Function Install-WebApplication {
<#
.SYNOPSIS
	Install a Web Application to the appropriate place

.DESCRIPTION
    Install a Web Application to the appropriate place.
	Will ensure appropriate app pool exists

.PARAMETER WebAppName
    [string] The name of the web application.

.PARAMETER SourcePath
    [string] The folder that contains the files. Typically a chocolatey path.

.PARAMETER NeedsShared
    [switch] Indicates that the legacy utility requires the use of the ORB shared folder. This is a typical configuration for the truly legacy Alkami ORB utility projects.

.PARAMETER IsClient
    [switch] Is this package installed to client?

.PARAMETER IsAdmin
    [switch] Is this package installed to admin?

.PARAMETER IsLegacy
    [switch] Is this package installed to the legacy site? (typically Default Web Site)

.PARAMETER NoManagedCode
    [switch] Is this .net core, or Managed code?

.PARAMETER AppPoolName
    [switch] App pool name. Required for .net core apps. That is, if -NoManagedCode is included.

.INPUTS
    WebAppName and SourcePath are required.
    Requires one of IsClient or IsAdmin or IsLegacy

.OUTPUTS
    Various diagnostic information about the install process

.EXAMPLE
    Install-WebApplication -WebAppName BankService -SourcePath C:\Orb\BankService -IsLegacy
 #>
    [CmdletBinding(DefaultParameterSetName='IsClient')]
    Param(
        [Parameter(ParameterSetName='IsAdmin',Mandatory=$true, Position=0)]
        [Parameter(ParameterSetName='IsClient',Mandatory=$true, Position=0)]
        [Parameter(ParameterSetName='IsLegacy',Mandatory=$true, Position=0)]
        [string]$WebAppName,
        [Parameter(ParameterSetName='IsAdmin',Mandatory=$true, Position=1)]
        [Parameter(ParameterSetName='IsClient',Mandatory=$true, Position=1)]
        [Parameter(ParameterSetName='IsLegacy',Mandatory=$true, Position=1)]
        [string]$SourcePath,
        [Parameter(ParameterSetName='IsAdmin',Mandatory=$false)]
        [Parameter(ParameterSetName='IsClient',Mandatory=$false)]
        [Parameter(ParameterSetName='IsLegacy',Mandatory=$false)]
        [switch]$NeedsShared,
        [Parameter(ParameterSetName='IsClient',Mandatory=$true)]
        [switch]$IsClient,
        [Parameter(ParameterSetName='IsAdmin',Mandatory=$true)]
        [switch]$IsAdmin,
        [Parameter(ParameterSetName='IsLegacy',Mandatory=$true)]
        [switch]$IsLegacy,
        [switch]$NoManagedCode,
        [string]$AppPoolName
    )
    process {
		$loglead = (Get-LogLeadName)

		if (!(Test-IsAdmin)){
			throw "You are not running as administrator. Can not continue."
		}

        if($NoManagedCode){
            if ([string]::IsNullOrWhiteSpace($AppPoolName)) {
                Write-Error "$logLead : When installing a .net core app, an App Pool Name is required."
            }
        }

        Write-Host "$loglead : $WebAppName being installed by $($env:username) on $($env:computername) at $(Get-Date)"

        ## Assumption: We never copy files for WebApplications being installed because the files already exist on disk
        ## Legacy: copied into C:\orb along with rest of deploy. Ex: BankService
        ## Not-Legacy: decompressed into choco-lib folder and linked to IIS from there: ex: CUFX
        ## Not-Legacy: may require shared folder link, see next block for $NeedsShared
        if (!(Test-Path $SourcePath)) {
            throw "Could not find the source path specified at $SourcePath";
        }

        if ($NeedsShared -and (Test-PathIsInApprovedPackageLocation $SourcePath)) {
            ## This is in a choco or similar location.
            ## We should take the parent of our path and ensure that a "Shared" symlink exists at that point
            ## The purpose of this is for Alkami.Ioc resolver to find the parent path in the lookup
            ## This introduces a hard-limit that no package can be called Shared (unless it's the Legacy ORB "Shared" folder from the build process)
            $SharedTargetPath = (Join-Path (Split-Path $SourcePath -Parent) "Shared")

            if (!(Test-Path $SharedTargetPath)) {
                ## Create the symlink here
                $sharedOrbPath = Get-OrbSharedPath
                New-Symlink -path $sharedOrbPath -Destination $SharedTargetPath
            }
        }

        ## If this is a legacy app, and we are on a web-server, we can't install it
        ## If this is a client or admin app, and we are on not on a web-server, we can't install it.
        ## If this is a developer machine we can install it
        if (Test-IsDeveloperMachine) {
            Write-Host "$loglead : Running as developer, should allow anything to occur"
        } elseif ((Test-IsWebServer) -and $IsLegacy) {
            Write-Warning "$loglead : Can not install app-tier web applications on the web tier"
			return
        } elseif (!(Test-IsWebServer) -and ($IsClient -or $IsAdmin)) {
			Write-Warning "$loglead : Can not install web-tier web applications on the app tier"
			return
		}

        if($NoManagedCode){
            if ($IsLegacy) {
                Install-AlkamiWebApplication -WebAppName $WebAppName -SourcePath $SourcePath -IsLegacy -NoManagedCode -AppPoolName $AppPoolName
            } elseif ($IsClient) {
                Install-AlkamiWebApplication -WebAppName $WebAppName -SourcePath $SourcePath -IsClient -NoManagedCode -AppPoolName $AppPoolName
            } elseif ($IsAdmin) {
                Install-AlkamiWebApplication -WebAppName $WebAppName -SourcePath $SourcePath -IsAdmin -NoManagedCode -AppPoolName $AppPoolName
            }
        }
        else{
            if ($IsLegacy) {
                $legacyTargetPath = Join-Path -Path (Get-OrbPath) -ChildPath $WebAppName
                $legacySourcePath = Join-Path $SourcePath -ChildPath "Content\App\*"
                if (-not (Test-Path -Path $legacySourcePath)) {
                    throw "$logLead : Could not find the expected path for the componentized WebApplication at [$legacySourcePath]. Did this package get built according to the Confluence documentation?"
                }
                if (-not (Test-Path -Path $legacyTargetPath)) {
                    New-Item -ItemType Directory -Path $legacyTargetPath -Force
                }
                Copy-Item -Path $legacySourcePath -Destination $legacyTargetPath -Recurse -Force
                Install-AlkamiWebApplication -WebAppName $WebAppName -SourcePath $legacyTargetPath -IsLegacy
            } elseif ($IsClient) {
                Install-AlkamiWebApplication -WebAppName $WebAppName -SourcePath $SourcePath -IsClient
            } elseif ($IsAdmin) {
                Install-AlkamiWebApplication -WebAppName $WebAppName -SourcePath $SourcePath -IsAdmin
            }
        }
    }
}