<?php

declare(strict_types=1);

namespace app\common\library\finance;

use app\common\service\GameHotDataRedis;
use support\think\Db;

/**
 * 提现打码量（流水）门槛工具库
 *
 * 业务口径（打码量即提现配额模型）：
 *   - 每笔提现消耗等额打码配额：折算 = withdraw_coin × ratio
 *   - lifetime_withdrawable_from_flow = bet_flow_coin / ratio
 *   - max_withdraw_by_flow = max(0, lifetime_withdrawable_from_flow - total_withdraw_coin)
 *   - 单笔上限：max_withdrawable = min(coin_balance, max_withdraw_by_flow)
 *   - ratio 来自 game_config.withdraw_bet_flow_ratio；ratio = 0 代表不限制打码量，此时
 *     max_withdraw_by_flow 视为"无限大"（由 UNLIMITED_FLOW 哨兵值表示，API 层兜底用余额）
 *
 * 向后兼容：原门槛 bet_flow_coin >= (total_deposit - total_withdraw) × ratio 已被
 * "单笔上限 ≤ max_withdraw_by_flow" 取代且语义等价更细腻：任何通过新校验的请求必然
 * 也满足旧门槛口径。字段 required_bet_flow / remaining_bet_flow / eligible 保留仅作展示。
 */
final class WithdrawFlow
{
    public const CONFIG_KEY = 'withdraw_bet_flow_ratio';

    public const DEFAULT_RATIO = '1.00';

    /** 当 ratio = 0（不限打码）时，max_withdraw_by_flow 用此哨兵表示"无限"。14 位整数位足够覆盖任何业务金额。 */
    public const UNLIMITED_FLOW = '99999999999999.99';

    /** 单用户最多允许同时存在的「待审核」(withdraw_order.status=0) 提现订单数。 */
    public const MAX_PENDING_WITHDRAW = 3;

    /**
     * 读取当前打码倍数（字符串 2 位小数，至少 0）
     */
    public static function ratio(): string
    {
        $row = GameHotDataRedis::gameConfigRow(self::CONFIG_KEY);
        if (!$row) {
            return self::DEFAULT_RATIO;
        }
        $val = $row['config_value'] ?? '';
        if (!is_string($val) || trim($val) === '' || !is_numeric(trim($val))) {
            return self::DEFAULT_RATIO;
        }
        $normalized = bcadd(trim($val), '0', 2);
        if (bccomp($normalized, '0', 2) < 0) {
            return '0.00';
        }
        return $normalized;
    }

    /**
     * 归一化金额字段到 2 位小数字符串，非法输入返回 '0.00'
     */
    public static function amountString($raw): string
    {
        if ($raw === null || $raw === '') {
            return '0.00';
        }
        if (is_string($raw)) {
            $s = trim($raw);
        } elseif (is_int($raw) || is_float($raw)) {
            $s = strval($raw);
        } else {
            return '0.00';
        }
        if (!is_numeric($s)) {
            return '0.00';
        }
        return bcadd($s, '0', 2);
    }

    /**
     * 核算玩家当前打码量状态
     *
     * @param array{
     *     total_deposit_coin?: mixed,
     *     total_withdraw_coin?: mixed,
     *     bet_flow_coin?: mixed,
     * }|null $userSnapshot 允许外部传入字典（节省一次查询）；为 null 时按 $userId 从库取
     *
     * @return array{
     *     ratio: string,
     *     net_deposit: string,
     *     required_bet_flow: string,
     *     bet_flow_coin: string,
     *     remaining_bet_flow: string,
     *     eligible: bool,
     *     max_withdraw_by_flow: string,
     *     flow_unlimited: bool,
     * }
     */
    public static function status(?int $userId, ?array $userSnapshot = null): array
    {
        if ($userSnapshot === null && $userId !== null) {
            $userSnapshot = Db::name('user')
                ->field(['total_deposit_coin', 'total_withdraw_coin', 'bet_flow_coin'])
                ->where('id', $userId)
                ->find();
        }
        $userSnapshot = is_array($userSnapshot) ? $userSnapshot : [];

        $deposit = self::amountString($userSnapshot['total_deposit_coin'] ?? '0');
        $withdraw = self::amountString($userSnapshot['total_withdraw_coin'] ?? '0');
        $flow = self::amountString($userSnapshot['bet_flow_coin'] ?? '0');

        $net = bcsub($deposit, $withdraw, 2);
        if (bccomp($net, '0', 2) < 0) {
            $net = '0.00';
        }

        $ratio = self::ratio();
        $required = bcmul($net, $ratio, 2);
        $remaining = bcsub($required, $flow, 2);
        if (bccomp($remaining, '0', 2) < 0) {
            $remaining = '0.00';
        }
        $eligible = bccomp($flow, $required, 2) >= 0;

        // max_withdraw_by_flow = max(0, bet_flow_coin / ratio - total_withdraw_coin)
        $unlimited = bccomp($ratio, '0', 2) === 0;
        if ($unlimited) {
            $maxByFlow = self::UNLIMITED_FLOW;
        } else {
            $lifetime = bcdiv($flow, $ratio, 2);
            $maxByFlow = bcsub($lifetime, $withdraw, 2);
            if (bccomp($maxByFlow, '0', 2) < 0) {
                $maxByFlow = '0.00';
            }
        }

        return [
            'ratio'                => $ratio,
            'net_deposit'          => $net,
            'required_bet_flow'    => $required,
            'bet_flow_coin'        => $flow,
            'remaining_bet_flow'   => $remaining,
            'eligible'             => $eligible,
            'max_withdraw_by_flow' => $maxByFlow,
            'flow_unlimited'       => $unlimited,
        ];
    }

    /**
     * 取单笔最大可提现额 = min(coin_balance, max_withdraw_by_flow)。
     * 返回值为 2 位小数字符串，已与 ratio=0（不限）逻辑兼容。
     */
    public static function maxWithdrawable(string $coinBalance, array $flowStatus): string
    {
        $coin = self::amountString($coinBalance);
        if (bccomp($coin, '0', 2) < 0) {
            $coin = '0.00';
        }
        if (!empty($flowStatus['flow_unlimited'])) {
            return $coin;
        }
        $byFlow = self::amountString($flowStatus['max_withdraw_by_flow'] ?? '0');
        return bccomp($coin, $byFlow, 2) <= 0 ? $coin : $byFlow;
    }
}