# PersistMemory CLI installer for Windows.
#
#   irm https://persistmemory.com/install.ps1 | iex
#
# Read it first if you would rather:
#   irm https://persistmemory.com/install.ps1
#
# Environment:
#   PM_VERSION   install a specific npm version (default: latest)

$ErrorActionPreference = "Stop"

function Install-PersistMemory {
  function Write-Step($text) { Write-Host ("==> " + $text) -ForegroundColor Cyan }
  function Write-Note($text) { Write-Host ("    " + $text) -ForegroundColor DarkGray }

  function Write-Failure($text) {
    Write-Host ""
    Write-Host ("error: " + $text) -ForegroundColor Red
    Write-Host ""
  }

  Write-Step "Installing the PersistMemory CLI"

  # Node, checked BEFORE anything is downloaded, so the failure arrives before
  # the work rather than after it.
  if (-not (Get-Command node -ErrorAction SilentlyContinue)) {
    Write-Failure "Node.js 20 or newer is required, and 'node' was not found on PATH."
    Write-Note "Install it from https://nodejs.org and run this again."
    return
  }

  # Redirection on the command itself, not on a parenthesised expression:
  # an assignment with a redirected sub-expression is a parse error in some
  # PowerShell versions, and an installer that fails to parse takes the whole
  # one-liner with it.
  $major = & node -p "process.versions.node.split('.')[0]" 2>$null
  if ([int]$major -lt 20) {
    Write-Failure ("Node.js 20 or newer is required; found " + (& node -v) + ".")
    return
  }

  if (-not (Get-Command npm -ErrorAction SilentlyContinue)) {
    Write-Failure "'npm' was not found on PATH. It ships with Node.js."
    return
  }

  $package = "@persistmemory/cli"
  if ($env:PM_VERSION) {
    $package = "@persistmemory/cli@" + $env:PM_VERSION
  }

  Write-Step ("Fetching " + $package)

  # No elevation. An installer that opens an Administrator prompt on its own is
  # one the user cannot audit after the fact; if the global prefix is not
  # writable, npm says so and the guidance below explains the safe ways round.
  & npm install -g $package 2>&1 | Out-Null

  if ($LASTEXITCODE -ne 0) {
    Write-Host ""
    Write-Note "npm could not install globally. That is usually a permissions"
    Write-Note "problem with npm's own prefix rather than anything to do with"
    Write-Note "this package. Two ways forward, neither needing Administrator:"
    Write-Host ""
    Write-Host "  1. Point npm somewhere you own:"
    Write-Host ('       npm config set prefix "' + $env:LOCALAPPDATA + '\npm"')
    Write-Host "       irm https://persistmemory.com/install.ps1 | iex"
    Write-Host ""
    Write-Host "  2. Skip installing and run it on demand:"
    Write-Host "       npx @persistmemory/cli auth login"
    Write-Host ""
    Write-Failure "install failed"
    return
  }

  if (-not (Get-Command pm -ErrorAction SilentlyContinue)) {
    Write-Host ""
    Write-Note "Installed, but 'pm' is not on your PATH. Add npm's global"
    Write-Note "directory to it, then open a new terminal:"
    Write-Host ""
    Write-Host ('       $env:Path += ";' + (& npm prefix -g) + '"')
    Write-Host ""
  }

  Write-Step "Installed"
  Write-Host ""
  Write-Host "Next:"
  Write-Host "  pm auth login                    sign in with your browser"
  Write-Host '  pm remember "we chose Postgres"  capture something'
  Write-Host "  pm                               start a session"
  Write-Host ""
  Write-Host "Docs: https://persistmemory.com/docs/cli"
}

Install-PersistMemory