Ads Dynamite: Inject user-agent into app's shared preferences

package com.google.android.gms.dynamite.descriptors.com.google.android.gms.ads.dynamite;

import android.annotation.SuppressLint;

import android.content.Context;

import android.content.ContextWrapper;

import android.webkit.WebSettings;

import android.content.SharedPreferences;

import android.util.Log;

import androidx.annotation.Keep;

import java.util.Locale;

import static android.os.Build.DEVICE;

import static android.os.Build.DISPLAY;

import static android.os.Build.VERSION.RELEASE;

@Keep

public class ModuleDescriptor {

    public static final String MODULE_ID = "com.google.android.gms.ads.dynamite";

    public static final int MODULE_VERSION = 230500001;

    private static final String TAG = "AdsDynamiteModule";

    /**

     * The ads module might try to access the user agent, requiring initialization on the main thread,

     * which may result in deadlocks when invoked from any other thread. This only happens with microG,

     * because we don't use the highly privileged SELinux Sandbox that regular Play Services uses

     * (which allows apps to read the user-agent from Play Services instead of the WebView). To prevent

     * the issue we pre-emptively initialize the WebView.

     * the issue we pre-emptively write a user agent in the local storage of the app.

     */

    public static void init(Context context) {

        do {

            try {

                injectUserAgentSharedPreference(context);

            } catch (Exception e) {

            }

            if (context instanceof ContextWrapper) {

            context = ((ContextWrapper) context).getBaseContext();

                Context baseContext = ((ContextWrapper) context).getBaseContext();

                if (context == baseContext) break;

                context = baseContext;

            } else {

                break;

            }

        } while (context != null);

    }

    /**

     * @return A user-agent representing a browser on the current device.

     */

    private static String buildDefaultUserAgent() {

        StringBuilder sb = new StringBuilder();

        sb.append("Mozilla/5.0 (Linux; U; Android");

        if (RELEASE != null) sb.append(" ").append(RELEASE);

        sb.append("; ").append(Locale.getDefault());

        if (DEVICE != null) {

            sb.append("; ").append(DEVICE);

            if (DISPLAY != null) sb.append(" Build/").append(DISPLAY);

        }

        sb.append(") AppleWebKit/533 Version/4.0 Safari/533");

        return sb.toString();

    }

    @SuppressLint("ApplySharedPref")

    private static void injectUserAgentSharedPreference(Context context) {

        SharedPreferences preferences = context.getSharedPreferences("admob_user_agent", Context.MODE_PRIVATE);

        if (!preferences.contains("user_agent")) {

            preferences.edit().putString("user_agent", buildDefaultUserAgent()).commit();

            Log.d(TAG, "Injected admob_user_agent into package " + context.getPackageName());

        }

        WebSettings.getDefaultUserAgent(context);

    }

}