/*
 * Copyright © 2020 Atomist, 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.
 */

import { Parameter, Parameters } from "@atomist/automation-client/lib/decorators";
import { HandlerResult } from "@atomist/automation-client/lib/HandlerResult";
import { logger } from "@atomist/automation-client/lib/util/logger";
import * as _ from "lodash";
import { slackSuccessMessage } from "../../../api-helper/misc/slack/messages";
import { CommandListenerInvocation } from "../../../api/listener/CommandListener";
import { SoftwareDeliveryMachine } from "../../../api/machine/SoftwareDeliveryMachine";
import { CommandHandlerRegistration } from "../../../api/registration/CommandHandlerRegistration";
import { deleteApplication } from "../kubernetes/application";
import { cleanName } from "../support/name";
import { K8sDefaultNamespace } from "../support/namespace";
import { syncApplication } from "../sync/application";

@Parameters()
export class KubernetesUndeployParameters {
    @Parameter({
        displayName: "Name",
        description: "name of resources to remove",
        pattern: /^[a-z](?:[-a-z0-9]*[a-z0-9])?$/,
        validInput:
            "a valid Kubernetes resource name, beginning with a lowercase letter, ending with a lowercase" +
            "letter or number, and containing only lowercase letters, numbers, and dashes (-)",
        minLength: 1,
        maxLength: 63,
        required: true,
    })
    public name: string;

    @Parameter({
        displayName: "Namespace",
        description: "namespace of resources to remove",
        pattern: /^[a-z](?:[-a-z0-9]*[a-z0-9])?$/,
        validInput:
            "a valid Kubernetes namespace, beginning with a lowercase letter, ending with a lowercase" +
            "letter or number, and containing only lowercase letters, numbers, and dashes (-)",
        minLength: 1,
        maxLength: 63,
        required: false,
    })
    public ns: string = K8sDefaultNamespace;
}

/**
 * Safely remove all resources related to a Kubernetes application.
 *
 * If the SDM configuration says this packs commands should be added,
 * i.e., `sdm.configuration.sdm.k8s.options.addCommands` is `true`,
 * the command will have the intent `kube undeploy SDM_NAME`.
 * Otherwise the command will be registered without an intent.
 */
export function kubernetesUndeploy(sdm: SoftwareDeliveryMachine): CommandHandlerRegistration<KubernetesUndeployParameters> {
    const cmd: CommandHandlerRegistration<KubernetesUndeployParameters> = {
        name: "KubernetesUndeploy",
        description: "remove all resources related to an application from Kubernetes cluster",
        paramsMaker: KubernetesUndeployParameters,
        listener: kubeUndeploy,
    };
    if (_.get(sdm, "configuration.sdm.k8s.options.addCommands", false)) {
        cmd.intent = `kube undeploy ${cleanName(sdm.configuration.name)}`;
    }
    return cmd;
}

/**
 * Delete an application from a Kubernetes cluster.  If any of the
 * application resources do not exist in the cluster, they are
 * ignored.  In other words, it is not an error to try to delete
 * something that does not exist.  If a sync repo is configured, the
 * corresponding resource specs are deleted from the sync repo.
 */
async function kubeUndeploy(ci: CommandListenerInvocation<KubernetesUndeployParameters>): Promise<HandlerResult> {
    const slug = `${ci.parameters.ns}/${ci.parameters.name}`;
    const delApp = {
        name: ci.parameters.name,
        ns: ci.parameters.ns,
        workspaceId: ci.context.workspaceId,
    };
    const result: HandlerResult = {
        code: 0,
        message: `Successfully deleted ${slug} resources from Kubernetes`,
    };
    try {
        const deleted = await deleteApplication(delApp);
        logger.info(result.message);
        try {
            await syncApplication(delApp, deleted, "delete");
        } catch (err) {
            result.code++;
            const msg = `Failed to delete resource specs from sync repo: ${err.message}`;
            logger.error(msg);
            result.message = `${result.message} but ${msg}`;
        }
        try {
            await ci.context.messageClient.respond(slackSuccessMessage("Kubernetes Undeploy", result.message));
        } catch (err) {
            const msg = `Failed to send response message: ${err.message}`;
            logger.error(msg);
            result.message = `${result.message} but ${msg}`;
        }
    } catch (e) {
        result.code++;
        result.message = `Failed to delete all ${slug} resources from Kubernetes: ${e.message}`;
        logger.error(result.message);
        try {
            await ci.context.messageClient.respond(result.message);
        } catch (err) {
            result.code++;
            result.message = `${result.message}; Failed to send response message: ${err.message}`;
            logger.error(result.message);
        }
    }
    return result;
}