<?php

namespace App\Http\Controllers\Api\Posts;

use App\Http\Controllers\Controller;
use App\Models\Post;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Gate;

/**
 * POST   /api/posts/{id}/pin
 * DELETE /api/posts/{id}/pin
 */
class PostPinController extends Controller
{
    private const MAX_PINNED = 3;

    public function pin(Request $request, int $id): JsonResponse
    {
        $post = Post::where('status', Post::STATUS_PUBLISHED)->findOrFail($id);
        Gate::authorize('update', $post);

        $user = $request->user();

        // Count existing pinned posts
        $pinnedCount = Post::where('user_id', $user->id)
            ->where('is_pinned', true)
            ->count();

        if ($post->is_pinned) {
            return response()->json(['message' => 'Post is already pinned.'], 409);
        }

        if ($pinnedCount >= self::MAX_PINNED) {
            return response()->json([
                'message' => 'You can pin a maximum of ' . self::MAX_PINNED . ' posts.',
            ], 422);
        }

        $nextOrder = Post::where('user_id', $user->id)
            ->where('is_pinned', true)
            ->max('pinned_order') ?? 0;

        $post->update([
            'is_pinned'    => true,
            'pinned_order' => $nextOrder + 1,
        ]);

        return response()->json(['message' => 'Post pinned.', 'post_id' => $post->id]);
    }

    public function unpin(int $id): JsonResponse
    {
        $post = Post::findOrFail($id);
        Gate::authorize('update', $post);

        if (! $post->is_pinned) {
            return response()->json(['message' => 'Post is not pinned.'], 409);
        }

        $post->update(['is_pinned' => false, 'pinned_order' => null]);

        return response()->json(['message' => 'Post unpinned.', 'post_id' => $post->id]);
    }
}