<?php

namespace App\Support;

use App\Services\Domain\DomainPricingService;

class DomainConfig
{
    private const PRIORITY_TLDS = [
        'com', 'org', 'net', 'ai', 'io', 'co', 'app', 'dev',
        'store', 'shop', 'online', 'site', 'tech', 'cloud', 'pro', 'me',
        'xyz', 'club', 'live', 'com.ng', 'com.gh', 'co.za', 'co.uk', 'info', 'biz',
    ];

    private const DEFAULT_PAGE_SIZE = 20;

    /**
     * Get featured TLDs for initial display (lightweight).
     *
     * @return list<string>
     */
    public static function featuredTlds(): array
    {
        $allTlds = self::allTlds();
        $featured = array_values(array_intersect(self::PRIORITY_TLDS, $allTlds));

        if ($featured !== []) {
            return $featured;
        }

        return array_slice($allTlds, 0, self::DEFAULT_PAGE_SIZE);
    }

    /**
     * Get all available TLDs sorted by priority.
     *
     * @return list<string>
     */
    public static function allTlds(): array
    {
        $current = self::normalizeTlds(config('domain.search_tlds', []));
        $legacy = self::normalizeTlds(config('mailinfra.domain_search_tlds', []));

        $tlds = $legacy !== [] ? $legacy : $current;
        $livePricedTlds = self::livePricedTlds();

        if ($livePricedTlds === []) {
            return [];
        }

        $livePricedLookup = array_flip($livePricedTlds);
        $tlds = array_values(array_filter(
            $tlds,
            static fn (string $tld): bool => isset($livePricedLookup[$tld])
        ));

        return self::sortWithPriority($tlds);
    }

    /**
     * Get paginated TLDs (excluding featured ones).
     *
     * @return array{tlds: list<string>, hasMore: bool, total: int}
     */
    public static function paginatedTlds(int $page = 1, int $perPage = self::DEFAULT_PAGE_SIZE): array
    {
        $allTlds = self::allTlds();
        $featured = self::featuredTlds();

        $remaining = array_values(array_filter($allTlds, fn ($tld) => !in_array($tld, $featured, true)));
        $total = count($remaining);

        $offset = ($page - 1) * $perPage;
        $tlds = array_slice($remaining, $offset, $perPage);

        return [
            'tlds' => $tlds,
            'hasMore' => ($offset + $perPage) < $total,
            'total' => $total,
        ];
    }

    /**
     * @deprecated Use featuredTlds() or allTlds() instead
     * @return list<string>
     */
    public static function searchTlds(): array
    {
        return self::featuredTlds();
    }

    /**
     * Build the TLD list and query term for a search page request.
     *
     * @return array{query: string, tlds: list<string>, hasMore: bool, exact_domain: string|null}
     */
    public static function searchPageConfig(string $query, int $page = 1, int $perPage = self::DEFAULT_PAGE_SIZE): array
    {
        $query = strtolower(trim($query));
        $allTlds = self::allTlds();

        if ($allTlds === []) {
            return [
                'query' => $query,
                'tlds' => [],
                'hasMore' => false,
                'exact_domain' => null,
            ];
        }

        $exactDomain = self::normalizeExactDomain($query);

        if ($exactDomain === null) {
            if ($page === 1) {
                $featured = self::featuredTlds();
                $paginatedData = self::paginatedTlds(1, $perPage);

                return [
                    'query' => $query,
                    'tlds' => $featured,
                    'hasMore' => $paginatedData['hasMore'] || count($paginatedData['tlds']) > 0,
                    'exact_domain' => null,
                ];
            }

            $paginatedData = self::paginatedTlds($page - 1, $perPage);

            return [
                'query' => $query,
                'tlds' => $paginatedData['tlds'],
                'hasMore' => $paginatedData['hasMore'],
                'exact_domain' => null,
            ];
        }

        $exactTld = self::extractTld($exactDomain);
        $keyword = explode('.', $exactDomain, 2)[0] ?? $exactDomain;
        $firstPageTlds = array_values(array_unique(array_filter([
            $exactTld,
            ...self::featuredTlds(),
        ])));
        $remainingTlds = array_values(array_filter(
            $allTlds,
            static fn (string $tld): bool => ! in_array($tld, $firstPageTlds, true)
        ));

        if ($page === 1) {
            return [
                'query' => $keyword,
                'tlds' => $firstPageTlds,
                'hasMore' => $remainingTlds !== [],
                'exact_domain' => $exactDomain,
            ];
        }

        $offset = max(0, ($page - 2) * $perPage);

        return [
            'query' => $keyword,
            'tlds' => array_slice($remainingTlds, $offset, $perPage),
            'hasMore' => ($offset + $perPage) < count($remainingTlds),
            'exact_domain' => $exactDomain,
        ];
    }

    /**
     * Sort domain search results by TLD priority.
     *
     * @param  array<int, array{domain: string, ...}>  $results
     * @return array<int, array{domain: string, ...}>
     */
    public static function sortResultsByTldPriority(array $results, ?string $query = null): array
    {
        $priorityMap = array_flip(self::PRIORITY_TLDS);
        $exactDomain = self::normalizeExactDomain((string) $query);

        usort($results, static function (array $a, array $b) use ($priorityMap, $exactDomain): int {
            $aDomain = strtolower((string) ($a['domain'] ?? ''));
            $bDomain = strtolower((string) ($b['domain'] ?? ''));

            $aExact = $exactDomain !== null && $aDomain === $exactDomain ? 0 : 1;
            $bExact = $exactDomain !== null && $bDomain === $exactDomain ? 0 : 1;

            if ($aExact !== $bExact) {
                return $aExact <=> $bExact;
            }

            $aPremium = self::isPremiumResult($a) ? 0 : 1;
            $bPremium = self::isPremiumResult($b) ? 0 : 1;

            if ($aPremium !== $bPremium) {
                return $aPremium <=> $bPremium;
            }

            $aAvailable = ! empty($a['available']) ? 0 : 1;
            $bAvailable = ! empty($b['available']) ? 0 : 1;

            if ($aAvailable !== $bAvailable) {
                return $aAvailable <=> $bAvailable;
            }

            $aTld = self::extractTld($a['domain'] ?? '');
            $bTld = self::extractTld($b['domain'] ?? '');

            $aPriority = $priorityMap[$aTld] ?? PHP_INT_MAX;
            $bPriority = $priorityMap[$bTld] ?? PHP_INT_MAX;

            if ($aPriority !== $bPriority) {
                return $aPriority <=> $bPriority;
            }

            return $aDomain <=> $bDomain;
        });

        return $results;
    }

    /**
     * Extract TLD from a domain name.
     */
    private static function extractTld(string $domain): string
    {
        $parts = explode('.', strtolower($domain), 2);

        return $parts[1] ?? '';
    }

    private static function normalizeExactDomain(string $query): ?string
    {
        $query = strtolower(trim($query));

        if ($query === '' || str_starts_with($query, '.') || str_ends_with($query, '.') || ! str_contains($query, '.')) {
            return null;
        }

        return preg_match('/^(?=.{1,253}$)(?!-)(?:[a-z0-9-]{1,63}\.)+[a-z]{2,63}$/', $query) === 1
            ? $query
            : null;
    }

    /**
     * @param  array<string, mixed>  $result
     */
    private static function isPremiumResult(array $result): bool
    {
        $premium = $result['premium'] ?? false;

        if (is_bool($premium)) {
            return $premium;
        }

        return in_array(strtolower(trim((string) $premium)), ['1', 'yes', 'true', 'premium'], true);
    }

    /**
     * @param  list<string>  $tlds
     * @return list<string>
     */
    private static function sortWithPriority(array $tlds): array
    {
        $priorityMap = array_flip(self::PRIORITY_TLDS);
        $pricingMap = self::pricingMapForTlds($tlds);

        usort($tlds, static function (string $a, string $b) use ($priorityMap, $pricingMap): int {
            $aPriority = $priorityMap[$a] ?? PHP_INT_MAX;
            $bPriority = $priorityMap[$b] ?? PHP_INT_MAX;

            if ($aPriority !== $bPriority) {
                return $aPriority <=> $bPriority;
            }

            $aPrice = (int) ($pricingMap[$a]['register'] ?? 0);
            $bPrice = (int) ($pricingMap[$b]['register'] ?? 0);

            if ($aPrice !== $bPrice) {
                return $bPrice <=> $aPrice;
            }

            return $a <=> $b;
        });

        return $tlds;
    }

    /**
     * @return array<string, string>
     */
    public static function resellerClubTldProductKeys(): array
    {
        return array_replace(
            self::normalizeProductKeyMap(config('domain.resellerclub.tld_product_keys', [])),
            self::normalizeProductKeyMap(config('mailinfra.resellerclub_tld_product_keys', []))
        );
    }

    public static function resellerClubProductKeyCacheTtlSeconds(): int
    {
        $ttl = (int) config('domain.resellerclub.product_key_cache_ttl_seconds', 86400);

        return $ttl > 0 ? $ttl : 86400;
    }

    /**
     * @param  mixed  $value
     * @return list<string>
     */
    private static function normalizeTlds(mixed $value): array
    {
        if (! is_array($value)) {
            return [];
        }

        return array_values(array_unique(array_filter(array_map(
            static fn ($tld): string => ltrim(strtolower(trim((string) $tld)), '.'),
            $value
        ))));
    }

    /**
     * @param  mixed  $value
     * @return array<string, string>
     */
    private static function normalizeProductKeyMap(mixed $value): array
    {
        if (! is_array($value)) {
            return [];
        }

        $map = [];

        foreach ($value as $tld => $productKey) {
            $normalizedTld = ltrim(strtolower(trim((string) $tld)), '.');
            $normalizedProductKey = trim((string) $productKey);

            if ($normalizedTld === '' || $normalizedProductKey === '') {
                continue;
            }

            $map[$normalizedTld] = $normalizedProductKey;
        }

        return $map;
    }

    /**
     * @return list<string>
     */
    private static function livePricedTlds(): array
    {
        try {
            return app(DomainPricingService::class)->getLivePricedTlds();
        } catch (\Throwable) {
            return [];
        }
    }

    /**
     * @param  list<string>  $tlds
     * @return array<string, array{register: int, renew: int, transfer: int, currency: string}>
     */
    private static function pricingMapForTlds(array $tlds): array
    {
        try {
            return app(DomainPricingService::class)->getPricingForTlds($tlds);
        } catch (\Throwable) {
            return [];
        }
    }
}