<?php

namespace App\Services;

use App\Models\TimelineGroup;
use Illuminate\Support\Facades\Cache;

class TimelineService
{
    /**
     * Cache duration in minutes
     */
    private const CACHE_TTL = 15;

    /**
     * Cache key for timeline data
     */
    private const CACHE_KEY = 'timeline_data';

    /**
     * Get all published timeline data with caching
     *
     * @return array{groups: array, yearTabs: array}
     */
    public function getTimelineData(): array
    {
        return Cache::remember(self::CACHE_KEY, self::CACHE_TTL * 60, function () {
            return $this->fetchTimelineData();
        });
    }

    /**
     * Clear timeline cache
     *
     * @return void
     */
    public function clearCache(): void
    {
        Cache::forget(self::CACHE_KEY);
    }

    /**
     * Fetch timeline data from database
     *
     * @return array{groups: array, yearTabs: array}
     */
    private function fetchTimelineData(): array
    {
        $groups = TimelineGroup::query()
            ->published()
            ->ordered()
            ->with([
                'years' => function ($query) {
                    $query->published()
                        ->ordered()
                        ->with([
                            'items' => function ($q) {
                                $q->published()->ordered();
                            }
                        ]);
                }
            ])
            ->get();

        // Transform to DTO format
        $groupsData = $groups->map(function ($group) {
            return [
                'title' => $group->title,
                'subtitle' => $group->subtitle,
                'years' => $group->years->map(function ($year) {
                    return [
                        'year' => $year->year,
                        'image' => $year->image
                            ? asset('storage/' . $year->image)
                            : asset('images/img-timeline.png'),
                        'items' => $year->items->map(function ($item) {
                            return [
                                'title' => $item->title,
                                'type' => $item->type,
                            ];
                        })->values()->toArray(),
                    ];
                })->values()->toArray(),
            ];
        })->values()->toArray();

        // Extract all years for yearTabs
        $yearTabs = $groups->flatMap(function ($group) {
            return $group->years->pluck('year');
        })->unique()->sort()->values()->reverse()->values()->toArray();

        return [
            'groups' => $groupsData,
            'yearTabs' => $yearTabs,
        ];
    }
}