<?php

declare(strict_types=1);

namespace app\common\service;

use support\think\Db;

/**
 * 代理管理员树形分红：子代理从上级分红中按 commission_share_rate 抽取，上级保留剩余部分
 */
class AdminCommissionDistributionService
{
    /**
     * @return int[]
     */
    public static function getDescendantAdminIds(int $adminId): array
    {
        if ($adminId <= 0) {
            return [];
        }
        $childIds = Db::name('admin')
            ->where('parent_admin_id', $adminId)
            ->where('status', 'enable')
            ->column('id');
        $all = [];
        foreach ($childIds as $cid) {
            $cid = intval($cid);
            if ($cid <= 0) {
                continue;
            }
            $all[] = $cid;
            foreach (self::getDescendantAdminIds($cid) as $descId) {
                $all[] = $descId;
            }
        }
        return $all;
    }

    /**
     * 非超管可见管理员 ID；超管返回空数组表示不限制
     *
     * @return int[]
     */
    public static function getVisibleAdminIdsForOperator(int $operatorAdminId, bool $isSuperAdmin): array
    {
        if ($isSuperAdmin || $operatorAdminId <= 0) {
            return [];
        }
        $ids = self::getDescendantAdminIds($operatorAdminId);
        $ids[] = $operatorAdminId;
        return array_values(array_unique($ids));
    }

    /**
     * @return array{used_rate:string,remaining_rate:string}
     */
    public static function getShareRemainder(int $parentAdminId, ?int $excludeAdminId = null): array
    {
        $used = '0.00';
        if ($parentAdminId <= 0) {
            return ['used_rate' => $used, 'remaining_rate' => '100.00'];
        }
        $query = Db::name('admin')
            ->where('parent_admin_id', $parentAdminId)
            ->where('status', 'enable');
        if ($excludeAdminId !== null && $excludeAdminId > 0) {
            $query->where('id', '<>', $excludeAdminId);
        }
        $rows = $query->column('commission_share_rate');
        foreach ($rows as $rate) {
            if ($rate === null || $rate === '') {
                continue;
            }
            $used = bcadd($used, bcadd(strval($rate), '0', 2), 2);
        }
        $remaining = bcsub('100.00', $used, 2);
        if (bccomp($remaining, '0', 2) < 0) {
            $remaining = '0.00';
        }
        return ['used_rate' => $used, 'remaining_rate' => $remaining];
    }

    /**
     * 同渠道下顶级代理（无上级）已占用的渠道分红比例
     *
     * @return array{used_rate:string,remaining_rate:string}
     */
    public static function getChannelRootShareRemainder(int $channelId, ?int $excludeAdminId = null): array
    {
        $used = '0.00';
        if ($channelId <= 0) {
            return ['used_rate' => $used, 'remaining_rate' => '100.00'];
        }
        $query = Db::name('admin')
            ->where('channel_id', $channelId)
            ->where('status', 'enable')
            ->whereRaw('(parent_admin_id IS NULL OR parent_admin_id = 0)');
        if ($excludeAdminId !== null && $excludeAdminId > 0) {
            $query->where('id', '<>', $excludeAdminId);
        }
        $rows = $query->column('commission_share_rate');
        foreach ($rows as $rate) {
            if ($rate === null || $rate === '') {
                continue;
            }
            $used = bcadd($used, bcadd(strval($rate), '0', 2), 2);
        }
        $remaining = bcsub('100.00', $used, 2);
        if (bccomp($remaining, '0', 2) < 0) {
            $remaining = '0.00';
        }
        return ['used_rate' => $used, 'remaining_rate' => $remaining];
    }

    public static function validateChannelRootCommissionShareRate(int $channelId, mixed $rateRaw, ?int $excludeAdminId = null): ?string
    {
        if ($channelId <= 0) {
            return (string) __('Channel is required for top-level agent commission share');
        }
        if ($rateRaw === null || $rateRaw === '') {
            return (string) __('Top-level agent commission share rate is required');
        }
        $rate = bcadd(strval($rateRaw), '0', 2);
        if (bccomp($rate, '0', 2) <= 0 || bccomp($rate, '100', 2) > 0) {
            return (string) __('Commission share rate must be between 0 and 100');
        }
        $remainder = self::getChannelRootShareRemainder($channelId, $excludeAdminId);
        if (bccomp(bcadd($remainder['used_rate'], $rate, 2), '100.00', 2) > 0) {
            return (string) __('Sum of channel top-level commission share rates cannot exceed 100%');
        }
        return null;
    }

    public static function validateCommissionShareRate(?int $parentAdminId, mixed $rateRaw, ?int $excludeAdminId = null): ?string
    {
        if ($parentAdminId === null || $parentAdminId <= 0) {
            return null;
        }
        if ($rateRaw === null || $rateRaw === '') {
            return (string) __('Sub-agent commission share rate is required');
        }
        $rate = bcadd(strval($rateRaw), '0', 2);
        if (bccomp($rate, '0', 2) < 0 || bccomp($rate, '100', 2) > 0) {
            return (string) __('Commission share rate must be between 0 and 100');
        }
        $remainder = self::getShareRemainder($parentAdminId, $excludeAdminId);
        if (bccomp(bcadd($remainder['used_rate'], $rate, 2), '100.00', 2) > 0) {
            return (string) __('Sum of sibling commission share rates cannot exceed 100%');
        }
        return null;
    }

    /**
     * 代理费前佣金占渠道本期总佣金的比例（%）
     */
    public static function calcCommissionSharePercent(string $gross, string $totalCommission): string
    {
        if (bccomp($totalCommission, '0', 2) <= 0 || bccomp($gross, '0', 2) <= 0) {
            return '0.00';
        }
        return bcdiv(bcmul($gross, '100', 4), $totalCommission, 2);
    }

    /**
     * 按百分比计算手续费金额：手续费 = 费前佣金 × (费率% / 100)
     */
    public static function calcHandlingFeeAmount(string $gross, string $ratePercent): string
    {
        $rate = bcadd($ratePercent, '0', 2);
        if (bccomp($gross, '0', 2) <= 0 || bccomp($rate, '0', 2) <= 0) {
            return '0.00';
        }
        if (bccomp($rate, '100', 2) > 0) {
            $rate = '100.00';
        }
        return bcmul($gross, bcdiv($rate, '100', 4), 2);
    }

    /**
     * 将渠道本期总佣金按管理员树分配，返回各管理员实得金额（费前）
     *
     * @param array<int, string>|null $handlingFeeRateByAdmin admin_id => 手续费比例(%)
     * @return array<int, array{admin_id:int,commission_amount:string,commission_rate:string,calc_base_amount:string,handling_fee_rate:string,handling_fee:string,net_commission_amount:string}>
     */
    public static function distributeChannelCommission(
        int $channelId,
        string $totalCommission,
        string $calcBaseAmount,
        string $defaultHandlingFeeRate = '0.00',
        ?array $handlingFeeRateByAdmin = null
    ): array {
        $nodes = self::collectHierarchicalNodes($channelId, $totalCommission);
        if ($nodes === []) {
            return [];
        }
        $defaultRate = self::normalizeHandlingFeeRatePercent($defaultHandlingFeeRate);
        $merged = [];
        foreach ($nodes as $node) {
            $adminId = intval($node['admin_id'] ?? 0);
            if ($adminId <= 0) {
                continue;
            }
            $gross = strval($node['commission_amount'] ?? '0.00');
            if (bccomp($gross, '0', 2) <= 0) {
                continue;
            }
            $settlementBase = strval($node['settlement_base_amount'] ?? '0.00');
            $feeRate = $defaultRate;
            if ($handlingFeeRateByAdmin !== null && isset($handlingFeeRateByAdmin[$adminId])) {
                $feeRate = self::normalizeHandlingFeeRatePercent(strval($handlingFeeRateByAdmin[$adminId]));
            }
            $feeAmount = self::calcHandlingFeeAmount($gross, $feeRate);
            $net = bcsub($gross, $feeAmount, 2);
            if (bccomp($net, '0', 2) < 0) {
                $net = '0.00';
            }
            $effectiveRate = bccomp($settlementBase, '0', 2) <= 0
                ? '0.0000'
                : bcdiv($gross, $settlementBase, 6);
            $merged[$adminId] = [
                'admin_id' => $adminId,
                'commission_amount' => $gross,
                'commission_rate' => $effectiveRate,
                'calc_base_amount' => $settlementBase,
                'commission_share_percent' => self::calcCommissionSharePercent($gross, $totalCommission),
                'handling_fee_rate' => $feeRate,
                'handling_fee' => $feeAmount,
                'net_commission_amount' => $net,
            ];
        }
        return array_values($merged);
    }

    /**
     * 层级分配预览（先序遍历），含结算基数与手续费
     *
     * @param array<int, string>|null $handlingFeeRateByAdmin admin_id => 手续费比例(%)
     * @return array<int, array<string, mixed>>
     */
    public static function buildSplitPreview(
        int $channelId,
        string $commissionTotal,
        string $calcBaseAmount,
        string $defaultHandlingFeeRate = '0.00',
        ?array $handlingFeeRateByAdmin = null
    ): array {
        unset($calcBaseAmount);
        $nodes = self::collectHierarchicalNodes($channelId, $commissionTotal);
        if ($nodes === []) {
            return [];
        }
        $defaultRate = self::normalizeHandlingFeeRatePercent($defaultHandlingFeeRate);
        $out = [];
        foreach ($nodes as $node) {
            $adminId = intval($node['admin_id'] ?? 0);
            if ($adminId <= 0) {
                continue;
            }
            $gross = strval($node['commission_amount'] ?? '0.00');
            $feeRate = $defaultRate;
            if ($handlingFeeRateByAdmin !== null && isset($handlingFeeRateByAdmin[$adminId])) {
                $feeRate = self::normalizeHandlingFeeRatePercent(strval($handlingFeeRateByAdmin[$adminId]));
            }
            $feeAmount = self::calcHandlingFeeAmount($gross, $feeRate);
            $net = bcsub($gross, $feeAmount, 2);
            if (bccomp($net, '0', 2) < 0) {
                $net = '0.00';
            }
            $out[] = [
                'admin_id' => $adminId,
                'admin_username' => strval($node['admin_username'] ?? ('#' . $adminId)),
                'parent_admin_id' => intval($node['parent_admin_id'] ?? 0),
                'level' => intval($node['level'] ?? 0),
                'settlement_base_amount' => strval($node['settlement_base_amount'] ?? '0.00'),
                'share_rate' => strval($node['share_rate'] ?? '0.00'),
                'commission_amount' => $gross,
                'commission_share_percent' => self::calcCommissionSharePercent($gross, $commissionTotal),
                'handling_fee_rate' => $feeRate,
                'handling_fee' => $feeAmount,
                'net_commission_amount' => $net,
            ];
        }
        return $out;
    }

    private static function normalizeHandlingFeeRatePercent(string $rateRaw): string
    {
        $rate = bcadd($rateRaw, '0', 2);
        if (bccomp($rate, '0', 2) < 0) {
            return '0.00';
        }
        if (bccomp($rate, '100', 2) > 0) {
            return '100.00';
        }
        return $rate;
    }

    /**
     * @return array<int, array{admin_id:int,admin_username:string,parent_admin_id:int,level:int,settlement_base_amount:string,share_rate:string,commission_amount:string}>
     */
    private static function collectHierarchicalNodes(int $channelId, string $totalCommission): array
    {
        if ($channelId <= 0 || bccomp($totalCommission, '0', 2) <= 0) {
            return [];
        }
        $rootRows = Db::name('admin')
            ->where('channel_id', $channelId)
            ->where('status', 'enable')
            ->whereRaw('(parent_admin_id IS NULL OR parent_admin_id = 0)')
            ->order('id', 'asc')
            ->field(['id', 'commission_share_rate', 'username'])
            ->select()
            ->toArray();
        if ($rootRows === []) {
            return [];
        }
        $useRateSplit = true;
        foreach ($rootRows as $rootRow) {
            $rate = bcadd(strval($rootRow['commission_share_rate'] ?? '0'), '0', 2);
            if (bccomp($rate, '0', 2) <= 0) {
                $useRateSplit = false;
                break;
            }
        }
        $nodes = [];
        if ($useRateSplit) {
            foreach ($rootRows as $rootRow) {
                $rootId = intval($rootRow['id'] ?? 0);
                if ($rootId <= 0) {
                    continue;
                }
                $rate = bcadd(strval($rootRow['commission_share_rate'] ?? '0'), '0', 2);
                $rootAmount = bcmul($totalCommission, bcdiv($rate, '100', 4), 2);
                if (bccomp($rootAmount, '0', 2) <= 0) {
                    continue;
                }
                self::appendNodeTree($rootId, $rootAmount, 0, 0, $rate, $nodes);
            }
        } else {
            $rootCount = count($rootRows);
            $perRoot = bcdiv($totalCommission, strval($rootCount), 2);
            $assigned = '0.00';
            foreach ($rootRows as $index => $rootRow) {
                $rootId = intval($rootRow['id'] ?? 0);
                if ($rootId <= 0) {
                    continue;
                }
                $isLast = $index === $rootCount - 1;
                $rootAmount = $isLast ? bcsub($totalCommission, $assigned, 2) : $perRoot;
                if (!$isLast) {
                    $assigned = bcadd($assigned, $rootAmount, 2);
                }
                if (bccomp($rootAmount, '0', 2) <= 0) {
                    continue;
                }
                self::appendNodeTree($rootId, $rootAmount, 0, 0, '100.00', $nodes);
            }
        }
        return $nodes;
    }

    /**
     * @param array<int, array{admin_id:int,admin_username:string,parent_admin_id:int,level:int,settlement_base_amount:string,share_rate:string,commission_amount:string}> $nodes
     */
    private static function appendNodeTree(
        int $adminId,
        string $incomingAmount,
        int $level,
        int $parentAdminId,
        string $shareRateFromParent,
        array &$nodes
    ): void {
        if ($adminId <= 0 || bccomp($incomingAmount, '0', 2) <= 0) {
            return;
        }
        $adminRow = Db::name('admin')
            ->where('id', $adminId)
            ->field(['id', 'username', 'commission_share_rate'])
            ->find();
        if (!is_array($adminRow)) {
            return;
        }
        $children = Db::name('admin')
            ->where('parent_admin_id', $adminId)
            ->where('status', 'enable')
            ->order('id', 'asc')
            ->field(['id', 'commission_share_rate'])
            ->select()
            ->toArray();
        $givenToChildren = '0.00';
        $childPlans = [];
        foreach ($children as $child) {
            $childId = intval($child['id'] ?? 0);
            if ($childId <= 0) {
                continue;
            }
            $rate = bcadd(strval($child['commission_share_rate'] ?? '0'), '0', 2);
            if (bccomp($rate, '0', 2) <= 0) {
                continue;
            }
            $childAmount = bcmul($incomingAmount, bcdiv($rate, '100', 4), 2);
            if (bccomp($childAmount, '0', 2) <= 0) {
                continue;
            }
            $givenToChildren = bcadd($givenToChildren, $childAmount, 2);
            $childPlans[] = ['id' => $childId, 'amount' => $childAmount, 'rate' => $rate];
        }
        $selfKeep = bcsub($incomingAmount, $givenToChildren, 2);
        $nodes[] = [
            'admin_id' => $adminId,
            'admin_username' => strval($adminRow['username'] ?? ('#' . $adminId)),
            'parent_admin_id' => $parentAdminId,
            'level' => $level,
            'settlement_base_amount' => $incomingAmount,
            'share_rate' => $shareRateFromParent,
            'commission_amount' => bccomp($selfKeep, '0', 2) > 0 ? $selfKeep : '0.00',
        ];
        foreach ($childPlans as $plan) {
            self::appendNodeTree(intval($plan['id']), strval($plan['amount']), $level + 1, $adminId, strval($plan['rate']), $nodes);
        }
    }

    /**
     * @return array<int, string> admin_id => amount
     */
    private static function distributeFromAdmin(int $adminId, string $amount, string $calcBaseAmount): array
    {
        unset($calcBaseAmount);
        if ($adminId <= 0 || bccomp($amount, '0', 2) <= 0) {
            return [];
        }
        $children = Db::name('admin')
            ->where('parent_admin_id', $adminId)
            ->where('status', 'enable')
            ->order('id', 'asc')
            ->field(['id', 'commission_share_rate'])
            ->select()
            ->toArray();
        $givenToChildren = '0.00';
        $result = [];
        foreach ($children as $child) {
            $childId = intval($child['id'] ?? 0);
            if ($childId <= 0) {
                continue;
            }
            $rate = bcadd(strval($child['commission_share_rate'] ?? '0'), '0', 2);
            if (bccomp($rate, '0', 2) <= 0) {
                continue;
            }
            $childAmount = bcmul($amount, bcdiv($rate, '100', 4), 2);
            if (bccomp($childAmount, '0', 2) <= 0) {
                continue;
            }
            $givenToChildren = bcadd($givenToChildren, $childAmount, 2);
            $childParts = self::distributeFromAdmin($childId, $childAmount, '0.00');
            foreach ($childParts as $aid => $part) {
                if (!isset($result[$aid])) {
                    $result[$aid] = '0.00';
                }
                $result[$aid] = bcadd($result[$aid], $part, 2);
            }
        }
        $selfKeep = bcsub($amount, $givenToChildren, 2);
        if (bccomp($selfKeep, '0', 2) > 0) {
            if (!isset($result[$adminId])) {
                $result[$adminId] = '0.00';
            }
            $result[$adminId] = bcadd($result[$adminId], $selfKeep, 2);
        }
        return $result;
    }
}