<?php

declare(strict_types=1);

namespace plugin\saiadmin\app\service\agent;

use InvalidArgumentException;
use plugin\saiadmin\app\model\water\WaterCommissionSetting;
use plugin\saiadmin\app\model\water\WaterLedger;
use plugin\saiadmin\app\model\water\WaterModel;
use plugin\saiadmin\exception\ApiException;

/** Editable platform rates; each paid order keeps the rate used at accrual time. */
final class WaterCommissionPolicy
{
    private const RATE_FIELDS = [
        1 => 'level1_basis_points',
        2 => 'level2_basis_points',
        3 => 'level3_basis_points',
    ];

    public static function current(bool $lock = false): array
    {
        $query = WaterCommissionSetting::query();
        $row = ($lock ? $query->sharedLock() : $query)->find(1);
        if (!$row) {
            throw new ApiException('请先初始化供水佣金规则');
        }

        return [
            'level1_basis_points' => (int) $row->level1_basis_points,
            'level2_basis_points' => (int) $row->level2_basis_points,
            'level3_basis_points' => (int) $row->level3_basis_points,
            'revision' => (int) $row->revision,
            'updated_at' => $row->updated_at,
        ];
    }

    public static function rate(int $level, bool $lock = false): int
    {
        $field = self::RATE_FIELDS[$level] ?? throw new InvalidArgumentException('未知代理等级');

        return self::current($lock)[$field];
    }

    public static function message(): string
    {
        $rates = self::current();
        $percent = static fn (int $basisPoints): string => rtrim(rtrim(number_format($basisPoints / 100, 2, '.', ''), '0'), '.');

        return '新成交订单仅给归属代理计提：一级' . $percent($rates['level1_basis_points'])
            . '%、二级' . $percent($rates['level2_basis_points']) . '%、三级'
            . $percent($rates['level3_basis_points']) . '%；当前为待结算，提现尚未开放。';
    }

    public static function save(array $input, int $actor): array
    {
        $allowed = array_merge(array_values(self::RATE_FIELDS), ['revision']);
        if (array_diff(array_keys($input), $allowed)) {
            throw new ApiException('佣金规则包含不支持的字段');
        }
        $values = [];
        foreach (self::RATE_FIELDS as $field) {
            $values[$field] = self::integer($input[$field] ?? null, $field, 0, 10000);
        }
        $revision = self::integer($input['revision'] ?? null, 'revision', 1, 2147483646);

        return WaterModel::transaction(function () use ($values, $revision, $actor): array {
            $row = WaterCommissionSetting::query()->lockForUpdate()->find(1);
            if (!$row) {
                throw new ApiException('请先初始化供水佣金规则');
            }
            if ((int) $row->revision !== $revision) {
                throw new ApiException('佣金规则已被其他操作员修改，请重新打开后编辑');
            }
            $before = [(int) $row->level1_basis_points, (int) $row->level2_basis_points, (int) $row->level3_basis_points];
            $row->fill($values);
            $row->revision = $revision + 1;
            $row->updated_by = $actor;
            $row->updated_at = date('Y-m-d H:i:s');
            $row->save();
            WaterLedger::query()->create([
                'kind' => 'commission_policy',
                'created_by' => $actor,
                'sku_id' => 0,
                'enterprise_id' => 0,
                'quantity' => 0,
                'reference' => 'platform:commission:revision:' . $row->revision,
                'note' => '代理佣金比例调整（基点）：' . implode('/', $before) . '→' . implode('/', array_values($values)),
                'created_at' => $row->updated_at,
            ]);

            return self::current();
        });
    }

    public static function amount(int $baseAmountCents, int $level): int
    {
        return self::amountAtRate($baseAmountCents, self::rate($level));
    }

    public static function amountAtRate(int $baseAmountCents, int $rate): int
    {
        if ($baseAmountCents < 0) {
            throw new InvalidArgumentException('佣金基数不能为负数');
        }
        if ($rate < 0 || $rate > 10000) {
            throw new InvalidArgumentException('佣金比例必须在0到100%之间');
        }
        $whole = intdiv($baseAmountCents, 10000) * $rate;
        $fraction = intdiv(($baseAmountCents % 10000) * $rate + 5000, 10000);

        return $whole + $fraction;
    }

    private static function integer(mixed $value, string $field, int $min, int $max): int
    {
        if ((!is_int($value) && !is_string($value)) || filter_var($value, FILTER_VALIDATE_INT) === false
            || (int) $value < $min || (int) $value > $max) {
            throw new ApiException($field . ' 必须是 ' . $min . ' 到 ' . $max . ' 之间的整数');
        }

        return (int) $value;
    }
}