<?php

namespace App\Services\Agent;

use App\Models\Agent\Agent;
use App\Models\Agent\AgentCommission;
use App\Models\Agent\AgentFlowCommissionAssignment;
use App\Models\Agent\AgentFlowCommissionProfile;
use App\Models\Agent\AgentRebateRecord;
use Carbon\Carbon;
use Illuminate\Support\Facades\DB;

class AgentFlowCommissionAssignmentService
{
    public function at(Agent $agent, string $date): AgentFlowCommissionAssignment
    {
        $day = Carbon::parse($date)->toDateString();
        $assignment = AgentFlowCommissionAssignment::query()
            ->where('agent_id', $agent->id)
            ->where('effective_from', '<=', $day)
            ->orderByDesc('effective_from')->orderByDesc('id')->first();
        if (!$assignment) {
            throw new \RuntimeException("代理 {$agent->id} 缺少 {$day} 可用的流水佣金方案历史");
        }
        return $assignment;
    }

    public function assign(
        Agent $agent,
        AgentFlowCommissionProfile $profile,
        string $effectiveFrom,
        ?int $createdBy = null
    ): AgentFlowCommissionAssignment {
        $this->assignMany([(int)$agent->id], $profile, $effectiveFrom, $createdBy);
        return AgentFlowCommissionAssignment::query()
            ->where('agent_id', $agent->id)
            ->where('effective_from', Carbon::parse($effectiveFrom)->toDateString())
            ->firstOrFail();
    }

    public function assignMany(
        array $agentIds,
        AgentFlowCommissionProfile $profile,
        string $effectiveFrom,
        ?int $createdBy = null
    ): void {
        $agentIds = array_values(array_unique(array_filter(array_map('intval', $agentIds))));
        if ($agentIds === []) return;
        $day = Carbon::parse($effectiveFrom)->toDateString();
        $values = array_merge($profile->rateSnapshot(), [
            'flow_commission_profile_id' => (int)$profile->id,
            'profile_name' => (string)$profile->name,
            'created_by' => $createdBy,
        ]);
        DB::transaction(function () use ($agentIds, $day, $values) {
            $this->assertMutable($agentIds, $day);
            foreach (array_chunk($agentIds, 500) as $chunk) {
                foreach ($chunk as $agentId) {
                    AgentFlowCommissionAssignment::query()->updateOrCreate(
                        ['agent_id' => $agentId, 'effective_from' => $day],
                        $values
                    );
                }
            }
        });
    }

    private function assertMutable(array $agentIds, string $day): void
    {
        $newCredited = AgentRebateRecord::query()->whereIn('agent_id', $agentIds)
            ->where('settlement_date', '>=', $day)
            ->lockForUpdate()
            ->pluck('flow_status')
            ->contains(AgentRebateRecord::STATUS_CREDITED);
        $legacyCredited = AgentCommission::query()->whereIn('agent_id', $agentIds)
            ->where('type', 'flow')
            ->where('settlement_date', '>=', $day)
            ->lockForUpdate()
            ->pluck('status')
            ->contains(AgentRebateRecord::STATUS_CREDITED);
        if ($newCredited || $legacyCredited) {
            throw new \RuntimeException('生效日期已有流水佣金入账，不能修改比例方案');
        }
    }
}