# _detect_port.ps1 -- Detect the best serial port via arduino-cli
#
# Called by upload.bat and monitor.bat. Outputs a single port name
# (e.g. COM3) or nothing if no port is found.
#
# If .anvil.local contains a vid_pid, resolves the device to its
# current COM port (handles reassignment after replug).
# Falls back to saved port, then auto-detect.

param(
    [string]$VidPid = "",
    [string]$SavedPort = ""
)

$ErrorActionPreference = 'SilentlyContinue'

$raw = arduino-cli board list --format json 2>$null
if (-not $raw) {
    # No arduino-cli or no output; fall back to saved port
    if ($SavedPort) { Write-Output $SavedPort }
    exit
}

$data = $raw | ConvertFrom-Json
if (-not $data.detected_ports) {
    if ($SavedPort) { Write-Output $SavedPort }
    exit
}

$serial = $data.detected_ports | Where-Object { $_.port.protocol -eq 'serial' }
if (-not $serial) {
    if ($SavedPort) { Write-Output $SavedPort }
    exit
}

# -- Try VID:PID resolution first ------------------------------------------
if ($VidPid) {
    $parts = $VidPid -split ':'
    if ($parts.Count -eq 2) {
        $targetVid = $parts[0].ToLower()
        $targetPid = $parts[1].ToLower()

        foreach ($p in $serial) {
            $pVid = ($p.port.properties.vid -replace '^0x','').ToLower()
            $pPid = ($p.port.properties.pid -replace '^0x','').ToLower()
            if ($pVid -eq $targetVid -and $pPid -eq $targetPid) {
                Write-Output $p.port.address
                exit
            }
        }

        # VID:PID not found -- device not connected
        # Fall through to saved port / auto-detect
    }
}

# -- Fall back to saved port if it exists on the system --------------------
if ($SavedPort) {
    $found = $serial | Where-Object { $_.port.address -eq $SavedPort } | Select-Object -First 1
    if ($found) {
        Write-Output $SavedPort
        exit
    }
    # Saved port not present either; fall through to auto-detect
}

# -- Auto-detect: prefer USB serial ports ----------------------------------
$usb = $serial | Where-Object { $_.port.protocol_label -like '*USB*' } | Select-Object -First 1
if ($usb) {
    Write-Output $usb.port.address
    exit
}

# Fall back to any serial port
$any = $serial | Select-Object -First 1
if ($any) {
    Write-Output $any.port.address
}