/**
 * Copyright (c) 2021 OpenLens Authors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

import type WebSocket from "ws";
import { v4 as uuid } from "uuid";
import * as k8s from "@kubernetes/client-node";
import type { KubeConfig } from "@kubernetes/client-node";
import type { Cluster } from "../cluster";
import { ShellOpenError, ShellSession } from "./shell-session";
import { get } from "lodash";
import { Node, NodesApi } from "../../common/k8s-api/endpoints";
import { KubeJsonApi } from "../../common/k8s-api/kube-json-api";
import logger from "../logger";
import { TerminalChannels } from "../../renderer/api/terminal-api";

export class NodeShellSession extends ShellSession {
  ShellType = "node-shell";

  protected readonly podName = `node-shell-${uuid()}`;
  protected kc: KubeConfig;

  protected readonly cwd: string | undefined = undefined;

  constructor(socket: WebSocket, cluster: Cluster, protected nodeName: string, terminalId: string) {
    super(socket, cluster, terminalId);
  }

  public async open() {
    this.kc = await this.cluster.getProxyKubeconfig();
    const shell = await this.kubectl.getPath();

    try {
      await this.createNodeShellPod();
      await this.waitForRunningPod();
    } catch (error) {
      this.deleteNodeShellPod();
      this.send({
        type: TerminalChannels.STDOUT,
        data: `Error occurred: ${get(error, "response.body.message", error?.toString() || "unknown error")}`,
      });

      throw new ShellOpenError("failed to create node pod", error);
    }

    const env = await this.getCachedShellEnv();
    const args = ["exec", "-i", "-t", "-n", "kube-system", this.podName, "--"];
    const nodeApi = new NodesApi({
      objectConstructor: Node,
      request: KubeJsonApi.forCluster(this.cluster.id),
    });
    const node = await nodeApi.get({ name: this.nodeName });
    const nodeOs = node.getOperatingSystem();

    switch (nodeOs) {
      default:
        logger.warn(`[NODE-SHELL-SESSION]: could not determine node OS, falling back with assumption of linux`);
      case "linux":
        args.push("sh", "-c", "((clear && bash) || (clear && ash) || (clear && sh))");
        break;
      case "windows":
        args.push("powershell");
        break;
    }

    await this.openShellProcess(shell, args, env);
  }

  protected createNodeShellPod() {
    const imagePullSecrets = this.cluster.imagePullSecret
      ? [{
        name: this.cluster.imagePullSecret,
      }]
      : undefined;

    return this
      .kc
      .makeApiClient(k8s.CoreV1Api)
      .createNamespacedPod("kube-system", {
        metadata: {
          name: this.podName,
          namespace: "kube-system",
        },
        spec: {
          nodeName: this.nodeName,
          restartPolicy: "Never",
          terminationGracePeriodSeconds: 0,
          hostPID: true,
          hostIPC: true,
          hostNetwork: true,
          tolerations: [{
            operator: "Exists",
          }],
          containers: [{
            name: "shell",
            image: this.cluster.nodeShellImage,
            securityContext: {
              privileged: true,
            },
            command: ["nsenter"],
            args: ["-t", "1", "-m", "-u", "-i", "-n", "sleep", "14000"],
          }],
          imagePullSecrets,
        },
      });
  }

  protected waitForRunningPod(): Promise<void> {
    logger.debug(`[NODE-SHELL]: waiting for ${this.podName} to be running`);

    return new Promise((resolve, reject) => {
      new k8s.Watch(this.kc)
        .watch(`/api/v1/namespaces/kube-system/pods`,
          {},
          // callback is called for each received object.
          (type, { metadata: { name }, status }) => {
            if (name === this.podName) {
              switch (status.phase) {
                case "Running":
                  return resolve();
                case "Failed":
                  return reject(`Failed to be created: ${status.message || "unknown error"}`);
              }
            }
          },
          // done callback is called if the watch terminates normally
          (err) => {
            logger.error(`[NODE-SHELL]: ${this.podName} was not created in time`);
            reject(err);
          },
        )
        .then(req => {
          setTimeout(() => {
            logger.error(`[NODE-SHELL]: aborting wait for ${this.podName}, timing out`);
            req.abort();
            reject("Pod creation timed out");
          }, 2 * 60 * 1000); // 2 * 60 * 1000
        })
        .catch(error => {
          logger.error(`[NODE-SHELL]: waiting for ${this.podName} failed: ${error}`);
          reject(error);
        });
    });
  }

  protected exit() {
    super.exit();
    this.deleteNodeShellPod();
  }

  protected deleteNodeShellPod() {
    this
      .kc
      .makeApiClient(k8s.CoreV1Api)
      .deleteNamespacedPod(this.podName, "kube-system")
      .catch(error => logger.warn(`[NODE-SHELL]: failed to remove pod shell`, error));
  }
}