<?php

namespace App\Services;

use App\Models\Tenants\Receiving;
use Illuminate\Contracts\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;

class ReceivingService extends Service
{
    /**
     * 입고 목록 조회
     */
    public function index(array $params): LengthAwarePaginator
    {
        $tenantId = $this->tenantId();

        $query = Receiving::query()
            ->with(['creator:id,name', 'item:id,item_type,code,name'])
            ->where('tenant_id', $tenantId);

        // 검색어 필터
        if (! empty($params['search'])) {
            $search = $params['search'];
            $query->where(function ($q) use ($search) {
                $q->where('order_no', 'like', "%{$search}%")
                    ->orWhere('item_code', 'like', "%{$search}%")
                    ->orWhere('item_name', 'like', "%{$search}%")
                    ->orWhere('supplier', 'like', "%{$search}%");
            });
        }

        // 상태 필터
        if (! empty($params['status'])) {
            if ($params['status'] === 'receiving_pending') {
                // 입고대기: receiving_pending + inspection_pending
                $query->whereIn('status', ['receiving_pending', 'inspection_pending']);
            } elseif ($params['status'] === 'completed') {
                $query->where('status', 'completed');
            } else {
                $query->where('status', $params['status']);
            }
        }

        // 날짜 범위 필터 (작성일 기준)
        if (! empty($params['start_date'])) {
            $query->whereDate('created_at', '>=', $params['start_date']);
        }
        if (! empty($params['end_date'])) {
            $query->whereDate('created_at', '<=', $params['end_date']);
        }

        // 정렬
        $sortBy = $params['sort_by'] ?? 'created_at';
        $sortDir = $params['sort_dir'] ?? 'desc';
        $query->orderBy($sortBy, $sortDir);

        // 페이지네이션
        $perPage = $params['per_page'] ?? 20;
        $paginator = $query->paginate($perPage);

        // 수입검사 템플릿 연결 여부 계산
        $itemIds = $paginator->pluck('item_id')->filter()->unique()->values()->toArray();
        $itemsWithInspection = $this->getItemsWithInspectionTemplate($itemIds);

        // has_inspection_template 필드 추가
        $paginator->getCollection()->transform(function ($receiving) use ($itemsWithInspection) {
            $receiving->has_inspection_template = $receiving->item_id
                ? in_array($receiving->item_id, $itemsWithInspection)
                : false;

            return $receiving;
        });

        return $paginator;
    }

    /**
     * 수입검사 템플릿에 연결된 품목 ID 조회
     *
     * DocumentService::resolve()와 동일한 조건 사용:
     * - category: 영문 코드('incoming_inspection'), 한글('수입검사'), 부분 매칭 모두 지원
     * - linked_item_ids: int/string 타입 모두 매칭
     */
    private function getItemsWithInspectionTemplate(array $itemIds): array
    {
        if (empty($itemIds)) {
            return [];
        }

        $tenantId = $this->tenantId();

        // DocumentService::resolve()와 동일한 category 매칭 조건
        $categoryCode = 'incoming_inspection';
        $categoryName = '수입검사';

        $templates = DB::table('document_templates')
            ->where('tenant_id', $tenantId)
            ->where('is_active', true)
            ->whereNotNull('linked_item_ids')
            ->where(function ($q) use ($categoryCode, $categoryName) {
                $q->where('category', $categoryCode)
                    ->orWhere('category', $categoryName)
                    ->orWhere('category', 'LIKE', "%{$categoryName}%");
            })
            ->get(['linked_item_ids']);

        $linkedItemIds = [];
        foreach ($templates as $template) {
            $ids = json_decode($template->linked_item_ids, true) ?? [];
            // int/string 타입 모두 매칭되도록 정수로 통일
            foreach ($ids as $id) {
                $linkedItemIds[] = (int) $id;
            }
        }

        // 요청된 품목 ID도 정수로 통일하여 교집합
        $intItemIds = array_map('intval', $itemIds);

        return array_values(array_intersect($intItemIds, array_unique($linkedItemIds)));
    }

    /**
     * 입고 통계 조회
     */
    public function stats(): array
    {
        $tenantId = $this->tenantId();
        $today = now()->toDateString();

        $receivingPendingCount = Receiving::where('tenant_id', $tenantId)
            ->where('status', 'receiving_pending')
            ->count();

        $shippingCount = Receiving::where('tenant_id', $tenantId)
            ->where('status', 'shipping')
            ->count();

        $inspectionPendingCount = Receiving::where('tenant_id', $tenantId)
            ->where('status', 'inspection_pending')
            ->count();

        $todayReceivingCount = Receiving::where('tenant_id', $tenantId)
            ->where('status', 'completed')
            ->whereDate('receiving_date', $today)
            ->count();

        return [
            'receiving_pending_count' => $receivingPendingCount,
            'shipping_count' => $shippingCount,
            'inspection_pending_count' => $inspectionPendingCount,
            'today_receiving_count' => $todayReceivingCount,
        ];
    }

    /**
     * 입고 상세 조회
     */
    public function show(int $id): Receiving
    {
        $tenantId = $this->tenantId();

        return Receiving::query()
            ->where('tenant_id', $tenantId)
            ->with(['creator:id,name', 'item:id,item_type,code,name'])
            ->findOrFail($id);
    }

    /**
     * 입고 등록
     */
    public function store(array $data): Receiving
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        return DB::transaction(function () use ($data, $tenantId, $userId) {
            // 입고번호 자동 생성
            $receivingNumber = $this->generateReceivingNumber($tenantId);

            // item_id 조회 (전달되지 않은 경우 item_code로 조회)
            $itemId = $data['item_id'] ?? null;
            if (! $itemId && ! empty($data['item_code'])) {
                $itemId = $this->findItemIdByCode($tenantId, $data['item_code']);
            }

            $receiving = new Receiving;
            $receiving->tenant_id = $tenantId;
            $receiving->receiving_number = $receivingNumber;
            $receiving->order_no = $data['order_no'] ?? null;
            $receiving->order_date = $data['order_date'] ?? null;
            $receiving->item_id = $itemId;
            $receiving->item_code = $data['item_code'];
            $receiving->item_name = $data['item_name'];
            $receiving->specification = $data['specification'] ?? null;
            $receiving->supplier = $data['supplier'];
            $receiving->order_qty = $data['order_qty'] ?? null;
            $receiving->order_unit = $data['order_unit'] ?? 'EA';
            $receiving->due_date = $data['due_date'] ?? null;
            $receiving->receiving_qty = $data['receiving_qty'] ?? null;
            $receiving->receiving_date = $data['receiving_date'] ?? null;
            $receiving->lot_no = $data['lot_no'] ?? $this->generateLotNo();
            $receiving->status = $data['status'] ?? 'receiving_pending';
            $receiving->remark = $data['remark'] ?? null;

            // options 필드 처리 (제조사, 수입검사 등 확장 필드)
            $receiving->options = $this->buildOptions($data);

            $receiving->created_by = $userId;
            $receiving->updated_by = $userId;
            $receiving->save();

            return $receiving;
        });
    }

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

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

            if (! $receiving->canEdit()) {
                throw new \Exception(__('error.receiving.cannot_edit'));
            }

            if (isset($data['order_no'])) {
                $receiving->order_no = $data['order_no'];
            }
            if (isset($data['order_date'])) {
                $receiving->order_date = $data['order_date'];
            }
            if (isset($data['item_code'])) {
                $receiving->item_code = $data['item_code'];
                // item_code 변경 시 item_id도 업데이트
                if (! isset($data['item_id'])) {
                    $receiving->item_id = $this->findItemIdByCode($tenantId, $data['item_code']);
                }
            }
            if (isset($data['item_id'])) {
                $receiving->item_id = $data['item_id'];
            }
            if (isset($data['item_name'])) {
                $receiving->item_name = $data['item_name'];
            }
            if (array_key_exists('specification', $data)) {
                $receiving->specification = $data['specification'];
            }
            if (isset($data['supplier'])) {
                $receiving->supplier = $data['supplier'];
            }
            if (isset($data['order_qty'])) {
                $receiving->order_qty = $data['order_qty'];
            }
            if (isset($data['order_unit'])) {
                $receiving->order_unit = $data['order_unit'];
            }
            if (array_key_exists('due_date', $data)) {
                $receiving->due_date = $data['due_date'];
            }
            if (array_key_exists('remark', $data)) {
                $receiving->remark = $data['remark'];
            }

            // 상태 변경 감지
            $oldStatus = $receiving->status;
            $newStatus = $data['status'] ?? $oldStatus;
            $wasCompleted = $oldStatus === 'completed';

            // 입고완료(completed) 상태로 신규 전환
            $isCompletingReceiving = $newStatus === 'completed' && ! $wasCompleted;

            if ($isCompletingReceiving) {
                // 입고수량 설정 (없으면 발주수량 사용)
                $receiving->receiving_qty = $data['receiving_qty'] ?? $receiving->order_qty;
                $receiving->receiving_date = $data['receiving_date'] ?? now()->toDateString();
                $receiving->lot_no = $data['lot_no'] ?? $this->generateLotNo();
                $receiving->status = 'completed';
            } else {
                // 일반 필드 업데이트
                if (isset($data['receiving_qty'])) {
                    $receiving->receiving_qty = $data['receiving_qty'];
                }
                if (isset($data['receiving_date'])) {
                    $receiving->receiving_date = $data['receiving_date'];
                }
                if (isset($data['lot_no'])) {
                    $receiving->lot_no = $data['lot_no'];
                }
                if (isset($data['status'])) {
                    $receiving->status = $data['status'];
                }
            }

            // options 필드 업데이트 (제조사, 수입검사 등 확장 필드)
            $receiving->options = $this->mergeOptions($receiving->options, $data);

            $receiving->updated_by = $userId;
            $receiving->save();

            // 재고 연동
            if ($receiving->item_id) {
                $stockService = app(StockService::class);

                if ($isCompletingReceiving) {
                    // 대기 → 완료: 전량 재고 증가
                    $stockService->increaseFromReceiving($receiving);
                } elseif ($wasCompleted) {
                    // 기존 완료 상태에서 수정: 차이만큼 조정
                    // 완료→완료(수량변경): newQty = 변경된 수량
                    // 완료→대기: newQty = 0 (전량 차감)
                    $newQty = $newStatus === 'completed'
                        ? (float) $receiving->receiving_qty
                        : 0;
                    $stockService->adjustFromReceiving($receiving, $newQty);
                }
            }

            return $receiving->fresh();
        });
    }

    /**
     * 입고 삭제
     */
    public function destroy(int $id): bool
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

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

            if (! $receiving->canDelete()) {
                throw new \Exception(__('error.receiving.cannot_delete'));
            }

            $receiving->deleted_by = $userId;
            $receiving->save();
            $receiving->delete();

            return true;
        });
    }

    /**
     * 입고처리 (상태 변경 + 입고 정보 입력 + 재고 연동)
     */
    public function process(int $id, array $data): Receiving
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

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

            if (! $receiving->canProcess()) {
                throw new \Exception(__('error.receiving.cannot_process'));
            }

            // LOT번호 생성 (없으면 자동 생성)
            $lotNo = $data['lot_no'] ?? $this->generateLotNo();

            $receiving->receiving_qty = $data['receiving_qty'];
            $receiving->receiving_date = $data['receiving_date'] ?? now()->toDateString();
            $receiving->lot_no = $lotNo;
            $receiving->supplier_lot = $data['supplier_lot'] ?? null;
            $receiving->receiving_location = $data['receiving_location'] ?? null;
            $receiving->receiving_manager = $data['receiving_manager'] ?? null;
            $receiving->status = 'completed';
            $receiving->remark = $data['remark'] ?? $receiving->remark;
            $receiving->updated_by = $userId;
            $receiving->save();

            // 🆕 재고 연동: Stock + StockLot 생성/갱신
            if ($receiving->item_id) {
                app(StockService::class)->increaseFromReceiving($receiving);
            }

            return $receiving->fresh();
        });
    }

    /**
     * 입고번호 자동 생성
     */
    private function generateReceivingNumber(int $tenantId): string
    {
        $prefix = 'RV'.date('Ymd');

        $lastReceiving = Receiving::query()
            ->where('tenant_id', $tenantId)
            ->where('receiving_number', 'like', $prefix.'%')
            ->orderBy('receiving_number', 'desc')
            ->first();

        if ($lastReceiving) {
            $lastSeq = (int) substr($lastReceiving->receiving_number, -4);
            $newSeq = $lastSeq + 1;
        } else {
            $newSeq = 1;
        }

        return $prefix.str_pad($newSeq, 4, '0', STR_PAD_LEFT);
    }

    /**
     * LOT번호 자동 생성
     */
    private function generateLotNo(): string
    {
        $now = now();
        $year = $now->format('y');
        $month = $now->format('m');
        $day = $now->format('d');
        $seq = str_pad(rand(1, 99), 2, '0', STR_PAD_LEFT);

        return "{$year}{$month}{$day}-{$seq}";
    }

    /**
     * 품목코드로 품목 ID 조회
     */
    private function findItemIdByCode(int $tenantId, string $itemCode): ?int
    {
        $item = DB::table('items')
            ->where('tenant_id', $tenantId)
            ->where('code', $itemCode)
            ->whereNull('deleted_at')
            ->first(['id']);

        return $item?->id;
    }

    /**
     * options 필드 빌드 (등록 시)
     */
    private function buildOptions(array $data): ?array
    {
        $options = [];

        // 제조사
        if (isset($data['manufacturer'])) {
            $options[Receiving::OPTION_MANUFACTURER] = $data['manufacturer'];
        }

        // 거래처 자재번호
        if (isset($data['material_no'])) {
            $options[Receiving::OPTION_MATERIAL_NO] = $data['material_no'];
        }

        // 수입검사 상태 (적/부적/-)
        if (isset($data['inspection_status'])) {
            $options[Receiving::OPTION_INSPECTION_STATUS] = $data['inspection_status'];
        }

        // 검사일
        if (isset($data['inspection_date'])) {
            $options[Receiving::OPTION_INSPECTION_DATE] = $data['inspection_date'];
        }

        // 검사결과 (합격/불합격)
        if (isset($data['inspection_result'])) {
            $options[Receiving::OPTION_INSPECTION_RESULT] = $data['inspection_result'];
        }

        // 추가 확장 필드가 있으면 여기에 계속 추가 가능

        return ! empty($options) ? $options : null;
    }

    /**
     * options 필드 병합 (수정 시)
     */
    private function mergeOptions(?array $existing, array $data): ?array
    {
        $options = $existing ?? [];

        // 제조사
        if (array_key_exists('manufacturer', $data)) {
            if ($data['manufacturer'] === null || $data['manufacturer'] === '') {
                unset($options[Receiving::OPTION_MANUFACTURER]);
            } else {
                $options[Receiving::OPTION_MANUFACTURER] = $data['manufacturer'];
            }
        }

        // 거래처 자재번호
        if (array_key_exists('material_no', $data)) {
            if ($data['material_no'] === null || $data['material_no'] === '') {
                unset($options[Receiving::OPTION_MATERIAL_NO]);
            } else {
                $options[Receiving::OPTION_MATERIAL_NO] = $data['material_no'];
            }
        }

        // 수입검사 상태
        if (array_key_exists('inspection_status', $data)) {
            if ($data['inspection_status'] === null || $data['inspection_status'] === '') {
                unset($options[Receiving::OPTION_INSPECTION_STATUS]);
            } else {
                $options[Receiving::OPTION_INSPECTION_STATUS] = $data['inspection_status'];
            }
        }

        // 검사일
        if (array_key_exists('inspection_date', $data)) {
            if ($data['inspection_date'] === null || $data['inspection_date'] === '') {
                unset($options[Receiving::OPTION_INSPECTION_DATE]);
            } else {
                $options[Receiving::OPTION_INSPECTION_DATE] = $data['inspection_date'];
            }
        }

        // 검사결과
        if (array_key_exists('inspection_result', $data)) {
            if ($data['inspection_result'] === null || $data['inspection_result'] === '') {
                unset($options[Receiving::OPTION_INSPECTION_RESULT]);
            } else {
                $options[Receiving::OPTION_INSPECTION_RESULT] = $data['inspection_result'];
            }
        }

        return ! empty($options) ? $options : null;
    }
}