<?php

declare(strict_types=1);

namespace Aivie\WooCommerce\Mapper;

/**
 * Translates WooCommerce country/state values into the full names accepted
 * by Aivie's contact `country` and `state` choice lists.
 *
 * WooCommerce stores ISO codes ("CH", "ZH", "DE-BY") while Aivie (Mautic)
 * validates against full names ("Switzerland", "Zürich", "Bayern") from its
 * countries.json/regions.json choice lists. The lookup tables in data/ are
 * generated by scripts/generate-geo-data.php; a value that cannot be mapped
 * to a valid choice resolves to null so callers can omit the field instead
 * of having the whole contact rejected.
 */
class CountryStateMapper
{
    /**
     * Transliteration table for accent-insensitive matching. Kept as an
     * explicit table (instead of iconv/intl) so dev and production behave
     * identically regardless of platform.
     */
    private const TRANSLIT = [
        'à' => 'a', 'á' => 'a', 'â' => 'a', 'ã' => 'a', 'ä' => 'a', 'å' => 'a', 'ā' => 'a', 'ă' => 'a', 'ą' => 'a',
        'ç' => 'c', 'ć' => 'c', 'č' => 'c', 'ĉ' => 'c', 'ċ' => 'c',
        'ď' => 'd', 'đ' => 'd',
        'è' => 'e', 'é' => 'e', 'ê' => 'e', 'ë' => 'e', 'ē' => 'e', 'ė' => 'e', 'ę' => 'e', 'ě' => 'e',
        'ğ' => 'g', 'ģ' => 'g',
        'ì' => 'i', 'í' => 'i', 'î' => 'i', 'ï' => 'i', 'ī' => 'i', 'į' => 'i', 'ı' => 'i',
        'ķ' => 'k',
        'ľ' => 'l', 'ļ' => 'l', 'ł' => 'l',
        'ñ' => 'n', 'ń' => 'n', 'ň' => 'n', 'ņ' => 'n',
        'ò' => 'o', 'ó' => 'o', 'ô' => 'o', 'õ' => 'o', 'ö' => 'o', 'ø' => 'o', 'ō' => 'o', 'ő' => 'o',
        'ŕ' => 'r', 'ř' => 'r',
        'ś' => 's', 'š' => 's', 'ş' => 's', 'ș' => 's',
        'ť' => 't', 'ț' => 't', 'þ' => 'th',
        'ù' => 'u', 'ú' => 'u', 'û' => 'u', 'ü' => 'u', 'ū' => 'u', 'ů' => 'u', 'ű' => 'u', 'ų' => 'u',
        'ý' => 'y', 'ÿ' => 'y',
        'ź' => 'z', 'ż' => 'z', 'ž' => 'z',
        'ß' => 'ss', 'æ' => 'ae', 'œ' => 'oe',
    ];

    /** @var array{countries: array<string, string>, states: array<string, array<string, string>>}|null */
    private static ?array $codeMaps = null;

    /** @var string[]|null */
    private static ?array $countries = null;

    /** @var array<string, string[]>|null */
    private static ?array $regions = null;

    /**
     * Resolve a WooCommerce country value (ISO code or full name) to a valid
     * Aivie country name, or null when there is no equivalent.
     */
    public static function countryName(string $country): ?string
    {
        $country = trim($country);
        if ('' === $country) {
            return null;
        }

        $byCode = self::codeMaps()['countries'];
        if (isset($byCode[strtoupper($country)])) {
            return $byCode[strtoupper($country)];
        }

        // Already a valid Aivie value, or one that differs only in case/accents.
        if (in_array($country, self::countries(), true)) {
            return $country;
        }
        $folded = self::fold($country);
        foreach (self::countries() as $name) {
            if (self::fold($name) === $folded) {
                return $name;
            }
        }

        return null;
    }

    /**
     * Resolve a WooCommerce state value (state code or free text) to a valid
     * Aivie region name for the given country, or null when there is no
     * equivalent. Without a mappable country the state cannot be resolved.
     */
    public static function stateName(string $country, string $state): ?string
    {
        $state       = trim($state);
        $countryName = self::countryName($country);
        if ('' === $state || null === $countryName) {
            return null;
        }

        $byCode = self::codeMaps()['states'][strtoupper(trim($country))] ?? [];
        if (isset($byCode[strtoupper($state)])) {
            return $byCode[strtoupper($state)];
        }

        // Free-text state (countries without a WooCommerce state list).
        $regions = self::regions()[$countryName] ?? [];
        if (in_array($state, $regions, true)) {
            return $state;
        }
        $folded = self::fold($state);
        foreach ($regions as $region) {
            if (self::fold($region) === $folded) {
                return $region;
            }
        }

        return null;
    }

    /**
     * Normalize a place name for matching: decode entities, lowercase,
     * strip accents and punctuation ("Hawke’s Bay" === "Hawkes bay").
     */
    public static function fold(string $value): string
    {
        $value = html_entity_decode($value, ENT_QUOTES, 'UTF-8');
        $value = mb_strtolower(trim($value), 'UTF-8');
        $value = strtr($value, self::TRANSLIT);

        return (string) preg_replace('/[^a-z0-9]+/', '', $value);
    }

    /**
     * @return array{countries: array<string, string>, states: array<string, array<string, string>>}
     */
    private static function codeMaps(): array
    {
        return self::$codeMaps ??= include __DIR__ . '/data/code-maps.php';
    }

    /**
     * @return string[]
     */
    private static function countries(): array
    {
        // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- Reads bundled local JSON data, not a remote URL.
        return self::$countries ??= json_decode((string) file_get_contents(__DIR__ . '/data/countries.json'), true) ?: [];
    }

    /**
     * @return array<string, string[]>
     */
    private static function regions(): array
    {
        // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- Reads bundled local JSON data, not a remote URL.
        return self::$regions ??= json_decode((string) file_get_contents(__DIR__ . '/data/regions.json'), true) ?: [];
    }
}