Add an option to set how the app is started

src/cli/android-znca-api-server-frida.ts

@@ -38,6 +38,10 @@ export function builder(yargs: Argv<ParentArguments>) {
         describe: 'Path to the frida-server executable on the device',
         type: 'string',
         default: '/data/local/tmp/frida-server',
+    }).option('start-method', {
+        describe: 'Method to ensure the app is running (one of "spawn", "none", "activity", "service")',
+        type: 'string',
+        default: 'service',
     }).option('strict-validate', {
         describe: 'Validate data exactly matches the format that would be generated by Nintendo\'s Android app',
         type: 'boolean',
@@ -55,6 +59,21 @@ export function builder(yargs: Argv<ParentArguments>) {
 
 type Arguments = YargsArguments<ReturnType<typeof builder>>;
 
+enum StartMethod {
+    /** Spawn the app process with Frida, even if the app is already running (recommended) */
+    SPAWN,
+    /** Start the app's main activity using the am command */
+    ACTIVITY,
+    /**
+     * Start a background service using the am command (default)
+     * This tricks Android into not killing the app for some reason and allows the process to be started
+     * in the background.
+     */
+    SERVICE,
+    /** Do not attempt to start the app - if it is not already running the server will fail */
+    NONE,
+}
+
 interface PackageInfo {
     name: string;
     version: string;
@@ -101,12 +120,18 @@ interface FResult {
 }
 
 export async function handler(argv: ArgumentsCamelCase<Arguments>) {
+    const start_method =
+        argv.startMethod === 'spawn' ? StartMethod.SPAWN :
+        argv.startMethod === 'activity' ? StartMethod.ACTIVITY :
+        argv.startMethod === 'service' ? StartMethod.SERVICE :
+        StartMethod.NONE;
+
     await mkdirp(script_dir);
 
     const storage = await initStorage(argv.dataPath);
-    await setup(argv);
+    await setup(argv, start_method);
 
-    let {session, script} = await attach(argv);
+    let {session, script} = await attach(argv, start_method);
     let ready: Promise<void> | null = null;
 
     let api: {
@@ -144,7 +169,7 @@ export async function handler(argv: ArgumentsCamelCase<Arguments>) {
 
         debug('Attempting to reconnect to the device');
 
-        ready = attach(argv).then(async a => {
+        ready = attach(argv, start_method).then(async a => {
             ready = null;
             session = a.session;
             script = a.script;
@@ -406,12 +431,14 @@ export async function handler(argv: ArgumentsCamelCase<Arguments>) {
 
 const frida_script = `
 const perform = callback => new Promise((rs, rj) => {
-    Java.scheduleOnMainThread(() => {
-        try {
-            rs(callback());
-        } catch (err) {
-            rj(err);
-        }
+    Java.perform(() => {
+        Java.scheduleOnMainThread(() => {
+            try {
+                rs(callback());
+            } catch (err) {
+                rj(err);
+            }
+        });
     });
 });
 
@@ -520,6 +547,7 @@ rpc.exports = {
 
 const setup_script = (options: {
     frida_server_path: string;
+    start_method: StartMethod;
 }) => `#!/system/bin/sh
 
 # Ensure frida-server is running
@@ -534,10 +562,16 @@ fi
 
 sleep 1
 
+${(options.start_method === StartMethod.ACTIVITY ? `
+# Ensure the app is running
+echo "Starting com.nintendo.znca in foreground"
+am start-activity com.nintendo.znca/com.nintendo.coral.ui.boot.BootActivity
+` : options.start_method === StartMethod.SERVICE ? `
 # Ensure the app is running
 echo "Starting com.nintendo.znca"
 am start-foreground-service com.nintendo.znca/com.google.firebase.messaging.FirebaseMessagingService
 am start-service com.nintendo.znca/com.google.firebase.messaging.FirebaseMessagingService
+` : '').trim()}
 
 if [ "$?" != "0" ]; then
     echo "Failed to start com.nintendo.znca"
@@ -554,7 +588,7 @@ echo "Releasing wake lock"
 echo androidzncaapiserver > /sys/power/wake_unlock
 `;
 
-async function setup(argv: ArgumentsCamelCase<Arguments>) {
+async function setup(argv: ArgumentsCamelCase<Arguments>, start_method: StartMethod) {
     debug('Connecting to device %s', argv.device);
     let co = execFileSync('adb', [
         'connect',
@@ -583,11 +617,12 @@ async function setup(argv: ArgumentsCamelCase<Arguments>) {
 
     await pushScript(argv.device, setup_script({
         frida_server_path: argv.fridaServerPath,
+        start_method,
     }), '/data/local/tmp/android-znca-api-server-setup.sh');
     await pushScript(argv.device, shutdown_script, '/data/local/tmp/android-znca-api-server-shutdown.sh');
 }
 
-async function attach(argv: ArgumentsCamelCase<Arguments>) {
+async function attach(argv: ArgumentsCamelCase<Arguments>, start_method: StartMethod) {
     const frida = await import('frida');
     type Session = import('frida').Session;
 
@@ -602,11 +637,17 @@ async function attach(argv: ArgumentsCamelCase<Arguments>) {
     let session: Session;
 
     try {
-        const process = await device.getProcess('Nintendo Switch Online');
+        const process = start_method === StartMethod.SPAWN ?
+            {pid: await device.spawn('com.nintendo.znca')} :
+            await device.getProcess('Nintendo Switch Online');
 
         debug('process', process);
 
         session = await device.attach(process.pid);
+
+        if (start_method === StartMethod.SPAWN) {
+            await device.resume(session.pid);
+        }
     } catch (err) {
         debug('Could not attach to process', err);
         throw new Error('Failed to attach to process');