chore: import upstream snapshot with attribution

python/semantic_kernel/agents/group_chat/agent_group_chat.py

@@ -0,0 +1,228 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import logging
+from collections.abc import AsyncIterable
+from copy import deepcopy
+from typing import TYPE_CHECKING, Any, cast
+
+from pydantic import Field
+
+from semantic_kernel.agents import Agent, AgentChat
+from semantic_kernel.agents.strategies import (
+    DefaultTerminationStrategy,
+    SequentialSelectionStrategy,
+)
+from semantic_kernel.agents.strategies.selection.selection_strategy import SelectionStrategy
+from semantic_kernel.agents.strategies.termination.termination_strategy import TerminationStrategy
+from semantic_kernel.contents.chat_message_content import ChatMessageContent
+from semantic_kernel.contents.history_reducer.chat_history_reducer import ChatHistoryReducer
+from semantic_kernel.contents.utils.author_role import AuthorRole
+from semantic_kernel.exceptions.agent_exceptions import AgentChatException
+from semantic_kernel.utils.feature_stage_decorator import experimental
+
+if TYPE_CHECKING:
+    from semantic_kernel.contents.chat_history import ChatHistory
+
+logger: logging.Logger = logging.getLogger(__name__)
+
+
+@experimental
+class AgentGroupChat(AgentChat):
+    """An agent chat that supports multi-turn interactions."""
+
+    agent_ids: set[str]
+    agents: list[Agent] = Field(default_factory=list)
+
+    is_complete: bool = False
+    termination_strategy: TerminationStrategy = Field(
+        default_factory=DefaultTerminationStrategy,
+        description="The termination strategy to use. The default strategy never terminates and has a max iterations of 5.",  # noqa: E501
+    )
+    selection_strategy: SelectionStrategy = Field(default_factory=SequentialSelectionStrategy)
+
+    def __init__(
+        self,
+        agents: list[Agent] | None = None,
+        termination_strategy: TerminationStrategy | None = None,
+        selection_strategy: SelectionStrategy | None = None,
+        chat_history: "ChatHistory | None" = None,
+    ) -> None:
+        """Initialize a new instance of AgentGroupChat.
+
+        Args:
+            agents: The agents to add to the group chat.
+            termination_strategy: The termination strategy to use.
+            selection_strategy: The selection strategy
+            chat_history: The chat history.
+        """
+        agent_ids = {agent.id for agent in agents} if agents else set()
+
+        if agents is None:
+            agents = []
+
+        args: dict[str, Any] = {
+            "agents": agents,
+            "agent_ids": agent_ids,
+        }
+
+        if termination_strategy is not None:
+            args["termination_strategy"] = termination_strategy
+        if selection_strategy is not None:
+            args["selection_strategy"] = selection_strategy
+        if chat_history is not None:
+            args["history"] = chat_history
+
+        super().__init__(**args)
+
+    def add_agent(self, agent: Agent) -> None:
+        """Add an agent to the group chat.
+
+        Args:
+            agent: The agent to add.
+        """
+        if agent.id not in self.agent_ids:
+            self.agent_ids.add(agent.id)
+            self.agents.append(agent)
+
+    async def invoke_single_turn(self, agent: Agent) -> AsyncIterable[ChatMessageContent]:
+        """Invoke the agent chat for a single turn.
+
+        Args:
+            agent: The agent to invoke.
+
+        Yields:
+            The chat message.
+        """
+        async for message in self.invoke(agent, is_joining=True):
+            if message.role == AuthorRole.ASSISTANT:
+                task = self.termination_strategy.should_terminate(agent, self.history.messages)
+                self.is_complete = await task
+            yield message
+
+    async def invoke_stream_single_turn(self, agent: Agent) -> AsyncIterable[ChatMessageContent]:
+        """Invoke the agent chat for a single turn.
+
+        Args:
+            agent: The agent to invoke.
+
+        Yields:
+            The chat message.
+        """
+        async for message in self.invoke_stream(agent, is_joining=True):
+            yield message
+
+        self.is_complete = await self.termination_strategy.should_terminate(agent, self.history.messages)
+
+    async def invoke(self, agent: Agent | None = None, is_joining: bool = True) -> AsyncIterable[ChatMessageContent]:
+        """Invoke the agent chat asynchronously.
+
+        Handles both group interactions and single agent interactions based on the provided arguments.
+
+        Args:
+            agent: The agent to invoke. If not provided, the method processes all agents in the chat.
+            is_joining: Controls whether the agent joins the chat. Defaults to True.
+
+        Yields:
+            The chat message.
+        """
+        if agent is not None:
+            if is_joining:
+                self.add_agent(agent)
+
+            async for message in super().invoke_agent(agent):
+                if message.role == AuthorRole.ASSISTANT:
+                    task = self.termination_strategy.should_terminate(agent, self.history.messages)
+                    self.is_complete = await task
+                yield message
+
+            return
+
+        if not self.agents:
+            raise AgentChatException("No agents are available")
+
+        if self.is_complete:
+            if not self.termination_strategy.automatic_reset:
+                raise AgentChatException("Chat is already complete")
+
+            self.is_complete = False
+
+        for _ in range(self.termination_strategy.maximum_iterations):
+            try:
+                selected_agent = await self.selection_strategy.next(self.agents, self.history.messages)
+            except Exception as ex:
+                logger.error(f"Failed to select agent: {ex}")
+                raise AgentChatException("Failed to select agent") from ex
+
+            async for message in super().invoke_agent(selected_agent):
+                if message.role == AuthorRole.ASSISTANT:
+                    task = self.termination_strategy.should_terminate(selected_agent, self.history.messages)
+                    self.is_complete = await task
+                yield message
+
+            if self.is_complete:
+                break
+
+    async def invoke_stream(
+        self, agent: Agent | None = None, is_joining: bool = True
+    ) -> AsyncIterable[ChatMessageContent]:
+        """Invoke the agent chat stream asynchronously.
+
+        Handles both group interactions and single agent interactions based on the provided arguments.
+
+        Args:
+            agent: The agent to invoke. If not provided, the method processes all agents in the chat.
+            is_joining: Controls whether the agent joins the chat. Defaults to True.
+
+        Yields:
+            The chat message.
+        """
+        if agent is not None:
+            if is_joining:
+                self.add_agent(agent)
+
+            async for message in super().invoke_agent_stream(agent):
+                if message.role == AuthorRole.ASSISTANT:
+                    task = self.termination_strategy.should_terminate(agent, self.history.messages)
+                    self.is_complete = await task
+                yield message
+
+            return
+
+        if not self.agents:
+            raise AgentChatException("No agents are available")
+
+        if self.is_complete:
+            if not self.termination_strategy.automatic_reset:
+                raise AgentChatException("Chat is already complete")
+
+            self.is_complete = False
+
+        for _ in range(self.termination_strategy.maximum_iterations):
+            try:
+                selected_agent = await self.selection_strategy.next(self.agents, self.history.messages)
+            except Exception as ex:
+                logger.error(f"Failed to select agent: {ex}")
+                raise AgentChatException("Failed to select agent") from ex
+
+            async for message in super().invoke_agent_stream(selected_agent):
+                yield message
+
+            self.is_complete = await self.termination_strategy.should_terminate(selected_agent, self.history.messages)
+
+            if self.is_complete:
+                break
+
+    async def reduce_history(self) -> bool:
+        """Perform the reduction on the provided history, returning True if reduction occurred."""
+        if not isinstance(self.history, ChatHistoryReducer):
+            return False
+
+        result = await self.history.reduce()
+        if result is None:
+            return False
+
+        reducer = cast(ChatHistoryReducer, result)
+        reduced_history = deepcopy(reducer.messages)
+        await self.reset()
+        await self.add_chat_messages(reduced_history)
+        return True