param(
    [string]$HostName = "0.0.0.0",
    [int]$Port = 31106,
    [switch]$NoKillExisting,
    [switch]$DryRun
)

$ErrorActionPreference = "Stop"

function Get-ListeningProcessIds([int]$TargetPort) {
    $listeners = Get-NetTCPConnection -LocalPort $TargetPort -State Listen -ErrorAction SilentlyContinue
    if (-not $listeners) {
        return @()
    }
    return ($listeners | Select-Object -ExpandProperty OwningProcess -Unique)
}

function Stop-ListeningProcesses([int]$TargetPort) {
    $pids = Get-ListeningProcessIds -TargetPort $TargetPort
    if (-not $pids -or $pids.Count -eq 0) {
        Write-Host "[start] port $TargetPort is free."
        return
    }

    foreach ($pidValue in $pids) {
        $proc = Get-Process -Id $pidValue -ErrorAction SilentlyContinue
        if ($null -eq $proc) {
            continue
        }
        Write-Host "[start] port $TargetPort is used by PID=$pidValue Name=$($proc.ProcessName)"
        if ($DryRun) {
            Write-Host "[start] DryRun: skip stopping PID=$pidValue"
            continue
        }
        Stop-Process -Id $pidValue -Force
        Write-Host "[start] stopped PID=$pidValue"
    }

    Start-Sleep -Milliseconds 400
}

function Ensure-PortAvailable([int]$TargetPort) {
    $pids = Get-ListeningProcessIds -TargetPort $TargetPort
    if ($pids.Count -gt 0) {
        throw "port $TargetPort is still occupied, cannot start service."
    }
}

$scriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
Set-Location $scriptDir

Write-Host "[start] project dir: $scriptDir"
Write-Host "[start] target: http://$HostName`:$Port"

if (-not $NoKillExisting) {
    Stop-ListeningProcesses -TargetPort $Port
} else {
    $existing = Get-ListeningProcessIds -TargetPort $Port
    if ($existing.Count -gt 0) {
        throw "port $Port is occupied and -NoKillExisting is set."
    }
}

Ensure-PortAvailable -TargetPort $Port

if ($DryRun) {
    Write-Host "[start] DryRun: checks passed, skip launching."
    exit 0
}

Write-Host "[start] launching service..."
$env:SURUGAYA_APP_HOST = $HostName
$env:SURUGAYA_APP_PORT = "$Port"
# python -m app.main
uvicorn app.main:app --host $HostName --port $Port