terminal: command to show last N items in a chat (#582)

src/Simplex/Chat.hs

@@ -560,6 +560,10 @@ processChatCommand = \case
     editedItemId <- withStore $ \st -> getGroupChatItemIdByText st user groupId (Just localDisplayName) (safeDecodeUtf8 editedMsg)
     let mc = MCText $ safeDecodeUtf8 msg
     processChatCommand $ APIUpdateChatItem CTGroup groupId editedItemId mc
+  LastMessages (Just c@(ChatName cType _)) count -> do
+    chatId <- getChatId c
+    CRLastMessages . aChatItems . chat <$> (processChatCommand . APIGetChat cType chatId $ CPLast count)
+  LastMessages Nothing _count -> pure $ chatCmdError "not implemented"
   -- old file protocol
   -- SendFile cName f -> withUser $ \User {userId} -> do
   --   contactId <- withStore $ \st -> getContactIdByName st userId cName
@@ -655,6 +659,11 @@ processChatCommand = \case
     -- use function below to make commands "synchronous"
     procCmd :: m ChatResponse -> m ChatResponse
     procCmd = id
+    getChatId :: ChatName -> m Int64
+    getChatId (ChatName cType name) = withUser $ \user@User {userId} -> case cType of
+      CTDirect -> withStore $ \st -> getContactIdByName st userId name
+      CTGroup -> withStore $ \st -> getGroupIdByName st user name
+      _ -> throwChatError $ CECommandError "not supported"
     connectViaContact :: UserId -> ConnectionRequestUri 'CMContact -> Profile -> m ChatResponse
     connectViaContact userId cReq profile = withChatLock $ do
       let cReqHash = ConnReqUriHash . C.sha256Hash $ strEncode cReq
@@ -1957,6 +1966,7 @@ chatCommandP =
     <|> ("\\@" <|> "\\ @") *> (DeleteMessage <$> displayName <* A.space <*> A.takeByteString)
     <|> ("!@" <|> "! @") *> (EditMessage <$> displayName <* A.space <*> (quotedMsg <|> pure "") <*> A.takeByteString)
     <|> "/feed " *> (SendMessageBroadcast <$> A.takeByteString)
+    <|> ("/tail" <|> "/t") *> (LastMessages <$> optional chatNameP <*> msgCountP)
     <|> ("/file #" <|> "/f #") *> (SendGroupFile <$> displayName <* A.space <*> filePath)
     <|> ("/file_v2 #" <|> "/f_v2 #") *> (SendGroupFileInv <$> displayName <* A.space <*> filePath)
     <|> ("/file @" <|> "/file " <|> "/f @" <|> "/f ") *> (SendFile <$> displayName <* A.space <*> filePath)
@@ -2024,6 +2034,8 @@ chatCommandP =
         <|> (" admin" $> GRAdmin)
         <|> (" member" $> GRMember)
         <|> pure GRAdmin
+    chatNameP = A.space *> (ChatName <$> chatTypeP <*> displayName)
+    msgCountP = A.space *> A.decimal <|> pure 10
 
 adminContactReq :: ConnReqContact
 adminContactReq =

src/Simplex/Chat/Controller.hs

@@ -146,6 +146,7 @@ data ChatCommand
   | SendGroupMessageQuote {groupName :: GroupName, contactName_ :: Maybe ContactName, quotedMsg :: ByteString, message :: ByteString}
   | DeleteGroupMessage GroupName ByteString
   | EditGroupMessage {groupName :: ContactName, editedMsg :: ByteString, message :: ByteString}
+  | LastMessages (Maybe ChatName) Int
   | SendFile ContactName FilePath
   | SendFileInv ContactName FilePath
   | SendGroupFile GroupName FilePath
@@ -166,6 +167,7 @@ data ChatResponse
   | CRChatRunning
   | CRApiChats {chats :: [AChat]}
   | CRApiChat {chat :: AChat}
+  | CRLastMessages {chatItems :: [AChatItem]}
   | CRApiParsedMarkdown {formattedText :: Maybe MarkdownList}
   | CRUserSMPServers {smpServers :: [SMPServer]}
   | CRNewChatItem {chatItem :: AChatItem}

src/Simplex/Chat/Messages.hs

@@ -41,6 +41,9 @@ import Simplex.Messaging.Util ((<$?>))
 data ChatType = CTDirect | CTGroup | CTContactRequest | CTContactConnection
   deriving (Show, Generic)
 
+data ChatName = ChatName ChatType Text
+  deriving (Show)
+
 instance ToJSON ChatType where
   toJSON = J.genericToJSON . enumJSON $ dropPrefix "CT"
   toEncoding = J.genericToEncoding . enumJSON $ dropPrefix "CT"
@@ -198,6 +201,11 @@ instance ToJSON AChatItem where
 data JSONAnyChatItem c d = JSONAnyChatItem {chatInfo :: ChatInfo c, chatItem :: ChatItem c d}
   deriving (Generic)
 
+aChatItems :: AChat -> [AChatItem]
+aChatItems (AChat ct Chat {chatInfo, chatItems}) = map aChatItem chatItems
+  where
+    aChatItem (CChatItem md ci) = AChatItem ct md chatInfo ci
+
 instance MsgDirectionI d => ToJSON (JSONAnyChatItem c d) where
   toJSON = J.genericToJSON J.defaultOptions
   toEncoding = J.genericToEncoding J.defaultOptions

src/Simplex/Chat/View.hs

@@ -50,6 +50,7 @@ responseToView testView = \case
   CRApiParsedMarkdown ft -> [plain . bshow $ J.encode ft]
   CRUserSMPServers smpServers -> viewSMPServers smpServers testView
   CRNewChatItem (AChatItem _ _ chat item) -> viewChatItem chat item
+  CRLastMessages chatItems -> concatMap (\(AChatItem _ _ chat item) -> viewChatItem chat item) chatItems
   CRChatItemStatusUpdated _ -> []
   CRChatItemUpdated (AChatItem _ _ chat item) -> viewItemUpdate chat item
   CRChatItemDeleted (AChatItem _ _ chat deletedItem) (AChatItem _ _ _ toItem) -> viewItemDelete chat deletedItem toItem