<?php

namespace App\Services;

use App\Models\Materials\NonconformingReport;
use App\Models\Materials\NonconformingReportItem;
use Illuminate\Support\Facades\DB;

class NonconformingReportService extends Service
{
    /**
     * 목록 조회 (필터/검색/페이지네이션)
     */
    public function index(array $params): mixed
    {
        $tenantId = $this->tenantId();
        $perPage = $params['per_page'] ?? 20;
        $page = $params['page'] ?? 1;

        $query = NonconformingReport::query()
            ->where('tenant_id', $tenantId)
            ->with(['creator:id,name', 'item:id,name', 'order:id,order_number']);

        // 필터
        if (! empty($params['status'])) {
            $query->where('status', $params['status']);
        }
        if (! empty($params['nc_type'])) {
            $query->where('nc_type', $params['nc_type']);
        }
        if (! empty($params['from_date'])) {
            $query->where('occurred_at', '>=', $params['from_date']);
        }
        if (! empty($params['to_date'])) {
            $query->where('occurred_at', '<=', $params['to_date']);
        }

        // 검색
        if (! empty($params['search'])) {
            $search = $params['search'];
            $query->where(function ($q) use ($search) {
                $q->where('nc_number', 'like', "%{$search}%")
                    ->orWhere('site_name', 'like', "%{$search}%")
                    ->orWhereHas('item', function ($q2) use ($search) {
                        $q2->where('name', 'like', "%{$search}%");
                    });
            });
        }

        $query->orderByDesc('occurred_at')->orderByDesc('id');

        return $query->paginate($perPage, ['*'], 'page', $page);
    }

    /**
     * 단건 조회
     */
    public function show(int $id): NonconformingReport
    {
        return NonconformingReport::query()
            ->where('tenant_id', $this->tenantId())
            ->with([
                'items',
                'order:id,order_number,site_name',
                'item:id,name',
                'department:id,name',
                'creator:id,name',
                'actionManager:id,name',
                'relatedEmployee:id,name',
                'files',
            ])
            ->findOrFail($id);
    }

    /**
     * 등록 (items 일괄 저장)
     */
    public function store(array $data): NonconformingReport
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        return DB::transaction(function () use ($data, $tenantId, $userId) {
            // 채번
            $ncNumber = $this->generateNcNumber($tenantId);

            // 비용 계산
            $items = $data['items'] ?? [];
            $materialCost = $data['material_cost'] ?? $this->sumItemAmounts($items);
            $shippingCost = $data['shipping_cost'] ?? 0;
            $constructionCost = $data['construction_cost'] ?? 0;
            $otherCost = $data['other_cost'] ?? 0;
            $totalCost = $materialCost + $shippingCost + $constructionCost + $otherCost;

            $report = NonconformingReport::create([
                'tenant_id' => $tenantId,
                'nc_number' => $ncNumber,
                'status' => NonconformingReport::STATUS_RECEIVED,
                'nc_type' => $data['nc_type'],
                'occurred_at' => $data['occurred_at'],
                'confirmed_at' => $data['confirmed_at'] ?? null,
                'site_name' => $data['site_name'] ?? null,
                'department_id' => $data['department_id'] ?? null,
                'order_id' => $data['order_id'] ?? null,
                'item_id' => $data['item_id'] ?? null,
                'defect_quantity' => $data['defect_quantity'] ?? null,
                'unit' => $data['unit'] ?? null,
                'defect_description' => $data['defect_description'] ?? null,
                'cause_analysis' => $data['cause_analysis'] ?? null,
                'corrective_action' => $data['corrective_action'] ?? null,
                'action_completed_at' => $data['action_completed_at'] ?? null,
                'action_manager_id' => $data['action_manager_id'] ?? null,
                'related_employee_id' => $data['related_employee_id'] ?? null,
                'material_cost' => $materialCost,
                'shipping_cost' => $shippingCost,
                'construction_cost' => $constructionCost,
                'other_cost' => $otherCost,
                'total_cost' => $totalCost,
                'remarks' => $data['remarks'] ?? null,
                'drawing_location' => $data['drawing_location'] ?? null,
                'created_by' => $userId,
            ]);

            // 자재 상세 내역 저장
            $this->syncItems($report, $items, $tenantId);

            return $this->show($report->id);
        });
    }

    /**
     * 수정 (items sync)
     */
    public function update(int $id, array $data): NonconformingReport
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        return DB::transaction(function () use ($id, $data, $tenantId, $userId) {
            $report = NonconformingReport::query()
                ->where('tenant_id', $tenantId)
                ->findOrFail($id);

            if ($report->isClosed()) {
                abort(403, __('error.nonconforming.closed_cannot_edit'));
            }

            // items가 전달되면 자재비 재계산
            $hasItems = array_key_exists('items', $data);
            if ($hasItems) {
                $this->syncItems($report, $data['items'] ?? [], $tenantId);
                $data['material_cost'] = (int) $report->items()->sum('amount');
            }

            // 비용 합계 재계산
            $materialCost = $data['material_cost'] ?? $report->material_cost;
            $shippingCost = $data['shipping_cost'] ?? $report->shipping_cost;
            $constructionCost = $data['construction_cost'] ?? $report->construction_cost;
            $otherCost = $data['other_cost'] ?? $report->other_cost;
            $data['total_cost'] = $materialCost + $shippingCost + $constructionCost + $otherCost;
            $data['updated_by'] = $userId;

            // items 키는 모델 필드가 아니므로 제거
            unset($data['items']);

            $report->update($data);

            return $this->show($report->id);
        });
    }

    /**
     * 삭제 (소프트)
     */
    public function destroy(int $id): void
    {
        $report = NonconformingReport::query()
            ->where('tenant_id', $this->tenantId())
            ->findOrFail($id);

        if ($report->isClosed()) {
            abort(403, __('error.nonconforming.closed_cannot_delete'));
        }

        $report->deleted_by = $this->apiUserId();
        $report->save();
        $report->delete();
    }

    /**
     * 상태 변경
     */
    public function changeStatus(int $id, string $newStatus): NonconformingReport
    {
        $report = NonconformingReport::query()
            ->where('tenant_id', $this->tenantId())
            ->findOrFail($id);

        $this->validateStatusTransition($report, $newStatus);

        $report->status = $newStatus;
        $report->updated_by = $this->apiUserId();
        $report->save();

        return $this->show($report->id);
    }

    /**
     * 상태별 통계
     */
    public function stats(array $params): array
    {
        $tenantId = $this->tenantId();

        $statusCounts = NonconformingReport::query()
            ->where('tenant_id', $tenantId)
            ->selectRaw('status, COUNT(*) as count')
            ->groupBy('status')
            ->pluck('count', 'status')
            ->toArray();

        $totalCost = NonconformingReport::query()
            ->where('tenant_id', $tenantId)
            ->sum('total_cost');

        return [
            'by_status' => [
                'RECEIVED' => $statusCounts['RECEIVED'] ?? 0,
                'ANALYZING' => $statusCounts['ANALYZING'] ?? 0,
                'RESOLVED' => $statusCounts['RESOLVED'] ?? 0,
                'CLOSED' => $statusCounts['CLOSED'] ?? 0,
            ],
            'total_count' => array_sum($statusCounts),
            'total_cost' => (int) $totalCost,
        ];
    }

    // ── private ──

    /**
     * 채번: NC-YYYYMMDD-NNN
     */
    private function generateNcNumber(int $tenantId): string
    {
        $prefix = 'NC';
        $date = now()->format('Ymd');
        $pattern = "{$prefix}-{$date}-";

        $lastNumber = NonconformingReport::withTrashed()
            ->where('tenant_id', $tenantId)
            ->where('nc_number', 'like', "{$pattern}%")
            ->orderByDesc('nc_number')
            ->value('nc_number');

        $seq = $lastNumber ? ((int) substr($lastNumber, -3) + 1) : 1;

        return sprintf('%s-%s-%03d', $prefix, $date, $seq);
    }

    /**
     * 자재 상세 내역 동기화 (삭제 후 재생성)
     */
    private function syncItems(NonconformingReport $report, array $items, int $tenantId): void
    {
        $report->items()->delete();

        foreach ($items as $index => $itemData) {
            $quantity = $itemData['quantity'] ?? 0;
            $unitPrice = $itemData['unit_price'] ?? 0;

            NonconformingReportItem::create([
                'tenant_id' => $tenantId,
                'nonconforming_report_id' => $report->id,
                'item_id' => $itemData['item_id'] ?? null,
                'item_name' => $itemData['item_name'],
                'specification' => $itemData['specification'] ?? null,
                'quantity' => $quantity,
                'unit_price' => $unitPrice,
                'amount' => (int) ($quantity * $unitPrice),
                'sort_order' => $index,
                'remarks' => $itemData['remarks'] ?? null,
            ]);
        }
    }

    /**
     * items 배열에서 금액 합계 계산
     */
    private function sumItemAmounts(array $items): int
    {
        $total = 0;
        foreach ($items as $item) {
            $qty = $item['quantity'] ?? 0;
            $price = $item['unit_price'] ?? 0;
            $total += (int) ($qty * $price);
        }

        return $total;
    }

    /**
     * 상태 전이 검증
     */
    private function validateStatusTransition(NonconformingReport $report, string $newStatus): void
    {
        $allowed = [
            NonconformingReport::STATUS_RECEIVED => [NonconformingReport::STATUS_ANALYZING],
            NonconformingReport::STATUS_ANALYZING => [NonconformingReport::STATUS_RESOLVED],
            NonconformingReport::STATUS_RESOLVED => [NonconformingReport::STATUS_CLOSED],
            NonconformingReport::STATUS_CLOSED => [],
        ];

        $current = $report->status;

        if (! in_array($newStatus, $allowed[$current] ?? [])) {
            abort(422, __('error.nonconforming.invalid_status_transition', [
                'from' => NonconformingReport::STATUSES[$current] ?? $current,
                'to' => NonconformingReport::STATUSES[$newStatus] ?? $newStatus,
            ]));
        }

        // ANALYZING → RESOLVED: 원인분석 + 시정조치 필수
        if ($newStatus === NonconformingReport::STATUS_RESOLVED) {
            if (empty($report->cause_analysis) || empty($report->corrective_action)) {
                abort(422, __('error.nonconforming.analysis_required'));
            }
        }
    }
}