amethyst/app/src/main/java/com/vitorpamplona/amethyst/EncryptedStorage.kt

package com.vitorpamplona.amethyst

import androidx.security.crypto.EncryptedSharedPreferences
import androidx.security.crypto.MasterKey

object EncryptedStorage {
    private const val PREFERENCES_NAME = "secret_keeper"

    fun prefsFileName(npub: String? = null): String {
        return if (npub == null) PREFERENCES_NAME else "${PREFERENCES_NAME}_$npub"
    }

    fun preferences(npub: String? = null): EncryptedSharedPreferences {
        val context = Amethyst.instance
        val masterKey: MasterKey = MasterKey.Builder(context, MasterKey.DEFAULT_MASTER_KEY_ALIAS)
            .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
            .build()

        val preferencesName = prefsFileName(npub)

        return EncryptedSharedPreferences.create(
            context,
            preferencesName,
            masterKey,
            EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
            EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
        ) as EncryptedSharedPreferences
    }
}