const ApiError = require('../errorClass');
const config = require('../../../config-handler');

async function isAuthorExists (authorId) {
	if (!authorId) return false;
	return (await global.database.authors.promiseMode().get({ where : { id : authorId } })).length !== 0;
}

async function checkSyntaxArgs (req, res) {
	return !!(
		(  // Проверка поля type.
			['author', 'muzic'].indexOf(req.json?.type) !== -1
		) &&
		(  // Проверка поля name.
			typeof req.json.name === 'string' && req.json.name.length >= 2 && (
				req.json.type === 'muzic' ? true : config().authors_blacklist.filter((blacklisted) => {
					return req.json.name.toLowerCase().includes(blacklisted.toLowerCase());
				}).length === 0
			)
		) &&
		(  // Дополнительные поля для muzic
			req.json.type === 'muzic' ? !!(  // Для `muzic`
				(  // Проверка поля author_id.
					await isAuthorExists(req.json.author_id)
				) &&
				(  // Проверка поля data. (Передаётся либо ничего, либо строка с base64)
					req.json.data === undefined ? true : (
						typeof req.json.data === 'string'
					)
				)
			) : true
		)
	)
}

module.exports = async (req, res) => {
	if (req.json === undefined) {
		// console.log(req.headers);
		throw new ApiError("METHOD_MUST_BE_POST_JSON", {
			request_method : req.method,
			'content-type' : !req.headers['content-type'] ? null : req.headers['content-type']
		});
	}
	if (!await checkSyntaxArgs(req, res)) {
		throw new ApiError("INVALID_OR_UNSYNTAX_PARAMS", {
			request_method : req.method,
			params         : {
				type : req.json?.type === undefined ? null : req.json.type,
				name : req.json?.name === undefined ? null : req.json.name,
				...(req.json?.type === 'muzic' ? ({
					author_id : req.json?.author_id === undefined ? null : req.json?.author_id,
					data      : req.json?.data === undefined ? null : req.json.data,
				}) : ({}))
			}
		});
	}
	if (req.json.type === 'author') {
		let result = await global.database.authors.promiseMode().add({
			name : req.json.name,
			time : Math.round(new Date().getTime() / 1000)
		});
		return result.dataValues.id;
	}
	else {
		let result = await global.database.muzic.promiseMode().add({
			name      : req.json.name,
			author_id : req.json.author_id,
			data      : req.json.data === undefined ? undefined : Buffer.from(req.json.data, 'base64'),
			time      : Math.round(new Date().getTime() / 1000)
		});
		return result.dataValues.id;
	}
}