<?php

namespace App\Services\AgentSettlement;

use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;

/**
 * 已锁定账单的补差/冲正单（§21.1、§21.2）。
 */
final class AgentSettlementBillAdjustmentService
{
    public function __construct(
        private readonly AgentSettlementBillGuard $billGuard,
        private readonly AgentSettlementPeriodCompletionService $periodCompletion,
    ) {}

    public function createAdjustment(
        int $originalBillId,
        int $amount,
        string $adjustmentType,
        ?string $reason,
        int $adminUserId,
    ): int {
        $original = DB::table('settlement_bills')->where('id', $originalBillId)->first();
        if ($original === null) {
            throw new \InvalidArgumentException('bill_not_found');
        }

        if ($this->periodCompletion->isPeriodReadOnly((int) $original->settlement_period_id)) {
            throw ValidationException::withMessages([
                'period' => ['completed'],
            ]);
        }

        if (! in_array((string) $original->status, ['confirmed', 'partial_paid', 'settled', 'overdue'], true)) {
            throw ValidationException::withMessages([
                'bill' => ['not_locked'],
            ]);
        }

        if ($amount === 0) {
            throw ValidationException::withMessages([
                'amount' => ['zero'],
            ]);
        }

        $type = in_array($adjustmentType, ['adjustment', 'reversal'], true)
            ? $adjustmentType
            : 'adjustment';

        return (int) DB::transaction(function () use ($original, $amount, $type, $reason, $adminUserId): int {
            $now = now();
            $newBillId = (int) DB::table('settlement_bills')->insertGetId([
                'settlement_period_id' => (int) $original->settlement_period_id,
                'bill_type' => $type,
                'owner_type' => (string) $original->owner_type,
                'owner_id' => (int) $original->owner_id,
                'counterparty_type' => (string) $original->counterparty_type,
                'counterparty_id' => (int) $original->counterparty_id,
                'gross_win_loss' => 0,
                'rebate_amount' => 0,
                'adjustment_amount' => $amount,
                'platform_rounding_adjustment' => 0,
                'net_amount' => $amount,
                'paid_amount' => 0,
                'unpaid_amount' => abs($amount),
                'status' => 'pending_confirm',
                'reversed_bill_id' => (int) $original->id,
                'meta_json' => json_encode([
                    'original_bill_id' => (int) $original->id,
                    'original_net_amount' => (int) $original->net_amount,
                ]),
                'created_at' => $now,
                'updated_at' => $now,
            ]);

            DB::table('settlement_adjustments')->insert([
                'settlement_period_id' => (int) $original->settlement_period_id,
                'original_bill_id' => (int) $original->id,
                'adjustment_type' => $type,
                'amount' => $amount,
                'reason' => $reason,
                'created_by' => $adminUserId > 0 ? $adminUserId : null,
                'created_at' => $now,
                'updated_at' => $now,
            ]);

            return $newBillId;
        });
    }
}