From de0a37d356b0d74e1cc2cf9768a3e245abf03e33 Mon Sep 17 00:00:00 2001
From: Greyson Parrelli <greyson@signal.org>
Date: Thu, 30 Mar 2023 17:17:10 -0400
Subject: [PATCH] Fix possible dangling thread records.

---
 .../helpers/SignalDatabaseMigrations.kt       |  7 ++-
 .../V181_ThreadTableForeignKeyCleanup.kt      | 53 +++++++++++++++++++
 2 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 app/src/main/java/org/thoughtcrime/securesms/database/helpers/migration/V181_ThreadTableForeignKeyCleanup.kt

diff --git a/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SignalDatabaseMigrations.kt b/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SignalDatabaseMigrations.kt
index 4b2a967f277..369eb71e3d6 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SignalDatabaseMigrations.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SignalDatabaseMigrations.kt
@@ -36,6 +36,7 @@ import org.thoughtcrime.securesms.database.helpers.migration.V177_MessageSendLog
 import org.thoughtcrime.securesms.database.helpers.migration.V178_ReportingTokenColumnMigration
 import org.thoughtcrime.securesms.database.helpers.migration.V179_CleanupDanglingMessageSendLogMigration
 import org.thoughtcrime.securesms.database.helpers.migration.V180_RecipientNicknameMigration
+import org.thoughtcrime.securesms.database.helpers.migration.V181_ThreadTableForeignKeyCleanup
 
 /**
  * Contains all of the database migrations for [SignalDatabase]. Broken into a separate file for cleanliness.
@@ -44,7 +45,7 @@ object SignalDatabaseMigrations {
 
   val TAG: String = Log.tag(SignalDatabaseMigrations.javaClass)
 
-  const val DATABASE_VERSION = 180
+  const val DATABASE_VERSION = 181
 
   @JvmStatic
   fun migrate(context: Application, db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
@@ -175,6 +176,10 @@ object SignalDatabaseMigrations {
     if (oldVersion < 180) {
       V180_RecipientNicknameMigration.migrate(context, db, oldVersion, newVersion)
     }
+
+    if (oldVersion < 181) {
+      V181_ThreadTableForeignKeyCleanup.migrate(context, db, oldVersion, newVersion)
+    }
   }
 
   @JvmStatic
diff --git a/app/src/main/java/org/thoughtcrime/securesms/database/helpers/migration/V181_ThreadTableForeignKeyCleanup.kt b/app/src/main/java/org/thoughtcrime/securesms/database/helpers/migration/V181_ThreadTableForeignKeyCleanup.kt
new file mode 100644
index 00000000000..88a3731a7c5
--- /dev/null
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/helpers/migration/V181_ThreadTableForeignKeyCleanup.kt
@@ -0,0 +1,53 @@
+package org.thoughtcrime.securesms.database.helpers.migration
+
+import android.app.Application
+import net.zetetic.database.sqlcipher.SQLiteDatabase
+import org.signal.core.util.Stopwatch
+import org.signal.core.util.logging.Log
+
+/**
+ * We saw evidence (via failed backup restores) that some people have recipients in their thread table that do not exist in the recipient table.
+ * This is likely the result of a bad past migration, since a foreign key is in place. Cleaning it up now.
+ */
+object V181_ThreadTableForeignKeyCleanup : SignalDatabaseMigration {
+
+  val TAG = Log.tag(V181_ThreadTableForeignKeyCleanup::class.java)
+
+  override fun migrate(context: Application, db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
+    val stopwatch = Stopwatch("deletes")
+
+    try {
+      val threadDeleteCount = db.delete("thread", "recipient_id NOT IN (SELECT _id FROM recipient)", null)
+      Log.i(TAG, "Deleted $threadDeleteCount threads.")
+      stopwatch.split("threads")
+
+      if (threadDeleteCount == 0) {
+        Log.w(TAG, "No threads deleted. Finishing early.")
+        return
+      }
+
+      val messageDeleteCount = db.delete("message", "thread_id NOT IN (SELECT _id FROM thread)", null)
+      Log.i(TAG, "Deleted $messageDeleteCount messages.")
+      stopwatch.split("messages")
+
+      if (messageDeleteCount == 0) {
+        Log.w(TAG, "No messages deleted. Finishing early.")
+        return
+      }
+
+      val storySendDeleteCount = db.delete("story_sends", "message_id NOT IN (SELECT _id FROM message)", null)
+      Log.i(TAG, "Deleted $storySendDeleteCount story_sends.")
+      stopwatch.split("story_sends")
+
+      val reactionDeleteCount = db.delete("reaction", "message_id NOT IN (SELECT _id FROM message)", null)
+      Log.i(TAG, "Deleted $reactionDeleteCount reactions.")
+      stopwatch.split("reactions")
+
+      val callDeleteCount = db.delete("call", "message_id NOT IN (SELECT _id FROM message)", null)
+      Log.i(TAG, "Deleted $callDeleteCount calls.")
+      stopwatch.split("calls")
+    } finally {
+      stopwatch.stop(TAG)
+    }
+  }
+}