core: restrict to delete user contact and display name (#3822)

simplex-chat.cabal

@@ -136,6 +136,7 @@ library
       Simplex.Chat.Migrations.M20240122_indexes
       Simplex.Chat.Migrations.M20240214_redirect_file_id
       Simplex.Chat.Migrations.M20240222_app_settings
+      Simplex.Chat.Migrations.M20240226_users_restrict
       Simplex.Chat.Mobile
       Simplex.Chat.Mobile.File
       Simplex.Chat.Mobile.Shared

src/Simplex/Chat/Migrations/M20240226_users_restrict.hs

@@ -0,0 +1,30 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Chat.Migrations.M20240226_users_restrict where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20240226_users_restrict :: Query
+m20240226_users_restrict =
+  [sql|
+PRAGMA writable_schema=1;
+
+UPDATE sqlite_master
+SET sql = replace(sql, 'ON DELETE CASCADE', 'ON DELETE RESTRICT')
+WHERE name = 'users' AND type = 'table';
+
+PRAGMA writable_schema=0;
+|]
+
+down_m20240226_users_restrict :: Query
+down_m20240226_users_restrict =
+  [sql|
+PRAGMA writable_schema=1;
+
+UPDATE sqlite_master
+SET sql = replace(sql, 'ON DELETE RESTRICT', 'ON DELETE CASCADE')
+WHERE name = 'users' AND type = 'table';
+
+PRAGMA writable_schema=0;
+|]

src/Simplex/Chat/Migrations/chat_schema.sql

@@ -22,7 +22,7 @@ CREATE TABLE contact_profiles(
 );
 CREATE TABLE users(
   user_id INTEGER PRIMARY KEY,
-  contact_id INTEGER NOT NULL UNIQUE REFERENCES contacts ON DELETE CASCADE
+  contact_id INTEGER NOT NULL UNIQUE REFERENCES contacts ON DELETE RESTRICT
   DEFERRABLE INITIALLY DEFERRED,
   local_display_name TEXT NOT NULL UNIQUE,
   active_user INTEGER NOT NULL DEFAULT 0,
@@ -37,7 +37,7 @@ CREATE TABLE users(
   user_member_profile_updated_at TEXT, -- 1 for active user
   FOREIGN KEY(user_id, local_display_name)
   REFERENCES display_names(user_id, local_display_name)
-  ON DELETE CASCADE
+  ON DELETE RESTRICT
   ON UPDATE CASCADE
   DEFERRABLE INITIALLY DEFERRED
 );

src/Simplex/Chat/Store/Migrations.hs

@@ -100,6 +100,7 @@ import Simplex.Chat.Migrations.M20240115_block_member_for_all
 import Simplex.Chat.Migrations.M20240122_indexes
 import Simplex.Chat.Migrations.M20240214_redirect_file_id
 import Simplex.Chat.Migrations.M20240222_app_settings
+import Simplex.Chat.Migrations.M20240226_users_restrict
 import Simplex.Messaging.Agent.Store.SQLite.Migrations (Migration (..))
 
 schemaMigrations :: [(String, Query, Maybe Query)]
@@ -199,7 +200,8 @@ schemaMigrations =
     ("20240115_block_member_for_all", m20240115_block_member_for_all, Just down_m20240115_block_member_for_all),
     ("20240122_indexes", m20240122_indexes, Just down_m20240122_indexes),
     ("20240214_redirect_file_id", m20240214_redirect_file_id, Just down_m20240214_redirect_file_id),
-    ("20240222_app_settings", m20240222_app_settings, Just down_m20240222_app_settings)
+    ("20240222_app_settings", m20240222_app_settings, Just down_m20240222_app_settings),
+    ("20240226_users_restrict", m20240226_users_restrict, Just down_m20240226_users_restrict)
   ]
 
 -- | The list of migrations in ascending order by date