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 id.
			Number.isInteger(req.json.id) && req.json.type === 'author' ? await isAuthorExists(req.json.id) : 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') {
		// Удаляем всю музыку этого исполнителя
		await global.database.muzic.promiseMode().remove({
			where: {
				author_id: req.json.id
			}
		});
		// Удаляем исполнителя
		await global.database.authors.promiseMode().remove({
			where: {
				id: req.json.id
			}
		});
	}
	else {
		await global.database.muzic.promiseMode().remove({
			where: {
				id: req.json.id
			}
		});
	}
	return 'ok';
}