'use strict';

const path = require('path');
const express = require('express');
const { gregorianToRepublican } = require('./src/republicanCalendar');

const app = express();
const port = process.env.PORT || 3000;

app.use(express.static(path.join(__dirname, 'public')));
app.use('/locales', express.static(path.join(__dirname, 'locales')));

function nowUtc() {
  const now = new Date();
  return {
    year: now.getUTCFullYear(),
    month: now.getUTCMonth() + 1,
    day: now.getUTCDate(),
  };
}

function convertAndRespond(res, gregorianDate) {
  try {
    const republicanDate = gregorianToRepublican(gregorianDate);
    res.json({ ok: true, republicanDate });
  } catch (error) {
    if (error.message === 'BEFORE_EPOCH') {
      res.status(400).json({
        ok: false,
        error: 'BEFORE_EPOCH',
        message: 'The Republican calendar begins on 22 September 1792.',
      });
      return;
    }
    res.status(400).json({
      ok: false,
      error: 'INVALID_DATE',
      message: 'The given date does not exist in the Gregorian calendar.',
    });
  }
}

app.get('/api/today', (req, res) => {
  convertAndRespond(res, nowUtc());
});

app.get('/api/convert', (req, res) => {
  const year = Number.parseInt(req.query.year, 10);
  const month = Number.parseInt(req.query.month, 10);
  const day = Number.parseInt(req.query.day, 10);

  if (!Number.isInteger(year) || !Number.isInteger(month) || !Number.isInteger(day)) {
    res.status(400).json({
      ok: false,
      error: 'INVALID_DATE',
      message: 'year, month and day query parameters are required integers.',
    });
    return;
  }

  convertAndRespond(res, { year, month, day });
});

app.listen(port, () => {
  console.log(`Calendrier republicain server listening on port ${port}`);
});