<?php

declare(strict_types=1);

namespace App\Observers;

use App\Events\Achievements\AchievementCheckRequested;
use App\Models\Artwork;
use App\Jobs\RecComputeSimilarByTagsJob;
use App\Jobs\RecComputeSimilarHybridJob;
use App\Jobs\Posts\AutoUploadPostJob;
use App\Services\ArtworkSearchIndexer;
use App\Services\HomepageService;
use App\Services\Profile\CreatorJourneyService;
use App\Services\UserStatsService;
use App\Services\XPService;
use Illuminate\Support\Facades\Cache;

/**
 * Syncs artwork documents to Meilisearch on every relevant model event.
 * Also keeps user_statistics.uploads_count and last_upload_at in sync.
 *
 * All operations are dispatched to the queue — no blocking calls.
 */
class ArtworkObserver
{
    public function __construct(
        private readonly ArtworkSearchIndexer $indexer,
        private readonly UserStatsService $userStats,
        private readonly XPService $xp,
        private readonly HomepageService $homepage,
        private readonly CreatorJourneyService $journeys,
    ) {}

    /** New artwork created — index; bump uploadscount + last_upload_at. */
    public function created(Artwork $artwork): void
    {
        $this->indexer->index($artwork);
        $this->userStats->incrementUploads($artwork->user_id);
        $this->userStats->setLastUploadAt($artwork->user_id, $artwork->created_at);
        $this->journeys->requestRebuild((int) $artwork->user_id);

        if ($artwork->is_public && $artwork->is_approved && $artwork->published_at !== null) {
            $this->bumpExploreCacheVersion();
        }

        if ($artwork->published_at !== null) {
            $this->xp->awardArtworkPublished((int) $artwork->user_id, (int) $artwork->id);
            event(new AchievementCheckRequested((int) $artwork->user_id));
        }
    }

    /** Artwork updated — covers publish, approval, metadata changes. */
    public function updated(Artwork $artwork): void
    {
        // When soft-deleted, remove from index immediately.
        if ($artwork->isDirty('deleted_at') && $artwork->deleted_at !== null) {
            $this->indexer->delete($artwork->id);
            return;
        }

        $this->indexer->update($artwork);

        // §7.5 On-demand: recompute similarity when tags/categories could have changed.
        // The pivot sync happens outside this observer, so we dispatch on every
        // meaningful update and let the job be idempotent (cheap if nothing changed).
        if ($artwork->is_public && $artwork->published_at) {
            if ($artwork->wasChanged('published_at') || $artwork->wasChanged('created_at')) {
                $this->userStats->setLastUploadAt($artwork->user_id, $artwork->created_at ?? $artwork->published_at);
            }

            RecComputeSimilarByTagsJob::dispatch($artwork->id)->delay(now()->addSeconds(30));
            RecComputeSimilarHybridJob::dispatch($artwork->id)->delay(now()->addMinutes(1));

            // Auto-upload post: fire only when artwork transitions to published for the first time
            if ($artwork->wasChanged('published_at') && $artwork->published_at !== null) {
                $this->xp->awardArtworkPublished((int) $artwork->user_id, (int) $artwork->id);
                event(new AchievementCheckRequested((int) $artwork->user_id));

                $user = $artwork->user;
                $autoPost = $user?->profile?->auto_post_upload ?? true;
                if ($autoPost) {
                    AutoUploadPostJob::dispatch($artwork->id, $artwork->user_id)
                        ->delay(now()->addSeconds(5));
                }
            }
        }

        if ($this->shouldClearFeaturedCaches($artwork)) {
            $this->homepage->clearFeaturedAndMedalCaches();
        }

        if ($artwork->wasChanged(['published_at', 'is_public', 'is_approved', 'deleted_at'])) {
            $this->bumpExploreCacheVersion();
        }

        if ($artwork->wasChanged(['published_at', 'is_public', 'is_approved', 'visibility', 'deleted_at', 'published_as_type', 'published_as_id'])) {
            $this->journeys->requestRebuild((int) $artwork->user_id);
        }
    }

    /** Soft delete — remove from search and decrement uploads_count. */
    public function deleted(Artwork $artwork): void
    {
        $this->indexer->delete($artwork->id);
        $this->userStats->decrementUploads($artwork->user_id);
        $this->journeys->requestRebuild((int) $artwork->user_id);
        $this->bumpExploreCacheVersion();

        if ($artwork->features()->exists()) {
            $this->homepage->clearFeaturedAndMedalCaches();
        }
    }

    /** Force delete — ensure removal from index; only decrement if NOT already soft-deleted. */
    public function forceDeleted(Artwork $artwork): void
    {
        $this->indexer->delete($artwork->id);
        $this->journeys->requestRebuild((int) $artwork->user_id);
        $this->bumpExploreCacheVersion();

        // If deleted_at was null the artwork was not soft-deleted before;
        // the deleted() event did NOT fire, so we decrement here.
        if ($artwork->deleted_at === null) {
            $this->userStats->decrementUploads($artwork->user_id);
        }
    }

    /** Restored from soft-delete — re-index and re-increment uploads_count. */
    public function restored(Artwork $artwork): void
    {
        $this->indexer->index($artwork);
        $this->userStats->incrementUploads($artwork->user_id);
        $this->journeys->requestRebuild((int) $artwork->user_id);
        $this->bumpExploreCacheVersion();

        if ($artwork->features()->exists()) {
            $this->homepage->clearFeaturedAndMedalCaches();
        }
    }

    private function bumpExploreCacheVersion(): void
    {
        Cache::forever('explore.cache.version', ((int) Cache::get('explore.cache.version', 1)) + 1);
    }

    private function shouldClearFeaturedCaches(Artwork $artwork): bool
    {
        if (! $artwork->wasChanged(['published_at', 'is_public', 'is_approved', 'deleted_at', 'has_missing_thumbnails'])) {
            return false;
        }

        return $artwork->features()->exists();
    }
}