// re-exports
export * from '@line/bot-sdk';

import './polyfill';
import { resolve } from 'path';
import * as express from 'express';
import * as getPort from 'get-port';
import * as clipboardy from 'clipboardy';
import { middleware, Client, WebhookEvent, Message } from '@line/bot-sdk';
import { args, script, config } from './opts';
import { createSender } from './sender';
import { ngrok } from './ngrok';
import * as keypress from './keypress';
import { ModuleLoader } from './moduleloader';

type KaedeContext = {
  client: Client;
  baseUrl: string | null;
  staticRoot: string;
};
type KaedeHandler =
  (event: WebhookEvent, ctx: KaedeContext) => AsyncIterable<Message>;

export async function main() {
  const app = express();
  const ctx: KaedeContext = {
    client: new Client(config),
    baseUrl: null,
    staticRoot: resolve(args.static),
  };

  const loader = new ModuleLoader<KaedeHandler>(script);
  function reload() {
    loader.reload();
    console.log('updated');
  }
  keypress.on('enter', reload);
  keypress.on('return', reload);

  app.use(express.static(ctx.staticRoot));

  app.post('*', middleware(config), (req, res) => {
    // early return
    res.end();

    const events: Array<WebhookEvent> = req.body.events;

    events.forEach(async event => {
      const sender = createSender(ctx.client, event);
      try {
        for await (const message of loader.content(event, ctx)) {
          await sender.send(message);
        }
      } catch (err) {
        console.error(err);
      } finally {
        await sender.flush();
      }
    });
  });

  const port = await getPort();

  await new Promise(resolve => app.listen(port, resolve));
  ctx.baseUrl = await ngrok(port);
  console.log(`Listening at ${ctx.baseUrl}`);

  const baseUrlWithoutProtocol = ctx.baseUrl.split('//')[1]; // remove https://
  await clipboardy.write(baseUrlWithoutProtocol);
  console.log(`${baseUrlWithoutProtocol} is copied to the clipboard\n`);

  keypress.init();
  console.log('Press Enter/Return to reload the bot script');
  console.log('Press Ctrl+C/D to quit');
}