/**
* @license Apache-2.0
*
* Copyright (c) 2021 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

'use strict';

// MODULES //

var hasOwnProp = require( '@stdlib/assert/has-own-property' );
var isObject = require( '@stdlib/assert/is-object' );
var isString = require( '@stdlib/assert/is-string' ).isPrimitive;


// MAIN //

/**
* Validates function options.
*
* @param {Object} opts - destination object
* @param {Object} options - options to validate
* @param {string} [options.token] - GitHub access token
* @param {string} [options.username] - GitHub username
* @param {string} [options.useragent] - user agent string
* @param {string} [options.method] - rank method
* @returns {(Error|null)} error or null
*/
function validate( opts, options ) {
	if ( !isObject( options ) ) {
		return new TypeError( 'invalid argument. Options argument must be an object. Value: `' + options + '`.' );
	}
	if ( hasOwnProp( options, 'token' ) ) {
		opts.token = options.token;
		if ( !isString( opts.token ) ) {
			return new TypeError( 'invalid option. Token option must be a string primitive. Option: `' + opts.token + '`.' );
		}
	}
	if ( hasOwnProp( options, 'username' ) ) {
		opts.username = options.username;
		if ( !isString( opts.username ) ) {
			return new TypeError( 'invalid option. Username option must be a string primitive. Option: `' + opts.username + '`.' );
		}
	}
	if ( hasOwnProp( options, 'useragent' ) ) {
		opts.useragent = options.useragent;
		if ( !isString( opts.useragent ) ) {
			return new TypeError( 'invalid option. User agent option must be a string primitive. Option: `' + opts.useragent + '`.' );
		}
	}
	if ( hasOwnProp( options, 'method' ) ) {
		opts.method = options.method;
		if ( !isString( opts.method ) ) {
			return new TypeError( 'invalid option. Method option must be a string primitive. Option: `' + opts.method + '`.' );
		}
	}
	return null;
}


// EXPORTS //

module.exports = validate;
