<?php

namespace App\Utils;

class DiskInfoHelper
{
    /**
     * 获取所有磁盘信息
     */
    public static function getAllDisks(): array
    {
        if (PHP_OS_FAMILY === 'Windows') {
            return self::getWindowsDisks();
        }

        return self::getLinuxDisks();
    }

    /**
     * Linux 系统：通过 df -T 获取磁盘信息
     */
    protected static function getLinuxDisks(): array
    {
        $output = [];
        @exec('df -T -B1 2>/dev/null', $output);

        $disks = [];
        $ignoreFs = ['tmpfs', 'devtmpfs', 'overlay', 'squashfs', 'proc', 'sysfs', 'cgroup'];

        foreach ($output as $line) {
            if (str_starts_with($line, 'Filesystem') || empty(trim($line))) {
                continue;
            }

            [$filesystem, $type, $size, $used, $avail, $usePercent, $mount] = preg_split('/\s+/', $line);

            if (in_array($type, $ignoreFs)) {
                continue; // 过滤掉虚拟文件系统
            }

            $size = (int)$size;
            $used = (int)$used;
            $avail = (int)$avail;
            $usePercent = rtrim($usePercent, '%');

            $disks[] = [
                'path'         => $mount,
                'filesystem'   => $filesystem,
                'type'         => $type,
                'total'        => self::formatBytes($size),
                'used'         => self::formatBytes($used),
                'available'    => self::formatBytes($avail),
                'used_percent' => (float)$usePercent . '%',
            ];
        }

        return $disks;
    }

    /**
     * Windows 系统：通过 wmic 获取磁盘信息
     */
    protected static function getWindowsDisks(): array
    {
        $output = [];
        @exec('wmic logicaldisk get Caption,FileSystem,Size,FreeSpace,Description /format:list', $output);

        $disks = [];
        $current = [];

        foreach ($output as $line) {
            $line = trim($line);
            if ($line === '') {
                if (!empty($current)) {
                    $disks[] = self::formatWindowsDisk($current);
                    $current = [];
                }
                continue;
            }

            [$key, $value] = array_map('trim', explode('=', $line, 2) + [null, null]);
            if ($key) {
                $current[$key] = $value;
            }
        }

        if (!empty($current)) {
            $disks[] = self::formatWindowsDisk($current);
        }

        return $disks;
    }

    /**
     * 格式化 Windows 磁盘数据
     */
    protected static function formatWindowsDisk(array $data): array
    {
        $size = isset($data['Size']) ? (int)$data['Size'] : 0;
        $free = isset($data['FreeSpace']) ? (int)$data['FreeSpace'] : 0;
        $used = $size - $free;
        $usedPercent = $size > 0 ? round($used / $size * 100, 2) : 0;

        return [
            'path'          => $data['Caption'] ?? '',
            'filesystem'    => $data['FileSystem'] ?? '',
            'type'          => $data['Description'] ?? '',
            'total'         => self::formatBytes($size),
            'used'          => self::formatBytes($used),
            'available'     => self::formatBytes($free),
            'used_percent'  => $usedPercent . "%",
        ];
    }

    /**
     * 格式化字节为易读形式
     */
    protected static function formatBytes(int $bytes): string
    {
        if ($bytes <= 0) {
            return '0 B';
        }

        $units = ['B', 'KB', 'MB', 'GB', 'TB', 'PB'];
        $i = (int)floor(log($bytes, 1024));
        return sprintf('%.2f %s', $bytes / pow(1024, $i), $units[$i]);
    }
}