/*
 * ============================================================================
 * Projekt.....: rs2322tcp
 * Datei.......: internal/client/runtime_integration_test.go
 * Copyright (C) 2026 Dieter Lang
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * Beschreibung:
 * Integrationstest für die clientseitige Runtime mit einem echten
 * rs2322tcp-Server und einem virtuellen seriellen Client-Port.
 *
 * Der Test verwendet die vorhandene virtuelle serielle Test-Schnittstelle
 * aus integration_test.go und prüft den vollständigen Datenweg:
 *
 *     /dev/ttyUSB100
 *            ↕
 *         Bridge
 *            ↕
 *     TCP Data Connection
 *            ↕
 *     rs2322tcp Server
 *            ↕
 *       serielle PTY
 *
 * Beide Übertragungsrichtungen werden geprüft.
 * ============================================================================
 */
package client_test

import (
	"net"
	"os"
	"path/filepath"
	"testing"
	"time"

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

///////////////////////////////////////////////////////////////////////////////
// Tests
///////////////////////////////////////////////////////////////////////////////

func TestClientRuntimeSerialIntegration(t *testing.T) {
	serialA, serialB, cleanup := startVirtualSerialPair(t)
	defer cleanup()

	const virtualPortPath = "/dev/ttyUSB100"

	home, err := os.UserHomeDir()
	if err != nil {
		t.Fatalf("get user home directory: %v", err)
	}

	internalPortPath := filepath.Join(
		home,
		".rs2322tcp",
		"virtual",
		"ttyUSB100",
	)

	////////////////////////////////////////////////////////////////////////////
	// Server
	////////////////////////////////////////////////////////////////////////////

	controlProbe, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("find free control port: %v", err)
	}

	controlPort := controlProbe.Addr().(*net.TCPAddr).Port

	if err := controlProbe.Close(); err != nil {
		t.Fatalf("close control probe: %v", err)
	}

	serverConfig := &config.ServerConfig{
		Listen: config.ListenConfig{
			Address: "127.0.0.1",
			Port:    controlPort,
		},
		HardwareErrorResponse: testHardwareErrorResponse,
		Devices: []config.DeviceConfig{
			{
				ID:         "radio",
				Name:       "Funkgerät",
				SerialPort: serialA,
				BaudRate:   9600,
				DataBits:   8,
				Parity:     "none",
				StopBits:   1,
			},
		},
	}

	srv, err := server.NewControlServer(serverConfig)
	if err != nil {
		t.Fatalf("NewControlServer() failed: %v", err)
	}

	if err := srv.Listen(); err != nil {
		t.Fatalf("server Listen() failed: %v", err)
	}
	defer srv.Close()

	go func() {
		_ = srv.Serve()
	}()

	////////////////////////////////////////////////////////////////////////////
	// Client and Runtime
	////////////////////////////////////////////////////////////////////////////

	c, err := client.New(srv.Addr().String())
	if err != nil {
		t.Fatalf("client.New() failed: %v", err)
	}
	defer c.Close()

	manager := client.NewVirtualPortManager(
		config.VirtualPortRangeConfig{
			First: 100,
			Last:  199,
		},
	)

	runtime, err := client.NewRuntime(c, manager)
	if err != nil {
		t.Fatalf("NewRuntime() failed: %v", err)
	}
	defer runtime.Close()

	clientConfig := config.ClientConfig{
		Server: config.ServerConnectionConfig{
			Address: "127.0.0.1",
			Port:    controlPort,
		},
		VirtualPorts: []config.VirtualPortConfig{
			{
				Port:         virtualPortPath,
				RemoteDevice: "radio",
			},
		},
	}

	////////////////////////////////////////////////////////////////////////////
	// Start Runtime
	////////////////////////////////////////////////////////////////////////////

	runtimeDone := make(chan error, 1)

	go func() {
		runtimeDone <- runtime.Run(clientConfig)
	}()

	////////////////////////////////////////////////////////////////////////////
	// Open client-side virtual serial endpoint
	////////////////////////////////////////////////////////////////////////////

	var virtualSerial *os.File

	deadline := time.Now().Add(2 * time.Second)

	for {
		virtualSerial, err = os.OpenFile(
			internalPortPath,
			os.O_RDWR,
			0,
		)
		if err == nil {
			break
		}

		if time.Now().After(deadline) {
			t.Fatalf(
				"timeout opening virtual serial port %s: %v",
				internalPortPath,
				err,
			)
		}

		time.Sleep(10 * time.Millisecond)
	}

	defer virtualSerial.Close()

	////////////////////////////////////////////////////////////////////////////
	// Client virtual serial -> Bridge -> Server -> serial
	////////////////////////////////////////////////////////////////////////////

	clientMessage := []byte("hello from runtime")

	if _, err := virtualSerial.Write(clientMessage); err != nil {
		t.Fatalf(
			"write to virtual serial port failed: %v",
			err,
		)
	}

	serialReceived := make([]byte, len(clientMessage))

	serialPeer, err := os.OpenFile(
		serialB,
		os.O_RDWR,
		0,
	)
	if err != nil {
		t.Fatalf(
			"open server serial peer: %v",
			err,
		)
	}
	defer serialPeer.Close()

	readExactWithTimeout(
		t,
		serialPeer,
		serialReceived,
		2*time.Second,
	)

	if string(serialReceived) != string(clientMessage) {
		t.Fatalf(
			"serial received %q, want %q",
			string(serialReceived),
			string(clientMessage),
		)
	}

	////////////////////////////////////////////////////////////////////////////
	// Server serial -> Bridge -> Client virtual serial
	////////////////////////////////////////////////////////////////////////////

	serverMessage := []byte("hello from server")

	if _, err := serialPeer.Write(serverMessage); err != nil {
		t.Fatalf(
			"write to server serial peer failed: %v",
			err,
		)
	}

	clientReceived := make([]byte, len(serverMessage))

	readExactWithTimeout(
		t,
		virtualSerial,
		clientReceived,
		2*time.Second,
	)

	if string(clientReceived) != string(serverMessage) {
		t.Fatalf(
			"virtual serial received %q, want %q",
			string(clientReceived),
			string(serverMessage),
		)
	}

	///////////////////////////////////////////////////////////////////////////////
	// Terminate Runtime
	///////////////////////////////////////////////////////////////////////////////

	if err := virtualSerial.Close(); err != nil {
		t.Fatalf("close virtual serial port: %v", err)
	}

	if err := runtime.Close(); err != nil {
		t.Fatalf("close runtime: %v", err)
	}

	select {
	case <-runtimeDone:
		// Runtime termination is expected after Runtime.Close().
	case <-time.After(2 * time.Second):
		t.Fatal("runtime did not terminate after Runtime.Close()")
	}
}