import { ChildProcess, spawn } from "child_process";
import { waitUntilUsed } from "tcp-port-used";
import { broadcastMessage } from "../common/ipc";
import type { Cluster } from "./cluster";
import { Kubectl } from "./kubectl";
import logger from "./logger";
import * as url from "url";
import { getPortFrom } from "./utils/get-port";

export interface KubeAuthProxyLog {
  data: string;
  error?: boolean; // stream=stderr
}

const startingServeRegex = /^starting to serve on (?<address>.+)/i;

export class KubeAuthProxy {
  public lastError: string;

  public get port(): number {
    return this._port;
  }

  protected _port: number;
  protected cluster: Cluster;
  protected env: NodeJS.ProcessEnv = null;
  protected proxyProcess: ChildProcess;
  protected kubectl: Kubectl;

  constructor(cluster: Cluster, env: NodeJS.ProcessEnv) {
    this.env = env;
    this.cluster = cluster;
    this.kubectl = Kubectl.bundled();
  }

  get acceptHosts() {
    return url.parse(this.cluster.apiUrl).hostname;
  }

  public async run(): Promise<void> {
    if (this.proxyProcess) {
      return;
    }

    const proxyBin = await this.kubectl.getPath();
    const args = [
      "proxy",
      "-p", "0",
      "--kubeconfig", `${this.cluster.kubeConfigPath}`,
      "--context", `${this.cluster.contextName}`,
      "--accept-hosts", this.acceptHosts,
      "--reject-paths", "^[^/]"
    ];

    if (process.env.DEBUG_PROXY === "true") {
      args.push("-v", "9");
    }
    logger.debug(`spawning kubectl proxy with args: ${args}`);

    this.proxyProcess = spawn(proxyBin, args, { env: this.env, });
    this.proxyProcess.on("error", (error) => {
      this.sendIpcLogMessage({ data: error.message, error: true });
      this.exit();
    });

    this.proxyProcess.on("exit", (code) => {
      this.sendIpcLogMessage({ data: `proxy exited with code: ${code}`, error: code > 0 });
      this.exit();
    });

    this.proxyProcess.stderr.on("data", (data) => {
      this.lastError = this.parseError(data.toString());
      this.sendIpcLogMessage({ data: data.toString(), error: true });
    });

    this._port = await getPortFrom(this.proxyProcess.stdout, {
      lineRegex: startingServeRegex,
      onFind: () => this.sendIpcLogMessage({ data: "Authentication proxy started\n" }),
    });

    this.proxyProcess.stdout.on("data", (data: any) => {
      this.sendIpcLogMessage({ data: data.toString() });
    });

    return waitUntilUsed(this.port, 500, 10000);
  }

  protected parseError(data: string) {
    const error = data.split("http: proxy error:").slice(1).join("").trim();
    let errorMsg = error;
    const jsonError = error.split("Response: ")[1];

    if (jsonError) {
      try {
        const parsedError = JSON.parse(jsonError);

        errorMsg = parsedError.error_description || parsedError.error || jsonError;
      } catch (_) {
        errorMsg = jsonError.trim();
      }
    }

    return errorMsg;
  }

  protected sendIpcLogMessage(res: KubeAuthProxyLog) {
    const channel = `kube-auth:${this.cluster.id}`;

    logger.info(`[KUBE-AUTH]: out-channel "${channel}"`, { ...res, meta: this.cluster.getMeta() });
    broadcastMessage(channel, res);
  }

  public exit() {
    if (!this.proxyProcess) return;
    logger.debug("[KUBE-AUTH]: stopping local proxy", this.cluster.getMeta());
    this.proxyProcess.kill();
    this.proxyProcess.removeAllListeners();
    this.proxyProcess.stderr.removeAllListeners();
    this.proxyProcess.stdout.removeAllListeners();
    this.proxyProcess = null;
  }
}