import Fastify from "fastify";
import { restartable } from "@fastify/restartable";
import FastifyStatic from "@fastify/static";
import path from "path";
import fs from "fs";
import chokidar from "chokidar";
import nunjucks from "nunjucks";

export const description = "Runs your app.";

export const options = [];

export const required = [];

let CONFIGURED = false;

// nunjucks does it's own reload so let it do that
nunjucks.configure("templates", { watch: true });

const configure = async (fastify, opts) => {

  // MAGIC: this is how you trick the importer to reload modules
  // that have changed. Since it uses a URL you can add a query
  // to it, but that isn't parsed as the file. Using a date then
  // tags the module as being "new" when it's still the same file
  // TODO: maybe use fs timestamps instead?
  // BUG: sometimes reload is too fast for vim and crashes
  const controller = await import(`../controllers/todo.js?update=${new Date()}`);

  const handler = new controller.Todo();
  const app = fastify(opts);

  // this is a sample that uses the handler we dynamic load
  // to handle the /todo but not sure how to work the actual
  // URL mappings for it.  Also not sure about using classes
  app.get("/todo", async (req, rep) => {
    try {
      await handler.get(req, rep);
    } catch(error) {
      console.error(error);
      console.error(error.stack);
      console.error(error.source);
    }
  });

  app.register(FastifyStatic, {
    root: path.join(path.resolve("."), 'static'),
    prefix: '/', // optional: default '/'
    constraints: {}, // optional: default {}
    index: "index.html"
  });

  // this is from fastify/restartable
  app.addHook('onClose', async () => {
    if(!app.closingRestartable) {
      console.log('closing the app because of restart')
    } else{
      console.log('closing the app because server is stopping')
    }
  })

  return app;
}

const app = await await restartable(configure, { logger: true});
const host = await app.listen({port: 3000});

const reload = () => {
  if(CONFIGURED) {
    app.restart();
  }
}

export const main = async (arg, opts) => {
  try {
    chokidar.watch(["lib","commands","controllers","static","migrations","tests"])
    .on("add", path => reload())
    .on("change", path => reload())
    .on("unlink", path => reload())
    .on("ready", () => CONFIGURED = true);
  } catch(err) {
    fastify.log.error(err);
    process.exit(1);
  }
}