# =========================================================
# MAX 网络工具箱 - 局域网发现
# LAN 设备扫描 / ARP 表查看与导出
# =========================================================

$Common = "C:\Setup\windows\lib\common.ps1"
if (Test-Path $Common) { . $Common }

# =========================================================
# 辅助函数
# =========================================================

function Get-PrimaryIPv4Info {
    try {
        $Config = Get-CimInstance Win32_NetworkAdapterConfiguration |
            Where-Object {
                $_.IPEnabled -eq $true -and
                $_.IPAddress -ne $null -and
                $_.DefaultIPGateway -ne $null
            } |
            Select-Object -First 1

        if ($null -eq $Config) {
            return $null
        }

        $IPv4 = $Config.IPAddress |
            Where-Object {
                $_ -match '^\d{1,3}(\.\d{1,3}){3}$' -and
                $_ -notlike '169.254.*'
            } |
            Select-Object -First 1

        $Gateway = $Config.DefaultIPGateway |
            Where-Object { $_ -match '^\d{1,3}(\.\d{1,3}){3}$' } |
            Select-Object -First 1

        if ([string]::IsNullOrWhiteSpace($IPv4)) {
            return $null
        }

        $Parts = $IPv4.Split(".")
        $SubnetPrefix = "$($Parts[0]).$($Parts[1]).$($Parts[2])"
        $DefaultSubnet = "$SubnetPrefix.0/24"

        return [PSCustomObject]@{
            IPv4          = $IPv4
            Gateway       = $Gateway
            SubnetPrefix  = $SubnetPrefix
            DefaultSubnet = $DefaultSubnet
        }
    }
    catch {
        return $null
    }
}

function Get-SubnetPrefixFromInput {
    param([string]$InputValue)

    $InputValue = $InputValue.Trim()

    if ($InputValue -match '^(\d{1,3}\.\d{1,3}\.\d{1,3})\.0/24$') {
        return $Matches[1]
    }
    if ($InputValue -match '^(\d{1,3}\.\d{1,3}\.\d{1,3})$') {
        return $Matches[1]
    }
    if ($InputValue -match '^(\d{1,3}\.\d{1,3}\.\d{1,3})\.\d{1,3}$') {
        return $Matches[1]
    }

    return $null
}

function Resolve-HostNameSafe {
    param([string]$TargetIP)

    try {
        $Result = [System.Net.Dns]::GetHostEntry($TargetIP)
        if ($Result -and $Result.HostName) {
            return $Result.HostName
        }
    }
    catch {}

    return ""
}

function Get-MacFromArp {
    param([string]$TargetIP)

    try {
        $ArpOutput = arp -a $TargetIP 2>$null

        foreach ($Line in $ArpOutput) {
            if ($Line -match [regex]::Escape($TargetIP)) {
                $Columns = $Line -split '\s+'

                foreach ($Column in $Columns) {
                    if ($Column -match '^([0-9a-fA-F]{2}-){5}[0-9a-fA-F]{2}$') {
                        return $Column
                    }
                }
            }
        }
    }
    catch {}

    return ""
}

function Test-IPv4Address {
    param([string]$Address)

    if ([string]::IsNullOrWhiteSpace($Address)) {
        return $false
    }

    if ($Address -notmatch '^\d{1,3}(\.\d{1,3}){3}$') {
        return $false
    }

    $Parts = $Address.Split(".")

    foreach ($Part in $Parts) {
        $Number = 0

        if (-not [int]::TryParse($Part, [ref]$Number)) {
            return $false
        }
        if ($Number -lt 0 -or $Number -gt 255) {
            return $false
        }
    }

    return $true
}

# =========================================================
# 扫描函数
# =========================================================

function Scan-SubnetFast {
    param([string]$SubnetPrefix)

    Write-Section "快速扫描 $SubnetPrefix.0/24"

    $Results = @()

    for ($i = 1; $i -le 254; $i++) {
        $TargetIP = "$SubnetPrefix.$i"

        Write-Host "`r  进度: $i / 254" -NoNewline -ForegroundColor DarkGray

        try {
            $Online = Test-Connection -ComputerName $TargetIP -Count 1 -Quiet -ErrorAction SilentlyContinue
        }
        catch {
            $Online = $false
        }

        if ($Online) {
            $Mac = Get-MacFromArp -TargetIP $TargetIP

            $Item = [PSCustomObject]@{
                IP       = $TargetIP
                Status   = "Online"
                MAC      = $Mac
                HostName = ""
            }

            $Results += $Item
            Write-OK "在线: $TargetIP  MAC: $Mac"
        }
    }

    Write-Host ""
    Write-OK "快速扫描完成，在线设备: $($Results.Count)"

    if ($Results.Count -gt 0) {
        $Results | Format-Table -AutoSize
    }

    return $Results
}

function Scan-SubnetDeep {
    param([string]$SubnetPrefix)

    Write-Section "深度扫描 $SubnetPrefix.0/24"
    Write-Warn "深度扫描会尝试获取 MAC 和主机名，速度较慢"

    $Results = @()

    for ($i = 1; $i -le 254; $i++) {
        $TargetIP = "$SubnetPrefix.$i"

        Write-Host "`r  进度: $i / 254" -NoNewline -ForegroundColor DarkGray

        try {
            $Online = Test-Connection -ComputerName $TargetIP -Count 1 -Quiet -ErrorAction SilentlyContinue
        }
        catch {
            $Online = $false
        }

        if ($Online) {
            $Mac = Get-MacFromArp -TargetIP $TargetIP
            $Name = Resolve-HostNameSafe -TargetIP $TargetIP

            $Item = [PSCustomObject]@{
                IP       = $TargetIP
                Status   = "Online"
                MAC      = $Mac
                HostName = $Name
            }

            $Results += $Item
            Write-OK "在线: $TargetIP  MAC: $Mac  主机名: $Name"
        }
    }

    Write-Host ""
    Write-OK "深度扫描完成，在线设备: $($Results.Count)"

    if ($Results.Count -gt 0) {
        $Results | Format-Table -AutoSize
    }

    return $Results
}

function Show-ArpTable {
    Write-Section "查看 ARP 表"

    try {
        arp -a
    }
    catch {
        Write-Err "读取 ARP 表失败"
        Write-Muted $_.Exception.Message
    }
}

function Export-ArpTable {
    Write-Section "导出 ARP 表"

    $ExportDir = "C:\Setup\Logs"
    New-Item -ItemType Directory -Path $ExportDir -Force | Out-Null

    $Time = Get-Date -Format "yyyyMMdd-HHmmss"
    $TxtFile = Join-Path $ExportDir "arp-table-$Time.txt"
    $CsvFile = Join-Path $ExportDir "arp-table-$Time.csv"

    try {
        $ArpOutput = arp -a
        $ArpOutput | Out-File -FilePath $TxtFile -Encoding UTF8

        $Rows = @()

        foreach ($Line in $ArpOutput) {
            if ($Line -match '^\s*(\d{1,3}(\.\d{1,3}){3})\s+(([0-9a-fA-F]{2}-){5}[0-9a-fA-F]{2})\s+(\w+)') {
                $Rows += [PSCustomObject]@{
                    IP   = $Matches[1]
                    MAC  = $Matches[3]
                    Type = $Matches[5]
                }
            }
        }

        if ($Rows.Count -gt 0) {
            $Rows | Export-Csv -Path $CsvFile -NoTypeInformation -Encoding UTF8
        }

        Write-OK "ARP 表已导出:"
        Write-Info $TxtFile
        Write-Info $CsvFile
    }
    catch {
        Write-Err "导出 ARP 表失败"
        Write-Muted $_.Exception.Message
    }
}

function Export-ScanResults {
    param([array]$Results)

    if (-not $Results -or $Results.Count -eq 0) {
        Write-Warn "没有可导出的扫描结果"
        return
    }

    $ExportDir = "C:\Setup\Logs"
    New-Item -ItemType Directory -Path $ExportDir -Force | Out-Null

    $Time = Get-Date -Format "yyyyMMdd-HHmmss"
    $CsvFile = Join-Path $ExportDir "lan-scan-$Time.csv"

    try {
        $Results | Export-Csv -Path $CsvFile -NoTypeInformation -Encoding UTF8
        Write-OK "扫描结果已导出:"
        Write-Info $CsvFile
    }
    catch {
        Write-Err "导出扫描结果失败"
        Write-Muted $_.Exception.Message
    }
}

# =========================================================
# 主循环
# =========================================================

$LastScanResults = @()

do {
    $Info = Get-PrimaryIPv4Info

    Write-Header "局域网发现"

    if ($Info) {
        Write-Info "本机 IP: $($Info.IPv4)"
        Write-Info "默认网关: $($Info.Gateway)"
        Write-Info "默认网段: $($Info.DefaultSubnet)"
    } else {
        Write-Warn "未能自动获取本机 IPv4 信息"
    }

    Write-Line

    Write-Section "操作菜单"
    Write-Info "1. 快速扫描默认网段"
    Write-Info "2. 深度扫描默认网段"
    Write-Info "3. 自定义 /24 网段扫描"
    Write-Info "4. 查看 ARP 表"
    Write-Info "5. 导出 ARP 表"
    Write-Info "6. 导出上次扫描结果"
    Write-Info "0. 退出"
    Write-Host ""

    $Choice = Read-Host "  请选择"

    Write-Line

    switch ($Choice.Trim()) {
        "1" {
            if ($Info) {
                $LastScanResults = Scan-SubnetFast -SubnetPrefix $Info.SubnetPrefix
            } else {
                Write-Err "无法获取默认网段"
            }
            Pause-Max
        }
        "2" {
            if ($Info) {
                $LastScanResults = Scan-SubnetDeep -SubnetPrefix $Info.SubnetPrefix
            } else {
                Write-Err "无法获取默认网段"
            }
            Pause-Max
        }
        "3" {
            $InputSubnet = Read-Host "  请输入网段，例如 192.168.1.0/24 或 192.168.1"
            $SubnetPrefix = Get-SubnetPrefixFromInput -InputValue $InputSubnet

            if ([string]::IsNullOrWhiteSpace($SubnetPrefix)) {
                Write-Err "网段格式不正确"
            } else {
                Write-Host ""
                Write-Info "1. 快速扫描"
                Write-Info "2. 深度扫描"
                Write-Host ""

                $Mode = Read-Host "  请选择扫描模式"

                if ($Mode.Trim() -eq "2") {
                    $LastScanResults = Scan-SubnetDeep -SubnetPrefix $SubnetPrefix
                } else {
                    $LastScanResults = Scan-SubnetFast -SubnetPrefix $SubnetPrefix
                }
            }

            Pause-Max
        }
        "4" {
            Show-ArpTable
            Pause-Max
        }
        "5" {
            Export-ArpTable
            Pause-Max
        }
        "6" {
            Export-ScanResults -Results $LastScanResults
            Pause-Max
        }
        "0" {
            Write-OK "已退出"
            break
        }
        default {
            Write-Warn "无效选项"
            Pause-Max
        }
    }
} while ($Choice -ne "0")