[Idea] Rework app "log" files

[Tiefkuehlpizze]

One thing, that bothered me for a while is the structure and information in the "log" files of the backups.

Let's start with the simplest thing: The name. It's not a log in terms of logging. It's a properties file. Let's change that.

Let's talk about the structure:

    "label": "dict.cc",
    "versionName": "10.7",
    "versionCode": 100700,
    "packageName": "cc.dict.dictcc",
    "sourceDir": "",
    "dataDir": "\/data\/user\/0\/cc.dict.dictcc",
    "deviceProtectedDataDir": "\/data\/user_de\/0\/cc.dict.dictcc",
    "lastBackupMillis": 1594380999312,
    "isEncrypted": false,
    "isSystem": false,
    "backupMode": 2
}

First point out, what makes sense and why:

• label - Display it in UI, so the user knows what app hides behind the package name
• versionName and versionCode - good to know
• lastBackupMillis - the age of the backup. Very useful.
• isSystem - For the sake of simplicity, we just store it
• isEncrypted - We could try to guess, but why take the risk?

Questionable attributes:

• packageName - a bit redundant, it's already the directory's name
• splitApks - We could just assume all apks in the directory must be installed, important is only to know which is the main apk, but maybe it's good to know the exact names…

Poor attributes:

• sourceDir - it's even empty in my example
• dataDir + devicesProtectedDataDir - package manager knows it better for sure + it not multi user compatible

Bugged Attributes:

• backupMode - it stores what happened last time, so if I backed up an app with data and after a few days just the data, oabx would only offer to restore the data. It should be separated what the backup contains

What we are missing/ideas to add:

• Maybe a format version. The oabx is changing a lot. Add it now or wait until we have the first change in the format, that needs to know about a change
• Encryption Cipher - to make this more dynamic and offer stronger encryption on newer Android versions
• Some information about the backup source (for later, to inform the user that the backup comes from another device/architecture/Android version and might not be compatible)

And just more order in the backup directory and in preparation of multiple backup versions (and users?): We should talk about the directory structure. It should be simple but with a defined structure:

• /sdcard/OABX
  -- package.Name
  --- UserId (0 is main user, 10 may be work profile)
  ---- YYYY-MM-DD-HH-mm-ss
  ----- app
  ----- data
  ----- deviceProtectedData
  ----- externalData
  ----- obbData
  ----- backup.properties

On the UI, the user can then choose which version to restore and in case of app+data, it should calculate a matching backup combination.

2020-07-07-15-00-00: app + data
2020-07-06-15-00-00: data
2020-07-05-15-00-00: app
2020-07-04-15-00-00: data
2020-07-03-15-00-00: data
2020-07-02-15-00-00: app + data
2020-07-01-15-00-00: app + data

If I select 2020-07-06-15-00-00 for app + data restore, it should offer to restore a combination of 2020-07-06-15-00-00 (data) and 2020-07-05-15-00-00 (app).

Just an idea…

For reference: A properties file from the same app from Titanium Backup

#Sun Jul 12 23:40:42 GMT+02:00 2020
sys_ro.product.model=ONEPLUS A5010
app_is_forward_locked=0
has_prefsdata=0
app_version_name=10.7
sys_ro.build.date.utc=1593396966
has_prefsdata_jpu=0
app_apk_codec=GZIP
app_version_code=100700
app_label=dict.cc
app_gui_icon=<truncated>
sys_ro.build.version.release=10
sys_ro.serialno=xxxxxx
has_dbdata=0
app_apk_md5=6e289b5d5416865ceb68bd5ad1574fc3
app_is_system=0
generation=1
sys_ro.build.description=OnePlus5T-user 10 QKQ1.191014.012 2006012146 release-keys
app_apk_location=internal
app_gui_label=dict.cc 10.7```