<?php

namespace App\Http\Controllers\Finance;

use App\Http\Controllers\Controller;
use App\Models\Finance\VatRecord;
use App\Models\Finance\CardTransaction;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;

class VatRecordController extends Controller
{
    public function index(Request $request): JsonResponse
    {
        $tenantId = session('selected_tenant_id', 1);

        $query = VatRecord::forTenant($tenantId);

        if ($search = $request->input('search')) {
            $query->where(function ($q) use ($search) {
                $q->where('partner_name', 'like', "%{$search}%");
            });
        }

        if ($period = $request->input('period')) {
            $query->where('period', $period);
        }

        if ($type = $request->input('type')) {
            if ($type !== 'all') {
                $query->where('type', $type);
            }
        }

        if ($taxType = $request->input('tax_type')) {
            if ($taxType !== 'all') {
                $query->where('tax_type', $taxType);
            }
        }

        if ($status = $request->input('status')) {
            if ($status !== 'all') {
                $query->where('status', $status);
            }
        }

        $records = $query->orderBy('invoice_date', 'desc')
            ->get()
            ->map(function ($record) {
                return [
                    'id' => $record->id,
                    'period' => $record->period,
                    'type' => $record->type,
                    'taxType' => $record->tax_type ?? 'taxable',
                    'partnerName' => $record->partner_name,
                    'invoiceNo' => $record->invoice_no,
                    'invoiceDate' => $record->invoice_date?->format('Y-m-d'),
                    'supplyAmount' => $record->supply_amount,
                    'vatAmount' => $record->vat_amount,
                    'totalAmount' => $record->total_amount,
                    'status' => $record->status,
                    'memo' => $record->memo,
                    'isCardTransaction' => false,
                ];
            });

        // 카드 공제분 매입 반영
        $cardRecords = collect();
        $cardPurchaseSupply = 0;
        $cardPurchaseVat = 0;

        if ($period = $request->input('period')) {
            [$startDate, $endDate] = $this->periodToDateRange($period);

            if ($startDate && $endDate) {
                $cardQuery = CardTransaction::forTenant($tenantId)
                    ->where('deduction_type', 'deductible')
                    ->whereBetween('transaction_date', [$startDate, $endDate]);

                $cardTransactions = $cardQuery->orderBy('transaction_date', 'desc')->get();

                $cardRecords = $cardTransactions->map(function ($card) use ($period) {
                    $supply = (int) round($card->amount / 1.1);
                    $vat = $card->amount - $supply;
                    return [
                        'id' => 'card_' . $card->id,
                        'period' => $period,
                        'type' => 'purchase',
                        'taxType' => 'taxable',
                        'partnerName' => $card->merchant,
                        'invoiceNo' => $card->approval_no ?? '',
                        'invoiceDate' => $card->transaction_date?->format('Y-m-d'),
                        'supplyAmount' => $supply,
                        'vatAmount' => $vat,
                        'totalAmount' => $card->amount,
                        'status' => 'filed',
                        'memo' => $card->memo,
                        'isCardTransaction' => true,
                    ];
                });

                $cardPurchaseSupply = $cardRecords->sum('supplyAmount');
                $cardPurchaseVat = $cardRecords->sum('vatAmount');
            }
        }

        // 통합 records
        $allRecords = $records->concat($cardRecords)->values();

        // 해당 기간 통계
        $periodQuery = VatRecord::forTenant($tenantId);
        if ($period = $request->input('period')) {
            $periodQuery->where('period', $period);
        }
        $periodRecords = $periodQuery->get();

        $stats = [
            'salesSupply' => $periodRecords->where('type', 'sales')->sum('supply_amount'),
            'salesVat' => $periodRecords->where('type', 'sales')->sum('vat_amount'),
            'purchaseSupply' => $periodRecords->where('type', 'purchase')->sum('supply_amount') + $cardPurchaseSupply,
            'purchaseVat' => $periodRecords->where('type', 'purchase')->sum('vat_amount') + $cardPurchaseVat,
            'cardPurchaseSupply' => $cardPurchaseSupply,
            'cardPurchaseVat' => $cardPurchaseVat,
            'total' => $periodRecords->count(),
        ];

        // 사용 중인 기간 목록
        $periods = VatRecord::forTenant($tenantId)
            ->select('period')
            ->distinct()
            ->orderBy('period', 'desc')
            ->pluck('period')
            ->toArray();

        return response()->json([
            'success' => true,
            'data' => $allRecords,
            'stats' => $stats,
            'periods' => $periods,
        ]);
    }

    public function store(Request $request): JsonResponse
    {
        $request->validate([
            'partnerName' => 'required|string|max:100',
            'period' => 'required|string|max:20',
            'type' => 'required|in:sales,purchase',
            'taxType' => 'nullable|in:taxable,zero_rated,exempt',
            'supplyAmount' => 'required|integer|min:0',
        ]);

        $tenantId = session('selected_tenant_id', 1);

        $record = VatRecord::create([
            'tenant_id' => $tenantId,
            'period' => $request->input('period'),
            'type' => $request->input('type', 'sales'),
            'tax_type' => $request->input('taxType', 'taxable'),
            'partner_name' => $request->input('partnerName'),
            'invoice_no' => $request->input('invoiceNo'),
            'invoice_date' => $request->input('invoiceDate'),
            'supply_amount' => $request->input('supplyAmount', 0),
            'vat_amount' => $request->input('vatAmount', 0),
            'total_amount' => $request->input('totalAmount', 0),
            'status' => $request->input('status', 'pending'),
            'memo' => $request->input('memo'),
        ]);

        return response()->json([
            'success' => true,
            'message' => '세금계산서가 등록되었습니다.',
            'data' => ['id' => $record->id],
        ]);
    }

    public function update(Request $request, int $id): JsonResponse
    {
        $tenantId = session('selected_tenant_id', 1);
        $record = VatRecord::forTenant($tenantId)->findOrFail($id);

        $request->validate([
            'partnerName' => 'required|string|max:100',
            'period' => 'required|string|max:20',
            'type' => 'required|in:sales,purchase',
            'taxType' => 'nullable|in:taxable,zero_rated,exempt',
            'supplyAmount' => 'required|integer|min:0',
        ]);

        $record->update([
            'period' => $request->input('period'),
            'type' => $request->input('type'),
            'tax_type' => $request->input('taxType', $record->tax_type),
            'partner_name' => $request->input('partnerName'),
            'invoice_no' => $request->input('invoiceNo'),
            'invoice_date' => $request->input('invoiceDate'),
            'supply_amount' => $request->input('supplyAmount', 0),
            'vat_amount' => $request->input('vatAmount', 0),
            'total_amount' => $request->input('totalAmount', 0),
            'status' => $request->input('status'),
            'memo' => $request->input('memo'),
        ]);

        return response()->json([
            'success' => true,
            'message' => '세금계산서가 수정되었습니다.',
        ]);
    }

    public function destroy(int $id): JsonResponse
    {
        $tenantId = session('selected_tenant_id', 1);
        $record = VatRecord::forTenant($tenantId)->findOrFail($id);
        $record->delete();

        return response()->json([
            'success' => true,
            'message' => '세금계산서가 삭제되었습니다.',
        ]);
    }

    /**
     * 부가세 신고기간을 날짜 범위로 변환
     * YYYY-1P: 1기 예정 (0101~0331)
     * YYYY-1C: 1기 확정 (0401~0630)
     * YYYY-2P: 2기 예정 (0701~0930)
     * YYYY-2C: 2기 확정 (1001~1231)
     */
    private function periodToDateRange(string $period): array
    {
        $parts = explode('-', $period);
        if (count($parts) !== 2) {
            return [null, null];
        }

        $year = $parts[0];
        $code = $parts[1];

        $ranges = [
            '1P' => ["{$year}-01-01", "{$year}-03-31"],
            '1C' => ["{$year}-04-01", "{$year}-06-30"],
            '2P' => ["{$year}-07-01", "{$year}-09-30"],
            '2C' => ["{$year}-10-01", "{$year}-12-31"],
        ];

        return $ranges[$code] ?? [null, null];
    }
}