# Install the pixy client on Windows.
#
#   irm https://get.demotwo.site/install.ps1 | iex
#
# Installs to %LOCALAPPDATA%\Programs\pixy and adds it to the user PATH.
# No administrator rights are needed.

$ErrorActionPreference = 'Stop'

$BaseUrl = if ($env:PIXY_BASE_URL) { $env:PIXY_BASE_URL } else { 'https://get.demotwo.site' }
$Dest    = if ($env:PIXY_INSTALL)  { $env:PIXY_INSTALL }  else { Join-Path $env:LOCALAPPDATA 'Programs\pixy' }

function Info($m) { Write-Host "  $m" }
function Die($m)  { Write-Host "error: $m" -ForegroundColor Red; exit 1 }

# TLS 1.2 is not the default on older Windows PowerShell and the download fails
# without it.
try { [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12 } catch {}

$arch = switch ($env:PROCESSOR_ARCHITECTURE) {
    'AMD64' { 'amd64' }
    'ARM64' { 'arm64' }
    'x86'   { Die '32-bit Windows is not supported' }
    default { 'amd64' }
}

$asset = "pixy-windows-$arch.exe"
$tmp   = Join-Path ([IO.Path]::GetTempPath()) "pixy-$([guid]::NewGuid().ToString('N')).exe"

Write-Host ''
Info "downloading $asset"
try {
    Invoke-WebRequest -Uri "$BaseUrl/$asset" -OutFile $tmp -UseBasicParsing
} catch {
    Die "download failed: $BaseUrl/$asset`n  $($_.Exception.Message)"
}

# Verify against the published checksum list when it is reachable.
try {
    $sums = (Invoke-WebRequest -Uri "$BaseUrl/checksums.txt" -UseBasicParsing).Content
    $want = ($sums -split "`n" | Where-Object { $_ -match [regex]::Escape($asset) } |
             Select-Object -First 1) -replace '\s.*$', ''
    if ($want) {
        $got = (Get-FileHash -Path $tmp -Algorithm SHA256).Hash.ToLower()
        if ($got -ne $want.ToLower()) {
            Remove-Item $tmp -Force
            Die "checksum mismatch for $asset"
        }
        Info 'checksum verified'
    }
} catch {
    Info 'could not fetch checksums.txt; skipping verification'
}

New-Item -ItemType Directory -Force -Path $Dest | Out-Null
$target = Join-Path $Dest 'pixy.exe'

# A running pixy.exe cannot be overwritten, so say so plainly rather than
# failing with a generic access error.
try {
    Move-Item -Path $tmp -Destination $target -Force
} catch {
    Remove-Item $tmp -Force -ErrorAction SilentlyContinue
    Die "could not write $target (is pixy still running?)`n  $($_.Exception.Message)"
}
Info "installed $target"

# Add to the *user* PATH, persistently, without duplicating the entry.
$userPath = [Environment]::GetEnvironmentVariable('Path', 'User')
if ($userPath -notlike "*$Dest*") {
    $newPath = if ([string]::IsNullOrEmpty($userPath)) { $Dest } else { "$userPath;$Dest" }
    [Environment]::SetEnvironmentVariable('Path', $newPath, 'User')
    Info "added $Dest to your PATH"
    $pathChanged = $true
}
# Make it usable in this session too, so the next command just works.
if ($env:Path -notlike "*$Dest*") { $env:Path = "$env:Path;$Dest" }

Write-Host ''
Write-Host '  pixy installed' -ForegroundColor Green
Write-Host ''
Write-Host '  Next:'
Write-Host '    pixy login --token <your-token>'
Write-Host '    pixy'
Write-Host ''
if ($pathChanged) {
    Write-Host '  (Open a new terminal for PATH changes to apply everywhere.)'
    Write-Host ''
}