# Prefetch official Node, Corepack pnpm, and lockfile packages into in-repo caches.
# Run on the same OS/CPU as the later install, while nodejs.org and the npm registry
# are reachable. Node/pnpm cannot use socks5h:// proxies; pass an HTTP proxy via
# DSH_NPM_HTTP_PROXY (example: http://127.0.0.1:3067). That overlay is applied only
# around Corepack/pnpm and is restored before the script returns, so a caller SOCKS
# proxy stays in the current PowerShell session. curl keeps the inherited proxy
# (SOCKS included). Optional DSH_NODE_VERSION (no leading v) pins the Node distro;
# otherwise the running Node is used, or the newest v24.x from nodejs.org/dist/index.json.
#
# Usage (repo root):  powershell -File scripts/offline/download-deps.ps1
$ErrorActionPreference = 'Stop'
Set-StrictMode -Version Latest

$Root = (Resolve-Path (Join-Path $PSScriptRoot '..\..')).Path
Set-Location $Root

$ProxyVarNames = @('HTTPS_PROXY', 'HTTP_PROXY', 'ALL_PROXY', 'https_proxy', 'http_proxy', 'all_proxy')

function Get-ProcessVar([string]$Name) {
  return [Environment]::GetEnvironmentVariable($Name, 'Process')
}

function Get-InheritedProxy {
  foreach ($name in $ProxyVarNames) {
    $value = Get-ProcessVar $name
    if ($value) { return $value }
  }
  return $null
}

function Resolve-NodeHttpProxy {
  $override = Get-ProcessVar 'DSH_NPM_HTTP_PROXY'
  if ($override) {
    if ($override -match '^socks5') {
      throw "DSH_NPM_HTTP_PROXY=$override. Node and pnpm cannot fetch through SOCKS. Use an HTTP proxy (for example http://127.0.0.1:3067)."
    }
    return $override
  }
  $socks = $null
  foreach ($name in $ProxyVarNames) {
    $value = Get-ProcessVar $name
    if (-not $value) { continue }
    if ($value -match '^socks5') {
      $socks = "$name=$value"
      continue
    }
    return $value
  }
  if ($socks) {
    throw "$socks. Node and pnpm cannot fetch through SOCKS. Set DSH_NPM_HTTP_PROXY to an HTTP proxy (for example http://127.0.0.1:3067)."
  }
  return $null
}

function Invoke-WithNodeHttpProxy([scriptblock]$Action) {
  $http = Resolve-NodeHttpProxy
  if (-not $http) {
    & $Action
    return
  }
  $saved = @{}
  foreach ($name in $ProxyVarNames) {
    $saved[$name] = Get-ProcessVar $name
  }
  try {
    foreach ($name in $ProxyVarNames) {
      [Environment]::SetEnvironmentVariable($name, $http, 'Process')
    }
    & $Action
  } finally {
    foreach ($name in $ProxyVarNames) {
      [Environment]::SetEnvironmentVariable($name, $saved[$name], 'Process')
    }
  }
}

function Get-CurlProxyArgs {
  $proxy = Get-InheritedProxy
  if (-not $proxy) { $proxy = Get-ProcessVar 'DSH_NPM_HTTP_PROXY' }
  if ($proxy) { @('--proxy', $proxy) } else { @() }
}

function Save-Url([string]$Url, [string]$Destination) {
  $dir = Split-Path -Parent $Destination
  New-Item -ItemType Directory -Force -Path $dir | Out-Null
  $curl = Get-Command curl.exe -ErrorAction SilentlyContinue
  if ($null -eq $curl) {
    throw 'curl.exe is required to download Node (bundled with Windows 10+).'
  }
  & $curl.Source -fsSL --retry 3 @(Get-CurlProxyArgs) -o $Destination $Url
  if ($LASTEXITCODE -ne 0) {
    throw "Download failed ($LASTEXITCODE): $Url"
  }
}

function Get-NodePlatform {
  $arch = $env:PROCESSOR_ARCHITECTURE
  if ($arch -eq 'ARM64') { return 'win-arm64' }
  if ($arch -eq 'AMD64') { return 'win-x64' }
  throw "Unsupported Windows architecture: $arch"
}

function Get-NodeArchiveName([string]$Version, [string]$Platform) {
  return "node-v$Version-$Platform.zip"
}

function Resolve-NodeVersion([string]$Platform) {
  if ($env:DSH_NODE_VERSION) {
    return $env:DSH_NODE_VERSION.TrimStart('v')
  }
  $node = Get-Command node -ErrorAction SilentlyContinue
  if ($null -ne $node) {
    $running = (& $node.Source --version).Trim().TrimStart('v')
    $parts = $running.Split('.')
    $major = [int]$parts[0]
    $minor = [int]$parts[1]
    if (-not (($major -eq 22 -and $minor -ge 19) -or ($major -ge 24))) {
      throw "Running Node v$running is outside engines.node (^22.19.0 || >=24.0.0). Set DSH_NODE_VERSION."
    }
    return $running
  }
  $indexPath = Join-Path $env:TEMP 'dsh-node-index.json'
  $distBase = if ($env:DSH_NODE_DIST_BASE) { $env:DSH_NODE_DIST_BASE.TrimEnd('/') } else { 'https://nodejs.org/dist' }
  Save-Url "$distBase/index.json" $indexPath
  $releases = Get-Content $indexPath -Raw | ConvertFrom-Json
  $wantedFile = if ($Platform -eq 'win-arm64') { 'win-arm64-zip' } else { 'win-x64-zip' }
  foreach ($release in $releases) {
    $ver = [string]$release.version
    if ($ver -notmatch '^v24\.') { continue }
    if (@($release.files) -notcontains $wantedFile) { continue }
    return $ver.TrimStart('v')
  }
  throw "No Node v24.x zip published for $Platform at $distBase."
}

function Assert-NodeChecksum([string]$SumsPath, [string]$ArchivePath, [string]$ArchiveName) {
  $expected = $null
  foreach ($line in Get-Content $SumsPath) {
    if ($line -match ('^[0-9a-fA-F]{64}  ' + [regex]::Escape($ArchiveName) + '$')) {
      $expected = $line.Substring(0, 64)
      break
    }
  }
  if (-not $expected) {
    throw "SHASUMS256.txt has no entry for $ArchiveName"
  }
  $actual = (Get-FileHash -Algorithm SHA256 -Path $ArchivePath).Hash
  if ($actual.ToLowerInvariant() -ne $expected.ToLowerInvariant()) {
    throw "SHA256 mismatch for $ArchiveName"
  }
}

$manifest = Get-Content (Join-Path $Root 'package.json') -Raw | ConvertFrom-Json
$packageManager = [string]$manifest.packageManager
if ($packageManager -notmatch '^pnpm@') {
  throw "package.json packageManager must be pnpm@<version>, got $packageManager"
}

$distBase = if ($env:DSH_NODE_DIST_BASE) { $env:DSH_NODE_DIST_BASE.TrimEnd('/') } else { 'https://nodejs.org/dist' }
$platform = Get-NodePlatform
$nodeVersion = Resolve-NodeVersion $platform
$archiveName = Get-NodeArchiveName $nodeVersion $platform
$nodeCache = Join-Path $Root '.offline-cache\node'
$archivePath = Join-Path $nodeCache $archiveName
$sumsPath = Join-Path $nodeCache "SHASUMS256-v$nodeVersion.txt"
$runtimeDir = Join-Path $nodeCache 'runtime'
$nodeHome = Join-Path $runtimeDir "node-v$nodeVersion-$platform"

Write-Host "Prefetch Node v$nodeVersion ($platform)"
Save-Url "$distBase/v$nodeVersion/SHASUMS256.txt" $sumsPath
Save-Url "$distBase/v$nodeVersion/$archiveName" $archivePath
Assert-NodeChecksum $sumsPath $archivePath $archiveName
if (-not (Test-Path (Join-Path $nodeHome 'node.exe'))) {
  if (Test-Path $runtimeDir) { Remove-Item -Recurse -Force $runtimeDir }
  New-Item -ItemType Directory -Force -Path $runtimeDir | Out-Null
  Expand-Archive -LiteralPath $archivePath -DestinationPath $runtimeDir
}
if (-not (Test-Path (Join-Path $nodeHome 'node.exe'))) {
  throw "Unpacked Node is missing: $nodeHome\node.exe"
}
  $json = @{
    version = $nodeVersion
    archive = $archiveName
    platform = $platform
  } | ConvertTo-Json
  [System.IO.File]::WriteAllText((Join-Path $nodeCache 'runtime.json'), $json)

$storeDir = Join-Path $Root '.offline-store'
$corepackHome = Join-Path $Root '.offline-cache\corepack'
New-Item -ItemType Directory -Force -Path $storeDir, $corepackHome | Out-Null
$env:COREPACK_HOME = $corepackHome
$env:PATH = "$nodeHome;$env:PATH"

Write-Host "Node $((& (Join-Path $nodeHome 'node.exe') --version)); prefetch $packageManager into $storeDir"
Invoke-WithNodeHttpProxy {
  & (Join-Path $nodeHome 'corepack.cmd') prepare $packageManager --activate
  if ($LASTEXITCODE -ne 0) { throw "corepack prepare failed ($LASTEXITCODE)" }
  & (Join-Path $nodeHome 'corepack.cmd') pnpm fetch --frozen-lockfile --store-dir $storeDir
  if ($LASTEXITCODE -ne 0) { throw "pnpm fetch failed ($LASTEXITCODE)" }
}

Write-Host @"
Prefetch complete (Node v$nodeVersion zip + pnpm store).
Copy this checkout (including .offline-store and .offline-cache) to the offline machine.
Then run: powershell -File scripts/offline/install-deps.ps1
"@