Report team private channel membership

Import-Module MicrosoftTeams -Force

$Modules = Get-Module | Select-Object -ExpandProperty Name
If ($Modules -notcontains 'MicrosoftTeams') {
    Write-Host "Importing Microsoft Teams module..." -ForegroundColor Yellow
    Import-Module MicrosoftTeams -Force
    Try {
        Write-Host "Connecting to Microsoft Teams..." -ForegroundColor Yellow
        Connect-MicrosoftTeams -ErrorAction Stop
    } Catch {
        Write-Host "Failed to connect to Microsoft Teams. Please ensure you have the necessary permissions and try again." -ForegroundColor Red
        Exit
    }
}
 
Write-Output "Fetching teams data..." -ForegroundColor Green
[array]$Teams = Get-Team
 
$ChannelsList = [System.Collections.Generic.List[Object]]::new()
[int]$i = 0
ForEach ($Team in $Teams) {
    $i++
    Write-Host ("Processing {0} ({1}/{2})" -f $Team.DisplayName, $i, $Teams.Count)
    [array]$Channels = Get-TeamAllChannel -GroupId $Team.GroupId -MembershipType "Private"
    ForEach ($Channel in $Channels) {
        Write-Host ("Found private channel {0} in team {1}" -f $Channel.DisplayName, $Team.DisplayName)
        [array]$ChannelMembers = Get-TeamChannelUser -GroupId $Team.GroupId -DisplayName $Channel.DisplayName
        If ($ChannelMembers) {
            ForEach ($Member in $ChannelMembers) {
            $ChannelLine = [PSCustomObject][Ordered]@{ # Write out details of the private channel and its members
                Team                = $Team.DisplayName
                Channel             = $Channel.DisplayName
                Description         = $Channel.Description
                Member              = $Member.Name
                MemberUPN           = $Member.User
                Role                = $Member.Role
                HostTeam            = $Channel.HostTeamId
                Id                  = $Channel.Id
            }
            $ChannelsList.Add($ChannelLine)
            } # End ForEach Member
 
        }  Else { # Deal with private channels that have no members (which can happen if the channel is created and then all members are removed, or if the channel is created and never had any members added to it)
            $ChannelLine = [PSCustomObject][Ordered]@{ # Write out details of the private channel with no members
                Team                = $Team.DisplayName + " (No members)"
                Channel             = $Channel.DisplayName + " (No members)"
                Description         = $Channel.Description
                Member              = $Null
                MemberUPN           = $Null
                Role                = $Null
                HostTeam            = $Channel.HostTeamId
                Id                  = $Channel.Id
            }
            $ChannelsList.Add($ChannelLine)
        }
    }
} # End ForEach Team
 
$ChannelsList | Out-GridView -Title "Teams Private Channel Membership Report"
 
# Set up to use the ImportExcel module to generate Excel worksheets if it is available. If not, the report will be generated in CSV format instead.
If (Get-Module ImportExcel -ListAvailable) {
    $ExcelGenerated = $True
    Import-Module ImportExcel -ErrorAction SilentlyContinue
}
 
# Generate the attachment in either Excel worksheet or CSV format, depending on if the ImportExcel module is available
If ($ExcelGenerated) {
    $OutputFile = ((New-Object -ComObject Shell.Application).Namespace('shell:Downloads').Self.Path) + "\TeamsPrivateChannelMembership.xlsx"
    $ChannelsList | Export-Excel -Path $OutputFile -WorksheetName "PrivateChannelMembership" -Title ("Teams Private Channel Membership {0}" -f (Get-Date -format 'dd-MMM-yyyy')) -TitleBold -TableName "PrivateChannels"
} Else {
    $OutputFile = ((New-Object -ComObject Shell.Application).Namespace('shell:Downloads').Self.Path) + "\TeamsPrivateChannelMembership.csv"
    $ChannelsList | Export-Csv -Path $OutputFile     -NoTypeInformation -Encoding Utf8
}
 
Write-Host "Report generated in: $OutputFile" -ForegroundColor Green