[Android] Introduce AndroidApkFileReplacerTask task (#44993)

tools-local/tasks/mobile.tasks/AndroidAppBuilder/AndroidApkFileReplacerTask.cs

@@ -0,0 +1,38 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.IO;
+using System.Linq;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+
+public class AndroidApkFileReplacerTask : Task
+{
+    [Required]
+    public string FilePath { get; set; } = ""!;
+
+    [Required]
+    public string OutputDir { get; set; } = ""!;
+
+    public string? AndroidSdk { get; set; }
+
+    public string? MinApiLevel { get; set; }
+
+    public string? BuildToolsVersion { get; set; }
+
+    public string? KeyStorePath { get; set; }
+
+
+    public override bool Execute()
+    {
+        var apkBuilder = new ApkBuilder();
+        apkBuilder.OutputDir = OutputDir;
+        apkBuilder.AndroidSdk = AndroidSdk;
+        apkBuilder.MinApiLevel = MinApiLevel;
+        apkBuilder.BuildToolsVersion = BuildToolsVersion;
+        apkBuilder.KeyStorePath = KeyStorePath;
+        apkBuilder.ReplaceFileInApk(FilePath);
+        return true;
+    }
+}

tools-local/tasks/mobile.tasks/AndroidAppBuilder/AndroidAppBuilder.cs

@@ -23,9 +23,10 @@ public class AndroidAppBuilderTask : Task
     [Required]
     public string RuntimeIdentifier { get; set; } = ""!;
 
-    public string? ProjectName { get; set; }
+    [Required]
+    public string OutputDir { get; set; } = ""!;
 
-    public string? OutputDir { get; set; }
+    public string? ProjectName { get; set; }
 
     public string? AndroidSdk { get; set; }
 
@@ -78,20 +79,13 @@ public override bool Execute()
         return true;
     }
 
-    private string DetermineAbi()
-    {
-        switch (RuntimeIdentifier)
+    private string DetermineAbi() =>
+        RuntimeIdentifier switch
         {
-            case "android-x86":
-                return "x86";
-            case "android-x64":
-                return "x86_64";
-            case "android-arm":
-                return "armeabi-v7a";
-            case "android-arm64":
-                return "arm64-v8a";
-            default:
-                throw new ArgumentException(RuntimeIdentifier + " is not supported for Android");
-        }
-    }
+            "android-x86" => "x86",
+            "android-x64" => "x86_64",
+            "android-arm" => "armeabi-v7a",
+            "android-arm64" => "arm64-v8a",
+            _ => throw new ArgumentException($"{RuntimeIdentifier} is not supported for Android"),
+        };
 }

tools-local/tasks/mobile.tasks/AndroidAppBuilder/ApkBuilder.cs

@@ -16,7 +16,7 @@ public class ApkBuilder
     public string? MinApiLevel { get; set; }
     public string? BuildApiLevel { get; set; }
     public string? BuildToolsVersion { get; set; }
-    public string? OutputDir { get; set; }
+    public string OutputDir { get; set; } = ""!;
     public bool StripDebugSymbols { get; set; }
     public string? NativeMainSource { get; set; }
     public string? KeyStorePath { get; set; }
@@ -50,9 +50,6 @@ public class ApkBuilder
                 ProjectName = Path.GetFileNameWithoutExtension(entryPointLib);
         }
 
-        if (string.IsNullOrEmpty(OutputDir))
-            OutputDir = Path.Combine(sourceDir, "bin-" + abi);
-
         if (ProjectName.Contains(' '))
             throw new ArgumentException($"ProjectName='{ProjectName}' shouldn't not contain spaces.");
 
@@ -134,7 +131,6 @@ public class ApkBuilder
         string apksigner = Path.Combine(buildToolsFolder, "apksigner");
         string androidJar = Path.Combine(AndroidSdk, "platforms", "android-" + BuildApiLevel, "android.jar");
         string androidToolchain = Path.Combine(AndroidNdk, "build", "cmake", "android.toolchain.cmake");
-        string keytool = "keytool";
         string javac = "javac";
         string cmake = "cmake";
         string zip = "zip";
@@ -244,30 +240,66 @@ public class ApkBuilder
         // we don't need the unaligned one any more
         File.Delete(apkFile);
 
-        // 5. Generate key
+        // 5. Generate key (if needed) & sign the apk
+        SignApk(alignedApk, apksigner);
+
+        Utils.LogInfo($"\nAPK size: {(new FileInfo(alignedApk).Length / 1000_000.0):0.#} Mb.\n");
+
+        return (alignedApk, packageId);
+    }
+
+    private void SignApk(string apkPath, string apksigner)
+    {
+        string defaultKey = Path.Combine(OutputDir, "debug.keystore");
+        string signingKey = string.IsNullOrEmpty(KeyStorePath) ?
+            defaultKey : Path.Combine(KeyStorePath, "debug.keystore");
 
-        string signingKey = Path.Combine(OutputDir, "debug.keystore");
-        if (!string.IsNullOrEmpty(KeyStorePath))
-            signingKey = Path.Combine(KeyStorePath, "debug.keystore");
         if (!File.Exists(signingKey))
         {
-            Utils.RunProcess(keytool, "-genkey -v -keystore debug.keystore -storepass android -alias " +
+            Utils.RunProcess("keytool", "-genkey -v -keystore debug.keystore -storepass android -alias " +
                 "androiddebugkey -keypass android -keyalg RSA -keysize 2048 -noprompt " +
                 "-dname \"CN=Android Debug,O=Android,C=US\"", workingDir: OutputDir, silent: true);
         }
-        else
+        else if (Path.GetFullPath(signingKey) != Path.GetFullPath(defaultKey))
         {
             File.Copy(signingKey, Path.Combine(OutputDir, "debug.keystore"));
         }
+        Utils.RunProcess(apksigner, $"sign --min-sdk-version {MinApiLevel} --ks debug.keystore " +
+            $"--ks-pass pass:android --key-pass pass:android {apkPath}", workingDir: OutputDir);
+    }
 
-        // 6. Sign APK
+    public void ReplaceFileInApk(string file)
+    {
+        if (string.IsNullOrEmpty(AndroidSdk))
+            AndroidSdk = Environment.GetEnvironmentVariable("ANDROID_SDK_ROOT");
 
-        Utils.RunProcess(apksigner, $"sign --min-sdk-version {MinApiLevel} --ks debug.keystore " +
-            $"--ks-pass pass:android --key-pass pass:android {alignedApk}", workingDir: OutputDir);
+        if (string.IsNullOrEmpty(AndroidSdk) || !Directory.Exists(AndroidSdk))
+            throw new ArgumentException($"Android SDK='{AndroidSdk}' was not found or incorrect (can be set via ANDROID_SDK_ROOT envvar).");
 
-        Utils.LogInfo($"\nAPK size: {(new FileInfo(alignedApk).Length / 1000_000.0):0.#} Mb.\n");
+        if (string.IsNullOrEmpty(BuildToolsVersion))
+            BuildToolsVersion = GetLatestBuildTools(AndroidSdk);
 
-        return (alignedApk, packageId);
+        if (string.IsNullOrEmpty(MinApiLevel))
+            MinApiLevel = DefaultMinApiLevel;
+
+        string buildToolsFolder = Path.Combine(AndroidSdk, "build-tools", BuildToolsVersion);
+        string aapt = Path.Combine(buildToolsFolder, "aapt");
+        string apksigner = Path.Combine(buildToolsFolder, "apksigner");
+
+        string apkPath = "";
+        if (string.IsNullOrEmpty(ProjectName))
+            apkPath = Directory.GetFiles(Path.Combine(OutputDir, "bin"), "*.apk").First();
+        else
+            apkPath = Path.Combine(OutputDir, "bin", $"{ProjectName}.apk");
+
+        if (!File.Exists(apkPath))
+            throw new Exception($"{apkPath} was not found");
+
+        Utils.RunProcess(aapt, $"remove -v bin/{Path.GetFileName(apkPath)} {file}", workingDir: OutputDir);
+        Utils.RunProcess(aapt, $"add -v bin/{Path.GetFileName(apkPath)} {file}", workingDir: OutputDir);
+
+        // we need to re-sign the apk
+        SignApk(apkPath, apksigner);
     }
 
     /// <summary>