Show the Permission set on the Users Calendar via PowerShell

Get-CalendarPermission.ps1

#region License

<#
	{
		"info": {
			"Statement": "Code is poetry",
			"Author": "Joerg Hochwald",
			"Contact": "joerg.hochwald@outlook.com",
			"Link": "http://hochwald.net",
			"Support": "https://github.com/jhochwald/MyPowerShellStuff/issues"
		},
		"Copyright": "(c) 2012-2016 by Joerg Hochwald & Associates. All rights reserved."
	}

	Redistribution and use in source and binary forms, with or without modification,
	are permitted provided that the following conditions are met:

	1. Redistributions of source code must retain the above copyright notice, this list of
	   conditions and the following disclaimer.

	2. Redistributions in binary form must reproduce the above copyright notice,
	   this list of conditions and the following disclaimer in the documentation and/or
	   other materials provided with the distribution.

	3. Neither the name of the copyright holder nor the names of its contributors may
	   be used to endorse or promote products derived from this software without
	   specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
	IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
	AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
	CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
	OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	POSSIBILITY OF SUCH DAMAGE.

	By using the Software, you agree to the License, Terms and Conditions above!

	#################################################
	# modified by     : Joerg Hochwald
	# last modified   : 2016-03-25
	#################################################
#>

#endregion License

Function Global:Get-CalendarPermission {
<#
	.SYNOPSIS
		Show the Permission set on the Users Calendar

	.DESCRIPTION
		Show the Permission set on the Users Calendar

	.PARAMETER User
		User name or UPN

	.PARAMETER Cloud
		Apply to Exchange Online

	.EXAMPLE
				PS C:\> Get-CalendarPermission -User 'John.Doe'

				RunspaceId   : a8ccfa99-b28b-4427-8c19-5991efed413b
				Identity     : John.doe:\Calendar
				FolderName   : Calendar
				User         : Default
				AccessRights : {AvailabilityOnly}
				IsValid      : True
				ObjectState  : New

				RunspaceId   : a8ccfa99-b28b-4427-8c19-5991efed413b
				Identity     : John.doe:\Calendar
				FolderName   : Calendar
				User         : Anonymous
				AccessRights : {None}
				IsValid      : True
				ObjectState  : New

				RunspaceId   : a8ccfa99-b28b-4427-8c19-5991efed413b
				Identity     : John.doe:\Calendar
				FolderName   : Calendar
				User         : ExchangePublishedUser.Jane.Doe@contoso.com
				AccessRights : {AvailabilityOnly}
				IsValid      : True
				ObjectState  : New

		Perform the search against an on Premises user

	.EXAMPLE
				PS C:\> Get-CalendarPermission -User 'John.Doe' -Cloud

				RunspaceId   : a8ccfa99-b28b-4427-8c19-5991efed413b
				Identity     : John.doe:\Calendar
				FolderName   : Calendar
				User         : Default
				AccessRights : {AvailabilityOnly}
				IsValid      : True
				ObjectState  : New

				RunspaceId   : a8ccfa99-b28b-4427-8c19-5991efed413b
				Identity     : John.doe:\Calendar
				FolderName   : Calendar
				User         : Anonymous
				AccessRights : {None}
				IsValid      : True
				ObjectState  : New

				RunspaceId   : a8ccfa99-b28b-4427-8c19-5991efed413b
				Identity     : John.doe:\Calendar
				FolderName   : Calendar
				User         : ExchangePublishedUser.Jane.Doe@contoso.com
				AccessRights : {AvailabilityOnly}
				IsValid      : True
				ObjectState  : New

		Perform the search against an on Exchange Online user

	.EXAMPLE
				[Office365] PS C:\> Get-CalendarPermission -User "John.Doe" -WhatIf
				What if: Performing the operation "Get Calendar permission" on target "User Obejct John.Doe@contoso.com".

		Dry Run for the Command, show what will happen but do NOTHING!

	.NOTES
		Hybrid Command: Works for on Premises, Exchange Online and hybrid instances
#>

	[CmdletBinding(ConfirmImpact = 'None',
				   SupportsShouldProcess = $true)]
	param
	(
		[Parameter(ValueFromPipeline = $true,
				   Position = 0,
				   HelpMessage = 'User name or UPN')]
		[ValidateNotNullOrEmpty()]
		[Alias('UPN')]
		[System.String]$User,
		[Parameter(Position = 1,
				   HelpMessage = 'Apply to Exchange Online')]
		[switch]$Cloud
	)

	BEGIN {
		if (-not ($user -like "*@$localDomain")) {
			$user = ($user + "@" + $localDomain)
		}
	}

	PROCESS {
		if ($pscmdlet.ShouldProcess("User Obejct $User", "Get Calendar permission")) {
			try {
				if ($Cloud) {
					$CalendarFolder = ((Get-CloudMailboxFolderStatistics $user | Where { ($_.FolderType -eq "Calendar") }).FolderPath.Replace("/", "\"))
				} else {
					$CalendarFolder = ((Get-MailboxFolderStatistics $user | Where { ($_.FolderType -eq "Calendar") }).FolderPath.Replace("/", "\"))
				}

				$UserString = ($user + ':' + $CalendarFolder)

				if ($Cloud) {
					$CalendarPermission = (Get-CloudMailboxFolderPermission $UserString -ErrorAction:Stop -WarningAction:SilentlyContinue)
				} else {
					$CalendarPermission = (Get-MailboxFolderPermission $UserString -ErrorAction:Stop -WarningAction:SilentlyContinue)
				}
			} catch [System.Exception] {
				Write-Error -Message "Error: $($_.Exception.Message) - Line Number: $($_.InvocationInfo.ScriptLineNumber)" -ErrorAction Stop

				# Aw Snap! We are still here? Fix that the Bruce Willis way: DIE HARD!
				exit 1
			} catch {
				Write-Error -Message "Unable to search for $user" -ErrorAction Stop

				# Still here? Make sure we are done!
				break

				# Aw Snap! We are still here? Fix that the Bruce Willis way: DIE HARD!
				exit 1
			}
		}
	}

	END {
		if ($CalendarPermission) {
			Return $CalendarPermission
		}
	}
}