Modules/ExchangeDscDiskPart/ExchangeDscDiskPart.psm1

<#
    .SYNOPSIS
        Adds the array of commands to a single temp file, and has DiskPart
        execute the temp file.
 
    .PARAMETER Commands
        An array of commands to have DiskPart execute, in order.
 
    .PARAMETER ShowOutput
        Whether the output from DiskPart should be shown. Defaults to False.
#>

function Start-DiskPart
{
    [CmdletBinding()]
    [OutputType([System.String])]
    param
    (
        [Parameter()]
        [System.Array]
        $Commands,

        [Parameter()]
        [System.Boolean]
        $ShowOutput = $true
    )

    $Tempfile = [System.IO.Path]::GetTempFileName()

    foreach ($Com in $Commands)
    {
        $CMDLine = $CMDLine + $Com + ", "
        Add-Content $Tempfile $Com
    }

    $Output = DiskPart /s $Tempfile

    if ($ShowOutput)
    {
        Write-Verbose -Message "Executed Diskpart commands: $(Convert-StringArrayToCommaSeparatedString -Array $Commands). Result:"
        Write-Verbose -Message "$Output"
    }

    Remove-Item $Tempfile

    return $Output
}

<#
    .SYNOPSIS
        Uses DiskPart to obtain information on the disks and volumes that
        already exist on the system.
#>

function Get-DiskInfo
{
    [CmdletBinding()]
    [OutputType([System.Collections.Hashtable])]
    param ()

    [System.Collections.Hashtable] $diskInfo = @{
        DiskToVolumeMap       = @{ }
        VolumeToMountPointMap = @{ }
        DiskSizeMap           = @{ }
    }

    [int[]] $diskNums = @()

    $diskList = Start-DiskPart -Commands "List Disk" -ShowOutput $false

    $foundDisks = $false

    # First parse out the list of disks
    foreach ($line in $diskList)
    {
        if ($foundDisks -eq $true)
        {
            if ($line.Contains("Disk "))
            {
                # First find the disk number
                $startIndex = " Disk ".Length
                $endIndex = " -------- ".Length
                $diskNumStr = $line.Substring($startIndex, $endIndex - $startIndex).Trim()

                if ($diskNumStr.Length -gt 0)
                {
                    $diskNum = [int]::Parse($diskNumStr)
                    $diskNums += $diskNum
                }

                # Now find the disk size
                $startIndex = " -------- ------------- ".Length
                $endIndex = " -------- ------------- ------- ".Length
                $diskSize = $line.Substring($startIndex, $endIndex - $startIndex).Trim()

                if ($diskSize.Length -gt 0 -and $null -ne $diskNum)
                {
                    $diskInfo.DiskSizeMap.Add($diskNum, $diskSize)
                }
            }
        }
        elseif ($line.Contains("-------- ------------- ------- ------- --- ---")) # Scroll forward until we find the where the list of disks starts
        {
            $foundDisks = $true
        }
    }

    # Now get info on the disks
    foreach ($diskNum in $diskNums)
    {
        $diskDetails = Start-DiskPart -Commands "Select Disk $($diskNum)", "Detail Disk" -ShowOutput $false

        $foundVolumes = $false

        for ($i = 0; $i -lt $diskDetails.Count; $i++)
        {
            $line = $diskDetails[$i]

            if ($foundVolumes -eq $true)
            {
                if ($line.StartsWith(" Volume "))
                {
                    # First find the volume number
                    $volStart = " Volume ".Length
                    $volEnd = " ---------- ".Length
                    $volStr = $line.Substring($volStart, $volEnd - $volStart).Trim()

                    if ($volStr.Length -gt 0)
                    {
                        $volNum = [int]::Parse($volStr)

                        Add-ObjectToObjectArrayMap -Map $diskInfo.DiskToVolumeMap -Key $diskNum -Value $volNum

                        # Now parse out the drive letter if it's set
                        $letterStart = " ---------- ".Length
                        $letterEnd = $line.IndexOf(" ---------- --- ") + " ---------- --- ".Length
                        $letter = $line.Substring($letterStart, $letterEnd - $letterStart).Trim()

                        if ($letter.Length -eq 1)
                        {
                            Add-ObjectToObjectArrayMap -Map $diskInfo.VolumeToMountPointMap -Key $volNum -Value $letter
                        }

                        # Now find all the mount points
                        do
                        {
                            $line = $diskDetails[++$i]

                            if ($null -eq $line -or $line.StartsWith(" Volume ") -or $line.Trim().Length -eq 0) # We've hit the next volume, or the end of all info
                            {
                                $i-- # Move $i back one as we may have overrun the start of the next volume info
                                break
                            }
                            else
                            {
                                $mountPoint = $line.Trim()

                                Add-ObjectToObjectArrayMap -Map $diskInfo.VolumeToMountPointMap -Key $volNum -Value $mountPoint
                            }

                        } while ($i -lt $diskDetails.Count)

                    }
                }
            }
            elseif ($line.Contains("There are no volumes."))
            {
                [System.String[]] $emptyArray = @()
                $diskInfo.DiskToVolumeMap[$diskNum] = $emptyArray

                break
            }
            elseif ($line.Contains("---------- --- ----------- ----- ---------- ------- --------- --------"))
            {
                $foundVolumes = $true
            }
        }
    }

    return $diskInfo
}

<#
    .SYNOPSIS
        Takes an array of String objects and converts it into a single, comma
        separated string.
 
    .PARAMETER Array
        The String array to convert.
#>

function Convert-StringArrayToCommaSeparatedString
{
    [CmdletBinding()]
    [OutputType([System.String])]
    param
    (
        [Parameter()]
        [System.String[]]
        $Array
    )

    $string = ""

    if ($null -ne $Array -and $Array.Count -gt 0)
    {
        $string = $Array[0]

        for ($i = 1; $i -lt $Array.Count; $i++)
        {
            $string += ",$($Array[$i])"
        }
    }

    return $string
}

<#
    .SYNOPSIS
        Takes a Hashtable, where all members are Object arrays, and adds the
        input Value to the Hashtable member with the given Key.
 
    .PARAMETER Map
        The Hashtable obejct to add to.
 
    .PARAMETER Key
        The Key within the Hashtable to add the given Value to.
 
    .PARAMETER Value
        The Value to add to the Hashtable at the given Key.
#>

function Add-ObjectToObjectArrayMap
{
    [CmdletBinding()]
    param
    (
        [Parameter()]
        [System.Collections.Hashtable]
        $Map,

        [Parameter()]
        [System.Object]
        $Key,

        [Parameter()]
        [System.Object]
        $Value
    )

    if ($Map.ContainsKey($Key))
    {
        $Map[$Key] += $Value
    }
    else
    {
        [Object[]] $Array = $Value
        $Map[$Key] = $Array
    }
}

<#
    .SYNOPSIS
        Checks whether the mount point specified in the given path already
        exists as a mount point. Returns the volume number if it does exist,
        else -1.
 
    .PARAMETER Path
        The mount point path to look for.
 
    .PARAMETER DiskInfo
        A Hashtable containing discovered disk information.
#>

function Get-MountPointVolumeNumber
{
    [CmdletBinding()]
    [OutputType([System.Int32])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Path,

        [Parameter(Mandatory = $true)]
        [System.Collections.Hashtable]
        $DiskInfo
    )

    foreach ($key in $DiskInfo.VolumeToMountPointMap.Keys)
    {
        foreach ($value in $DiskInfo.VolumeToMountPointMap[$key])
        {
            # Make sure both paths end with the same character
            if (($value.EndsWith("\")) -eq $false)
            {
                $value += "\"
            }

            if (($Path.EndsWith("\")) -eq $false)
            {
                $Path += "\"
            }

            # Do the comparison
            if ($value -like $Path)
            {
                return $key
            }
        }
    }

    return -1
}