const Ajv = require('ajv');
const {customThrow} = require('../helpers');

const parseAndValidateBody = async (schema, body) => {
  let parsedBody;

  try {
    parsedBody = JSON.parse(body);
  } catch (err) {
    customThrow(400, 'Error. Malformed event.parsedBody.');
  }

  const validation = validateBody(schema, parsedBody);

  if (!validation.isValid) {
    customThrow(400, validation.error);
  }

  return parsedBody;
};

const validateBody = (schema, body) => {
  const ajv = new Ajv({$data: true});
  const validate = ajv.compile(schema);
  const isValid = validate(body);

  return {
    isValid: isValid,
    error: JSON.stringify(validate.errors)
  }
};

module.exports = {
  parseAndValidateBody,
};