# ConnectExchangeDatacenter.ps1
# Copyright (c) 2010 Microsoft Corporation. All rights reserved.
#
# THIS CODE IS MADE AVAILABLE AS IS, WITHOUT WARRANTY OF ANY KIND. THE ENTIRE RISK
# OF THE USE OR THE RESULTS FROM THE USE OF THIS CODE REMAINS WITH THE USER. 

# Type get-help [script name] to get help of the script

param(
	[Parameter(Position = 0, Mandatory = $false)]
	[string]$LookForUpdates="Prompt",
	
	[Parameter(Position = 1, Mandatory = $false)]
	[string]$Authentication="Basic",
	
	[Parameter(Position = 2, Mandatory = $false)]
	[switch]$ClearCache
)

## Declare all local and global variables ######################################
# The color of the msg text
$foreColor = "Green"

# There will be separate version number for each script
$ConnectScriptVersion="14.0.1"

# This tag is used to search the version number from HTML content (or script code)
# With separate tag, we can update scripts independently
$connectScriptVersionTag = "ConnectScriptVersion"
$commonFunctionsScriptVersionTag = "CommonFunctionsScriptVersion"

$connectionScriptName =  "ConnectExchangeDatacenter.ps1"
$commonFunctionsScriptName =  "CommonConnectFunctions.ps1"

$connectionScriptUrl = "http://gallery.technet.microsoft.com/ScriptCenter/en-us/15876b57-d0ed-492d-bc8d-dc17cdf2d103"
$commonFunctionsScriptUrl = "http://gallery.technet.microsoft.com/ScriptCenter/en-us/cd04703f-aaee-4abe-a169-e6bd1a3fd5d4"

$fqdn = "ps.outlook.com"
$connectionUri = "https://$fqdn/powershell?serializationLevel=Full"

# We need this global variable to break recursive script call during auto update and script restart
if ($global:versionCheckComplete -eq $null)
{
	$global:versionCheckComplete = $false
}

## COMMON CONNECTION FUNCTIONS #################################################

if (test-path $commonFunctionsScriptName)
{
	. CommonConnectFunctions.ps1
}
else
{
	Write-Error "Cannot find $commonFunctionsScriptName. Please download the script from $commonFunctionsScriptUrl"
}

## Declare all local functions ###############################################

function GetScriptTextFromWeb([string]$scriptName,[string]$scriptUrl)
{
	$WebClient = New-Object System.Net.WebClient
	
	# first download the html content (including script) from script center gallery
	$htmlText = $WebClient.DownloadString($scriptUrl)
	
	if ($htmlText -eq $null)
	{
		Write-Host -fore "Red" "Currently the script is not available at $scriptUrl. Please contact Exchange support for more details. Cannot do verion check and auto update this time."
		return
	}
	
	# parse and load the Html content 
	$h = new-object -com "HTMLFILE"

	$h.IHTMLDocument2_write($htmltext)
	
	# find the script text from html content
	foreach ($child in $h.body.childNodes)
	{
		if ($child.tagName -eq "DIV")
		{
			$scriptText = $child.innerText
			break
		}
	}

	if ($scriptText -ne $null)
	{
		$scriptLine = select-string -InputObject $scriptText -Pattern $scriptName -AllMatches
		if ($scriptLine -ne $null)
		{
			# we have placed a marker string (the string name) at the beginning and at the end of each script, so that we can extract the script text based on the markers
			if ($scriptLine.matches.length -lt 2)
			{
				Write-Warning "Invalid script format. The script should contain script name as comment at the beginning and at the end of the script. Skipping version check..."
				return
			}
			$start = $scriptLine.matches[0]
			$end = $scriptLine.matches[$scriptLine.matches.length-1]
			$scriptText = $scriptText.SubString($start.Index-2, $end.Index - $start.Index +  $scriptName.length + 2)
		}
	}
	$scriptText
}

function AutoUpdateScript([string]$scriptName, [string]$scriptText, [string]$scriptUrl, [string]$currentScriptVersion)
{
	$backupScriptName = ($scriptName.split(".")[0]+"_"+$currentScriptVersion+"."+$scriptName.split(".")[1])
	copy-item $scriptName $backupScriptName
	set-content -path $scriptName -value $scriptText
	Write-Host -fore $foreColor "Auto update complete. The script has been backed up as $backupScriptName"
	if ($scriptName -eq "ConnectExchangeDatacenter.ps1")
	{
		Write-Host "Restarting the script $scriptName"
		$global:versionCheckComplete = $true
		$cmd = "$scriptName $script:paramString" 
		iex $cmd  
		Exit
	}
}

function check-version ([string]$scriptName, [string]$scriptUrl, [string]$currentScriptVersion, [string]$currentScriptVersionTag)
{
	Write-Host -fore $foreColor "Checking version of the script $scriptName. Current version is $currentScriptVersion"
	
	$scriptText = GetScriptTextFromWeb $scriptName $scriptUrl
	
	if ($scriptText -ne $null)
	{
		# now look for the script version tag in script header
		$uploadedScriptVersionLine = select-string -InputObject $scriptText -Pattern $currentScriptVersionTag
		
		if ($uploadedScriptVersionLine -ne $null)
		{
			# script version is 6 charcter i.e. 14.0.0
			$uploadedScriptVersion = $uploadedScriptVersionLine.Line.Substring($uploadedScriptVersionLine.matches[0].Index + $currentScriptVersionTag.length + 2, 6)
			if ($uploadedScriptVersion -ne $null)
			{
				Write-Host -fore $foreColor "The version of the uploaded script is $uploadedScriptVersion"
				$currentVersion = New-Object System.Version $currentScriptVersion
				$uploadedVersion = New-Object System.Version $uploadedScriptVersion
				if ($uploadedVersion -gt $currentVersion)
				{
					Write-Host -fore $foreColor "The version of the script $scriptName is older than the version of the uploaded script in $scriptUrl"
					AutoUpdateScript $scriptName $scriptText $scriptUrl $currentScriptVersion
				}
				elseif ($uploadedVersion -lt $currentVersion)
				{
					Write-Warning "The version number in $scriptName is higher than the version number in the uploaded script. Skipping version check..."
				}
				else
				{
					Write-Host -fore $foreColor "The version of your script matched with the version of the uploaded script."
				}
			}
			else
			{
				Write-Warning "Could not find the version number in $scriptName. Skipping version check..."
			}
		}
		else
		{
			Write-Warning "Could not find the script version tag $currentScriptVersionTag in $scriptName. Skipping version check..."
		}
	}
}

function Nego2Enabled
{
	$osVer = [environment]::osversion
	$isWin7 = ($osVer.Version.Major -ge 7) -or (($osVer.Version.Major -ge 6) -and ($osVer.Version.Minor -ge 1))
	$isWin7
}

## FILTERS #################################################################
## Assembles a message and writes it to file from many sequential BinaryFileDataObject instances 
Filter AssembleMessage ([String] $Path) { Add-Content -Path:"$Path" -Encoding:"Byte" -Value:$_.FileData }

## now actually call the functions

if ($global:versionCheckComplete -eq $false)
{
	if ($LookForUpdates -eq "Skip")
	{
		Write-Host -fore $foreColor "Skipping version check..."
	} 
	elseif ($LookForUpdates -eq "Prompt")
	{
		$optCheckVersion = Read-Host "Do you want to check the version of the current script and do auto update (y/n)?"
	}
	
	if (($LookForUpdates -eq "Auto") -or ($optCheckVersion -eq "y"))
	{
		# we need to save the user input parameters for the next recursive call during auto update
		$matchResult = select-string -InputObject $myinvocation.Line -pattern " -"
		if ($matchResult -ne $null)
		{
			$script:paramString = $matchResult.Line.Substring($matchResult.Matches[0].Index + 1, $matchResult.Line.Length - $matchResult.Matches[0].Index - 1)
		}
		check-version $commonFunctionsScriptName $commonFunctionsScriptUrl $CommonFunctionsScriptVersion $commonFunctionsScriptVersionTag
		check-version $connectionScriptName $connectionScriptUrl $ConnectScriptVersion $connectScriptVersionTag
	}
	elseif ($optCheckVersion -eq "n")
	{
		Write-Warning "You have skipped version check and auto update for $connectionScriptName. The current script might not work correctly. You can download the updated script from $connectionScriptUrl"
	}
	elseif ($optCheckVersion -ne $null)
	{
		Write-Warning "Invalid response. Skipping version check and auto update..."
	}
	
	if (($LookForUpdates -ne "Skip") -and ($LookForUpdates -ne "Prompt") -and ($LookForUpdates -ne "Auto")) 
	{
		Write-Host -fore Red "Invalid value for parameter LookForUpdates. Valid values are 'Skip', 'Prompt' and 'Auto'"
		Exit
	}
}
else
{
	Write-Host -fore $foreColor "Skipping version check for script restart..."
}

if ($global:versionCheckComplete -ne $null)
{
	Remove-Variable versionCheckComplete -Scope Global
}

## First clear up any existing sessions and modules in the current runspace. Ideally there should be only one session in the runspace ###

Write-Host -fore Yellow "Removing any existing sessions and modules from the current runspace..."
Get-PSSession | Remove-PSSession
Get-Module | Remove-Module

## Now establish the connection with Exchange Datacenter Server #################

Write-Host -fore Yellow "Connecting to Exchange Server $fqdn ..."
Write-Host -fore $foreColor ("Using Powershell version {0} (Build version {1})" -f $PSVersionTable.PSVersion.ToString(),$PSVersionTable.BuildVersion.Tostring())

# by default connecting using Basic auth
if ($Authentication -eq "Basic")
{
	Write-Host -fore $foreColor "Using Basic authentication...."
	$userName = Read-Host "Please enter your Username"
	$secureString = Read-Host -AsSecureString Password
	$credential = New-Object System.Management.Automation.PSCredential -ArgumentList $userName,$secureString
	$global:remoteSession = new-pssession -connectionURI $connectionUri -ConfigurationName Microsoft.Exchange -Authentication Basic -credential $credential -AllowRedirection
}
elseif ($Authentication -eq "Nego2")	#using Nego2 Auth
{
	if (-not (Nego2Enabled))
	{
		Write-Host -fore Yellow "The current OS is not Win7, Nego2 Authentication might not work correctly in a non-Win7 OS. If you have installed any Identity Client Runtime Library (i.e. wllogin.msi) or enabled Windows Live ID sign-in assistant in outlook, then ignore this warning"
	}
	Write-Host -fore $foreColor "Using Nego2 authentication...."
	$connectionUri = ($connectionUri.Split("?")[0]+"/PowerShell.htm")
	$credential = Get-ExLiveIDCredential -connectionUri $connectionUri
	$global:remoteSession = new-pssession -connectionURI $connectionUri -ConfigurationName Microsoft.Exchange -Authentication Negotiate -credential $credential -AllowRedirection
}
else
{
	Write-Error "Invalid value for -Authentication. Use either 'Basic' or 'Nego2' Authentication. By default 'Basic' Authentication is used"
	Exit
}

if ($global:remoteSession -ne $null)
{
	$global:connectedFqdn = $fqdn
	Write-Host -fore $foreColor "Importing session (i.e. Exchange cmdlets/scripts) in the current runspace ..."

	if ($ClearCache)
	{
		ImportPSSession -ClearCache:$true
	}
	else
	{
		ImportPSSession -ClearCache:$false
	}
}
else
{
	$forumUrl = "http://outlookliveanswers.com/forums/11.aspx"
	$powershellFAQUrl = "http://help.outlook.com/en-us/140/cc875890.aspx"
	Write-Host -fore $foreColor "Please consult the Powershell FAQ at $powershellFAQUrl and discussion forum at $forumUrl for troubleshootng information. For more help please contact outlook support"
}

# .SYNOPSIS
#   Creates a new remote powershell session to the Microsoft Exchange Hosted Datacenter and 
#   imports the session into the current user's runspace.
#
# .DESCRIPTION
#   Use this script to create a new remote powershell session to one of the Microsoft
#   Exchange Hosted Datacenter.  By default, it connects to ps.outlook.com and redirects to 
#	appropriate site based on user credential.
#
# .PARAMETER LookForUpdates
#   Check the version of the current scripts and do auto update
#	values: 
#		Skip - Skip version check and auto update
#		Prompt (default value) - Prompt before version check and auto update
#		Auto -  Do version check and auto update without user prompt
# .PARAMETER Authentication
#   Currently supported Authentication types are 'Basic' and 'Nego2'
#	In both cases it will prompt for user credential
#   Default: Basic
# .PARAMETER ClearCache
#   When remote powershell session is created for the first time, then the session is cached 
#   locally at %APPDATA%\Microsoft\Exchange\RemotePowerShell, so that we can use the cache  
#   from next remote powershell connections.
#	Use of this switch will clear the cache before creating a new remote powershell session
#   Default: false
#
# .EXAMPLE 
#   ConnectExchangeDatacenter.ps1
#
#   Creates a new remote powershell session to ps.outlook.com endpoint.  
#	It will prompt for version check and auto upate. It will also prompt 
#   for credentials and will use Basic Auth 
#
# .EXAMPLE 
#   ConnectExchangeDatacenter.ps1 -LookForUpdates:Skip
#
#	It will skip version check and auto upate.  
#   It will prompt for credentials and will use Basic Auth 
#
# .EXAMPLE 
#   ConnectExchangeDatacenter.ps1 -LookForUpdates:Prompt
#
#	It will prompt before version check and auto update 
#
# .EXAMPLE 
#   ConnectExchangeDatacenter.ps1 -LookForUpdates:Auto
#
#	It will do version check and auto update without user prompt
#
# .EXAMPLE 
#   ConnectExchangeDatacenter.ps1 -LookForUpdates:Auto -Authentication:Nego2
#
#	It will not prompt for version check or auto upate.  
#   It will prompt for credentials and will use Nego2 Authentication
#
# .EXAMPLE 
#   ConnectExchangeDatacenter.ps1 -ClearCache
#
#	It will clear the cached session before creating new remote powershell session.  
# ConnectExchangeDatacenter.ps1