<?php

namespace App\Services\ItemMaster;

use App\Models\ItemMaster\EntityRelationship;
use App\Models\ItemMaster\ItemField;
use App\Services\Service;
use App\Traits\LockCheckTrait;
use Illuminate\Database\Eloquent\Collection;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

class ItemFieldService extends Service
{
    use LockCheckTrait;

    /**
     * 모든 필드 목록 조회
     *
     * GET /api/v1/item-master/fields
     */
    public function index(): Collection
    {
        $tenantId = $this->tenantId();

        return ItemField::where('tenant_id', $tenantId)
            ->orderBy('created_at', 'desc')
            ->get();
    }

    /**
     * 독립 필드 생성 (섹션 연결 없음)
     *
     * POST /api/v1/item-master/fields
     */
    public function storeIndependent(array $data): ItemField
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        $field = ItemField::create([
            'tenant_id' => $tenantId,
            'group_id' => $data['group_id'] ?? 1,
            'field_name' => $data['field_name'],
            'field_type' => $data['field_type'],
            'order_no' => 0,
            'is_required' => $data['is_required'] ?? false,
            'default_value' => $data['default_value'] ?? null,
            'placeholder' => $data['placeholder'] ?? null,
            'display_condition' => $data['display_condition'] ?? null,
            'validation_rules' => $data['validation_rules'] ?? null,
            'options' => $data['options'] ?? null,
            'properties' => $data['properties'] ?? null,
            'category' => $data['category'] ?? null,
            'description' => $data['description'] ?? null,
            'is_common' => $data['is_common'] ?? false,
            'created_by' => $userId,
        ]);

        return $field;
    }

    /**
     * 필드 복제
     *
     * POST /api/v1/item-master/fields/{id}/clone
     */
    public function clone(int $id): ItemField
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        $original = ItemField::where('tenant_id', $tenantId)
            ->where('id', $id)
            ->first();

        if (! $original) {
            throw new NotFoundHttpException(__('error.field_not_found'));
        }

        $cloned = ItemField::create([
            'tenant_id' => $tenantId,
            'group_id' => $original->group_id,
            'field_name' => $original->field_name.' (복사본)',
            'field_type' => $original->field_type,
            'order_no' => 0,
            'is_required' => $original->is_required,
            'default_value' => $original->default_value,
            'placeholder' => $original->placeholder,
            'display_condition' => $original->display_condition,
            'validation_rules' => $original->validation_rules,
            'options' => $original->options,
            'properties' => $original->properties,
            'category' => $original->category,
            'description' => $original->description,
            'is_common' => $original->is_common,
            'created_by' => $userId,
        ]);

        return $cloned;
    }

    /**
     * 필드 사용처 조회 (어떤 섹션/페이지에 연결되어 있는지)
     *
     * GET /api/v1/item-master/fields/{id}/usage
     */
    public function getUsage(int $id): array
    {
        $tenantId = $this->tenantId();

        $field = ItemField::where('tenant_id', $tenantId)
            ->where('id', $id)
            ->first();

        if (! $field) {
            throw new NotFoundHttpException(__('error.field_not_found'));
        }

        // entity_relationships 기반 연결
        $linkedSections = $field->linkedSections()->get();
        $linkedPages = $field->linkedPages()->get();

        return [
            'field_id' => $id,
            'linked_sections' => $linkedSections,
            'linked_pages' => $linkedPages,
            'total_usage_count' => $linkedSections->count() + $linkedPages->count(),
        ];
    }

    /**
     * 필드 생성 및 섹션에 연결
     */
    public function store(int $sectionId, array $data): ItemField
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        // order_no 자동 계산 (해당 섹션에 연결된 마지막 필드 + 1)
        $maxOrder = EntityRelationship::where('parent_type', EntityRelationship::TYPE_SECTION)
            ->where('parent_id', $sectionId)
            ->where('child_type', EntityRelationship::TYPE_FIELD)
            ->max('order_no');

        // 필드 생성
        $field = ItemField::create([
            'tenant_id' => $tenantId,
            'group_id' => $data['group_id'] ?? 1,
            'field_name' => $data['field_name'],
            'field_type' => $data['field_type'],
            'order_no' => ($maxOrder ?? -1) + 1,
            'is_required' => $data['is_required'] ?? false,
            'default_value' => $data['default_value'] ?? null,
            'placeholder' => $data['placeholder'] ?? null,
            'display_condition' => $data['display_condition'] ?? null,
            'validation_rules' => $data['validation_rules'] ?? null,
            'options' => $data['options'] ?? null,
            'properties' => $data['properties'] ?? null,
            'created_by' => $userId,
        ]);

        // 섹션-필드 관계 생성
        EntityRelationship::link(
            EntityRelationship::TYPE_SECTION,
            $sectionId,
            EntityRelationship::TYPE_FIELD,
            $field->id,
            $tenantId,
            $data['group_id'] ?? 1,
            ($maxOrder ?? -1) + 1
        );

        return $field;
    }

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

        $field = ItemField::where('tenant_id', $tenantId)
            ->where('id', $id)
            ->first();

        if (! $field) {
            throw new NotFoundHttpException(__('error.not_found'));
        }

        $field->update([
            'field_name' => $data['field_name'] ?? $field->field_name,
            'field_type' => $data['field_type'] ?? $field->field_type,
            'is_required' => $data['is_required'] ?? $field->is_required,
            'default_value' => $data['default_value'] ?? $field->default_value,
            'placeholder' => $data['placeholder'] ?? $field->placeholder,
            'display_condition' => $data['display_condition'] ?? $field->display_condition,
            'validation_rules' => $data['validation_rules'] ?? $field->validation_rules,
            'options' => $data['options'] ?? $field->options,
            'properties' => $data['properties'] ?? $field->properties,
            'category' => $data['category'] ?? $field->category,
            'description' => $data['description'] ?? $field->description,
            'is_common' => $data['is_common'] ?? $field->is_common,
            'updated_by' => $userId,
        ]);

        return $field;
    }

    /**
     * 필드 삭제 (Soft Delete)
     *
     * 독립 엔티티 아키텍처: 필드 삭제 시 모든 부모 관계도 해제
     */
    public function destroy(int $id): void
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        $field = ItemField::where('tenant_id', $tenantId)
            ->where('id', $id)
            ->first();

        if (! $field) {
            throw new NotFoundHttpException(__('error.not_found'));
        }

        // 잠금 체크: 이 필드가 잠금된 연결로 보호되고 있는지 확인
        $this->checkCanDelete(EntityRelationship::TYPE_FIELD, $id);

        // 1. entity_relationships에서 이 필드의 모든 부모 관계 해제
        //    (section→field, page→field 관계에서 이 필드 제거)
        //    주의: 잠금된 연결이 있으면 위에서 예외 발생
        EntityRelationship::where('child_type', EntityRelationship::TYPE_FIELD)
            ->where('child_id', $id)
            ->where('is_locked', false)
            ->delete();

        // 2. 필드 Soft Delete
        $field->update(['deleted_by' => $userId]);
        $field->delete();
    }

    /**
     * 필드 순서 변경 (entity_relationships 기반)
     *
     * @param  array  $items  [['id' => 1, 'order_no' => 0], ['id' => 2, 'order_no' => 1], ...]
     */
    public function reorder(int $sectionId, array $items): void
    {
        foreach ($items as $item) {
            // entity_relationships에서 순서 업데이트
            EntityRelationship::where('parent_type', EntityRelationship::TYPE_SECTION)
                ->where('parent_id', $sectionId)
                ->where('child_type', EntityRelationship::TYPE_FIELD)
                ->where('child_id', $item['id'])
                ->update(['order_no' => $item['order_no']]);

            // 필드 자체의 order_no도 동기화
            ItemField::where('id', $item['id'])
                ->update(['order_no' => $item['order_no']]);
        }
    }
}