#
# Prerequisite.ps1
#
# If debugging is not working open PowerShell.exe and paste the command "Set-ExecutionPolicy Bypass -Scope Process"
# To remove execution policy: paste in PowerShell the command "Set-ExecutionPolicy Undefined -Scope Process"

function Get-Installed-Framework-Detail-Versions() {

    Write-Host ""

    Get-ChildItem ‘HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP’ -Recurse | Get-ItemProperty -Name version -EA 0 | Where { $_.PSChildName -Match ‘^(?!S)\p{L}’} | Select PSChildName, version

    Write-Host ""    
}

function Get-Installed-Framework-Versions() {    
    $installedFrameworks = @()
    if (Is-Key-Present "HKLM:\Software\Microsoft\.NETFramework\Policy\v1.0" "3705") { $installedFrameworks += "Installed .Net Framework 1.0" }
    if (Is-Key-Present "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v1.1.4322" "Install") { $installedFrameworks += "Installed .Net Framework 1.1" }
    if (Is-Key-Present "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v2.0.50727" "Install") { $installedFrameworks += "Installed .Net Framework 2.0" }
    if (Is-Key-Present "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v3.0\Setup" "InstallSuccess") { $installedFrameworks += "Installed .Net Framework 3.0" }
    if (Is-Key-Present "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v3.5" "Install") { $installedFrameworks += "Installed .Net Framework 3.5" }
    if (Is-Key-Present "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v4\Client" "Install") { $installedFrameworks += "Installed .Net Framework 4.0c" }
    if (Is-Key-Present "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v4\Full" "Install") { $installedFrameworks += "Installed .Net Framework 4.0" }   
    
    Write-Host ""
    
    return $installedFrameworks
}

function Get-Framework-Versions-And-Handle-Operation() {
    $version = Get-Framework40-Family-Version;
    if ($version -ge 1) { 
        #.NET Framework installed
    }
    else {
        Download-And-Install-Framework
    }
}

function Get-Framework40-Family-Version() {
    $result = -1
    if (Is-Key-Present "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v4\Client" "Install" -or Is-Key-Present "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v4\Full" "Install") {
        # .net 4.0 is installed
        $result = 0
        $version = Get-Framework-Value "HKLM:\Software\Microsoft\NET Framework Setup\NDP\v4\Full" "Release"
        
        if ($version -ge 528040) {
            # .net 4.8
            Write-Host "Installed .Net Framework 4.8 or greater" -foregroundcolor Green
            $result = 10
        }
        elseif ($version -ge 461808 -Or $version -ge 461814) {
            # .net 4.7.2
            Write-Host "Installed .Net Framework 4.7.2" -foregroundcolor Green
            $result = 9
        }
        elseif ($version -ge 461308 -Or $version -ge 461310) {
            # .net 4.7.1
            Write-Host "Installed .Net Framework 4.7.1" -foregroundcolor Green
            $result = 8
        }
        elseif ($version -ge 460798 -Or $version -ge 460805) {
            # .net 4.7
            Write-Host "Installed .Net Framework 4.7" -foregroundcolor Green
            $result = 7
        }
        elseif ($version -ge 394802 -Or $version -ge 394806) {
            # .net 4.6.2
            Write-Host "Installed .Net Framework 4.6.2" -foregroundcolor Green
            $result = 6
        }
        elseif ($version -ge 394254 -Or $version -ge 394271) {
            # .net 4.6.1
            Write-Host "Installed .Net Framework 4.6.1" -foregroundcolor Green
            $result = 5
        }
        elseif ($version -ge 393295 -Or $version -ge 393297) {
            # .net 4.6
            Write-Host "Installed .Net Framework 4.6" -foregroundcolor Green
            $result = 4
        }
        elseif ($version -ge 379893) {
            # .net 4.5.2
            Write-Host "Installed .Net Framework 4.5.2" -foregroundcolor Green
            $result = 3
        }
        elseif ($version -ge 378675) {
            # .net 4.5.1
            Write-Host "Installed .Net Framework 4.5.1" -foregroundcolor Green
            $result = 2
        }
        elseif ($version -ge 378389) {
            # .net 4.5
            Write-Host "Installed .Net Framework 4.5" -foregroundcolor Green
            $result = 1
        }   
    }
    else {
        # .net framework 4 family isn't installed
        $result = -1
    }
    return $result
}

# .Net Frameworks possible to download here: https://dotnet.microsoft.com/en-us/download/dotnet-framework
function Download-And-Install-Framework() {    
    $url = "https://download.visualstudio.microsoft.com/download/pr/014120d7-d689-4305-befd-3cb711108212/0fd66638cde16859462a6243a4629a50/ndp48-x86-x64-allos-enu.exe"
    $output = "$PSScriptRoot\NetFrameworkInstaller_4_8.exe"

    $yes = New-Object System.Management.Automation.Host.ChoiceDescription "&Yes","Description."
    $no = New-Object System.Management.Automation.Host.ChoiceDescription "&No","Description."    
    $options = [System.Management.Automation.Host.ChoiceDescription[]]($yes, $no)

    $title = ".Net Framework 4.8 is not installed" 
    $message = "Download and Install .Net Framework 4.8?"
    $result = $host.ui.PromptForChoice($title, $message, $options, 1)
    switch ($result) {
      0 {
            $start_time = Get-Date
    
            Write-Host ""
            Write-Host "Downloading .Net Framework 4.8" -foregroundcolor Cyan
       
            Invoke-WebRequest -Uri $url -OutFile $output  
            Write-Output "Time taken: $((Get-Date).Subtract($start_time).Seconds) second(s)"  
    
            Write-Host "" 
            Write-Host "Installing .Net Framework 4.8" -foregroundcolor Cyan

            Start-Process $PSScriptRoot\NetFrameworkInstaller_4_8.exe -Wait                
        }
      1
        {
            Write-Host ""
            Write-Host "The Web or Offline installer Runtime .Net Framework 4.8 can be downloaded from:" -foregroundcolor Cyan
            Write-Host "https://dotnet.microsoft.com/en-us/download/dotnet-framework/net48"
        }      
    }    
}
 
function Is-Key-Present([string]$path, [string]$key) {
    if (!(Test-Path $path)) { return $false }
    if ((Get-ItemProperty $path).$key -eq $null) { return $false }
    return $true
}

function Get-Framework-Value([string]$path, [string]$key) {
    if (!(Test-Path $path)) { return "-1" }
    
    return (Get-ItemProperty $path).$key  
}

try
{    
    #Write-Host ""
    #Write-Host "Computer Information" -foregroundcolor Green
    
    #$data = 'windows*','OsVersion', 'OsLocale', 'OsLocalDateTime', 'OsLastBootUpTime', 'OsArchitecture', 'OsLanguage', 'OsLanguage', 'OsProductType', 'OsInstallDate'
   
    #Get-ComputerInfo -Property $data

    Write-Host "Installed .NET Frameworks" -foregroundcolor Green
    
    # print all installed net frameworks
    Get-Installed-Framework-Versions

    # in case .net framework family 4 is present in system, script start application otherwise 
    # download and install predefined framework
    Get-Framework-Versions-And-Handle-Operation

    Write-Host ""
    Write-Host ""

    Read-Host -Prompt "Press any key to exit"
}
catch
{
    Write-Error $_.Exception.ToString()
    Read-Host -Prompt "Error. Press Enter to exit"
}