<?php
declare(strict_types=1);

namespace Soon\Api\Services;

use Soon\Api\Core\Config;
use Soon\Api\Core\Db;
use Soon\Api\Core\Json;

/**
 * 支付参数、密钥就绪检查与 Admin 读写。
 */
final class PaymentConfig
{
    /** @var array<string, list<string>> */
    private const REQUIRED = [
        'alipay' => ['site.base_url', 'alipay.app_id', 'alipay.private_key', 'alipay.public_key'],
        'wechat' => [
            'site.base_url',
            'wechat.app_id',
            'wechat.mch_id',
            'wechat.mch_serial_no',
            'wechat.mch_private_key',
            'wechat.api_v3_key',
            'wechat.platform_cert',
        ],
    ];

    /** @var array<string, array{label: string, hint: string}> */
    public const PARAM_FIELDS = [
        'site.base_url' => [
            'label' => 'API 外网地址',
            'hint' => '须 HTTPS 外网可达，用于支付 notify 回调',
        ],
        'site.front_base_url' => [
            'label' => '前端站点地址',
            'hint' => '支付宝支付完成后的 return_url 跳转',
        ],
        'alipay.app_id' => [
            'label' => '支付宝 APPID',
            'hint' => '开放平台应用 ID',
        ],
        'alipay.sandbox' => [
            'label' => '支付宝环境',
            'hint' => '沙箱仅联调使用',
        ],
        'wechat.app_id' => [
            'label' => '微信 AppID',
            'hint' => '关联支付的公众号/小程序/移动应用 AppID',
        ],
        'wechat.mch_id' => [
            'label' => '微信商户号',
            'hint' => '微信支付商户号 mch_id',
        ],
        'wechat.mch_serial_no' => [
            'label' => '商户证书序列号',
            'hint' => '商户 API 证书序列号，用于 V3 签名',
        ],
        'wechat.sandbox' => [
            'label' => '微信环境',
            'hint' => '当前实现共用正式网关，仅作标记',
        ],
        'payment.display_channels' => [
            'label' => '前端展示渠道',
            'hint' => '用户端可选的支付方式，默认仅支付宝',
        ],
    ];

    /** @return list<string> */
    public static function displayChannels(): array
    {
        $raw = Config::get('payment.display_channels');
        if ($raw === null || $raw === '') {
            return ['alipay'];
        }
        $parts = is_array($raw)
            ? $raw
            : (preg_split('/[\s,]+/', (string)$raw, -1, PREG_SPLIT_NO_EMPTY) ?: []);
        $allowed = ['alipay', 'wechat'];
        $out = [];
        foreach ($parts as $p) {
            $p = strtolower(trim((string)$p));
            if ($p !== '' && in_array($p, $allowed, true) && !in_array($p, $out, true)) {
                $out[] = $p;
            }
        }
        return $out !== [] ? $out : ['alipay'];
    }

    public static function assertChannelAllowed(string $channel): void
    {
        if (!in_array($channel, self::displayChannels(), true)) {
            Json::fail('bad_request', '该支付方式暂未开放', 400);
        }
    }

    public static function reloadRuntime(): void
    {
        $config = Config::all();
        PaymentConfigLoader::merge($config);
        SettingsConfigLoader::merge($config);
        Config::init($config);
    }

    /** @return array<string, string> */
    public static function paramValues(): array
    {
        $out = [];
        foreach (SettingsConfigLoader::PAYMENT_KEYS as $key) {
            $out[$key] = self::stringValue($key, Config::get($key));
        }
        return $out;
    }

    /** @param list<array{key: string, value: string}> $items */
    public static function saveParams(int $adminId, array $items): array
    {
        $allowed = array_flip(SettingsConfigLoader::PAYMENT_KEYS);
        $pdo = Db::pdo();
        $stmt = $pdo->prepare(
            'INSERT INTO settings (`key`, `value`, updated_at) VALUES (:k, :v, :ts) '
            . 'ON DUPLICATE KEY UPDATE `value`=VALUES(`value`), updated_at=VALUES(updated_at)'
        );
        $saved = [];
        $now = date('Y-m-d H:i:s');
        foreach ($items as $item) {
            if (!is_array($item)) {
                continue;
            }
            $key = trim((string)($item['key'] ?? ''));
            if ($key === '' || !isset($allowed[$key])) {
                continue;
            }
            $value = trim((string)($item['value'] ?? ''));
            if ($key === 'site.base_url' && $value !== '' && !str_starts_with(strtolower($value), 'https://')) {
                Json::fail('bad_request', 'API 外网地址须以 https:// 开头', 400);
            }
            if (str_ends_with($key, '.sandbox')) {
                $value = in_array(strtolower($value), ['1', 'true', 'yes', 'on'], true) ? '1' : '0';
            }
            if ($key === 'payment.display_channels') {
                $parsed = self::parseDisplayChannelsValue($value);
                if ($parsed === []) {
                    Json::fail('bad_request', '至少选择一种前端展示支付方式', 400);
                }
                $value = implode(',', $parsed);
            }
            $stmt->execute(['k' => $key, 'v' => $value, 'ts' => $now]);
            $saved[] = $key;
        }
        if ($saved === []) {
            Json::fail('bad_request', '无有效配置项', 400);
        }
        AuditService::log($adminId, 'payment.config.save', 'payment', ['keys' => $saved]);
        self::reloadRuntime();
        return ['keys' => $saved];
    }

    /** @return array<string, mixed> */
    public static function adminSnapshot(): array
    {
        $baseUrl = rtrim((string)Config::get('site.base_url', ''), '/');
        return [
            'params' => self::paramValues(),
            'display_channels' => self::displayChannels(),
            'readiness' => self::readiness(),
            'notify_urls' => [
                'alipay' => $baseUrl !== '' ? $baseUrl . '/api/v1/pay/alipay/notify' : '',
                'wechat' => $baseUrl !== '' ? $baseUrl . '/api/v1/pay/wechat/notify' : '',
            ],
            'return_url_hint' => rtrim((string)Config::get('site.front_base_url', Config::get('site.base_url', '')), '/')
                . '/pages/member.web.html?paid={order_no}',
        ];
    }

    /** @return array<string, array{ready: bool, missing: list<string>}> */
    public static function readiness(): array
    {
        $out = [];
        foreach (self::REQUIRED as $channel => $keys) {
            $missing = [];
            foreach ($keys as $key) {
                if (!self::isPresent($key)) {
                    $missing[] = self::missingLabel($key);
                }
            }
            $out[$channel] = ['ready' => $missing === [], 'missing' => $missing];
        }
        return $out;
    }

    private static function isPresent(string $key): bool
    {
        $val = Config::get($key);
        if (is_bool($val)) {
            return true;
        }
        if (is_string($val)) {
            return trim($val) !== '';
        }
        return $val !== null && $val !== '';
    }

    private static function missingLabel(string $key): string
    {
        if (isset(self::PARAM_FIELDS[$key])) {
            return self::PARAM_FIELDS[$key]['label'];
        }
        $map = [
            'alipay.private_key' => '应用私钥',
            'alipay.public_key' => '支付宝公钥',
            'wechat.mch_private_key' => '商户私钥',
            'wechat.api_v3_key' => 'APIv3 密钥',
            'wechat.platform_cert' => '平台证书',
        ];
        return $map[$key] ?? $key;
    }

    private static function stringValue(string $key, mixed $value): string
    {
        if (str_ends_with($key, '.sandbox')) {
            return $value ? '1' : '0';
        }
        if ($key === 'payment.display_channels') {
            if (is_array($value)) {
                return implode(',', self::parseDisplayChannelsList($value));
            }
            $parsed = self::parseDisplayChannelsValue((string)($value ?? ''));
            return $parsed !== [] ? implode(',', $parsed) : 'alipay';
        }
        return is_string($value) ? $value : (string)($value ?? '');
    }

    /** @return list<string> */
    private static function parseDisplayChannelsValue(string $value): array
    {
        return self::parseDisplayChannelsList(
            preg_split('/[\s,]+/', trim($value), -1, PREG_SPLIT_NO_EMPTY) ?: []
        );
    }

    /** @param list<string> $parts @return list<string> */
    private static function parseDisplayChannelsList(array $parts): array
    {
        $allowed = ['alipay', 'wechat'];
        $out = [];
        foreach ($parts as $p) {
            $p = strtolower(trim((string)$p));
            if ($p !== '' && in_array($p, $allowed, true) && !in_array($p, $out, true)) {
                $out[] = $p;
            }
        }
        return $out;
    }
}