Ability to retrieve message history, example improved

The example has been improved with more options (such as print
message history), and the TelegramClient now can retrieve the
message history from any given point in time or other offsets

main.py

@@ -2,6 +2,8 @@ import tl_generator
 from tl.telegram_client import TelegramClient
 from utils.helpers import load_settings
 
+from datetime import datetime
+
 
 if __name__ == '__main__':
     if not tl_generator.tlobjects_exist():
@@ -27,28 +29,51 @@ if __name__ == '__main__':
             code = input('Enter the code you just received: ')
             client.make_auth(settings['user_phone'], code)
 
-        # After that, load the top dialogs and show a list
-        # We use zip(*list_of_tuples) to pair all the elements together,
-        # hence being able to return a new list of each triple pair!
-        # See http://stackoverflow.com/a/12974504/4759433 for a better explanation
-        dialogs, displays, inputs = zip(*client.get_dialogs(8))
-
-        for i, display in enumerate(displays):
-            i += 1  # 1-based index for normies
-            print('{}. {}'.format(i, display))
-
-        # Let the user decide who they want to talk to
-        i = int(input('Who do you want to send messages to?: ')) - 1
-        dialog = dialogs[i]
-        display = displays[i]
-        input_peer = inputs[i]
-
-        # And start a while loop!
-        print('You are now sending messages to "{}". Type "!q" when you want to exit.'.format(display))
+        # Enter a while loop to chat as long as the user wants
         while True:
-            msg = input('Enter a message: ')
-            if msg == '!q':
+            # Retrieve the top dialogs
+            dialogs, displays, inputs = client.get_dialogs(8)
+
+            # Display them so the user can choose
+            for i, display in enumerate(displays):
+                i += 1  # 1-based index for normies
+                print('{}. {}'.format(i, display))
+
+            # Let the user decide who they want to talk to
+            i = int(input('Who do you want to send messages to (0 to exit)?: ')) - 1
+            if i == -1:
                 break
-            client.send_message(input_peer, msg, markdown=True, no_web_page=True)
+
+            # Retrieve the selected user
+            dialog = dialogs[i]
+            display = displays[i]
+            input_peer = inputs[i]
+
+            # Show some information
+            print('You are now sending messages to "{}". Available commands:'.format(display))
+            print('  !q: Quits the current chat.')
+            print('  !h: prints the latest messages (message History) of the chat.')
+
+            # And start a while loop to chat
+            while True:
+                msg = input('Enter a message: ')
+                # Quit
+                if msg == '!q':
+                    break
+
+                # History
+                elif msg == '!h':
+                    # First retrieve the messages and some information
+                    total_count, messages, senders = client.get_message_history(input_peer, limit=10)
+                    # Iterate over all (in reverse order so the latest appears the last in the console)
+                    # and print them in "[hh:mm] Sender: Message" text format
+                    for msg, sender in zip(reversed(messages), reversed(senders)):
+                        name = sender.first_name if sender else '???'
+                        date = datetime.fromtimestamp(msg.date)
+                        print('[{}:{}] {}: {}'.format(date.hour, date.minute, name, msg.message))
+
+                # Send chat message
+                else:
+                    client.send_message(input_peer, msg, markdown=True, no_web_page=True)
 
         print('Thanks for trying the interactive example! Exiting.')