<?php
declare(strict_types=1);

namespace WPMultiCity;

final class Helpers
{
    private static ?string $current_town_memo = null;
    private static bool $current_town_resolved = false;
    private static array $term_cache = [];
    private static array $page_unic_cache = [];
    private static int $bypass_depth = 0;

    public static function reset_cache(): void
    {
        self::$current_town_memo = null;
        self::$current_town_resolved = false;
        self::$term_cache = [];
        self::$page_unic_cache = [];
        self::$bypass_depth = 0;
    }

    public static function get_term_by_slug(string $slug, string $taxonomy = 'town'): ?\WP_Term
    {
        $key = $taxonomy . '|' . $slug;
        if (array_key_exists($key, self::$term_cache)) {
            return self::$term_cache[$key];
        }
        $term = \get_term_by('slug', $slug, $taxonomy);
        return self::$term_cache[$key] = ($term instanceof \WP_Term) ? $term : null;
    }

    public static function current_town(): ?string
    {
        if (self::$current_town_resolved) {
            return self::$current_town_memo;
        }

        $uri = $_SERVER['REQUEST_URI'] ?? '/';
        $first_segment = self::first_path_segment($uri);

        $resolved = null;
        if ($first_segment !== null) {
            $terms = \get_terms([
                'taxonomy'   => 'town',
                'hide_empty' => false,
                'fields'     => 'id=>slug',
            ]);
            if (is_array($terms) && in_array($first_segment, $terms, true)) {
                $resolved = $first_segment;
            }
        }

        if ($resolved === null) {
            $resolved = \apply_filters('wpmc_main_town_slug', null);
            if (!is_string($resolved) || $resolved === '') {
                $resolved = null;
            }
        }

        $resolved = \apply_filters('wpmc_current_town_slug', $resolved);
        if (!is_string($resolved) || $resolved === '') {
            $resolved = null;
        }

        self::$current_town_memo = $resolved;
        self::$current_town_resolved = true;
        return $resolved;
    }

    private static function first_path_segment(string $uri): ?string
    {
        $path = strtok($uri, '?');
        if ($path === false) {
            return null;
        }
        $parts = array_values(array_filter(explode('/', $path), static fn(string $p) => $p !== ''));
        return $parts[0] ?? null;
    }

    public static function alt_get_field(string $selector, $post_id = false, bool $format_value = true)
    {
        $post_id = \apply_filters('wpmc_alt_get_field_post_id', $post_id, $selector);
        if (!\function_exists('get_field')) {
            return null;
        }
        $value = \get_field($selector, $post_id, $format_value);
        return is_string($value) ? \do_shortcode($value) : $value;
    }

    public static function remove_domain_link(string $url): string
    {
        $parsed = parse_url($url);
        if ($parsed === false || empty($parsed['scheme'])) {
            return $url;
        }
        $scheme = strtolower((string) $parsed['scheme']);
        if ($scheme !== 'http' && $scheme !== 'https') {
            return $url;
        }
        $path = $parsed['path'] ?? '';
        $query = isset($parsed['query']) ? '?' . $parsed['query'] : '';
        $fragment = isset($parsed['fragment']) ? '#' . $parsed['fragment'] : '';
        return $path . $query . $fragment;
    }

    public static function index_town_alt_page_id(): ?int
    {
        if (!\function_exists('get_field')) {
            return null;
        }
        $value = \get_field('index_town_alt', 'option');
        $id = (int) $value;
        return $id > 0 ? $id : null;
    }

    public static function main_town_slug(): ?string
    {
        if (!\function_exists('get_field')) {
            return null;
        }
        $value = \get_field('main_town_slug', 'option');
        if ($value instanceof \WP_Term) {
            return $value->slug !== '' ? $value->slug : null;
        }
        return is_string($value) && $value !== '' ? $value : null;
    }

    public static function page_unic_swap(int $page_id_old, string $town_slug): ?int
    {
        $key = $page_id_old . '|' . $town_slug;
        if (array_key_exists($key, self::$page_unic_cache)) {
            return self::$page_unic_cache[$key];
        }
        $term = self::get_term_by_slug($town_slug);
        if ($term === null) {
            return self::$page_unic_cache[$key] = null;
        }
        if (!\function_exists('get_field')) {
            return self::$page_unic_cache[$key] = null;
        }
        $rows = \get_field('page_unic', 'option');
        if (!is_array($rows)) {
            return self::$page_unic_cache[$key] = null;
        }
        foreach ($rows as $row) {
            if (!is_array($row)) {
                continue;
            }
            if ((int) ($row['town'] ?? 0) === (int) $term->term_id
                && (int) ($row['page_old'] ?? 0) === $page_id_old) {
                $new = (int) ($row['page_new'] ?? 0);
                return self::$page_unic_cache[$key] = $new > 0 ? $new : null;
            }
        }
        return self::$page_unic_cache[$key] = null;
    }

    public static function is_routable_path(?string $path = null): bool
    {
        if ($path === null) {
            $path = $_SERVER['REQUEST_URI'] ?? '/';
        }
        if (!\function_exists('get_field')) {
            return true;
        }
        $exclusions = \get_field('page_no_rep', 'option');
        if (!is_array($exclusions) || $exclusions === []) {
            return true;
        }
        foreach ($exclusions as $row) {
            if (!is_array($row) || empty($row['link'])) {
                continue;
            }
            $needle = (string) $row['link'];
            if ($needle !== '' && strpos($path, $needle) !== false) {
                return false;
            }
        }
        return true;
    }

    public static function without_url_filters(callable $fn)
    {
        self::$bypass_depth++;
        try {
            return $fn();
        } finally {
            self::$bypass_depth--;
        }
    }

    public static function is_bypassed(): bool
    {
        return self::$bypass_depth > 0;
    }
}