     * @return A VduInstance object
     * @throws VduException Thrown if the sub-orchestrator API calls fail or if a timeout occurs. Various subclasses of
     *         VduException may be thrown.
     */
    public VduInstance queryVdu(CloudInfo cloudInfo, String vduInstanceId) throws VduException;


    /**
     * Delete a VDU instance by ID. If the VIM sub-orchestrator supports pre-installation of blueprints/models, the
     * blueprint itself may remain installed. This is recommended, since other VDU instances may be using it.
     * 
     * Some VIM orchestrators identify deployment instances by string UUIDs, and others by integers. In the latter case,
     * the ID will be passed in as a numeric string.
     * 
     * For some VIMs, deletion may be a single command (e.g. Heat -> delete stack) or a series of API calls (e.g.
     * Cloudify -> execute uninstall workflow, delete deployment). These details are hidden within the plug-in
     * implementation. The deletion should be fully completed before returning.
     * 
     * The successful return is a VduInstance object which contains the state of the VDU just prior to deletion, with a
     * status of DELETED. If the deployment was not found, the VduInstance object should be empty (with a status of
     * NOTFOUND). There is no rollback from a successful deletion.
     * 
     * A deletion failure will result in an undefined deployment state - the components may or may not have been all or
     * partially uninstalled, so the resulting deployment must be considered invalid.
     *
     * @param cloudInfo The target cloud + tenant identifiers for the VDU.
     * @param instanceId The unique id of the deployment to delete.
     * @param timeoutMinutes Timeout after which the delete action will be cancelled. Consider sending the entire model
     *        here, if it may be of use to the plug-in?
     * 
     * @return A VduInstance object, representing its state just prior to deletion.
     * 
     * @throws VduException Thrown if the API calls fail or if a timeout occurs. Various subclasses of VduException may
     *         be thrown.
     */
    public VduInstance deleteVdu(CloudInfo cloudInfo, String instanceId, int timeoutMinutes) throws VduException;


    /**
     * The updateVdu interface attempts to update a VDU in-place, using either new inputs or a new model definition
     * (i.e. updated templates/blueprints). This depends on the capabilities of the targeted sub-orchestrator, as not
     * all implementations are expected to support this ability. It is primary included initially only for Heat.
     *
     * It is expected that parameters have been validated and contain at minimum the required parameters for the given
     * template with no extra parameters. The VDU instance name cannot be updated.
     * 
     * The update should be fully completed before returning. The successful return is a VduInstance object containing
     * the updated VDU state.
     * 
     * An update failure will result in an undefined deployment state - the components may or may not have been all or
     * partially modified, deleted, recreated, etc. So the resulting VDU must be considered invalid.
     * 
     * @param cloudInfo The target cloud + tenant identifiers for the VDU.
     * @param instanceId The unique ID for the VDU instance to update.
     * @param inputs A map of key/value inputs. Values may be strings, numbers, or JSON objects. Will completely replace
     *        any inputs provided on the original instantiation.
     * @param vduModel Object containing the collection of templates and files that comprise the blueprint for this VDU.
     * @param rollbackOnFailure Flag to preserve or roll back the update on Failure. Should normally be True except in
     *        troubleshooting/debug cases. Might not be supported in all plug-ins.
     * 
     * @return A VduInfo object
     * @throws VduException Thrown if the sub-orchestrator API calls fail or if a timeout occurs. Various subclasses of
     *         VduException may be thrown.
     */
    public VduInstance updateVdu(CloudInfo cloudInfo, String instanceId, Map<String, Object> inputs,
            VduModelInfo vduModel, boolean rollbackOnFailure) throws VduException;

}