# llamay installer for Windows.
#
#   irm https://llamay.com/install.ps1 | iex
#
# Installs per user by default, which is what makes the one-liner work without
# an elevation prompt: %LOCALAPPDATA%\Programs\llamay is writable by the user
# who is running the shell. -AllInUsers installs to Program Files and needs an
# administrator shell.
#
# Overridable:
#
#   $env:LLAMAY_VERSION      a specific version, e.g. 1.2.3 (default: latest)
#   $env:LLAMAY_INSTALL_DIR  where the binary goes
#   $env:LLAMAY_NO_SERVICE   set to 1 to install the CLI and no startup task

[CmdletBinding()]
param(
    [switch]$AllUsers,
    [string]$Version = $env:LLAMAY_VERSION,
    [string]$InstallDir = $env:LLAMAY_INSTALL_DIR
)

$ErrorActionPreference = 'Stop'
$ProgressPreference = 'SilentlyContinue'   # the progress bar makes iwr crawl

# The artifacts live in a public repository of their own; the engine's source
# is private, and a private repository answers 404 to an unauthenticated
# download -- which is every user of this script.
$Repo = 'AzmxAI/llamay-releases'
$Base = "https://github.com/$Repo/releases"

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

# Windows on arm64 is a real target and `uname -m` has no equivalent here;
# PROCESSOR_ARCHITECTURE is what the shell knows, and under an x86 shell on an
# arm64 machine it is the emulated one, so PROCESSOR_ARCHITEW6432 wins if set.
$archRaw = if ($env:PROCESSOR_ARCHITEW6432) { $env:PROCESSOR_ARCHITEW6432 } else { $env:PROCESSOR_ARCHITECTURE }
$arch = switch ($archRaw) {
    'AMD64' { 'amd64' }
    'ARM64' { 'arm64' }
    default { Die "unsupported architecture: $archRaw" }
}

if (-not $Version) {
    # The redirect on /releases/latest names the tag, which avoids the API and
    # its rate limit for what is one lookup.
    $resp = Invoke-WebRequest -Uri "$Base/latest" -MaximumRedirection 0 -ErrorAction SilentlyContinue
    $loc = $resp.Headers.Location
    if (-not $loc) { $loc = (Invoke-WebRequest -Uri "$Base/latest" -UseBasicParsing).BaseResponse.ResponseUri.AbsoluteUri }
    $Version = ([string]$loc) -replace '.*/tag/v', ''
    if (-not $Version) { Die 'could not determine the latest version; set $env:LLAMAY_VERSION' }
}

if (-not $InstallDir) {
    $InstallDir = if ($AllUsers) { "$env:ProgramFiles\llamay" } else { "$env:LOCALAPPDATA\Programs\llamay" }
}

if ($AllUsers) {
    $admin = ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()
             ).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
    if (-not $admin) { Die '-AllUsers needs an administrator PowerShell' }
}

$asset = "llamay_${Version}_windows_${arch}.zip"
$url   = "$Base/download/v$Version/$asset"

Say "llamay $Version - windows/$arch"

$tmp = Join-Path ([IO.Path]::GetTempPath()) ("llamay-" + [Guid]::NewGuid())
New-Item -ItemType Directory -Path $tmp -Force | Out-Null
try {
    Say "downloading $asset"
    Invoke-WebRequest -Uri $url -OutFile "$tmp\$asset" -UseBasicParsing

    # The checksum is not optional. A release publishes SHA256SUMS over the
    # artifacts as uploaded; an installer that skips the check runs whatever it
    # was handed.
    Invoke-WebRequest -Uri "$Base/download/v$Version/SHA256SUMS" -OutFile "$tmp\SHA256SUMS" -UseBasicParsing
    $want = (Select-String -Path "$tmp\SHA256SUMS" -Pattern ([regex]::Escape($asset) + '$') |
             Select-Object -First 1).Line -split '\s+' | Select-Object -First 1
    if (-not $want) { Die "$asset is not listed in SHA256SUMS" }
    $got = (Get-FileHash "$tmp\$asset" -Algorithm SHA256).Hash.ToLower()
    if ($got -ne $want.ToLower()) { Die "checksum mismatch for ${asset}: got $got, expected $want" }
    Say 'checksum ok'

    Expand-Archive -Path "$tmp\$asset" -DestinationPath "$tmp\x" -Force
    $exe = Get-ChildItem -Path "$tmp\x" -Filter 'llamay.exe' -Recurse | Select-Object -First 1
    if (-not $exe) { Die 'the archive does not contain llamay.exe' }

    New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null

    # A running server holds the file open, so stop it before replacing the
    # binary. Without this an upgrade fails with a sharing violation and leaves
    # the old version in place while reporting success.
    Get-Process -Name 'llamay' -ErrorAction SilentlyContinue | Stop-Process -Force -ErrorAction SilentlyContinue
    Start-Sleep -Milliseconds 300

    Copy-Item $exe.FullName (Join-Path $InstallDir 'llamay.exe') -Force
    Say "installed $InstallDir\llamay.exe"

    # PATH, on the right hive for the scope this installed into.
    $scope = if ($AllUsers) { 'Machine' } else { 'User' }
    $path = [Environment]::GetEnvironmentVariable('Path', $scope)
    if ($path -notlike "*$InstallDir*") {
        [Environment]::SetEnvironmentVariable('Path', "$path;$InstallDir", $scope)
        Say "added $InstallDir to the $scope PATH - open a new terminal for it to take effect"
    }
    $env:Path = "$env:Path;$InstallDir"

    if ($env:LLAMAY_NO_SERVICE -ne '1') {
        # A logon scheduled task rather than a Windows service: llamay is a
        # plain console program with no service control handler, and a real
        # service would need one. The task gives the same result -- it is
        # running when the user is logged in -- without pretending.
        $task = 'llamay server'
        schtasks /Query /TN $task 2>$null | Out-Null
        if ($LASTEXITCODE -eq 0) { schtasks /Delete /TN $task /F | Out-Null }
        schtasks /Create /TN $task /TR "`"$InstallDir\llamay.exe`" serve" /SC ONLOGON /RL LIMITED /F | Out-Null
        if ($LASTEXITCODE -eq 0) {
            schtasks /Run /TN $task | Out-Null
            Say 'service running - schtasks /Query /TN "llamay server"'
        } else {
            Write-Host 'the startup task could not be created; run: llamay serve' -ForegroundColor Yellow
        }
    }

    Say ''
    Say "llamay $Version is installed"
    Say '  llamay pull hf:Qwen/Qwen2.5-0.5B-Instruct-GGUF/qwen2.5-0.5b-instruct-q4_k_m.gguf'
    Say "  llamay run -m qwen2.5-0.5b-instruct:q4_k_m -p 'hello'"
    Say '  the server is on http://127.0.0.1:11435'
}
finally {
    Remove-Item -Recurse -Force $tmp -ErrorAction SilentlyContinue
}