<?php

declare(strict_types=1);

namespace App\Http\Controllers\Web;

use App\Http\Controllers\Controller;
use App\Models\ActivityEvent;
use App\Models\Artwork;
use App\Models\User;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

/**
 * Community activity feed.
 *
 * GET /community/activity?type=global|following
 */
final class CommunityActivityController extends Controller
{
    private const PER_PAGE = 30;

    public function index(Request $request)
    {
        $user   = $request->user();
        $type   = $request->query('type', 'global'); // global | following
        $perPage = self::PER_PAGE;

        $query = ActivityEvent::query()
            ->orderByDesc('created_at')
            ->with(['actor:id,name,username']);

        if ($type === 'following' && $user) {
            // Show only events from followed users
            $followingIds = DB::table('user_followers')
                ->where('follower_id', $user->id)
                ->pluck('user_id')
                ->all();

            if (empty($followingIds)) {
                $query->whereRaw('0 = 1'); // empty result set
            } else {
                $query->whereIn('actor_id', $followingIds);
            }
        }

        $events   = $query->paginate($perPage)->withQueryString();
        $enriched = $this->enrich($events->getCollection());

        return view('web.community.activity', [
            'events'     => $events,
            'enriched'   => $enriched,
            'active_tab' => $type,
            'page_title' => 'Community Activity',
        ]);
    }

    /**
     * Attach target object data to each event for display.
     */
    private function enrich(\Illuminate\Support\Collection $events): \Illuminate\Support\Collection
    {
        // Collect artwork IDs and user IDs to eager-load
        $artworkIds = $events
            ->where('target_type', ActivityEvent::TARGET_ARTWORK)
            ->pluck('target_id')
            ->unique()
            ->values()
            ->all();

        $userIds = $events
            ->where('target_type', ActivityEvent::TARGET_USER)
            ->pluck('target_id')
            ->unique()
            ->values()
            ->all();

        $artworks = Artwork::whereIn('id', $artworkIds)
            ->with('user:id,name,username')
            ->get(['id', 'title', 'slug', 'user_id', 'hash', 'thumb_ext'])
            ->keyBy('id');

        $users = User::whereIn('id', $userIds)
            ->with('profile:user_id,avatar_hash')
            ->get(['id', 'name', 'username'])
            ->keyBy('id');

        return $events->map(function (ActivityEvent $event) use ($artworks, $users): array {
            $target = null;

            if ($event->target_type === ActivityEvent::TARGET_ARTWORK) {
                $artwork = $artworks->get($event->target_id);
                $target  = $artwork ? [
                    'id'    => $artwork->id,
                    'title' => $artwork->title,
                    'url'   => '/art/' . $artwork->id . '/' . $artwork->slug,
                    'thumb' => $artwork->thumbUrl('sm'),
                ] : null;
            } elseif ($event->target_type === ActivityEvent::TARGET_USER) {
                $u      = $users->get($event->target_id);
                $target = $u ? [
                    'id'       => $u->id,
                    'name'     => $u->name,
                    'username' => $u->username,
                    'url'      => '/@' . $u->username,
                ] : null;
            }

            return [
                'id'          => $event->id,
                'type'        => $event->type,
                'target_type' => $event->target_type,
                'actor'       => [
                    'id'       => $event->actor?->id,
                    'name'     => $event->actor?->name,
                    'username' => $event->actor?->username,
                    'url'      => '/@' . $event->actor?->username,
                ],
                'target'      => $target,
                'created_at'  => $event->created_at?->toIso8601String(),
            ];
        });
    }
}