param(
    [string]$Protoc = "",
    [string]$IncludePath = $env:PROTOC_INCLUDE,
    [string]$OutputPath = ""
)

$ErrorActionPreference = "Stop"

$repositoryRoot = Split-Path -Parent $PSScriptRoot
$protoRoot = Join-Path $repositoryRoot "api/proto"
$source = Join-Path $protoRoot "controlplane/v1/controlplane.proto"

if ([string]::IsNullOrWhiteSpace($Protoc)) {
    $Protoc = & (Join-Path $PSScriptRoot "install-protoc.ps1")
}
$protocCommand = Get-Command $Protoc -ErrorAction Stop
$protocVersion = (& $protocCommand.Source --version).Trim()
if ($protocVersion -ne "libprotoc 35.0") {
    throw "protoc 35.0 is required"
}
if ([string]::IsNullOrWhiteSpace($IncludePath)) {
    $installationRoot = Split-Path (Split-Path $protocCommand.Source -Parent) -Parent
    $candidates = @(
        (Join-Path $installationRoot "include"),
        "/usr/include",
        "/usr/local/include"
    )
    $IncludePath = $candidates |
        Where-Object { Test-Path (Join-Path $_ "google/protobuf/timestamp.proto") } |
        Select-Object -First 1
}
if ([string]::IsNullOrWhiteSpace($IncludePath) -or
    -not (Test-Path (Join-Path $IncludePath "google/protobuf/timestamp.proto"))) {
    throw "protoc well-known type include directory was not found; set PROTOC_INCLUDE"
}

if ([string]::IsNullOrWhiteSpace($OutputPath)) {
    $outputDirectory = Join-Path $repositoryRoot ".tmp-proto"
    New-Item -ItemType Directory -Force -Path $outputDirectory | Out-Null
    $OutputPath = Join-Path $outputDirectory "controlplane.pb"
}

& $protocCommand.Source `
    "--proto_path=$protoRoot" `
    "--proto_path=$IncludePath" `
    "--include_imports" `
    "--include_source_info" `
    "--descriptor_set_out=$OutputPath" `
    $source
if ($LASTEXITCODE -ne 0) {
    throw "protoc descriptor compilation failed with exit code $LASTEXITCODE"
}

$descriptor = Get-Item -LiteralPath $OutputPath
if ($descriptor.Length -le 0) {
    throw "protoc produced an empty descriptor set"
}
Write-Host "descriptor: $($descriptor.FullName) ($($descriptor.Length) bytes)"

$outputRoot = Join-Path $repositoryRoot ".tmp-proto/generated"
& (Join-Path $PSScriptRoot "generate-proto.ps1") `
    -Protoc $protocCommand.Source `
    -IncludePath $IncludePath `
    -OutputRoot $outputRoot

$generated = @(
    "gen/controlplane/v1/controlplane.pb.go",
    "gen/controlplane/v1/controlplane_grpc.pb.go"
)
foreach ($relative in $generated) {
    $committed = Join-Path $repositoryRoot $relative
    $candidate = Join-Path $outputRoot $relative
    if (-not (Test-Path -LiteralPath $committed) -or
        -not (Test-Path -LiteralPath $candidate) -or
        -not [System.Linq.Enumerable]::SequenceEqual(
            [System.IO.File]::ReadAllBytes($committed),
            [System.IO.File]::ReadAllBytes($candidate))) {
        throw "generated protobuf drift: $relative"
    }
}