<?php

namespace App\Services\SectionApproach;

use App\Enums\StaticPageType;
use App\Models\CategoryApproach;
use App\Models\SectionApproach;
use App\Models\StaticPage;

class SectionApproachService
{
    /**
     * Retrieve the data needed to populate create/edit forms.
     * Returns paginated categories and eligible static pages.
     */
    public function getFormData(): array
    {
        return [
            'categories' => CategoryApproach::query()->orderBy('name', 'ASC')->paginate(),
            'pages'      => StaticPage::whereIn('type', [StaticPageType::ouiCBon, StaticPageType::exitOutside])->paginate(),
        ];
    }

    /**
     * Create and persist a new section approach.
     * Throws an exception if the maximum number of sections per category/page is reached.
     *
     * @param  array  $validated  rules validated in request
     *
     * @throws \Exception
     */
    public function store(array $validated): SectionApproach
    {
        $pageId     = (int) $validated['page_id'];
        $categoryId = (int) $validated['category_id'];

        $page     = StaticPage::findOrFail($pageId);
        $category = CategoryApproach::findOrFail($categoryId);

        $count = SectionApproach::query()
            ->where('page_id', $pageId)
            ->where('category_id', $categoryId)
            ->lockForUpdate()
            ->count();

        if ($count >= SectionApproach::MAX_SECTIONS) {
            throw new \Exception(
                "Limite atteinte : La catégorie ''{$category->name}'' dans la page ''{$page->title}'' contient déjà " . SectionApproach::MAX_SECTIONS . ' sections.'
            );
        }

        $section = new SectionApproach();
        $section->fill($validated);
        $section->save();

        return $section;
    }

    /**
     * Update an existing section approach
     *
     * @param  \App\Models\SectionApproach  $section_approach  model
     * @param  array  $validated  rules validated in request
     *
     * @throws \Exception
     */
    public function update(SectionApproach $section_approach, array $validated): SectionApproach
    {
        $section = SectionApproach::query()
            ->whereKey($section_approach->id)
            ->lockForUpdate()
            ->firstOrFail();

        $oldPageId     = (int) $section->page_id;
        $oldCategoryId = (int) $section->category_id;
        $newPageId     = (int) ($validated['page_id'] ?? $oldPageId);
        $newCategoryId = (int) ($validated['category_id'] ?? $oldCategoryId);
        $isMoving      = ($oldPageId !== $newPageId) || ($oldCategoryId !== $newCategoryId);

        if ($isMoving) {
            // Checkcategory retains the minimum number of sections
            $sourceCount = SectionApproach::query()
                ->where('page_id', $oldPageId)
                ->where('category_id', $oldCategoryId)
                ->lockForUpdate()
                ->count();

            if ($sourceCount <= SectionApproach::MIN_SECTIONS) {
                throw new \Exception(
                    "Déplacement impossible : la catégorie d'origine doit garder au minimum " . SectionApproach::MIN_SECTIONS . ' sections.'
                );
            }

            // Check category has not reached the maximum number of sections
            $targetCount = SectionApproach::query()
                ->where('page_id', $newPageId)
                ->where('category_id', $newCategoryId)
                ->lockForUpdate()
                ->count();

            if ($targetCount >= SectionApproach::MAX_SECTIONS) {
                throw new \Exception(
                    'Déplacement impossible : la catégorie cible contient déjà ' . SectionApproach::MAX_SECTIONS . ' sections pour cette page.'
                );
            }
        }// end if

        $section->fill($validated);
        $section->save();

        return $section;
    }

    /**
     * Delete a section approach.
     * Throws an exception if the category would fall below the minimum required sections.
     *
     * @param  App\Models\SectionApproach  $section_approach
     *
     * @throws \Exception
     */
    public function destroy(SectionApproach $section_approach): void
    {
        $section = SectionApproach::query()
            ->whereKey($section_approach->id)
            ->lockForUpdate()
            ->firstOrFail();

        $count = SectionApproach::query()
            ->where('page_id', $section->page_id)
            ->where('category_id', $section->category_id)
            ->lockForUpdate()
            ->count();

        if ($count <= SectionApproach::MIN_SECTIONS) {
            throw new \Exception(
                'Suppression impossible : une catégorie doit contenir au minimum ' . SectionApproach::MIN_SECTIONS . ' sections dans une page.'
            );
        }

        $section->delete();
    }
}