import { customAlphabet } from '@nanoid';
import { STATUS_CODE, STATUS_TEXT, StatusCode } from '@std/http';

import config from '~config';

import dbClient from 'db/client.ts';

// Using custom alphabet to exclude - and _
const alphabet = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
const nanoid = customAlphabet(alphabet, 20);

const genericResponse = (status: StatusCode, customText = '') =>
  new Response(customText || STATUS_TEXT[status], { status: status, statusText: STATUS_TEXT[status] });

Deno.serve({ port: config.api.port }, async (req) => {
  const urlPath = req.url.split('?')[0] ?? '';
  const path = (urlPath.split('api')[1] ?? '').toLowerCase().trim();
  console.log(urlPath, path);

  if (req.method === 'GET') {
    // handle all gets
  } else if (req.method === 'POST' && (path === '/enroll' || path === '/enroll/')) {
    const body = await req.json();

    let readFailure = false;
    const userNameMatches = await dbClient.query('SELECT name FROM users WHERE name = ?', [body.name]).catch(() => {
      readFailure = true;
    });
    if (readFailure) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");

    if (userNameMatches.length === 0) {
      if (body.name.length < 4 || body.name.length > 20) return genericResponse(STATUS_CODE.BadRequest, `Name too ${body.name.length < 4 ? 'short' : 'long'}.`);
      if (body.pin.length < 4 || body.pin.length > 20) return genericResponse(STATUS_CODE.BadRequest, `PIN too ${body.pin.length < 4 ? 'short' : 'long'}.`);
      if (body.email.length > 20) return genericResponse(STATUS_CODE.BadRequest, `Email too long.`);

      const id = nanoid();

      let writeFailure = false;
      await dbClient.execute('INSERT INTO users(id,name,pin,email) values(?,?,?,?)', [id, body.name, body.pin, body.email]).catch(() => {
        writeFailure = true;
      });

      if (writeFailure) {
        return genericResponse(STATUS_CODE.InternalServerError, "Couldn't write DB.");
      } else {
        return genericResponse(STATUS_CODE.OK, JSON.stringify({ id }));
      }
    } else {
      return genericResponse(STATUS_CODE.BadRequest, 'Username Taken.');
    }
  } else {
    const body = await req.json();

    let readFailure = false;
    const loginMatch = await dbClient.query('SELECT id, email, deleteCode FROM users WHERE name = ? AND pin = ?', [body.name, body.pin]).catch(() => {
      readFailure = true;
    });
    if (readFailure) return genericResponse(STATUS_CODE.InternalServerError, "Couldn't read DB.");
    if (loginMatch.length === 0) return genericResponse(STATUS_CODE.Forbidden, 'Invalid name/PIN combination.');
    const id = loginMatch[0].id;
    const email = loginMatch[0].email;
    const deleteCode = loginMatch[0].deleteCode;

    switch (req.method) {
      case 'POST':
        if (path === '/auth' || path === '/auth/') {
          return genericResponse(STATUS_CODE.OK, JSON.stringify({ id, hasEmail: email.length > 0 }));
        }
        break;
      case 'PUT':
        break;
      case 'DELETE':
        if (path === '/unenroll' || '/unenroll/') {
          //
        }
        break;
    }
  }

  return genericResponse(STATUS_CODE.NotImplemented);
});