#
# Copyright (c) 2024-2026, Daily
#
# SPDX-License-Identifier: BSD 2-Clause License
#

"""Base user turn stop strategy for determining when the user stopped speaking."""

from dataclasses import dataclass

from pipecat.frames.frames import Frame
from pipecat.processors.frame_processor import FrameDirection
from pipecat.turns.types import ProcessFrameResult
from pipecat.utils.base_object import BaseObject


@dataclass
class UserTurnStoppedParams:
    """Parameters emitted when a user turn stops.

    These parameters are passed to the `on_user_turn_stopped` event and provide
    contextual information about how the end of user turn should be handled by
    the user aggregator.

    Parameters:
        enable_user_speaking_frames: Whether the user aggregator should emit
            frames indicating user speaking state (e.g., user stopped speaking).
            This is typically enabled by default, but may be disabled when another
            component (such as an STT service) is already responsible for
            generating user speaking frames.

    """

    enable_user_speaking_frames: bool


class BaseUserTurnStopStrategy(BaseObject):
    """Base class for strategies that determine when the user stops speaking.

    Subclasses should implement logic to detect when the user stops
    speaking. This could be based on analyzing incoming frames (such as
    transcriptions), conversation state, or other heuristics.

    Events triggered by strategies:

      - `on_push_frame`: Indicates the strategy wants to push a frame.
      - `on_user_turn_inference_triggered`: Signals that enough evidence
        exists to start LLM inference for the current user turn. In most
        cases this fires together with `on_user_turn_stopped`. Strategies
        that gate finalization on the LLM (e.g.
        ``LLMTurnCompletionUserTurnStopStrategy``) fire only this event
        upstream and a separate strategy fires `on_user_turn_stopped` once
        the LLM confirms the turn is complete.
      - `on_user_turn_stopped`: Signals that the user turn is semantically
        final. Observers, transcript appenders, and UI indicators should
        bind this event.

    """

    def __init__(self, *, enable_user_speaking_frames: bool = True, **kwargs):
        """Initialize the base user turn stop strategy.

        Args:
            enable_user_speaking_frames: If True, the aggregator will emit frames
                indicating when the user stops speaking. This is enabled by default,
                but you may want to disable it if another component (e.g., an STT
                service) is already generating these frames.
            **kwargs: Additional keyword arguments.
        """
        super().__init__(**kwargs)
        self._enable_user_speaking_frames = enable_user_speaking_frames
        self._register_event_handler("on_push_frame", sync=True)
        self._register_event_handler("on_broadcast_frame", sync=True)
        self._register_event_handler("on_user_turn_inference_triggered", sync=True)
        self._register_event_handler("on_user_turn_stopped", sync=True)

    async def cleanup(self):
        """Cleanup the strategy."""
        pass

    async def reset(self):
        """Reset the strategy to its initial state."""
        pass

    async def process_frame(self, frame: Frame) -> ProcessFrameResult | None:
        """Process an incoming frame to decide whether the user stopped speaking.

        Subclasses should override this to implement logic that decides whether
        the user has stopped speaking.

        Args:
            frame: The frame to be analyzed.

        Returns:
            A ProcessFrameResult indicating the outcome, or None (treated as
            CONTINUE for backward compatibility).
        """
        pass

    async def push_frame(self, frame: Frame, direction: FrameDirection = FrameDirection.DOWNSTREAM):
        """Emit on_push_frame to push a frame using the user aggreagtor.

        Args:
            frame: The frame to be pushed.
            direction: What direction the frame should be pushed to.
        """
        await self._call_event_handler("on_push_frame", frame, direction)

    async def broadcast_frame(self, frame_cls: type[Frame], **kwargs):
        """Emit on_broadcast_frame to broadcast a frame using the user aggreagtor.

        Args:
            frame_cls: The class of the frame to be broadcasted.
            **kwargs: Keyword arguments to be passed to the frame's constructor.
        """
        await self._call_event_handler("on_broadcast_frame", frame_cls, **kwargs)

    async def trigger_user_turn_stopped(self):
        """Fire both ``on_user_turn_inference_triggered`` and ``on_user_turn_stopped``.

        Most strategies call this when they decide a turn has ended. To
        defer finalization to another strategy (so this strategy fires
        only the inference-triggered event), wrap this strategy with
        :func:`~pipecat.turns.user_stop.deferred` instead of changing
        the trigger call.
        """
        await self.trigger_user_turn_inference_triggered()
        await self.trigger_user_turn_finalized()

    async def trigger_user_turn_inference_triggered(self):
        """Trigger only the `on_user_turn_inference_triggered` event."""
        await self._call_event_handler("on_user_turn_inference_triggered")

    async def trigger_user_turn_finalized(self):
        """Trigger only the `on_user_turn_stopped` event."""
        await self._call_event_handler(
            "on_user_turn_stopped",
            UserTurnStoppedParams(enable_user_speaking_frames=self._enable_user_speaking_frames),
        )
