How can you determine which messages from history should be deleted?

The determination of messages from history that should be deleted depends on the application's context and data retention requirements. Typically, the following criteria are considered:

• Message Age: messages older than a certain period (e.g., older than 30 days) are deleted.
• Storage Volume: if the history takes up too much space, the oldest or least important messages are deleted.
• Message Status: for example, only read or archived messages are deleted.
• Privacy Policy: some messages may be deleted upon user request or in accordance with legislation.

In Android applications, this can be implemented through periodic database or cache cleanup, using timers or events, for example, during app startup or when reaching a size limit.

Example in Kotlin for deleting messages older than 30 days:

val thirtyDaysAgo = System.currentTimeMillis() - 30L * 24 * 60 * 60 * 1000
val messagesToDelete = database.messageDao().getMessagesOlderThan(thirtyDaysAgo)
database.messageDao().delete(messagesToDelete)