[CmdletBinding()]
param(
    [string]$OutputDirectory = ''
)

Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'

$root = (Resolve-Path -LiteralPath $PSScriptRoot).Path
if ([string]::IsNullOrWhiteSpace($OutputDirectory)) {
    $OutputDirectory = Join-Path $root 'x64\RuntimeGuard'
}

$output = [System.IO.Path]::GetFullPath($OutputDirectory).TrimEnd('\') + '\'
$intermediateRoot = $output.TrimEnd('\') + '.int'
$vswhere = 'C:\Program Files (x86)\Microsoft Visual Studio\Installer\vswhere.exe'
if (-not (Test-Path -LiteralPath $vswhere)) {
    throw "vswhere not found: $vswhere"
}

$msbuild = & $vswhere -latest -products * -requires Microsoft.Component.MSBuild `
    -find 'MSBuild\**\Bin\MSBuild.exe' | Select-Object -First 1
if ([string]::IsNullOrWhiteSpace($msbuild)) {
    throw 'MSBuild was not found by vswhere.'
}

New-Item -ItemType Directory -Force -Path $output | Out-Null
New-Item -ItemType Directory -Force -Path $intermediateRoot | Out-Null

function Invoke-ProjectRebuild {
    param(
        [Parameter(Mandatory)] [string]$Project,
        [Parameter(Mandatory)] [string]$IntermediateName
    )

    $intermediate = (Join-Path $intermediateRoot $IntermediateName).TrimEnd('\') + '\'
    $arguments = @(
        $Project,
        '/m',
        '/t:Rebuild',
        '/p:Configuration=Release',
        '/p:Platform=x64',
        "/p:OutDir=$output",
        "/p:IntDir=$intermediate",
        '/v:minimal'
    )

    & $msbuild @arguments
    if ($LASTEXITCODE -ne 0) {
        throw "MSBuild failed for $Project with exit code $LASTEXITCODE."
    }
}

$selfTestProject = Join-Path $root 'CFramework.SelfTest\CFramework.SelfTest.vcxproj'
$overlayProject = Join-Path $root 'CFramework\CFramework.vcxproj'
$selfTestExe = Join-Path $output 'CFramework.SelfTest.exe'
$overlayExe = Join-Path $output 'CFramework.exe'

Write-Host '[guard] Rebuilding offline runtime tests...'
Invoke-ProjectRebuild -Project $selfTestProject -IntermediateName 'SelfTest'

Write-Host '[guard] Running offline runtime tests...'
& $selfTestExe
if ($LASTEXITCODE -ne 0) {
    throw "Runtime self-test failed with exit code $LASTEXITCODE. Overlay build blocked."
}

Write-Host '[guard] Tests passed; rebuilding Release x64 overlay...'
Invoke-ProjectRebuild -Project $overlayProject -IntermediateName 'CFramework'

$selfTestHash = (Get-FileHash -LiteralPath $selfTestExe -Algorithm SHA256).Hash
$overlayHash = (Get-FileHash -LiteralPath $overlayExe -Algorithm SHA256).Hash
Write-Host "[guard] PASS"
Write-Host "[guard] SelfTest: $selfTestExe"
Write-Host "[guard] SelfTest SHA256: $selfTestHash"
Write-Host "[guard] Overlay: $overlayExe"
Write-Host "[guard] Overlay SHA256: $overlayHash"