# Script Name: PyGo.ps1
# Description: This script checks if Python 3 is already installed on Windows 10/11.
# If not, it downloads and installs the latest version, it also supports uninstalling Python if the -Uninstall flag is provided.
#
# Author: Jan Gebser
# Date: 12.11.24
# Version: 1.3.2
# Contact: j.gebser@webservice.digital

<# WORKING ON SOME MORE IMPROVEMENTS AND FEATURES - also to fix the following issue below:
Get-ExecutionPolicy -List
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope LocalMachine

'''
PS C:\Users\WDAGUtilityAccount\Desktop> .\PyGo.ps1
.\PyGo.ps1 : File C:\Users\WDAGUtilityAccount\Desktop\PyGo.ps1 cannot be loaded because running scripts is disabled on this system. For more information, see about_Execution_Policies at https:/go.microsoft.com/fwlink/?LinkID=135170.
At line:1 char:1                                                                                                                                                                                                                             + .\PyGo.ps1                                                                                                                                                                                                                                 + ~~~~~~~~~~                                                                                                                                                                                                                                     + CategoryInfo          : SecurityError: (:) [], PSSecurityException                                                                                                                                                                         + FullyQualifiedErrorId : UnauthorizedAccess
PS C:\Users\WDAGUtilityAccount\Desktop> Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope LocalMachine
PS C:\Users\WDAGUtilityAccount\Desktop> .\PyGo.ps1
Python is not installed. Proceeding with installation...
Downloading Python installer from https://www.python.org/ftp/python/3.13.0/python-3.13.0-amd64.exe...
Download complete. Installing Python...
Installation complete. Cleaning up...
Cleanup complete. Verifying installation...
python : The term 'python' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At C:\Users\WDAGUtilityAccount\Desktop\PyGo.ps1:102 char:22
+     $pythonVersion = python --version
+                      ~~~~~~
    + CategoryInfo          : ObjectNotFound: (python:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

Python installation and verification complete.
Installed version:
Installation Date: 11/12/2024 10:56:27
Operating System Version: 2004
PS C:\Users\WDAGUtilityAccount\Desktop> .\PyGo.ps1
Python is not installed. Proceeding with installation...
Downloading Python installer from https://www.python.org/ftp/python/3.13.0/python-3.13.0-amd64.exe...
PS C:\Users\WDAGUtilityAccount\Desktop>
'''
#>

param (
    [switch]$Uninstall
)

# Function to check if Python is installed
function Check-PythonInstalled {
    try {
        $pythonVersion = python --version 2>&1
        if ($pythonVersion -match "Python (\d+\.\d+\.\d+)") {
            return $true, $matches[1]
        } else {
            return $false, $null
        }
    } catch {
        return $false, $null
    }
}

# Function to get installation statistics
function Get-InstallationStats {
    $installDate = Get-Date
    $osVersion = (Get-ComputerInfo).WindowsVersion
    return @{
        InstallDate = $installDate
        OSVersion = $osVersion
    }
}

# Function to uninstall Python
function Uninstall-Python {
    Write-Output "Uninstalling Python..."
    $pythonPath = (Get-Command python).Path
    $uninstallerPath = Join-Path (Split-Path $pythonPath -Parent) "uninstall.exe"
    if (Test-Path $uninstallerPath) {
        Start-Process -FilePath $uninstallerPath -ArgumentList "/quiet" -Wait
        Write-Output "Python uninstalled successfully."
    } else {
        Write-Output "Uninstaller not found. Manual uninstallation may be required."
    }
}

# Check if the -Uninstall flag is provided
if ($Uninstall) {
    $pythonInstalled, $installedVersion = Check-PythonInstalled
    if ($pythonInstalled) {
        Uninstall-Python
    } else {
        Write-Output "Python is not installed."
    }
    exit
}

# Check if Python is already installed
$pythonInstalled, $installedVersion = Check-PythonInstalled

if ($pythonInstalled) {
    Write-Output "Python is already installed."
    Write-Output "Version: $installedVersion"
    Write-Output "Installation path: $(Get-Command python).Path"
} else {
    Write-Output "Python is not installed. Proceeding with installation..."

    # Define the URL for the latest Python 3 installer
    $pythonUrl = "https://www.python.org/ftp/python/3.13.0/python-3.13.0-amd64.exe"
    $pythonInstaller = "$env:TEMP\python-installer.exe"

    # Output message: Starting download
    Write-Output "Downloading Python installer from $pythonUrl..."

    # Download the Python installer
    # @DESC: Downloads the Python installer from the specified URL and saves it to the defined path
    Invoke-WebRequest -Uri $pythonUrl -OutFile $pythonInstaller

    # Output message: Download complete
    Write-Output "Download complete. Installing Python..."

    # Install Python silently and add it to the PATH
    # @DESC: Executes the installer with silent mode, installs for all users, and adds Python to the system PATH
    Start-Process -FilePath $pythonInstaller -ArgumentList "/quiet InstallAllUsers=1 PrependPath=1" -Wait

    # Output message: Installation complete
    Write-Output "Installation complete. Cleaning up..."

    # Clean up the installer file
    # @DESC: Removes the installer file after installation to free up space
    Remove-Item -Path $pythonInstaller -Force

    # Output message: Cleanup complete
    Write-Output "Cleanup complete. Verifying installation..."

    # Verify the installation
    # @DESC: Prints the installed Python version to verify successful installation
    $pythonVersion = python --version
    Write-Output "Python installation and verification complete."
    Write-Output "Installed version: $pythonVersion"

    # Get installation statistics
    $stats = Get-InstallationStats
    Write-Output "Installation Date: $($stats.InstallDate)"
    Write-Output "Operating System Version: $($stats.OSVersion)"
}