DSCResources/MSFT_SPBlobCacheSettings/MSFT_SPBlobCacheSettings.psm1

function Get-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Collections.Hashtable])]
    param
    (
        [parameter(Mandatory = $true)]  
        [System.String] 
        $WebAppUrl,

        [parameter(Mandatory = $true)]  
        [ValidateSet("Default", "Intranet", "Internet", "Custom", "Extranet")] 
        [System.String] 
        $Zone,

        [parameter(Mandatory = $true)]  
        [System.Boolean] 
        $EnableCache,

        [parameter(Mandatory = $false)] 
        [System.String] 
        $Location,

        [parameter(Mandatory = $false)] 
        [System.UInt16] 
        $MaxSizeInGB,

        [parameter(Mandatory = $false)] 
        [System.UInt32] 
        $MaxAgeInSeconds,

        [parameter(Mandatory = $false)] 
        [System.String] 
        $FileTypes,

        [parameter(Mandatory = $false)] 
        [System.Management.Automation.PSCredential] 
        $InstallAccount
    )
    
    Write-Verbose -Message "Getting blob cache settings for $WebAppUrl"

    $result = Invoke-SPDSCCommand -Credential $InstallAccount `
                                  -Arguments $PSBoundParameters `
                                  -ScriptBlock {
        $params = $args[0]

        $webappsi = Get-SPServiceInstance -Server $env:COMPUTERNAME `
                                          -ErrorAction SilentlyContinue `
                        | Where-Object -FilterScript {
                            $_.TypeName -eq "Microsoft SharePoint Foundation Web Application"
                          }

        if ($null -eq $webappsi) 
        {
            Write-Verbose -Message "Server isn't running the Web Application role"
            return @{
                WebAppUrl = $null
                Zone = $null
                EnableCache = $false
                Location = $null
                MaxSizeInGB = $null
                MaxAgeInSeconds = $null
                FileTypes = $null
                InstallAccount = $params.InstallAccount
            }
        }

        $wa = Get-SPWebApplication -Identity $params.WebAppUrl `
                                   -ErrorAction SilentlyContinue

        if ($null -eq $wa) 
        {
            Write-Verbose -Message "Specified web application was not found."
            return @{
                WebAppUrl = $null
                Zone = $null
                EnableCache = $false
                Location = $null
                MaxSizeInGB = $null
                MaxAgeInSeconds = $null
                FileTypes = $null
                InstallAccount = $params.InstallAccount
            }
        }

        $zone = [Microsoft.SharePoint.Administration.SPUrlZone]::$($params.Zone)

        $sitePath = $wa.IisSettings[$zone].Path
        $webconfiglocation = Join-Path $sitePath "web.config"

        [xml]$webConfig = Get-Content -Path $webConfigLocation

        if ($webconfig.configuration.SharePoint.BlobCache.enabled -eq "true") 
        {
            $cacheEnabled = $true
        } 
        else 
        {
            $cacheEnabled = $false
        }

        try 
        {
            $maxsize = [Convert]::ToUInt16($webconfig.configuration.SharePoint.BlobCache.maxSize)
        }
        catch [FormatException] 
        {
            $maxsize = 0
        }
        catch 
        {
            throw "Error: $($_.Exception.Message)"
        }

        try 
        {
            $maxage = [Convert]::ToUInt32($webconfig.configuration.SharePoint.BlobCache."max-age")
        }
        catch [FormatException] 
        {
            $maxage = 0
        }
        catch 
        {
            throw "Error: $($_.Exception.Message)"
        }

        $returnval = @{
            WebAppUrl = $params.WebAppUrl
            Zone = $params.Zone
            EnableCache = $cacheEnabled
            Location = $webconfig.configuration.SharePoint.BlobCache.location
            MaxSizeInGB = $maxsize
            MaxAgeInSeconds = $maxage
            FileTypes = $webconfig.configuration.SharePoint.BlobCache.path
            InstallAccount = $params.InstallAccount
        }
        
        return $returnval
    }
    return $result
}

function Set-TargetResource
{
    [CmdletBinding()]
    param
    (
        [parameter(Mandatory = $true)]  
        [System.String] 
        $WebAppUrl,

        [parameter(Mandatory = $true)]  
        [ValidateSet("Default", "Intranet", "Internet", "Custom", "Extranet")] 
        [System.String] 
        $Zone,

        [parameter(Mandatory = $true)]  
        [System.Boolean] 
        $EnableCache,

        [parameter(Mandatory = $false)] 
        [System.String] 
        $Location,

        [parameter(Mandatory = $false)] 
        [System.UInt16] 
        $MaxSizeInGB,

        [parameter(Mandatory = $false)] 
        [System.UInt32] 
        $MaxAgeInSeconds,

        [parameter(Mandatory = $false)] 
        [System.String] 
        $FileTypes,

        [parameter(Mandatory = $false)] 
        [System.Management.Automation.PSCredential] 
        $InstallAccount
    )

    Write-Verbose -Message "Setting blob cache settings for $WebAppUrl"

    $CurrentValues = Get-TargetResource @PSBoundParameters
    
    $changes = @{}
    
    if ($PSBoundParameters.ContainsKey("EnableCache")) 
    {
        if ($CurrentValues.EnableCache -ne $EnableCache) 
        { 
            $changes.EnableCache = $EnableCache 
        }
    }
    
    if ($PSBoundParameters.ContainsKey("Location")) 
    {
        if ($CurrentValues.Location -ne $Location) 
        { 
            $changes.Location = $Location 
        }
    }
    
    if ($PSBoundParameters.ContainsKey("MaxSizeInGB")) 
    {
        if ($CurrentValues.MaxSizeInGB -ne $MaxSizeInGB) 
        { 
            $changes.MaxSizeInGB = $MaxSizeInGB 
        }
    }

    if ($PSBoundParameters.ContainsKey("MaxAgeInSeconds")) 
    {
        if ($CurrentValues.MaxAgeInSeconds -ne $MaxAgeInSeconds) 
        { 
            $changes.MaxAgeInSeconds = $MaxAgeInSeconds 
        }
    }
    
    if ($PSBoundParameters.ContainsKey("FileTypes")) 
    {
        if ($CurrentValues.FileTypes -ne $FileTypes) 
        { 
            $changes.FileTypes = $FileTypes 
        }
    }

    if ($changes.Count -ne 0) 
    {
        ## Perform changes
        Invoke-SPDSCCommand -Credential $InstallAccount `
                            -Arguments @($PSBoundParameters, $changes) `
                            -ScriptBlock {
            $params  = $args[0]
            $changes = $args[1]

            $webappsi = Get-SPServiceInstance -Server $env:COMPUTERNAME `
                                              -ErrorAction SilentlyContinue `
                            | Where-Object -FilterScript {
                                $_.TypeName -eq "Microsoft SharePoint Foundation Web Application"
                              }

            if ($null -eq $webappsi) 
            {
                throw "Server isn't running the Web Application role"
            }

            $wa = Get-SPWebApplication -Identity $params.WebAppUrl -ErrorAction SilentlyContinue

            if ($null -eq $wa) 
            {
                throw "Specified web application could not be found."
            }

            Write-Verbose -Message "Processing changes"

            $zone = [Microsoft.SharePoint.Administration.SPUrlZone]::$($params.Zone)

            $sitePath = $wa.IisSettings[$zone].Path
            $timestamp = Get-Date -Format "yyyyMMdd_HHmmss"
            $webconfiglocation = Join-Path -Path $sitePath -ChildPath "web.config"
            $webconfigbackuplocation = Join-Path -Path $sitePath -ChildPath "web_config-$timestamp.backup"
            Copy-Item -Path $webconfiglocation -Destination $webconfigbackuplocation

            [xml]$webConfig = Get-Content -Path $webConfigLocation

            if ($changes.ContainsKey("EnableCache")) 
            {
                $webconfig.configuration.SharePoint.BlobCache.enabled `
                    = $changes.EnableCache.ToString()
            }

            if ($changes.ContainsKey("Location")) 
            {
                $webconfig.configuration.SharePoint.BlobCache.location `
                    = $changes.Location
            }

            if ($changes.ContainsKey("MaxSizeInGB")) 
            {
                $webconfig.configuration.SharePoint.BlobCache.maxSize `
                    = $changes.MaxSizeInGB.ToString()
            }

            if ($changes.ContainsKey("MaxAgeInSeconds")) 
            {
                $webconfig.configuration.SharePoint.BlobCache."max-age" `
                    = $changes.MaxAgeInSeconds.ToString()
            }
            
            if ($changes.ContainsKey("FileTypes")) 
            {
                $webconfig.configuration.SharePoint.BlobCache.path `
                = $changes.FileTypes
            }
            $webconfig.Save($webconfiglocation)
        }
    }    
    
    ## Check Blob Cache folder
    if ($Location) 
    {
        if ( -not (Test-Path -Path $Location)) 
        {
            Write-Verbose "Create Blob Cache Folder $Location"
            try 
            {
                New-Item -Path $Location -ItemType Directory | Out-Null
            }
            catch [DriveNotFoundException] 
            {
                throw "Specified drive does not exist"
            }
            catch 
            {
                throw "Error creating Blob Cache folder: $($_.Exception.Message)"
            }
        }
    }    
}

function Test-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [parameter(Mandatory = $true)]  
        [System.String] 
        $WebAppUrl,

        [parameter(Mandatory = $true)]  
        [ValidateSet("Default", "Intranet", "Internet", "Custom", "Extranet")] 
        [System.String] 
        $Zone,

        [parameter(Mandatory = $true)]  
        [System.Boolean] 
        $EnableCache,

        [parameter(Mandatory = $false)] 
        [System.String] 
        $Location,

        [parameter(Mandatory = $false)] 
        [System.UInt16] 
        $MaxSizeInGB,

        [parameter(Mandatory = $false)] 
        [System.UInt32] 
        $MaxAgeInSeconds,

        [parameter(Mandatory = $false)] 
        [System.String] 
        $FileTypes,

        [parameter(Mandatory = $false)] 
        [System.Management.Automation.PSCredential] 
        $InstallAccount
    )

    Write-Verbose -Message "Testing blob cache settings for $WebAppUrl"

    if ($Location) 
    {
        if ( -not (Test-Path -Path $Location)) 
        {
            Write-Verbose "Blob Cache Folder $Location does not exist"
            return $false
        }
    }
    
    return Test-SPDscParameterState -CurrentValues (Get-TargetResource @PSBoundParameters) `
                                    -DesiredValues $PSBoundParameters `
                                    -ValuesToCheck @("EnableCache", 
                                                     "Location", 
                                                     "MaxSizeInGB", 
                                                     "FileType", 
                                                     "MaxAgeInSeconds")
}

Export-ModuleMember -Function *-TargetResource