[CmdletBinding()]
param(
    [Parameter(Mandatory = $true)]
    [string]$ManagedDll,

    [Parameter(Mandatory = $true)]
    [string]$OutputDirectory
)

$ErrorActionPreference = 'Stop'

function Get-PeMachine {
    param([Parameter(Mandatory = $true)][string]$Path)

    [byte[]]$bytes = [System.IO.File]::ReadAllBytes($Path)
    if ($bytes.Length -le 0x40 -or $bytes[0] -ne 0x4d -or $bytes[1] -ne 0x5a) {
        throw "Native runtime is not a PE file: $Path"
    }

    [int]$peOffset = [System.BitConverter]::ToInt32($bytes, 0x3c)
    if ($peOffset -lt 0 -or $peOffset + 6 -gt $bytes.Length -or $bytes[$peOffset] -ne 0x50 -or $bytes[$peOffset + 1] -ne 0x45) {
        throw "Native runtime has an invalid PE header: $Path"
    }

    return [System.BitConverter]::ToUInt16($bytes, $peOffset + 4)
}

function Test-SamePath {
    param([string]$Left, [string]$Right)

    return [string]::Equals($Left.TrimEnd([System.IO.Path]::DirectorySeparatorChar, [System.IO.Path]::AltDirectorySeparatorChar),
        $Right.TrimEnd([System.IO.Path]::DirectorySeparatorChar, [System.IO.Path]::AltDirectorySeparatorChar),
        [System.StringComparison]::OrdinalIgnoreCase)
}

$managedDllPath = [System.IO.Path]::GetFullPath($ManagedDll)
$outputDirectoryPath = [System.IO.Path]::GetFullPath($OutputDirectory)
$driveRoot = [System.IO.Path]::GetPathRoot($outputDirectoryPath)
$workspaceRoot = [System.IO.Path]::GetFullPath((Join-Path $PSScriptRoot '..\..'))

if (Test-SamePath $outputDirectoryPath $driveRoot) {
    throw 'Refusing to publish into a drive root.'
}
if (Test-SamePath $outputDirectoryPath $workspaceRoot) {
    throw 'Refusing to publish into the workspace root.'
}
if (-not [System.IO.File]::Exists($managedDllPath)) {
    throw "Managed DLL does not exist: $managedDllPath"
}
$visualizationDll = Join-Path ([System.IO.Path]::GetDirectoryName($managedDllPath)) 'TrajectoryPlanningVisualization.dll'
if (-not [System.IO.File]::Exists($visualizationDll)) {
    throw "Visualization DLL does not exist beside managed DLL: $visualizationDll"
}
if (-not [System.Environment]::Is64BitProcess) {
    throw 'Refusing to publish from a non-x64 PowerShell host.'
}

$clumsyPilotRoot = [System.IO.Path]::GetFullPath((Join-Path $PSScriptRoot '..'))
$osqpRoot = Join-Path $clumsyPilotRoot 'ThirdParty\OSQP'
$nativeDll = Join-Path $osqpRoot 'win-x64\osqp.dll'
$hashManifest = Join-Path $osqpRoot 'SHA256SUMS'
$license = Join-Path $osqpRoot 'LICENSE'
$notice = Join-Path $osqpRoot 'NOTICE'
$version = Join-Path $osqpRoot 'VERSION'
$requiredFiles = @($nativeDll, $hashManifest, $license, $notice, $version)
foreach ($requiredFile in $requiredFiles) {
    if (-not [System.IO.File]::Exists($requiredFile)) {
        throw "Required OSQP package file does not exist: $requiredFile"
    }
}

if ((Get-PeMachine $nativeDll) -ne 0x8664) {
    throw 'Refusing to publish a non-x64 OSQP runtime.'
}

$manifestTokens = @((Get-Content -Raw -LiteralPath $hashManifest) -split '\s+' | Where-Object { $_.Length -gt 0 })
if ($manifestTokens.Length -lt 2 -or $manifestTokens[1] -ne 'win-x64/osqp.dll') {
    throw 'SHA256SUMS does not describe the pinned win-x64 OSQP runtime.'
}
$expectedHash = $manifestTokens[0].ToLowerInvariant()
$actualHash = (Get-FileHash -Algorithm SHA256 -LiteralPath $nativeDll).Hash.ToLowerInvariant()
if ($actualHash -ne $expectedHash) {
    throw 'OSQP runtime SHA-256 does not match SHA256SUMS.'
}

[System.IO.Directory]::CreateDirectory($outputDirectoryPath) | Out-Null
$pluginsDirectory = Join-Path $outputDirectoryPath 'plugins'
$nonce = [System.Guid]::NewGuid().ToString('N')
$stagingDirectory = Join-Path $outputDirectoryPath ('.plugins-staging-' + $nonce)
$backupDirectory = Join-Path $outputDirectoryPath ('.plugins-backup-' + $nonce)
$movedExistingPlugins = $false

try {
    [System.IO.Directory]::CreateDirectory((Join-Path $stagingDirectory 'licenses')) | Out-Null
    [System.IO.File]::Copy($managedDllPath, (Join-Path $stagingDirectory 'ClumsyPilot.dll'), $false)
    [System.IO.File]::Copy($visualizationDll, (Join-Path $stagingDirectory 'TrajectoryPlanningVisualization.dll'), $false)
    [System.IO.File]::Copy($nativeDll, (Join-Path $stagingDirectory 'osqp.dll'), $false)
    [System.IO.File]::Copy($license, (Join-Path $stagingDirectory 'licenses\OSQP-LICENSE.txt'), $false)
    [System.IO.File]::Copy($notice, (Join-Path $stagingDirectory 'licenses\OSQP-NOTICE.txt'), $false)
    [System.IO.File]::Copy($version, (Join-Path $stagingDirectory 'licenses\OSQP-VERSION.txt'), $false)

    if ([System.IO.Directory]::Exists($pluginsDirectory)) {
        [System.IO.Directory]::Move($pluginsDirectory, $backupDirectory)
        $movedExistingPlugins = $true
    }

    [System.IO.Directory]::Move($stagingDirectory, $pluginsDirectory)

    if ($movedExistingPlugins -and [System.IO.Directory]::Exists($backupDirectory)) {
        [System.IO.Directory]::Delete($backupDirectory, $true)
    }
}
catch {
    if (-not [System.IO.Directory]::Exists($pluginsDirectory) -and $movedExistingPlugins -and
        [System.IO.Directory]::Exists($backupDirectory)) {
        [System.IO.Directory]::Move($backupDirectory, $pluginsDirectory)
    }
    throw
}
finally {
    if ([System.IO.Directory]::Exists($stagingDirectory)) {
        [System.IO.Directory]::Delete($stagingDirectory, $true)
    }
    if ([System.IO.Directory]::Exists($backupDirectory) -and [System.IO.Directory]::Exists($pluginsDirectory)) {
        [System.IO.Directory]::Delete($backupDirectory, $true)
    }
}