core: keep chat item edit history (#2410)

src/Simplex/Chat/Migrations/M20230505_chat_item_versions.hs

@@ -0,0 +1,29 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Chat.Migrations.M20230505_chat_item_versions where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20230505_chat_item_versions :: Query
+m20230505_chat_item_versions =
+  [sql|
+CREATE TABLE chat_item_versions ( -- contains versions only for edited chat items, including current version
+  chat_item_version_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  chat_item_id INTEGER NOT NULL REFERENCES chat_items ON DELETE CASCADE,
+  msg_content TEXT NOT NULL,
+  item_version_ts TEXT NOT NULL,
+  created_at TEXT NOT NULL DEFAULT(datetime('now')),
+  updated_at TEXT NOT NULL DEFAULT(datetime('now'))
+);
+
+CREATE INDEX idx_chat_item_versions_chat_item_id ON chat_item_versions(chat_item_id);
+|]
+
+down_m20230505_chat_item_versions :: Query
+down_m20230505_chat_item_versions =
+  [sql|
+DROP INDEX idx_chat_item_versions_chat_item_id;
+
+DROP TABLE chat_item_versions;
+|]

src/Simplex/Chat/Migrations/chat_schema.sql

@@ -454,6 +454,15 @@ CREATE TABLE msg_delivery_events(
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
 );
+CREATE TABLE chat_item_versions(
+  -- contains versions only for edited chat items, including current version
+  chat_item_version_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  chat_item_id INTEGER NOT NULL REFERENCES chat_items ON DELETE CASCADE,
+  msg_content TEXT NOT NULL,
+  item_version_ts TEXT NOT NULL,
+  created_at TEXT NOT NULL DEFAULT(datetime('now')),
+  updated_at TEXT NOT NULL DEFAULT(datetime('now'))
+);
 CREATE INDEX contact_profiles_index ON contact_profiles(
   display_name,
   full_name
@@ -595,3 +604,6 @@ CREATE INDEX idx_extra_xftp_file_descriptions_user_id ON extra_xftp_file_descrip
 CREATE INDEX idx_xftp_file_descriptions_user_id ON xftp_file_descriptions(
   user_id
 );
+CREATE INDEX idx_chat_item_versions_chat_item_id ON chat_item_versions(
+  chat_item_id
+);