import { PromUtil } from "../../src";
import { globalRoot } from "../../src/common/env/env.profile";

export type ProcessExitType = (
  `exit` | `SIGINT` | `SIGUSR1` | `SIGUSR2` | `uncaughtException` | `SIGTERM` | `graceful`
)
class ProcessExitHandler {
  allExitEvents = [`exit`, `SIGINT`, `SIGUSR1`, `SIGUSR2`, `uncaughtException`, `SIGTERM`] as ProcessExitType[];
  handlers = [] as { handler: (eventType: ProcessExitType) => any; source: Error }[];
  exiting = false;
  gracefulExitPromises = [] as Promise<any>[];
  defaultGracePeriod = 7000;
  addEndingTask(taskPromise: Promise<any>) {
    this.gracefulExitPromises.push(taskPromise);
  }
  gracefully(exitCode: number = 0, gracePeriod: number = this.defaultGracePeriod, lastCallback?: () => any) {
    if (!gracePeriod) { gracePeriod = this.defaultGracePeriod; }
    if (this.exiting) { return false; }
    this.exiting = true;
    for (const handlerData of this.handlers) {
      try { handlerData.handler(`graceful`); } catch (e) { console.error(e); }
    }
    PromUtil.allSettled(this.gracefulExitPromises).finally(() => {
      if (lastCallback) { lastCallback(); }
      setTimeout(() => { process.exit(exitCode); }, 100);
    });
    setTimeout(() => {
      if (lastCallback) { lastCallback(); }
      setTimeout(() => { process.exit(exitCode); }, 100);
    }, gracePeriod);
    return true;
  }
  addHandler(handler: (eventType: ProcessExitType) => any) {
    this.handlers.push({ handler, source: new Error });
    this.allExitEvents.forEach(eventType => {
      const bound = handler.bind(null, eventType);
      process.on(eventType, () => {
        try { bound(); } catch (e) { console.error(e); }
      });
    });
  }
}

const processExitHandler = new ProcessExitHandler;

if (!globalRoot.ProcessExitHandler) { globalRoot.ProcessExitHandler = processExitHandler; }

export const ProcessExit = new Proxy(globalRoot.ProcessExitHandler as ProcessExitHandler, {});