functions/Import-DbaXESessionTemplate.ps1

function Import-DbaXESessionTemplate {
    <#
    .SYNOPSIS
        Imports a new XESession XML Template
 
    .DESCRIPTION
        Imports a new XESession XML Template either from the dbatools repository or a file you specify.
 
    .PARAMETER SqlInstance
        The target SQL Server instance or instances. You must have sysadmin access and server version must be SQL Server version 2008 or higher.
 
    .PARAMETER SqlCredential
        Login to the target instance using alternative credentials. Accepts PowerShell credentials (Get-Credential).
 
        Windows Authentication, SQL Server Authentication, Active Directory - Password, and Active Directory - Integrated are all supported.
 
        For MFA support, please use Connect-DbaInstance.
 
    .PARAMETER Name
        The Name of the session to create.
 
    .PARAMETER Path
        The path to the xml file or files for the session(s).
 
    .PARAMETER Template
        Specifies the name of one of the templates from the dbatools repository. Press tab to cycle through the provided templates.
 
    .PARAMETER TargetFilePath
        By default, files will be created in the default xel directory. Use TargetFilePath to change all instances of
        filename = "file.xel" to filename = "$TargetFilePath\file.xel". Only specify the directory, not the file itself.
 
        This path is relative to the destination directory
 
    .PARAMETER TargetFileMetadataPath
        By default, files will be created in the default xem directory. Use TargetFileMetadataPath to change all instances of
        filename = "file.xem" to filename = "$TargetFilePath\file.xem". Only specify the directory, not the file itself.
 
        This path is relative to the destination directory
 
    .PARAMETER EnableException
        By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
        This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
        Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
 
    .NOTES
        Tags: ExtendedEvent, XE, XEvent
        Author: Chrissy LeMaire (@cl), netnerds.net
 
        Website: https://dbatools.io
        Copyright: (c) 2018 by dbatools, licensed under MIT
        License: MIT https://opensource.org/licenses/MIT
 
    .LINK
        https://dbatools.io/Import-DbaXESessionTemplate
 
    .EXAMPLE
        PS C:\> Import-DbaXESessionTemplate -SqlInstance sql2017 -Template db_query_wait_stats
 
        Creates a new XESession named db_query_wait_stats from the dbatools repository to the SQL Server sql2017.
 
    .EXAMPLE
        PS C:\> Import-DbaXESessionTemplate -SqlInstance sql2017 -Template db_query_wait_stats -Name "Query Wait Stats"
 
        Creates a new XESession named "Query Wait Stats" using the db_query_wait_stats template.
 
    .EXAMPLE
        PS C:\> Get-DbaXESession -SqlInstance sql2017 -Session 'Database Health 2014' | Remove-DbaXESession
        PS C:\> Import-DbaXESessionTemplate -SqlInstance sql2017 -Template 'Database Health 2014' | Start-DbaXESession
 
        Removes a session if it exists, then recreates it using a template.
 
    .EXAMPLE
        PS C:\> Get-DbaXESessionTemplate | Out-GridView -PassThru | Import-DbaXESessionTemplate -SqlInstance sql2017
 
        Allows you to select a Session template then import to an instance named sql2017.
 
    #>

    [CmdletBinding()]
    param (
        [parameter(Mandatory, ValueFromPipeline)]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [string]$Name,
        [parameter(ValueFromPipelineByPropertyName)]
        [Alias("FullName")]
        [string[]]$Path,
        [string[]]$Template,
        [string]$TargetFilePath,
        [string]$TargetFileMetadataPath,
        [switch]$EnableException
    )
    begin {
        $metadata = Import-Clixml "$script:PSModuleRoot\bin\xetemplates-metadata.xml"
    }
    process {
        if ((Test-Bound -ParameterName Path -Not) -and (Test-Bound -ParameterName Template -Not)) {
            Stop-Function -Message "You must specify Path or Template."
        }

        if (($Path.Count -gt 1 -or $Template.Count -gt 1) -and (Test-Bound -ParameterName Name)) {
            Stop-Function -Message "Name cannot be specified with multiple files or templates because the Session will already exist."
            return
        }

        foreach ($instance in $SqlInstance) {
            try {
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential -MinimumVersion 11
            } catch {
                Stop-Function -Message "Error occurred while establishing connection to $instance" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }

            $SqlConn = $server.ConnectionContext.SqlConnectionObject
            $SqlStoreConnection = New-Object Microsoft.SqlServer.Management.Sdk.Sfc.SqlStoreConnection $SqlConn
            $store = New-Object  Microsoft.SqlServer.Management.XEvent.XEStore $SqlStoreConnection

            foreach ($file in $template) {
                $templatepath = "$script:PSModuleRoot\bin\xetemplates\$file.xml"
                if ((Test-Path $templatepath)) {
                    $Path += $templatepath
                } else {
                    Stop-Function -Message "Invalid template ($templatepath does not exist)." -Continue
                }
            }

            foreach ($file in $Path) {

                if ((Test-Bound -Not -ParameterName TargetFilePath)) {
                    Write-Message -Level Verbose -Message "Importing $file to $instance"
                    try {
                        $xml = [xml](Get-Content $file -ErrorAction Stop)
                    } catch {
                        Stop-Function -Message "Failure" -ErrorRecord $_ -Target $file -Continue
                    }
                } else {
                    Write-Message -Level Verbose -Message "TargetFilePath specified, changing all file locations in $file for $instance."
                    Write-Message -Level Verbose -Message "TargetFileMetadataPath specified, changing all metadata file locations in $file for $instance."

                    # Handle whatever people specify
                    $TargetFilePath = $TargetFilePath.TrimEnd("\")
                    $TargetFileMetadataPath = $TargetFileMetadataPath.TrimEnd("\")
                    $TargetFilePath = "$TargetFilePath\"
                    $TargetFileMetadataPath = "$TargetFileMetadataPath\"

                    # Perform replace
                    $xelphrase = 'name="filename" value="'
                    $xemphrase = 'name="metadatafile" value="'

                    try {
                        $basename = (Get-ChildItem $file).Basename
                        $contents = Get-Content $file -ErrorAction Stop
                        $contents = $contents.Replace($xelphrase, "$xelphrase$TargetFilePath")
                        $contents = $contents.Replace($xemphrase, "$xemphrase$TargetFileMetadataPath")
                        $temp = ([System.IO.Path]::GetTempPath()).TrimEnd("").TrimEnd("\")
                        $tempfile = "$temp\$basename"
                        $null = Set-Content -Path $tempfile -Value $contents -Encoding UTF8
                        $xml = [xml](Get-Content $tempfile -ErrorAction Stop)
                        $file = $tempfile
                    } catch {
                        Stop-Function -Message "Failure" -ErrorRecord $_ -Target $file -Continue
                    }

                    Write-Message -Level Verbose -Message "$TargetFilePath does not exist on $server, creating now."
                    try {
                        if (-not (Test-DbaPath -SqlInstance $server -Path $TargetFilePath)) {
                            $null = New-DbaDirectory -SqlInstance $server -Path $TargetFilePath
                        }
                    } catch {
                        Stop-Function -Message "Failure" -ErrorRecord $_ -Target $file -Continue
                    }
                }

                if (-not $xml.event_sessions) {
                    Stop-Function -Message "$file is not a valid XESession template document." -Continue
                }

                if ((Test-Bound -ParameterName Name -not)) {
                    $Name = (Get-ChildItem $file).BaseName
                }

                # This could be done better but not today
                $no2012 = ($metadata | Where-Object Compatibility -gt 2012).Name
                $no2014 = ($metadata | Where-Object Compatibility -gt 2014).Name

                if ($Name -in $no2012 -and $server.VersionMajor -eq 11) {
                    Stop-Function -Message "$Name is not supported in SQL Server 2012 ($server)" -Continue
                }

                if ($Name -in $no2014 -and $server.VersionMajor -eq 12) {
                    Stop-Function -Message "$Name is not supported in SQL Server 2014 ($server)" -Continue
                }

                if ((Get-DbaXESession -SqlInstance $server -Session $Name)) {
                    Stop-Function -Message "$Name already exists on $instance" -Continue
                }

                try {
                    Write-Message -Level Verbose -Message "Importing $file as $Name "
                    $session = $store.CreateSessionFromTemplate($Name, $file)
                    $session.Create()
                    if ($file -eq $tempfile) {
                        Remove-Item $tempfile -ErrorAction SilentlyContinue
                    }
                    Get-DbaXESession -SqlInstance $server -Session $session.Name
                } catch {
                    Stop-Function -Message "Failure" -ErrorRecord $_ -Target $store -Continue
                }
            }
        }
    }
}