Billing/Billing/Billing.Android/MainActivity.cs

using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.Runtime;
using Android.OS;
using Android.Net;
using Android.Provider;
using Android.Database;

namespace Billing.Droid
{
    [Activity(
        Label = "@string/applabel",
        Icon = "@mipmap/icon",
        RoundIcon = "@mipmap/icon_round",
        Theme = "@style/MainTheme",
        ScreenOrientation = ScreenOrientation.Portrait,
        ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation | ConfigChanges.UiMode | ConfigChanges.ScreenLayout | ConfigChanges.SmallestScreenSize)]
    public class MainActivity : Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);

            string url;
            if (Intent.ActionView.Equals(Intent.Action) && Intent.Data is Uri uri)
            {
                if (uri.Authority == "org.tsanie.billing.shortcuts")
                {
                    url = uri.Path;
                }
                else
                {
                    url = GetFilePath(BaseContext, uri);
                }
            }
            else
            {
                url = null;
            }
            Xamarin.Essentials.Platform.Init(this, savedInstanceState);
            Xamarin.Forms.Forms.Init(this, savedInstanceState);
            Xamarin.FormsMaps.Init(this, savedInstanceState);
            LoadApplication(new App(url));
        }

        public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
        {
            Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);

            base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
        }

        private string GetFilePath(Context context, Uri uri)
        {
            if (DocumentsContract.IsDocumentUri(context, uri))
            {
                Uri contentUri;
                string[] split;
                switch (uri.Authority)
                {
                    case "com.android.externalstorage.documents":
                        split = DocumentsContract.GetDocumentId(uri).Split(':');
                        if (split[0] == "primary")
                        {
                            var external = ExternalCacheDir.Path;
                            external = external[..external.IndexOf("/Android/")];
                            return external + "/" + split[1];
                        }
                        break;

                    case "com.android.providers.downloads.documents":
                        contentUri = ContentUris.WithAppendedId(
                            Uri.Parse("content://downloads/public_downloads"),
                            long.Parse(DocumentsContract.GetDocumentId(uri)));
                        return GetDataColumn(context, contentUri, null, null);

                    case "com.android.providers.media.documents":
                        split = DocumentsContract.GetDocumentId(uri).Split(':');
                        contentUri = split[0] switch
                        {
                            "image" => MediaStore.Images.Media.ExternalContentUri,
                            "video" => MediaStore.Video.Media.ExternalContentUri,
                            "audio" => MediaStore.Audio.Media.ExternalContentUri,
                            _ => null
                        };
                        return GetDataColumn(context, contentUri, "_id=?", new[] { split[1] });
                }
            }
            else if (uri.Scheme == "content")
            {
                if (uri.Authority == "com.speedsoftware.rootexplorer.fileprovider")
                {
                    var path = uri.Path;
                    if (path.StartsWith("/root/"))
                    {
                        return path[5..];
                    }
                    return path;
                }
                return GetDataColumn(context, uri, null, null);
            }
            else if (uri.Scheme == "file")
            {
                return uri.Path;
            }
            return null;
        }

        private string GetDataColumn(Context context, Uri uri, string selection, string[] selectionArgs)
        {
            ICursor cursor = null;
            try
            {
                cursor = context.ContentResolver.Query(uri, new[] { "_data" }, selection, selectionArgs, null);
                if (cursor != null && cursor.MoveToFirst())
                {
                    var index = cursor.GetColumnIndexOrThrow("_data");
                    return cursor.GetString(index);
                }
            }
            finally
            {
                if (cursor != null)
                {
                    cursor.Close();
                }
            }
            return null;
        }
    }
}