<?php

namespace App\Element;

use App\Set\Set as DomainSet;
use App\Set\SetRepository;
use DomainException;
use Illuminate\Support\Facades\DB;

class EloquentElementRepository implements ElementRepository
{
    public function __construct(private SetRepository $setRepo)
    {
    }

    public function create(CreateElementDto $dto): Element
    {
        $parentElementId = $dto->parentElement?->getId();
        $model = ElementModel::create([
            'set_id' => $dto->set->getId(),
            'title' => $dto->title,
            'description' => $dto->description,
            'icon_image_url' => $dto->iconImageUrl,
            'rich_text' => $dto->richText,
            'short_pdf_path' => $dto->shortPdfPath,
            'long_pdf_path' => $dto->longPdfPath,
            'youtube_url' => $dto->youtubeUrl,
            'parent_element_id' => $parentElementId,
            'sort_order' => $this->nextSortOrder($dto->set, $parentElementId),
        ]);

        return new Element(
            id: $model->id,
            title: $dto->title,
            description: $dto->description,
            iconImageUrl: $dto->iconImageUrl,
            richText: $dto->richText,
            shortPdfPath: $dto->shortPdfPath,
            longPdfPath: $dto->longPdfPath,
            youtubeUrl: $dto->youtubeUrl,
            set: $dto->set,
            parentElement: $dto->parentElement,
        );
    }

    public function update(Element $element): Element
    {
        $model = ElementModel::find($element->getId());
        if ($model === null) {
            throw new DomainException(
                "Element with id: {$element->getId()} doesnt exist"
            );
        }

        $model->set_id = $element->getSet()->getId();
        $model->title = $element->getTitle();
        $model->description = $element->getDescription();
        $model->icon_image_url = $element->getIconImageUrl();
        $model->rich_text = $element->getRichText();
        $model->short_pdf_path = $element->getShortPdfPath();
        $model->long_pdf_path = $element->getLongPdfPath();
        $model->youtube_url = $element->getYoutubeUrl();
        $model->parent_element_id = $element->getParentElement()?->getId();
        $model->save();

        return $this->toDomain($model);
    }

    public function delete(Element $element): void
    {
        $model = ElementModel::find($element->getId());
        if ($model === null) {
            throw new DomainException(
                "Element with id: {$element->getId()} doesnt exist"
            );
        }

        $model->delete();
    }

    public function find(int $id): ?Element
    {
        $model = ElementModel::find($id);

        return $model === null ? null : $this->toDomain($model);
    }

    public function findRootBySet(DomainSet $set): ?Element
    {
        $model = ElementModel::where('set_id', $set->getId())
            ->whereNull('parent_element_id')
            ->orderBy('sort_order')
            ->orderBy('id')
            ->first();

        return $model === null ? null : $this->toDomain($model);
    }

    /**
     * @return Element[]
     */
    public function findBySet(DomainSet $set): array
    {
        $models = ElementModel::where('set_id', $set->getId())
            ->orderBy('id')
            ->get();
        $elements = [];
        foreach ($models as $model) {
            $elements[] = $this->toDomain($model);
        }

        return $elements;
    }

    /**
     * @return Element[]
     */
    public function findByParentElement(Element $parentElement): array
    {
        $models = ElementModel::where(
            'parent_element_id',
            $parentElement->getId(),
        )
            ->orderBy('sort_order')
            ->orderBy('id')
            ->get();
        $elements = [];
        foreach ($models as $model) {
            $elements[] = $this->toDomain($model);
        }

        return $elements;
    }

    /**
     * @param int[] $childElementIds
     * @return Element[]
     */
    public function reorderChildren(
        Element $parentElement,
        array $childElementIds,
    ): array {
        DB::transaction(function () use ($parentElement, $childElementIds) {
            $sortOrder = 1;
            foreach ($childElementIds as $childElementId) {
                ElementModel::where('id', $childElementId)
                    ->where('parent_element_id', $parentElement->getId())
                    ->update(['sort_order' => $sortOrder]);
                $sortOrder++;
            }
        });

        return $this->findByParentElement($parentElement);
    }

    private function nextSortOrder(
        DomainSet $set,
        ?int $parentElementId,
    ): int {
        $query = ElementModel::where('set_id', $set->getId());
        if ($parentElementId === null) {
            $query->whereNull('parent_element_id');
        } else {
            $query->where('parent_element_id', $parentElementId);
        }

        $currentMaxSortOrder = $query->max('sort_order');
        if ($currentMaxSortOrder === null) {
            return 1;
        }

        return (int) $currentMaxSortOrder + 1;
    }

    private function toDomain(ElementModel $model): Element
    {
        $set = $this->setRepo->find($model->set_id);
        if ($set === null) {
            throw new DomainException(
                "Set with id: {$model->set_id} doesnt exist"
            );
        }

        $parentElement = null;
        if ($model->parent_element_id !== null) {
            $parentElement = $this->find($model->parent_element_id);
            if ($parentElement === null) {
                throw new DomainException(
                    "Element with id: {$model->parent_element_id} doesnt exist"
                );
            }
        }

        return new Element(
            id: $model->id,
            title: $model->title,
            description: $model->description,
            iconImageUrl: $model->icon_image_url,
            richText: $model->rich_text,
            shortPdfPath: $model->short_pdf_path,
            longPdfPath: $model->long_pdf_path,
            youtubeUrl: $model->youtube_url,
            set: $set,
            parentElement: $parentElement,
        );
    }
}