Improve history handling

- Try to keep at least 3 messages from each channel in the history
- Use post processed messages for the history, instead of the raw
  messages from the openai API

tests/test_ai.py

@@ -1,4 +1,7 @@
 import unittest
+import tempfile
+import os
+import pickle
 from fjerkroa_bot import AIMessage, AIResponse
 from .test_main import TestBotBase
 
@@ -73,6 +76,51 @@ You always try to say something positive about the current day and the Fjærkroa
         self.assertAIResponse(response, AIResponse('test', True, 'something', None, False), scmp=lambda a, b: type(a) == str and len(a) > 5)
         print(f"\n{self.bot.airesponder.history}")
 
+    def test_update_history(self) -> None:
+        updater = self.bot.airesponder
+        updater.history = []
+        updater.history_file = None
+
+        question = {"channel": "test_channel", "content": "What is the meaning of life?"}
+        answer = {"channel": "test_channel", "content": "42"}
+
+        # Test case 1: Limit set to 2
+        updater.update_history(question, answer, 2)
+        self.assertEqual(updater.history, [question, answer])
+
+        # Test case 2: Limit set to 4, check limit enforcement (deletion)
+        new_question = {"channel": "test_channel", "content": "What is AI?"}
+        new_answer = {"channel": "test_channel", "content": "Artificial Intelligence"}
+        updater.update_history(new_question, new_answer, 3)
+        self.assertEqual(updater.history, [answer, new_question, new_answer])
+
+        # Test case 3: Limit set to 4, check limit enforcement (deletion)
+        other_question = {"channel": "other_channel", "content": "What is XXX?"}
+        other_answer = {"channel": "other_channel", "content": "Tripple X"}
+        updater.update_history(other_question, other_answer, 4)
+        self.assertEqual(updater.history, [new_question, new_answer, other_question, other_answer])
+
+        # Test case 4: Limit set to 4, check limit enforcement (deletion)
+        next_question = {"channel": "other_channel", "content": "What is YYY?"}
+        next_answer = {"channel": "other_channel", "content": "Tripple Y"}
+        updater.update_history(next_question, next_answer, 4)
+        self.assertEqual(updater.history, [new_answer, other_answer, next_question, next_answer])
+
+        # Test case 5: Limit set to 4, check limit enforcement (deletion)
+        next_question2 = {"channel": "other_channel", "content": "What is ZZZ?"}
+        next_answer2 = {"channel": "other_channel", "content": "Tripple Z"}
+        updater.update_history(next_question2, next_answer2, 4)
+        self.assertEqual(updater.history, [new_answer, next_answer, next_question2, next_answer2])
+
+        # Test case 5: Check history file save using mock
+        with unittest.mock.patch("builtins.open", unittest.mock.mock_open()) as mock_file:
+            _, temp_path = tempfile.mkstemp()
+            os.remove(temp_path)
+            self.bot.airesponder.history_file = temp_path
+            updater.update_history(question, answer, 2)
+            mock_file.assert_called_with(temp_path, 'wb')
+            mock_file().write.assert_called_with(pickle.dumps([question, answer]))
+
 
 if __name__ == "__mait__":
     unittest.main()