<?php

/*
The MIT License (MIT)

Copyright (c) 2015 Vectorface, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

namespace Vectorface\Whip\IpRange;

/**
 * A class representing the list of whitelisted IP addresses.
 * @copyright Vectorface, Inc 2015
 * @author Daniel Bruce <dbruce1126@gmail.com>
 */
class IpWhitelist
{
    /** The whitelist key for IPv4 addresses */
    const IPV4 = 'ipv4';

    /** The whitelist key for IPv6 addresses */
    const IPV6 = 'ipv6';

    /** an array of Ipv4Range items */
    private $ipv4Whitelist;

    /** an array of Ipv6Range items */
    private $ipv6Whitelist;

    /**
     * Constructor for the class.
     * @param array $whitelists An array with two keys ('ipv4' and 'ipv6') with
     *        each key mapping to an array of valid IP ranges.
     */
    public function __construct(array $whitelists)
    {
        $this->ipv4Whitelist = $this->constructWhiteListForKey(
            $whitelists,
            self::IPV4,
            Ipv4Range::class
        );
        $this->ipv6Whitelist = $this->constructWhiteListForKey(
            $whitelists,
            self::IPV6,
            Ipv6Range::class
        );
    }

    /**
     * Returns whether the given IP address is within the whitelist.
     *
     * @param string $ipAddress A valid IPv4 or IPv6 address.
     * @return bool Returns true if the IP address matches one of the
     *         whitelisted IP ranges and false otherwise.
     */
    public function isIpWhitelisted($ipAddress)
    {
        // determine whether this IP is IPv4 or IPv6
        $isIpv4Address = filter_var($ipAddress, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4);
        return $this->isIpInWhitelist(
            ($isIpv4Address) ? $this->ipv4Whitelist : $this->ipv6Whitelist,
            $ipAddress
        );
    }

    /**
     * Constructs the whitelist for the given key. Each element in the
     * whitelist gets mapped from a string to an instance of an Ipv4Range or
     * Ipv6Range.
     *
     * @param array $whitelist The input whitelist of ranges.
     * @param string $key The key to use from the input whitelist ('ipv4' or
     *        'ipv6').
     * @param string $class Each range string gets mapped to an instance of the
     *        specified $class.
     * @return array Returns an array of Ipv4Range or Ipv6Range elements.
     */
    private function constructWhiteListForKey(array $whitelist, $key, $class)
    {
        if (!isset($whitelist[$key]) || !is_array($whitelist[$key])) {
            return [];
        }
        return array_map(function ($range) use ($class) {
            return new $class($range);
        }, array_values($whitelist[$key]));
    }

    /**
     * Returns whether the given IP address is in the given whitelist.
     *
     * @param array $whitelist The given whitelist.
     * @param string $ipAddress The given IP address.
     * @return bool Returns true if the IP address is in the whitelist and
     *         false otherwise.
     */
    private function isIpInWhitelist(array $whitelist, $ipAddress)
    {
        foreach ($whitelist as $ipRange) {
            if ($ipRange->containsIp($ipAddress)) {
                return true;
            }
        }
        return false;
    }
}
