Load previous conversation

src/llm_chat/chat.py

@@ -80,15 +80,41 @@ class Chat:
         self,
         settings: OpenAISettings | None = None,
         context: list[Message] = [],
+        initial_system_messages: bool = True,
     ) -> None:
         self._settings = settings
         self.conversation = Conversation(
-            messages=INITIAL_SYSTEM_MESSAGES + context,
+            messages=INITIAL_SYSTEM_MESSAGES + context
+            if initial_system_messages
+            else context,
             model=self.settings.model,
             temperature=self.settings.temperature,
         )
         self._start_time = datetime.now(tz=ZoneInfo("UTC"))
 
+    @classmethod
+    def load(
+        cls, path: Path, api_key: str | None = None, history_dir: Path | None = None
+    ) -> ChatProtocol:
+        """Load a chat from a file."""
+        with path.open() as f:
+            conversation = Conversation.model_validate_json(f.read())
+        args = {
+            "model": conversation.model,
+            "temperature": conversation.temperature,
+        }
+        if api_key is not None:
+            args["api_key"] = api_key
+        if history_dir is not None:
+            args["history_dir"] = history_dir
+
+        settings = OpenAISettings(**args)
+        return cls(
+            settings=settings,
+            context=conversation.messages,
+            initial_system_messages=False,
+        )
+
     @property
     def settings(self) -> OpenAISettings:
         """Get OpenAI chat settings."""

src/llm_chat/cli.py

@@ -6,7 +6,7 @@ from prompt_toolkit import PromptSession
 from rich.console import Console
 from rich.markdown import Markdown
 
-from llm_chat.chat import ChatProtocol, get_chat
+from llm_chat.chat import Chat, ChatProtocol, get_chat
 from llm_chat.models import Message, Role
 from llm_chat.settings import DEFAULT_MODEL, DEFAULT_TEMPERATURE, Model, OpenAISettings
 
@@ -60,7 +60,28 @@ def display_cost(console: Console, chat: ChatProtocol) -> None:
     console.print(f"\n[bold green]Cost:[/bold green] ${chat.cost}\n")
 
 
-@app.command()
+def run_conversation(current_chat: ChatProtocol) -> None:
+    """Run a conversation."""
+    console = get_console()
+    session = get_session()
+
+    finished = False
+
+    console.print(f"[bold green]Model:[/bold green] {current_chat.settings.model}")
+    console.print(f"[bold green]Temperature:[/bold green] {current_chat.settings.temperature}")
+
+    while not finished:
+        prompt = read_user_input(session)
+        if prompt.strip() == "/q":
+            finished = True
+            current_chat.save()
+        else:
+            response = current_chat.send_message(prompt.strip())
+            console.print(Markdown(response))
+            display_cost(console, current_chat)
+
+
+@app.command("chat")
 def chat(
     api_key: Annotated[
         Optional[str],
@@ -102,7 +123,6 @@ def chat(
     ] = [],
 ) -> None:
     """Start a chat session."""
-    # TODO: Add option to load context from file.
     # TODO: Add option to provide context string as an argument.
     if api_key is not None:
         settings = OpenAISettings(api_key=api_key, model=model, temperature=temperature)
@@ -112,20 +132,43 @@ def chat(
     context_messages = [load_context(path) for path in context]
 
     current_chat = get_chat(settings=settings, context=context_messages)
-    console = get_console()
-    session = get_session()
 
-    finished = False
+    run_conversation(current_chat)
 
-    console.print(f"[bold green]Model:[/bold green] {settings.model}")
-    console.print(f"[bold green]Temperature:[/bold green] {settings.temperature}")
 
-    while not finished:
-        prompt = read_user_input(session)
-        if prompt.strip() == "/q":
-            finished = True
-            current_chat.save()
-        else:
-            response = current_chat.send_message(prompt.strip())
-            console.print(Markdown(response))
-            display_cost(console, current_chat)
+@app.command("load")
+def load(
+    path: Annotated[
+        Path,
+        typer.Argument(
+            help="Path to a conversation file.",
+            exists=True,
+            file_okay=True,
+            dir_okay=False,
+            readable=True,
+        ),
+    ],
+    api_key: Annotated[
+        Optional[str],
+        typer.Option(
+            ...,
+            "--api-key",
+            "-k",
+            help=(
+                "API key. Will read from the environment variable OPENAI_API_KEY "
+                "if not provided."
+            ),
+        ),
+    ] = None,
+) -> None:
+    """Load a conversation from a file."""
+    if api_key is not None:
+        current_chat = Chat.load(path, api_key=api_key)
+    else:
+        current_chat = Chat.load(path)
+    
+    run_conversation(current_chat)
+
+
+if __name__ == "__main__":
+    app()

tests/test_chat.py

@@ -46,6 +46,42 @@ def test_save_conversation(tmp_path: Path) -> None:
     assert conversation == conversation_from_file
 
 
+def test_load(tmp_path: Path) -> None:
+    # Create a conversation object to save
+    conversation = Conversation(
+        messages=[
+            Message(role=Role.SYSTEM, content="Hello!"),
+            Message(role=Role.USER, content="Hi!"),
+            Message(role=Role.ASSISTANT, content="How are you?"),
+        ],
+        model=Model.GPT3,
+        temperature=0.5,
+        completion_tokens=10,
+        prompt_tokens=15,
+        cost=0.000043,
+    )
+
+    # Save the conversation to a file
+    file_path = tmp_path / "conversation.json"
+    with file_path.open("w") as f:
+        f.write(conversation.model_dump_json())
+
+    # Load the conversation from the file
+    loaded_chat = Chat.load(file_path, api_key="foo", history_dir=tmp_path)
+
+    # Check that the loaded conversation matches the original conversation
+    assert loaded_chat.settings.model == conversation.model
+    assert loaded_chat.settings.temperature == conversation.temperature
+    assert loaded_chat.conversation.messages == conversation.messages
+    assert loaded_chat.settings.api_key == "foo"
+    assert loaded_chat.settings.history_dir == tmp_path
+
+    # We don't want to load the tokens or cost from the previous session
+    assert loaded_chat.conversation.completion_tokens == 0
+    assert loaded_chat.conversation.prompt_tokens == 0
+    assert loaded_chat.cost == 0
+
+
 def test_send_message() -> None:
     with patch("llm_chat.chat.Chat._make_request") as mock_make_request:
         mock_make_request.return_value = {

tests/test_cli.py

@@ -12,6 +12,7 @@ import llm_chat
 from llm_chat.chat import ChatProtocol
 from llm_chat.cli import app
 from llm_chat.models import Message, Role
+from llm_chat.settings import OpenAISettings
 
 runner = CliRunner()
 
@@ -21,8 +22,13 @@ class ChatFake:
 
     args: dict[str, Any]
     received_messages: list[str]
+    settings: OpenAISettings
 
-    def __init__(self) -> None:
+    def __init__(self, settings: OpenAISettings | None = None) -> None:
+        if settings is not None:
+            self.settings = settings
+        else:
+            self.settings = OpenAISettings()
         self.args = {}
         self.received_messages = []
 
@@ -34,6 +40,13 @@ class ChatFake:
         """Get the cost of the conversation."""
         return 0.0
     
+    @classmethod
+    def load(
+        cls, path: Path, api_key: str | None = None, history_dir: Path | None = None
+    ) -> ChatProtocol:
+        """Load a chat from a file."""
+        return cls()
+
     def save(self) -> None:
         """Dummy save method."""
         pass
@@ -61,7 +74,7 @@ def test_chat(monkeypatch: MonkeyPatch) -> None:
     monkeypatch.setattr(llm_chat.cli, "get_console", mock_get_console)
     monkeypatch.setattr(llm_chat.cli, "read_user_input", mock_read_user_input)
 
-    result = runner.invoke(app)
+    result = runner.invoke(app, ["chat"])
     assert result.exit_code == 0
     assert chat_fake.received_messages == ["Hello"]