#!/bin/bash
#
# Android backups using ADB
#

# Basic parameters
BASENAME="`basename $0`"
NAME="$1"

# Backup user files
function android_backup_files {
  if [ ! -z "$1" ]; then
    USER_ID="$1"
  else
    USER_ID="0"
  fi

  BASE="/storage"
  EMULATED="$BASE/emulated/$USER_ID"

  # Files: full copy
  #adb pull $EMULATED files/

  # Remove multimedia cache from backup
  #rm -rf files/Music

  # Files: full basic copy
  #adb shell ls -1 $EMULATED | grep -v ^Music | while read file; do
  #  adb pull $EMULATED/$file files/
  #done

  mkdir -p files/$USER_ID

  # Files: incremental basic copy
  for file in `adb shell ls -1 $EMULATED | grep -v '^Music'`; do
    adb-sync --delete --reverse $EMULATED/$file files/$USER_ID/
  done

  # SD cards
  for file in `adb shell ls -1 $BASE | grep -v "^self" | grep -v "^emulated"`; do
    adb-sync --delete --reverse $BASE/$file files/
  done
}

# Restore user files
function android_restore_files {
  if [ ! -z "$1" ]; then
    USER_ID="$1"
  else
    USER_ID="0"
  fi

  BASE="/storage/emulated/$USER_ID"

  # Files: complete copy
  #for file in `ls files`; do
  #  adb push files/$file $base/$file
  #done

  # Files: incremental copy
  for file in `ls $WORK/android-backup-$NAME-$DATE/files/$USER_ID`; do
    adb-sync --delete $WORK/android-backup-$NAME-$DATE/files/$USER_ID/$file/ $BASE/$file/
  done
}

function android_backup_backup {
  # Check previous backup
  if [ -d "$STORAGE/$DATE" ]; then
    echo "backup for $DATE already exists"
    exit 1
  fi

  # Work folder
  mkdir -p $WORK/android-backup-$NAME-$DATE && cd $WORK/android-backup-$NAME-$DATE &> /dev/null || exit 1

  # If you have a previous backup you might want to use it with hardlinks
  if [ -e "$STORAGE/$PREVIOUS/files" ]; then
    sudo cp -alf $STORAGE/$PREVIOUS/files files
  fi

  # Ensure we have a files folder
  mkdir -p files

  # Contacts. Export also to a .vcf directly from the contact app
  adb-export.sh           -e    content://com.android.contacts/contacts
  adb shell content query --uri content://com.android.contacts/contacts > contacts.rows

  # User and system information
  adb shell dumpsys user > users.dump
  adb shell dumpsys      > system.dump

  # Configurations
  # Right now this is possible only for the main user
  # https://stackoverflow.com/questions/50978678/adb-backup-restore-multiple-users-apps
  # https://android.stackexchange.com/questions/43043/non-root-backup-with-multiple-users-non-owner-or-secondary-users
  #adb backup -apk -shared -all
  adb backup -all

  # Backup each user files
  for USER in $USERS; do
    android_backup_files $USER
  done

  # Move backup to storage
  cd .. &> /dev/null && sudo mv android-backup-$NAME-$DATE $STORAGE/$DATE
}

function android_backup_restore {
  # Check for previous backups
  if [ -z "$PREVIOUS" ]; then
    echo "$BASENAME: no previous backups for device $NAME"
    exit 1
  fi

  # Copy files to workfolder
  mkdir -p $WORK && sudo cp -alf $STORAGE/$PREVIOUS $WORK/android-backup-$NAME-$DATE && chown -R `whoami`. android-backup-$NAME-$DATE

  # Check if copy was successful
  if [ ! -e "$WORK/android-backup-$NAME-$DATE" ]; then
    echo "$BASENAME: could not copy from $STORAGE/$PREVIOUS"
    exit 1
  fi

  # Restore each user files
  if [ -e "$WORK/android-backup-$NAME-$DATE" ]; then
    for USER in $USERS; do
      android_restore_files $USER
    done
  fi

  # Configurations
  adb restore android-backup-$NAME-$DATE/backup.ab

  # Cleanup
  rm -rf android-backup-$NAME-$DATE
}

# Syntax check
if [ -z "$NAME" ]; then
  echo "$BASENAME: missing phone name"
  exit 1
fi

# Additional parameters
WORK="/var/data/load"
DATE="`date +%Y%m%d`"
STORAGE="/var/backups/remote/$NAME.`facter domain`/"
USERS="`adb shell pm list users | grep '{' | cut -d '{' -f 2 | cut -d ':' -f 1 | xargs`"

# Dest folder and previous backups
sudo mkdir -p $STORAGE
PREVIOUS="`sudo ls -1 $STORAGE | tac | head -n 1`"

# Dispatch
if [ "$BASENAME" == "android-backup-adb" ]; then
  android_backup_backup
else
  android_backup_restore
fi