<#
.SYNOPSIS
  Helper script create virtual env.

.DESCRIPTION
  This script will detect Python installation, create venv and install
  all necessary packages from `requirements.txt` needed by Pype to be
  included during application freeze on Windows.

.EXAMPLE

PS> .\create_env.ps1

#>

function Exit-WithCode($exitcode) {
   # Only exit this host process if it's a child of another PowerShell parent process...
   $parentPID = (Get-CimInstance -ClassName Win32_Process -Filter "ProcessId=$PID" | Select-Object -Property ParentProcessId).ParentProcessId
   $parentProcName = (Get-CimInstance -ClassName Win32_Process -Filter "ProcessId=$parentPID" | Select-Object -Property Name).Name
   if ('powershell.exe' -eq $parentProcName) { $host.SetShouldExit($exitcode) }

   exit $exitcode
}


function Show-PSWarning() {
    if ($PSVersionTable.PSVersion.Major -lt 7) {
        Write-Host "!!! " -NoNewline -ForegroundColor Red
        Write-Host "You are using old version of PowerShell. $($PSVersionTable.PSVersion.Major).$($PSVersionTable.PSVersion.Minor)"
        Write-Host "Please update to at least 7.0 - " -NoNewline -ForegroundColor Gray
        Write-Host "https://github.com/PowerShell/PowerShell/releases" -ForegroundColor White
        Exit-WithCode 1
    }
}
$current_dir = Split-Path -Path $MyInvocation.MyCommand.Definition -Parent
$pype_root = (Get-Item $current_dir).parent.FullName

$art = @"


        ____________
       /\      ___  \
       \ \     \/_\  \
        \ \     _____/ ______   ___ ___ ___
         \ \    \___/ /\     \  \  \\  \\  \
          \ \____\    \ \_____\  \__\\__\\__\
           \/____/     \/_____/  . PYPE Club .

"@

Write-Host $art -ForegroundColor DarkGreen

# Enable if PS 7.x is needed.
# Show-PSWarning

$version_file = Get-Content -Path "$($pype_root)\pype\version.py"
$result = [regex]::Matches($version_file, '__version__ = "(?<version>\d+\.\d+.\d+)"')
$pype_version = $result[0].Groups['version'].Value
if (-not $pype_version) {
  Write-Host "!!! " -ForegroundColor yellow -NoNewline
  Write-Host "Cannot determine Pype version."
  Exit-WithCode 1
}

Write-Host ">>> " -NoNewline -ForegroundColor green
Write-Host "Detecting host Python ... " -NoNewline
if (-not (Get-Command "python" -ErrorAction SilentlyContinue)) {
    Write-Host "!!! Python not detected" -ForegroundColor red
    Exit-WithCode 1
}
$version_command = @'
import sys
print('{0}.{1}'.format(sys.version_info[0], sys.version_info[1]))
'@

$p = & python -c $version_command
$env:PYTHON_VERSION = $p
$m = $p -match '(\d+)\.(\d+)'
if(-not $m) {
  Write-Host "!!! Cannot determine version" -ForegroundColor red
  Exit-WithCode 1
}
# We are supporting python 3.6 and up
if(($matches[1] -lt 3) -or ($matches[2] -lt 7)) {
  Write-Host "FAILED Version [ $p ] is old and unsupported" -ForegroundColor red
  Exit-WithCode 1
}
Write-Host "OK [ $p ]" -ForegroundColor green

# Create venv directory if not exist
if (-not (Test-Path -PathType Container -Path "$($pype_root)\venv")) {
    New-Item -ItemType Directory -Force -Path "$($pype_root)\venv"
}

Write-Host "--- " -NoNewline -ForegroundColor yellow
Write-Host "Cleaning venv directory ..."

try {
    Remove-Item -Recurse -Force "$($pype_root)\venv\*"
}
catch {
    Write-Host "!!! " -NoNewline -ForegroundColor red
    Write-Host "Cannot clean venv directory, possibly another process is using it."
    Write-Host $_.Exception.Message
    Exit-WithCode 1
}

Write-Host ">>> " -NoNewline -ForegroundColor green
Write-Host "Creating virtual env ..."
& python -m venv venv
Write-Host ">>> " -NoNewline -ForegroundColor green
Write-Host "Entering venv ..."
try {
  . ("$($pype_root)\venv\Scripts\Activate.ps1")
}
catch {
    Write-Host "!!! Failed to activate" -ForegroundColor red
    Write-Host $_.Exception.Message
    Exit-WithCode 1
}
Write-Host ">>> " -NoNewline -ForegroundColor green
Write-Host "Updating pip ..."
& python -m pip install --upgrade pip

Write-Host ">>> " -NoNewline -ForegroundColor green
Write-Host "Installing packages to new venv ..."
& pip install -r "$($pype_root)\requirements.txt"

Write-Host ">>> " -NoNewline -ForegroundColor green
Write-Host "Cleaning cache files ... " -NoNewline
Get-ChildItem "$($pype_root)" -Filter "*.pyc" -Force -Recurse | Remove-Item -Force
Get-ChildItem "$($pype_root)" -Filter "__pycache__" -Force -Recurse | Remove-Item -Force -Recurse
Write-Host "OK" -ForegroundColor green

Write-Host ">>> " -NoNewline -ForegroundColor green
Write-Host "Deactivating venv ..."
deactivate