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

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