<?php

namespace App\Services;

use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Number;

class DiskSpaceService
{
    /**
     * Snapshot of free/used space for the recordings storage volume.
     *
     * @return array{
     *     total_bytes: int,
     *     free_bytes: int,
     *     used_bytes: int,
     *     used_percent: float,
     *     free_percent: float,
     *     total_human: string,
     *     free_human: string,
     *     used_human: string
     * }|null
     */
    public function snapshot(?string $path = null): ?array
    {
        $path ??= Storage::disk('local')->path('');

        /** @var array{total_bytes: int, free_bytes: int, used_bytes: int, used_percent: float, free_percent: float, total_human: string, free_human: string, used_human: string}|null */
        return Cache::remember(
            'disk-space:'.md5($path),
            now()->addSeconds(30),
            fn () => $this->measure($path),
        );
    }

    /**
     * @return array{
     *     total_bytes: int,
     *     free_bytes: int,
     *     used_bytes: int,
     *     used_percent: float,
     *     free_percent: float,
     *     total_human: string,
     *     free_human: string,
     *     used_human: string
     * }|null
     */
    private function measure(string $path): ?array
    {
        $total = @disk_total_space($path);
        $free = @disk_free_space($path);

        if ($total === false || $free === false || $total <= 0) {
            return null;
        }

        $totalBytes = (int) $total;
        $freeBytes = (int) max(0, $free);
        $usedBytes = (int) max(0, $totalBytes - $freeBytes);
        $usedPercent = round(($usedBytes / $totalBytes) * 100, 1);
        $freePercent = round(($freeBytes / $totalBytes) * 100, 1);

        return [
            'total_bytes' => $totalBytes,
            'free_bytes' => $freeBytes,
            'used_bytes' => $usedBytes,
            'used_percent' => $usedPercent,
            'free_percent' => $freePercent,
            'total_human' => Number::fileSize($totalBytes, precision: 1),
            'free_human' => Number::fileSize($freeBytes, precision: 1),
            'used_human' => Number::fileSize($usedBytes, precision: 1),
        ];
    }
}