#!/usr/bin/env node
// Determines total battle counts per format since the beginning of stats
// collection in order to determine what the fallback dates for the importer's
// `STATISTICS` map should be.

'use strict';

const smogon = require('smogon');
const importer = require('./importer');
const Dex = require('../../.sim-dist/dex').Dex;

const formats = new Map();
for (let gen = 1; gen <= 7; gen++) {
	for (const tier of importer.TIERS) {
		const format = Dex.getFormat(`gen${gen}${tier}`);
		if (format.exists) {
			formats.set(format.id, {});
		}
	}
}

(async () => {
	const index = await importer.fetch(smogon.Statistics.URL);
	const begin = new Date('Nov 2014');
	const end = new Date(smogon.Statistics.latest(index));
	end.setDate(end.getDate() + 1);
	for (const d = begin; d <= end; d.setMonth(d.getMonth() + 1)) {
		const month = `${d.getMonth() + 1}`.padStart(2, '0');
		const date = `${1900 + d.getYear()}-${month}`;
		const raw = await importer.fetch(`${smogon.Statistics.URL}${date}/`);
		for (const format of formats.keys()) {
			// Some formats changed names after Gen 6 (eg. 'ou' -> 'gen6ou.json' etc), but for
			// our purposes this doesn't really matter as there should still be the data we need
			// under the correct format ID.
			if (raw.includes(format)) {
				try {
					const usage = await importer.fetch(`${smogon.Statistics.URL}${date}/${format}-1500.txt`);
					formats.get(format)[date] = Number(usage.match(/Total battles: (.*)/)[1]);
				} catch (err) {
					if (!err.message.startsWith('HTTP 404')) throw err;
				}
			}
		}
	}

	console.log(JSON.stringify(Array.from(formats.entries()), null, 2));
})().catch(err => console.error(err));