from enum import Enum
from typing import Literal

from pydantic import UUID4, BaseModel


class ProgramElement(BaseModel):
    """
    Represents a basic element of our behavior program.

    :ivar name: The researcher-assigned name of the element.
    :ivar id: Unique identifier.
    """

    name: str
    id: UUID4

    # To make program elements hashable
    model_config = {"frozen": True}


class LogicalOperator(Enum):
    """
    Logical operators for combining beliefs.
    """

    AND = "AND"
    OR = "OR"


type Belief = KeywordBelief | SemanticBelief | InferredBelief
type BasicBelief = KeywordBelief | SemanticBelief


class KeywordBelief(ProgramElement):
    """
    Represents a belief that is activated when a specific keyword is detected in the user's speech.

    :ivar keyword: The string to look for in the transcription.
    """

    name: str = ""
    keyword: str


class SemanticBelief(ProgramElement):
    """
    Represents a belief whose truth value is determined by an LLM analyzing the conversation
    context.

    :ivar description: A natural language description of what this belief represents,
    used as a prompt for the LLM.
    """

    description: str


class InferredBelief(ProgramElement):
    """
    Represents a belief derived from other beliefs using logical operators.

    :ivar operator: The :class:`LogicalOperator` (AND/OR) to apply.
    :ivar left: The left operand (another belief).
    :ivar right: The right operand (another belief).
    """

    name: str = ""
    operator: LogicalOperator
    left: Belief
    right: Belief


class Norm(ProgramElement):
    """
    Base class for behavioral norms that guide the robot's interactions.

    :ivar norm: The textual description of the norm.
    :ivar critical: Whether this norm is considered critical and should be strictly enforced.
    """

    name: str = ""
    norm: str
    critical: bool = False


class BasicNorm(Norm):
    """
    A simple behavioral norm that is always considered for activation when its phase is active.
    """

    pass


class ConditionalNorm(Norm):
    """
    A behavioral norm that is only active when a specific condition (belief) is met.

    :ivar condition: The :class:`Belief` that must hold for this norm to be active.
    """

    condition: Belief


type PlanElement = Goal | Action


class Plan(ProgramElement):
    """
    Represents a list of steps to execute. Each of these steps can be a goal (with its own plan)
    or a simple action.

    :ivar steps: The actions or subgoals to execute, in order.
    """

    name: str = ""
    steps: list[PlanElement]


class BaseGoal(ProgramElement):
    """
    Represents an objective to be achieved. This base version does not include a plan to achieve
    this goal, and is used in semantic belief extraction.

    :ivar description: A description of the goal, used to determine if it has been achieved.
    :ivar can_fail: Whether we can fail to achieve the goal after executing the plan.
    """

    description: str = ""
    can_fail: bool = True


class Goal(BaseGoal):
    """
    Represents an objective to be achieved. To reach the goal, we should execute the corresponding
    plan. It inherits from the BaseGoal a variable `can_fail`, which if true will cause the
    completion to be determined based on the conversation.

    Instances of this goal are not hashable because a plan is not hashable.

    :ivar plan: The plan to execute.
    """

    plan: Plan


type Action = SpeechAction | GestureAction | LLMAction


class SpeechAction(ProgramElement):
    """
    An action where the robot speaks a predefined literal text.

    :ivar text: The text content to be spoken.
    """

    name: str = ""
    text: str


class Gesture(BaseModel):
    """
    Defines a physical gesture for the robot to perform.

    :ivar type: Whether to use a specific "single" gesture or a random one from a "tag" category.
    :ivar name: The identifier for the gesture or tag.
    """

    type: Literal["tag", "single"]
    name: str


class GestureAction(ProgramElement):
    """
    An action where the robot performs a physical gesture.

    :ivar gesture: The :class:`Gesture` definition.
    """

    name: str = ""
    gesture: Gesture


class LLMAction(ProgramElement):
    """
    An action that triggers an LLM-generated conversational response.

    :ivar goal: A temporary conversational goal to guide the LLM's response generation.
    """

    name: str = ""
    goal: str


class Trigger(ProgramElement):
    """
    Defines a reactive behavior: when the condition (belief) is met, the plan is executed.

    :ivar condition: The :class:`Belief` that triggers this behavior.
    :ivar plan: The :class:`Plan` to execute upon activation.
    """

    condition: Belief
    plan: Plan


class Phase(ProgramElement):
    """
    A logical stage in the interaction program, grouping norms, goals, and triggers.

    :ivar norms: List of norms active during this phase.
    :ivar goals: List of goals the robot pursues in this phase.
    :ivar triggers: List of reactive behaviors defined for this phase.
    """

    name: str = ""
    norms: list[BasicNorm | ConditionalNorm]
    goals: list[Goal]
    triggers: list[Trigger]


class Program(BaseModel):
    """
    The top-level container for a complete robot behavior definition.

    :ivar phases: An ordered list of :class:`Phase` objects defining the interaction flow.
    """

    phases: list[Phase]