From dd378738e31a3577c40cd81b727dd689b19f1796 Mon Sep 17 00:00:00 2001
From: agnostic-apollo <agnosticapollo@gmail.com>
Date: Thu, 17 Mar 2022 04:42:28 +0500
Subject: [PATCH] Fixed: Add `media-*` symlinks to `Android/media` for all
 storages and `external-0` symlink to `Android/media` of primary storage

The `~/external-0` and `~/media-0` should point to primary storage and `1+` to others, possibly portable sd cards.

Note that one can make portable sd card as primary storage as well instead of internal sd card with adoptable storage, which then links it to `/storage/emulated`, so the concept of `internal` and `external` sd card does not apply to primary storage for all cases.

https://android.stackexchange.com/questions/214233/how-to-free-internal-storage-by-moving-data-or-using-symlink-bind-mount-with-a/214706#214706

https://android.stackexchange.com/questions/217741/how-to-bind-mount-a-folder-inside-sdcard-with-correct-permissions/217936#217936

https://android.stackexchange.com/questions/205430/what-is-storage-emulated-0/205494#205494

https://source.android.com/devices/storage/adoptable

```
$ ls -l storage | cut -d ' ' -f 9-

audiobooks -> /storage/emulated/0/Audiobooks
dcim -> /storage/emulated/0/DCIM
documents -> /storage/emulated/0/Documents
downloads -> /storage/emulated/0/Download
external-0 -> /storage/emulated/0/Android/data/com.termux/files
external-1 -> /storage/XXXX-XXXX/Android/data/com.termux/files
media-0 -> /storage/emulated/0/Android/media/com.termux
media-1 -> /storage/XXXX-XXXX/Android/media/com.termux
movies -> /storage/emulated/0/Movies
music -> /storage/emulated/0/Music
pictures -> /storage/emulated/0/Pictures
podcasts -> /storage/emulated/0/Podcasts
shared -> /storage/emulated/0

```

Closes #2481
---
 .../java/com/termux/app/TermuxInstaller.java  | 27 ++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/com/termux/app/TermuxInstaller.java b/app/src/main/java/com/termux/app/TermuxInstaller.java
index d9980f61..c3d112ad 100644
--- a/app/src/main/java/com/termux/app/TermuxInstaller.java
+++ b/app/src/main/java/com/termux/app/TermuxInstaller.java
@@ -286,6 +286,7 @@ final class TermuxInstaller {
 
                     Logger.logInfo(LOG_TAG, "Setting up storage symlinks at ~/storage/shared, ~/storage/downloads, ~/storage/dcim, ~/storage/pictures, ~/storage/music and ~/storage/movies for directories in \"" + Environment.getExternalStorageDirectory().getAbsolutePath() + "\".");
 
+                    // Get primary storage root "/storage/emulated/0" symlink
                     File sharedDir = Environment.getExternalStorageDirectory();
                     Os.symlink(sharedDir.getAbsolutePath(), new File(storageDir, "shared").getAbsolutePath());
 
@@ -315,9 +316,17 @@ final class TermuxInstaller {
                         Os.symlink(audiobooksDir.getAbsolutePath(), new File(storageDir, "audiobooks").getAbsolutePath());
                     }
 
-                    final File[] dirs = context.getExternalFilesDirs(null);
-                    if (dirs != null && dirs.length > 1) {
-                        for (int i = 1; i < dirs.length; i++) {
+                    // Dir 0 should ideally be for primary storage
+                    // https://cs.android.com/android/platform/superproject/+/android-12.0.0_r32:frameworks/base/core/java/android/app/ContextImpl.java;l=818
+                    // https://cs.android.com/android/platform/superproject/+/android-12.0.0_r32:frameworks/base/core/java/android/os/Environment.java;l=219
+                    // https://cs.android.com/android/platform/superproject/+/android-12.0.0_r32:frameworks/base/core/java/android/os/Environment.java;l=181
+                    // https://cs.android.com/android/platform/superproject/+/android-12.0.0_r32:frameworks/base/services/core/java/com/android/server/StorageManagerService.java;l=3796
+                    // https://cs.android.com/android/platform/superproject/+/android-7.0.0_r36:frameworks/base/services/core/java/com/android/server/MountService.java;l=3053
+
+                    // Create "Android/data/com.termux" symlinks
+                    File[] dirs = context.getExternalFilesDirs(null);
+                    if (dirs != null && dirs.length > 0) {
+                        for (int i = 0; i < dirs.length; i++) {
                             File dir = dirs[i];
                             if (dir == null) continue;
                             String symlinkName = "external-" + i;
@@ -326,6 +335,18 @@ final class TermuxInstaller {
                         }
                     }
 
+                    // Create "Android/media/com.termux" symlinks
+                    dirs = context.getExternalMediaDirs();
+                    if (dirs != null && dirs.length > 0) {
+                        for (int i = 0; i < dirs.length; i++) {
+                            File dir = dirs[i];
+                            if (dir == null) continue;
+                            String symlinkName = "media-" + i;
+                            Logger.logInfo(LOG_TAG, "Setting up storage symlinks at ~/storage/" + symlinkName + " for \"" + dir.getAbsolutePath() + "\".");
+                            Os.symlink(dir.getAbsolutePath(), new File(storageDir, symlinkName).getAbsolutePath());
+                        }
+                    }
+
                     Logger.logInfo(LOG_TAG, "Storage symlinks created successfully.");
                 } catch (Exception e) {
                     Logger.logErrorAndShowToast(context, LOG_TAG, e.getMessage());