// <copyright file="AdbServer.cs" company="The Android Open Source Project, Ryan Conrad, Quamotion, yungd1plomat, wherewhere">

// Copyright (c) The Android Open Source Project, Ryan Conrad, Quamotion, yungd1plomat, wherewhere. All rights reserved.

// </copyright>

using System;

using System.Diagnostics;

using System.Globalization;

using System.Net;

using System.Net.Sockets;

using System.Threading;

namespace AdvancedSharpAdbClient

{

/// <summary>

/// <para>Provides methods for interacting with the adb server. The adb server must be running for

/// the rest of the <c>Managed.Adb</c> library to work.</para>

/// <para>The adb server is a background process that runs on the host machine.

/// Its purpose if to sense the USB ports to know when devices are attached/removed,

/// as well as when emulator instances start/stop. The ADB server is really one

/// giant multiplexing loop whose purpose is to orchestrate the exchange of data

/// between clients and devices.</para>

/// </summary>

[DebuggerDisplay($"{{{nameof(GetType)}().{nameof(Type.ToString)}(),nq}} \\{{ {nameof(EndPoint)} = {{{nameof(EndPoint)}}}, {nameof(CachedAdbPath)} = {{{nameof(CachedAdbPath)}}} }}")]

public partial class AdbServer : IAdbServer, IInternalCloneable<AdbServer>

{

/// <summary>

/// The minimum version of <c>adb.exe</c> that is supported by this library.

/// </summary>

public static readonly Version RequiredAdbVersion = new(1, 0, 20);

/// <summary>

/// The error code that is returned by the <see cref="SocketException"/> when the connection is refused.

/// </summary>

/// <remarks>No connection could be made because the target computer actively refused it.This usually

/// results from trying to connect to a service that is inactive on the foreign host—that is,

/// one with no server application running. <seealso href="https://msdn.microsoft.com/en-us/library/ms740668.aspx"/></remarks>

public const int ConnectionRefused = 10061;

/// <summary>

/// The error code that is returned by the <see cref="SocketException"/> when the connection was reset by the peer.

/// </summary>

/// <remarks>An existing connection was forcibly closed by the remote host. This normally results if the peer application on the

/// remote host is suddenly stopped, the host is rebooted, the host or remote network interface is disabled, or the remote

/// host uses a hard close. This error may also result if a connection was broken due to keep-alive activity detecting

/// a failure while one or more operations are in progress. <seealso href="https://msdn.microsoft.com/en-us/library/ms740668.aspx"/></remarks>

public const int ConnectionReset = 10054;

/// <summary>

/// The <see cref="Func{EndPoint, IAdbSocket}"/> to create <see cref="IAdbSocket"/>.

/// </summary>

protected readonly Func<EndPoint, IAdbSocket> AdbSocketFactory;

/// <summary>

/// Gets or sets a function that returns a new instance of a class that implements the

/// <see cref="IAdbCommandLineClient"/> interface, that can be used to interact with the

/// <c>adb.exe</c> command line client.

/// </summary>

protected readonly Func<string, IAdbCommandLineClient> AdbCommandLineClientFactory;

/// <summary>

/// Initializes a new instance of the <see cref="AdbServer"/> class.

/// </summary>

public AdbServer()

: this(AdbClient.AdbServerEndPoint, Factories.AdbSocketFactory, Factories.AdbCommandLineClientFactory)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="AdbServer"/> class.

/// </summary>

/// <param name="adbClient">A connection to an adb server.</param>

public AdbServer(IAdbClient adbClient)

: this(adbClient.EndPoint, Factories.AdbSocketFactory, Factories.AdbCommandLineClientFactory)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="AdbServer"/> class.

/// </summary>

/// <param name="endPoint">The <see cref="System.Net.EndPoint"/> at which the adb server is listening.</param>

public AdbServer(EndPoint endPoint)

: this(endPoint, Factories.AdbSocketFactory, Factories.AdbCommandLineClientFactory)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="AdbServer"/> class.

/// </summary>

/// <param name="host">The host address at which the adb server is listening.</param>

/// <param name="port">The port at which the adb server is listening.</param>

public AdbServer(string host, int port)

: this(Extensions.CreateDnsEndPoint(host, port), Factories.AdbSocketFactory, Factories.AdbCommandLineClientFactory)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="AdbServer"/> class.

/// </summary>

/// <param name="adbClient">A connection to an adb server.</param>

/// <param name="adbSocketFactory">The <see cref="Func{EndPoint, IAdbSocket}"/> to create <see cref="IAdbSocket"/>.</param>

/// <param name="adbCommandLineClientFactory">The <see cref="Func{String, IAdbCommandLineClient}"/> to create <see cref="IAdbCommandLineClient"/>.</param>

public AdbServer(IAdbClient adbClient, Func<EndPoint, IAdbSocket> adbSocketFactory, Func<string, IAdbCommandLineClient> adbCommandLineClientFactory)

: this(adbClient.EndPoint, adbSocketFactory, adbCommandLineClientFactory)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="AdbServer"/> class.

/// </summary>

/// <param name="endPoint">The <see cref="System.Net.EndPoint"/> at which the adb server is listening.</param>

/// <param name="adbSocketFactory">The <see cref="Func{EndPoint, IAdbSocket}"/> to create <see cref="IAdbSocket"/>.</param>

/// <param name="adbCommandLineClientFactory">The <see cref="Func{String, IAdbCommandLineClient}"/> to create <see cref="IAdbCommandLineClient"/>.</param>

public AdbServer(EndPoint endPoint, Func<EndPoint, IAdbSocket> adbSocketFactory, Func<string, IAdbCommandLineClient> adbCommandLineClientFactory)

{

ArgumentNullException.ThrowIfNull(endPoint);

if (endPoint is not (IPEndPoint or DnsEndPoint))

{

throw new NotSupportedException("Only TCP endpoints are supported");

}

EndPoint = endPoint;

AdbSocketFactory = adbSocketFactory ?? throw new ArgumentNullException(nameof(adbSocketFactory));

AdbCommandLineClientFactory = adbCommandLineClientFactory ?? throw new ArgumentNullException(nameof(adbCommandLineClientFactory));

}

/// <summary>

/// Initializes a new instance of the <see cref="AdbServer"/> class.

/// </summary>

/// <param name="host">The host address at which the adb server is listening.</param>

/// <param name="port">The port at which the adb server is listening.</param>

/// <param name="adbSocketFactory">The <see cref="Func{EndPoint, IAdbSocket}"/> to create <see cref="IAdbSocket"/>.</param>

/// <param name="adbCommandLineClientFactory">The <see cref="Func{String, IAdbCommandLineClient}"/> to create <see cref="IAdbCommandLineClient"/>.</param>

public AdbServer(string host, int port, Func<EndPoint, IAdbSocket> adbSocketFactory, Func<string, IAdbCommandLineClient> adbCommandLineClientFactory)

: this(Extensions.CreateDnsEndPoint(host, port), adbSocketFactory, adbCommandLineClientFactory)

{

}

/// <summary>

/// Initializes a new instance of the <see cref="AdbServer"/> class.

/// </summary>

/// <param name="adbSocketFactory">The <see cref="Func{EndPoint, IAdbSocket}"/> to create <see cref="IAdbSocket"/>.</param>

/// <param name="adbCommandLineClientFactory">The <see cref="Func{String, IAdbCommandLineClient}"/> to create <see cref="IAdbCommandLineClient"/>.</param>

public AdbServer(Func<EndPoint, IAdbSocket> adbSocketFactory, Func<string, IAdbCommandLineClient> adbCommandLineClientFactory)

: this(AdbClient.AdbServerEndPoint, adbSocketFactory, adbCommandLineClientFactory)

{

}

/// <summary>

/// Gets or sets the default instance of the <see cref="IAdbServer"/> interface.

/// </summary>

public static IAdbServer Instance

{

get => field ??= new AdbServer();

set;

}

/// <summary>

/// <see langword="true"/> if is starting adb server; otherwise, <see langword="false"/>.

/// </summary>

protected static bool IsStarting { get; set; }

/// <summary>

/// The path to the adb server. Cached from calls to <see cref="StartServer(string, bool)"/>. Used when restarting

/// the server to figure out where adb is located.

/// </summary>

protected string? CachedAdbPath { get; set; }

/// <summary>

/// Gets the <see cref="System.Net.EndPoint"/> at which the adb server is listening.

/// </summary>

public EndPoint EndPoint { get; init; }

/// <inheritdoc/>

public StartServerResult StartServer(string adbPath, bool restartServerIfNewer = false)

{

if (IsStarting) { return StartServerResult.Starting; }

try

{

AdbServerStatus serverStatus = GetStatus();

Version? commandLineVersion = null;

IAdbCommandLineClient commandLineClient = AdbCommandLineClientFactory(adbPath);

if (commandLineClient.CheckAdbFileExists(adbPath))

{

CachedAdbPath = adbPath;

commandLineVersion = commandLineClient.GetVersion().AdbVersion;

}

// If the server is running, and no adb path is provided, check if we have the minimum version

if (adbPath == null)

{

return !serverStatus.IsRunning

? throw new AdbException("The adb server is not running, but no valid path to the adb.exe executable was provided. The adb server cannot be started.")

: serverStatus.Version >= RequiredAdbVersion

? StartServerResult.AlreadyRunning

: throw new AdbException($"The adb daemon is running an outdated version ${commandLineVersion}, but not valid path to the adb.exe executable was provided. A more recent version of the adb server cannot be started.");

}

if (serverStatus.IsRunning)

{

if (serverStatus.Version < RequiredAdbVersion

|| (restartServerIfNewer && serverStatus.Version < commandLineVersion))

{

StopServer();

commandLineClient.StartServer(Timeout.Infinite);

return StartServerResult.RestartedOutdatedDaemon;

}

else

{

return StartServerResult.AlreadyRunning;

}

}

else

{

commandLineClient.StartServer(Timeout.Infinite);

return StartServerResult.Started;

}

}

finally

{

IsStarting = false;

}

}

/// <inheritdoc/>

public StartServerResult RestartServer() => StartServer(CachedAdbPath!, true);

/// <inheritdoc/>

public StartServerResult RestartServer(string adbPath) =>

string.IsNullOrWhiteSpace(adbPath) ? RestartServer() : StartServer(adbPath, true);

/// <inheritdoc/>

public void StopServer()

{

using IAdbSocket socket = CreateAdbSocket();

socket.SendAdbRequest("host:kill");

// The host will immediately close the connection after the kill

// command has been sent; no need to read the response.

}

/// <inheritdoc/>

public AdbServerStatus GetStatus()

{

// Try to connect to a running instance of the adb server

try

{

using IAdbSocket socket = CreateAdbSocket();

socket.SendAdbRequest("host:version");

AdbResponse response = socket.ReadAdbResponse();

string version = socket.ReadString();

int versionCode = int.Parse(version, NumberStyles.HexNumber);

return new AdbServerStatus(true, new Version(1, 0, versionCode));

}

catch (SocketException ex)

{

if (ex.SocketErrorCode == SocketError.ConnectionRefused)

{

return new AdbServerStatus(false, null);

}

else

{

// An unexpected exception occurred; re-throw the exception

throw;

}

}

}

/// <summary>

/// Creates a new <see cref="AdbClient"/> object with the specified <see cref="EndPoint"/>.

/// </summary>

/// <returns>A new <see cref="AdbClient"/> object with the specified <see cref="EndPoint"/>.</returns>

public IAdbSocket CreateAdbSocket() => AdbSocketFactory(EndPoint);

/// <inheritdoc/>

public override string ToString() => $"The {GetType()} communicate with adb at '{EndPoint}'.";

/// <summary>

/// Creates a new <see cref="AdbServer"/> object that is a copy of the current instance with new <see cref="EndPoint"/>.

/// </summary>

/// <param name="endPoint">The new <see cref="EndPoint"/> to use.</param>

/// <returns>A new <see cref="AdbServer"/> object that is a copy of this instance with new <see cref="EndPoint"/>.</returns>

public virtual AdbServer Clone(EndPoint endPoint) => new(endPoint, AdbSocketFactory, AdbCommandLineClientFactory);

/// <inheritdoc/>

public AdbServer Clone() => Clone(EndPoint);

/// <inheritdoc/>

object ICloneable.Clone() => Clone(EndPoint);

}

}