<?php

namespace App\Services\Quote;

use App\Models\Quote\QuoteFormulaCategory;
use Illuminate\Contracts\Pagination\LengthAwarePaginator;
use Illuminate\Database\Eloquent\Collection;
use Illuminate\Support\Facades\DB;

class QuoteFormulaCategoryService
{
    /**
     * 카테고리 목록 조회 (페이지네이션)
     */
    public function getCategories(array $filters = [], int $perPage = 15): LengthAwarePaginator
    {
        $tenantId = session('selected_tenant_id');

        $query = QuoteFormulaCategory::query()
            ->withCount('formulas')
            ->withCount(['formulas as active_formulas_count' => function ($q) {
                $q->where('is_active', true);
            }]);

        // 테넌트 필터
        if ($tenantId && $tenantId !== 'all') {
            $query->where('tenant_id', $tenantId);
        }

        // 검색
        if (! empty($filters['search'])) {
            $search = $filters['search'];
            $query->where(function ($q) use ($search) {
                $q->where('name', 'like', "%{$search}%")
                    ->orWhere('code', 'like', "%{$search}%")
                    ->orWhere('description', 'like', "%{$search}%");
            });
        }

        // 활성화 필터
        if (isset($filters['is_active']) && $filters['is_active'] !== '') {
            $query->where('is_active', (bool) $filters['is_active']);
        }

        // 정렬
        $sortBy = $filters['sort_by'] ?? 'sort_order';
        $sortDirection = $filters['sort_direction'] ?? 'asc';
        $query->orderBy($sortBy, $sortDirection);

        return $query->paginate($perPage);
    }

    /**
     * 전체 카테고리 목록 (선택용)
     */
    public function getAllCategories(): Collection
    {
        $tenantId = session('selected_tenant_id');

        return QuoteFormulaCategory::query()
            ->where('tenant_id', $tenantId)
            ->where('is_active', true)
            ->orderBy('sort_order')
            ->get();
    }

    /**
     * 활성 카테고리 목록 (드롭다운용)
     */
    public function getActiveCategories(): Collection
    {
        return $this->getAllCategories();
    }

    /**
     * 카테고리 상세 조회
     */
    public function getCategoryById(int $id): ?QuoteFormulaCategory
    {
        return QuoteFormulaCategory::with('formulas')->find($id);
    }

    /**
     * 카테고리 생성
     */
    public function createCategory(array $data): QuoteFormulaCategory
    {
        $tenantId = session('selected_tenant_id');

        return DB::transaction(function () use ($data, $tenantId) {
            // 자동 sort_order 할당
            if (! isset($data['sort_order'])) {
                $maxOrder = QuoteFormulaCategory::where('tenant_id', $tenantId)->max('sort_order');
                $data['sort_order'] = ($maxOrder ?? 0) + 1;
            }

            return QuoteFormulaCategory::create([
                'tenant_id' => $tenantId,
                'code' => $data['code'],
                'name' => $data['name'],
                'description' => $data['description'] ?? null,
                'sort_order' => $data['sort_order'],
                'is_active' => $data['is_active'] ?? true,
                'created_by' => auth()->id(),
            ]);
        });
    }

    /**
     * 카테고리 수정
     */
    public function updateCategory(int $id, array $data): QuoteFormulaCategory
    {
        $category = QuoteFormulaCategory::findOrFail($id);

        $category->update([
            'code' => $data['code'] ?? $category->code,
            'name' => $data['name'] ?? $category->name,
            'description' => array_key_exists('description', $data) ? $data['description'] : $category->description,
            'sort_order' => $data['sort_order'] ?? $category->sort_order,
            'is_active' => $data['is_active'] ?? $category->is_active,
            'updated_by' => auth()->id(),
        ]);

        return $category->fresh();
    }

    /**
     * 카테고리 삭제
     */
    public function deleteCategory(int $id): void
    {
        $category = QuoteFormulaCategory::findOrFail($id);

        // 연관 수식이 있으면 삭제 불가
        if ($category->formulas()->count() > 0) {
            throw new \Exception('연관된 수식이 있어 삭제할 수 없습니다. 먼저 수식을 삭제해주세요.');
        }

        $category->delete();
    }

    /**
     * 카테고리 순서 변경
     */
    public function reorderCategories(array $orderData): void
    {
        DB::transaction(function () use ($orderData) {
            foreach ($orderData as $item) {
                QuoteFormulaCategory::where('id', $item['id'])
                    ->update(['sort_order' => $item['sort_order']]);
            }
        });
    }

    /**
     * 카테고리 활성/비활성 토글
     */
    public function toggleActive(int $id): QuoteFormulaCategory
    {
        $category = QuoteFormulaCategory::findOrFail($id);

        $category->is_active = ! $category->is_active;
        $category->updated_by = auth()->id();
        $category->save();

        return $category;
    }

    /**
     * 코드 중복 체크
     */
    public function isCodeExists(string $code, ?int $excludeId = null): bool
    {
        $tenantId = session('selected_tenant_id');

        $query = QuoteFormulaCategory::where('tenant_id', $tenantId)
            ->where('code', $code);

        if ($excludeId) {
            $query->where('id', '!=', $excludeId);
        }

        return $query->exists();
    }

    /**
     * 카테고리 통계
     */
    public function getCategoryStats(): array
    {
        $tenantId = session('selected_tenant_id');

        return [
            'total' => QuoteFormulaCategory::where('tenant_id', $tenantId)->count(),
            'active' => QuoteFormulaCategory::where('tenant_id', $tenantId)->where('is_active', true)->count(),
            'inactive' => QuoteFormulaCategory::where('tenant_id', $tenantId)->where('is_active', false)->count(),
        ];
    }
}