<?php

declare(strict_types=1);

namespace App\Lib;

use Dxw\CIDR\IPv4Range;
use Dxw\CIDR\IPv6Range;
use Illuminate\Support\Facades\Cache;
use Symfony\Component\OptionsResolver\OptionsResolver;

/**
 * Configuration
 */
final class Options
{
    /**
     * @var array<string, mixed> The configuration options
     */
    private $options;

    /**
     * @var \Symfony\Component\OptionsResolver\OptionsResolver The options resolver
     */
    private $resolver;

    /**
     * The cache key where to store config cidr list.
     *
     * @var string
     */
    private static $cache_config_key = 'uwil_ip_cidr_config_list';

    /**
     * Class constructor.
     *
     * @param array<string, mixed> $options The configuration options.
     */
    public function __construct(array $options = [])
    {
        $this->resolver = new OptionsResolver();

        $this->configureOptions($this->resolver);

        $this->options = $this->resolver->resolve($options);
    }

    /**
     * Get cidr list
     *
     * @return array<\Dxw\CIDR\IPv4Range|\Dxw\CIDR\IPv6Range>
     */
    public function getCidrList(): array
    {
        return $this->options['cidrList'];
    }

    /**
     * Get cidr project allowed list
     *
     * @return array<\Dxw\CIDR\IPv4Range|\Dxw\CIDR\IPv6Range>
     */
    public function getCidrAllowedList(): array
    {
        return $this->options['cidrProjectAllowedList'];
    }

    /**
     * Configures the options of the client.
     *
     * @param \Symfony\Component\OptionsResolver\OptionsResolver $resolver The resolver for the options.
     * @return void
     */
    private function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults([
            'cidrList' => [],
            'cidrProjectAllowedList' => []
        ]);

        $resolver->setNormalizer('cidrList', \Closure::fromCallable([$this, 'normalizeCidrList']));
        $resolver->setNormalizer('cidrProjectAllowedList', \Closure::fromCallable([$this, 'normalizeCidrProjectList']));
    }

    /**
     * Normalise Cidr list for cidrList option
     *
     * @param \Symfony\Component\OptionsResolver\Options $options
     * @param string|null $value
     * @return array
     * @phpcs:disable Generic.CodeAnalysis.UnusedFunctionParameter.FoundBeforeLastUsed
     */
    private function normalizeCidrList(
        \Symfony\Component\OptionsResolver\Options $options,
        ?string $value
    ): array {
        // phpcs:enable
        return $this->doNormalizeCidrList($value, 'cidrList');
    }

    /**
     * Normalise Cidr list for cidrProjectAllowedList option
     *
     * @param \Symfony\Component\OptionsResolver\Options $options
     * @param string|null $value
     * @return array
     * @phpcs:disable Generic.CodeAnalysis.UnusedFunctionParameter.FoundBeforeLastUsed
     */
    private function normalizeCidrProjectList(
        \Symfony\Component\OptionsResolver\Options $options,
        ?string $value
    ): array {
        // phpcs:enable
        return $this->doNormalizeCidrList($value, 'cidrProjectAllowedList');
    }

    /**
     * Normalize CIDR list with specific cache key.
     *
     * @param string|null $value
     * @param string $optionName
     * @return array<\Dxw\CIDR\IPv4Range|\Dxw\CIDR\IPv6Range>
     */
    private function doNormalizeCidrList(?string $value, string $optionName): array
    {
        $cacheConfigKey = self::$cache_config_key . '_' . $optionName;
        $allowed_cidr_config_list = collect(explode(',', strval($value)))->filter();
        $allowed_cidr_config_list_hash = \md5($allowed_cidr_config_list->implode(','));
        $allowed_cidr_list = [];

        // Flush cache if config hash changed
        if ($allowed_cidr_config_list_hash !== \collect(Cache::get($cacheConfigKey))->get('hash')) {
            Cache::forget($cacheConfigKey);

            /** @var array<\Dxw\CIDR\IPv4Range|\Dxw\CIDR\IPv6Range> $allowed_cidr_list */
            $allowed_cidr_list = $allowed_cidr_config_list
                ->map(function (string $cidr) {
                    $ip_range = !IPv4Range::Make($cidr)->isErr() ? IPv4Range::Make($cidr) : IPv6Range::Make($cidr);
                    if ($ip_range->isErr()) {
                        throw new \Exception(\trans(
                            'CIDR LIST not valid (ipv4 or ipv6 cidr) :cidr',
                            [
                                'cidr' => $cidr
                            ]
                        ));
                    }
                    return $ip_range->unwrap();
                })->all();
        }

        /** @var array<\Dxw\CIDR\IPv4Range|\Dxw\CIDR\IPv6Range> $allowed_cidr_list */
        return \collect(Cache::rememberForever($cacheConfigKey, function() use ($allowed_cidr_list, $allowed_cidr_config_list_hash) {
            return [
                'list' => $allowed_cidr_list,
                'hash' => $allowed_cidr_config_list_hash
            ];
        }))->get('list');
    }
}