Add undo functionality for /reset command (#61)

Co-authored-by: TheLovinator1 <4153203+TheLovinator1@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Joakim Hellsén <tlovinator@gmail.com>

reset_undo_test.py

@@ -0,0 +1,201 @@
+from __future__ import annotations
+
+import pytest
+
+from main import (
+    add_message_to_memory,
+    last_trigger_time,
+    recent_messages,
+    reset_memory,
+    reset_snapshots,
+    undo_reset,
+    update_trigger_time,
+)
+
+
+@pytest.fixture(autouse=True)
+def clear_state() -> None:
+    """Clear all state before each test."""
+    recent_messages.clear()
+    last_trigger_time.clear()
+    reset_snapshots.clear()
+
+
+class TestResetMemory:
+    """Tests for the reset_memory function."""
+
+    def test_reset_memory_clears_messages(self) -> None:
+        """Test that reset_memory clears messages for the channel."""
+        channel_id = "test_channel_123"
+        add_message_to_memory(channel_id, "user1", "Hello")
+        add_message_to_memory(channel_id, "user2", "World")
+
+        assert channel_id in recent_messages
+        assert len(recent_messages[channel_id]) == 2
+
+        reset_memory(channel_id)
+
+        assert channel_id not in recent_messages
+
+    def test_reset_memory_clears_trigger_times(self) -> None:
+        """Test that reset_memory clears trigger times for the channel."""
+        channel_id = "test_channel_123"
+        update_trigger_time(channel_id, "user1")
+
+        assert channel_id in last_trigger_time
+
+        reset_memory(channel_id)
+
+        assert channel_id not in last_trigger_time
+
+    def test_reset_memory_creates_snapshot(self) -> None:
+        """Test that reset_memory creates a snapshot for undo."""
+        channel_id = "test_channel_123"
+        add_message_to_memory(channel_id, "user1", "Test message")
+        update_trigger_time(channel_id, "user1")
+
+        reset_memory(channel_id)
+
+        assert channel_id in reset_snapshots
+        messages_snapshot, trigger_snapshot = reset_snapshots[channel_id]
+        assert len(messages_snapshot) == 1
+        assert "user1" in trigger_snapshot
+
+    def test_reset_memory_no_snapshot_for_empty_channel(self) -> None:
+        """Test that reset_memory doesn't create snapshot for empty channel."""
+        channel_id = "empty_channel"
+
+        reset_memory(channel_id)
+
+        assert channel_id not in reset_snapshots
+
+
+class TestUndoReset:
+    """Tests for the undo_reset function."""
+
+    def test_undo_reset_restores_messages(self) -> None:
+        """Test that undo_reset restores messages."""
+        channel_id = "test_channel_123"
+        add_message_to_memory(channel_id, "user1", "Hello")
+        add_message_to_memory(channel_id, "user2", "World")
+
+        reset_memory(channel_id)
+        assert channel_id not in recent_messages
+
+        result = undo_reset(channel_id)
+
+        assert result is True
+        assert channel_id in recent_messages
+        assert len(recent_messages[channel_id]) == 2
+
+    def test_undo_reset_restores_trigger_times(self) -> None:
+        """Test that undo_reset restores trigger times."""
+        channel_id = "test_channel_123"
+        update_trigger_time(channel_id, "user1")
+        original_time = last_trigger_time[channel_id]["user1"]
+
+        reset_memory(channel_id)
+        assert channel_id not in last_trigger_time
+
+        result = undo_reset(channel_id)
+
+        assert result is True
+        assert channel_id in last_trigger_time
+        assert last_trigger_time[channel_id]["user1"] == original_time
+
+    def test_undo_reset_removes_snapshot(self) -> None:
+        """Test that undo_reset removes the snapshot after restoring."""
+        channel_id = "test_channel_123"
+        add_message_to_memory(channel_id, "user1", "Hello")
+
+        reset_memory(channel_id)
+        assert channel_id in reset_snapshots
+
+        undo_reset(channel_id)
+
+        assert channel_id not in reset_snapshots
+
+    def test_undo_reset_returns_false_when_no_snapshot(self) -> None:
+        """Test that undo_reset returns False when no snapshot exists."""
+        channel_id = "nonexistent_channel"
+
+        result = undo_reset(channel_id)
+
+        assert result is False
+
+    def test_undo_reset_only_works_once(self) -> None:
+        """Test that undo_reset only works once (snapshot is removed after undo)."""
+        channel_id = "test_channel_123"
+        add_message_to_memory(channel_id, "user1", "Hello")
+
+        reset_memory(channel_id)
+        first_undo = undo_reset(channel_id)
+        second_undo = undo_reset(channel_id)
+
+        assert first_undo is True
+        assert second_undo is False
+
+
+class TestResetUndoIntegration:
+    """Integration tests for reset and undo functionality."""
+
+    def test_reset_then_undo_preserves_content(self) -> None:
+        """Test that reset followed by undo preserves original content."""
+        channel_id = "test_channel_123"
+        add_message_to_memory(channel_id, "user1", "Message 1")
+        add_message_to_memory(channel_id, "user2", "Message 2")
+        add_message_to_memory(channel_id, "user3", "Message 3")
+        update_trigger_time(channel_id, "user1")
+        update_trigger_time(channel_id, "user2")
+
+        # Capture original state
+        original_messages = list(recent_messages[channel_id])
+        original_trigger_users = set(last_trigger_time[channel_id].keys())
+
+        reset_memory(channel_id)
+        undo_reset(channel_id)
+
+        # Verify restored state matches original
+        restored_messages = list(recent_messages[channel_id])
+        restored_trigger_users = set(last_trigger_time[channel_id].keys())
+
+        assert len(restored_messages) == len(original_messages)
+        assert restored_trigger_users == original_trigger_users
+
+    def test_multiple_resets_overwrite_snapshot(self) -> None:
+        """Test that multiple resets overwrite the previous snapshot."""
+        channel_id = "test_channel_123"
+
+        # First set of messages
+        add_message_to_memory(channel_id, "user1", "First message")
+        reset_memory(channel_id)
+
+        # Second set of messages
+        add_message_to_memory(channel_id, "user1", "Second message")
+        add_message_to_memory(channel_id, "user1", "Third message")
+        reset_memory(channel_id)
+
+        # Undo should restore the second set, not the first
+        undo_reset(channel_id)
+
+        assert channel_id in recent_messages
+        assert len(recent_messages[channel_id]) == 2
+
+    def test_different_channels_independent_undo(self) -> None:
+        """Test that different channels have independent undo functionality."""
+        channel_1 = "channel_1"
+        channel_2 = "channel_2"
+
+        add_message_to_memory(channel_1, "user1", "Channel 1 message")
+        add_message_to_memory(channel_2, "user2", "Channel 2 message")
+
+        reset_memory(channel_1)
+        reset_memory(channel_2)
+
+        # Undo only channel 1
+        undo_reset(channel_1)
+
+        assert channel_1 in recent_messages
+        assert channel_2 not in recent_messages
+        assert channel_1 not in reset_snapshots
+        assert channel_2 in reset_snapshots