Automatic preset importing

Thanks to @syntaxticsugr for helping with the preset detection regexes.

README.md

@@ -58,9 +58,9 @@ It contains many useability enhancements and all the major fixes needed to run `
   but is usually not needed either.
   You can still combine `ViPER4Android` with other audio mods
   using [`Audio Modification Library`](https://github.com/Magisk-Modules-Repo/aml) if you want to.
-* **Automatic VDC and IRS import** \
-  If you have [bought a VDC file](https://t.me/vdcservice) or downloaded an IRS file
-  which now lays in your Download directory,
+* **Automatic VDC, IRS and preset import** \
+  If you have [bought a VDC file](https://t.me/vdcservice)
+  or downloaded an IRS file or preset,
   you don't have to copy it over manually.
   The installer automatically finds and copies them to the correct place
   for `ViPER4Android` to find them

magiskmodule/customize.sh

@@ -75,6 +75,27 @@ if $CUSTOM_IRS_FOUND; then
   done
 fi
 
+presetCompatible() {
+  local file="$1"
+  grep -q '<int name="32775" value="[12]" />' < "$file" || return 1
+  grep -q '<string name="65540;65541;65542">.*</string>' < "$file" || return 1
+  return 0
+}
+
+mkdir -p "$FOLDER"/Preset
+CUSTOM_PRESET_FILES=$(find $SDCARD -name '*.xml' -not -path "$SDCARD/Android/*")
+if [ -n "$CUSTOM_PRESET_FILES" ]; then
+  ui_print "- Copying custom preset files"
+  for file in $CUSTOM_PRESET_FILES; do
+    ! presetCompatible "$file" && continue
+    ui_print "    $file"
+    cp -f "$file" "$FOLDER"/Preset
+  done
+else
+  ui_print "- Skipping preset copy"
+  ui_print "    custom preset files have not been found"
+fi
+
 ui_print "- Patching system audio files"
 AUDIO_EFFECTS_FILES="$( \
   find -H \