param(
  [string]$Compiler = 'clang',
  [string]$OutputDirectory = (Join-Path $PSScriptRoot '..\build\wasm-v23'),
  [switch]$Promote
)

$ErrorActionPreference = 'Stop'
$workspace = (Resolve-Path -LiteralPath (Join-Path $PSScriptRoot '..')).Path
$output = [System.IO.Path]::GetFullPath($OutputDirectory)
if (-not $output.StartsWith($workspace, [System.StringComparison]::OrdinalIgnoreCase)) { throw 'OutputDirectory must stay inside the workspace.' }
$lock = Get-Content -LiteralPath (Join-Path $workspace 'toolchain.lock.json') -Raw -Encoding UTF8 | ConvertFrom-Json
$versionLine = (& $Compiler --version | Select-Object -First 1)
if ($versionLine -notmatch [regex]::Escape($lock.version)) { throw "Expected clang $($lock.version), got: $versionLine" }
New-Item -ItemType Directory -Path $output -Force | Out-Null

$common = @('--target=wasm32-unknown-unknown') + @($lock.commonFlags)
$variants = @(
  [pscustomobject]@{ name='simd'; flags=@($lock.simdFlags) },
  [pscustomobject]@{ name='scalar'; flags=@($lock.scalarFlags) }
)
$modules = @(
  [pscustomobject]@{ symbol='WASM'; name='wasm'; source='shallow_kernel.c'; memory=2097152 },
  [pscustomobject]@{ symbol='DEEP'; name='deep'; source='deep_kernel.c'; memory=8388608 },
  [pscustomobject]@{ symbol='BLA'; name='bla'; source='bla_kernel_v18.c'; memory=33554432 },
  [pscustomobject]@{ symbol='COLOR'; name='color'; source='color_kernel.c'; memory=2097152 }
)
$payloads = @()
foreach ($module in $modules) {
  foreach ($variant in $variants) {
    $file = "$($module.name)-$($variant.name).wasm"
    $path = Join-Path $output $file
    $args = $common + @($variant.flags) + @("-Wl,--initial-memory=$($module.memory)", "-Wl,--max-memory=$($module.memory)", '-o', $path, (Join-Path $workspace "src\$($module.source)") )
    & $Compiler @args
    if ($LASTEXITCODE -ne 0) { throw "clang failed for $file" }
    $payloads += [ordered]@{
      symbol = "$($module.symbol)_$($variant.name.ToUpperInvariant())_B64"
      file = $file
      bytes = (Get-Item -LiteralPath $path).Length
      sha256 = (Get-FileHash -LiteralPath $path -Algorithm SHA256).Hash.ToLowerInvariant()
      source = "src/$($module.source)"
    }
  }
}
$manifest = [ordered]@{
  format = 'mandelbrot-source-wasm-manifest-v23'
  toolchain = $lock
  abi = 'src/abi.json'
  payloads = $payloads
}
$manifestPath = Join-Path $output 'manifest.json'
$manifest | ConvertTo-Json -Depth 8 | Set-Content -LiteralPath $manifestPath -Encoding UTF8

if ($Promote) {
  & powershell.exe -NoProfile -ExecutionPolicy Bypass -File (Join-Path $workspace 'tests\kernel-golden.ps1') -GeneratedDirectory $output
  if ($LASTEXITCODE -ne 0) { throw 'Generated-WASM golden gate failed; payloads were not promoted.' }
  $generatedKernels = Join-Path $output 'kernels.js'
  & powershell.exe -NoProfile -ExecutionPolicy Bypass -File (Join-Path $workspace 'scripts\build-kernels.ps1') -ManifestPath $manifestPath -OutputPath $generatedKernels
  if ($LASTEXITCODE -ne 0) { throw 'kernels.js generation failed; payloads were not promoted.' }
  $dist = Join-Path $workspace 'dist\wasm'
  foreach ($payload in $payloads) { Copy-Item -LiteralPath (Join-Path $output $payload.file) -Destination (Join-Path $dist $payload.file) -Force }
  Copy-Item -LiteralPath $manifestPath -Destination (Join-Path $dist 'manifest.json') -Force
  Copy-Item -LiteralPath $generatedKernels -Destination (Join-Path $workspace 'kernels.js') -Force
}
Write-Output $manifestPath