<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Http\Requests\StoreSettingsMediaRequest;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Http\Response;
use Illuminate\Http\UploadedFile;
use Illuminate\Support\Facades\Storage;
use RuntimeException;

class SettingsMediaController extends Controller
{
    private const BACKGROUND_MAX_SIDE = 1600;

    private const BACKGROUND_QUALITY = 86;

    public function store(StoreSettingsMediaRequest $request): JsonResponse
    {
        $processed = $this->processBackground($request->file('file'));
        $path = $this->backgroundPath((int) $request->user()->id);

        Storage::disk('local')->put($path, $processed['contents']);

        return response()->json([
            'data' => [
                'url' => '/settings/media/background?v='.time(),
                'width' => $processed['width'],
                'height' => $processed['height'],
                'mimeType' => 'image/jpeg',
                'size' => strlen($processed['contents']),
            ],
        ], 201);
    }

    public function show(Request $request): Response
    {
        $path = $this->backgroundPath((int) $request->user()->id);

        abort_unless(Storage::disk('local')->exists($path), 404);

        return response(Storage::disk('local')->get($path), 200, [
            'Content-Type' => 'image/jpeg',
            'Cache-Control' => 'private, max-age=604800',
        ]);
    }

    public function destroy(Request $request): JsonResponse
    {
        Storage::disk('local')->delete($this->backgroundPath((int) $request->user()->id));

        return response()->json(null, 204);
    }

    private function backgroundPath(int $userId): string
    {
        return "settings-media/{$userId}/background.jpg";
    }

    /**
     * @return array{contents: string, width: int, height: int}
     */
    private function processBackground(UploadedFile $file): array
    {
        $source = imagecreatefromstring((string) file_get_contents($file->getRealPath()));

        if (! $source) {
            throw new RuntimeException('The uploaded background image could not be processed.');
        }

        $sourceWidth = imagesx($source);
        $sourceHeight = imagesy($source);
        $scale = min(1, self::BACKGROUND_MAX_SIDE / max($sourceWidth, $sourceHeight));
        $width = max(1, (int) round($sourceWidth * $scale));
        $height = max(1, (int) round($sourceHeight * $scale));

        $canvas = imagecreatetruecolor($width, $height);
        $background = imagecolorallocate($canvas, 255, 255, 255);
        imagefilledrectangle($canvas, 0, 0, $width, $height, $background);
        imagecopyresampled($canvas, $source, 0, 0, 0, 0, $width, $height, $sourceWidth, $sourceHeight);

        imagedestroy($source);

        ob_start();
        imagejpeg($canvas, null, self::BACKGROUND_QUALITY);
        $contents = (string) ob_get_clean();
        imagedestroy($canvas);

        return [
            'contents' => $contents,
            'width' => $width,
            'height' => $height,
        ];
    }
}