<?php

namespace App\Services\ItemMaster;

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

class ItemFieldService extends Service
{
    /**
     * 독립 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,
            'section_id' => null,
            '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,
            '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,
            'section_id' => null,
            '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,
            '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'));
        }

        // 1. 기존 FK 기반 연결 (section_id)
        $directSection = $field->section;

        // 2. entity_relationships 기반 연결 - 섹션
        $linkedSectionIds = EntityRelationship::where('child_type', EntityRelationship::TYPE_FIELD)
            ->where('child_id', $id)
            ->where('parent_type', EntityRelationship::TYPE_SECTION)
            ->pluck('parent_id')
            ->toArray();

        // 3. entity_relationships 기반 연결 - 페이지 (직접 연결)
        $linkedPageIds = EntityRelationship::where('child_type', EntityRelationship::TYPE_FIELD)
            ->where('child_id', $id)
            ->where('parent_type', EntityRelationship::TYPE_PAGE)
            ->pluck('parent_id')
            ->toArray();

        return [
            'field_id' => $id,
            'direct_section' => $directSection,
            'linked_sections' => $field->linkedSections()->get(),
            'linked_pages' => $field->linkedPages()->get(),
            'total_usage_count' => ($directSection ? 1 : 0) + count($linkedSectionIds) + count($linkedPageIds),
        ];
    }

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

        // order_no 자동 계산 (해당 섹션의 마지막 필드 + 1)
        $maxOrder = ItemField::where('tenant_id', $tenantId)
            ->where('section_id', $sectionId)
            ->max('order_no');

        $field = ItemField::create([
            'tenant_id' => $tenantId,
            'section_id' => $sectionId,
            '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,
        ]);

        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,
            'updated_by' => $userId,
        ]);

        return $field;
    }

    /**
     * 필드 삭제 (Soft Delete)
     */
    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'));
        }

        $field->update(['deleted_by' => $userId]);
        $field->delete();
    }

    /**
     * 필드 순서 변경
     *
     * @param  array  $items  [['id' => 1, 'order_no' => 0], ['id' => 2, 'order_no' => 1], ...]
     */
    public function reorder(int $sectionId, array $items): void
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        foreach ($items as $item) {
            ItemField::where('tenant_id', $tenantId)
                ->where('section_id', $sectionId)
                ->where('id', $item['id'])
                ->update([
                    'order_no' => $item['order_no'],
                    'updated_by' => $userId,
                ]);
        }
    }
}