/*
 * ============================================================================
 * Projekt.....: rs2322tcp
 * Datei.......: internal/client/device.go
 * Copyright (C) 2026 Dieter Lang
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * Beschreibung:
 * Zuordnung eines lokalen virtuellen Ports zu einem vom Server gemeldeten
 * Remote-Gerät.
 * ============================================================================
 */
package client

import (
	"fmt"

	"git.lang-dieter.de/rs2322tcp/internal/config"
	"git.lang-dieter.de/rs2322tcp/internal/transport"
)

///////////////////////////////////////////////////////////////////////////////
// Remote device lookup
///////////////////////////////////////////////////////////////////////////////

// findRemoteDevice finds the server-provided device information matching
// the remote device ID configured for a local virtual port.
//
// The caller uses the returned RemoteDeviceInfo to open the session-specific
// TCP data connection.
func findRemoteDevice(
	virtualPort config.VirtualPortConfig,
	devices []transport.RemoteDeviceInfo,
) (transport.RemoteDeviceInfo, error) {
	if virtualPort.RemoteDevice == "" {
		return transport.RemoteDeviceInfo{}, fmt.Errorf(
			"remote device is empty for virtual port %q",
			virtualPort.Port,
		)
	}

	var found *transport.RemoteDeviceInfo

	for i := range devices {
		device := &devices[i]

		if device.ID != virtualPort.RemoteDevice {
			continue
		}

		if found != nil {
			return transport.RemoteDeviceInfo{}, fmt.Errorf(
				"remote device %q is ambiguous",
				virtualPort.RemoteDevice,
			)
		}

		found = device
	}

	if found == nil {
		return transport.RemoteDeviceInfo{}, fmt.Errorf(
			"remote device %q not found",
			virtualPort.RemoteDevice,
		)
	}

	return *found, nil
}