from typing import List, Optional

from langchain.tools import Tool
from pydantic.v1 import BaseModel, Field, root_validator

from .agent import Agent


class Task(BaseModel):
    """
    Class that represent a task to be executed.
    """

    description: str = Field(description="Description of the actual task.")
    agent: Optional[Agent] = Field(
        description="Agent responsible for the task.", default=None
    )
    tools: Optional[List[Tool]] = Field(
        description="Tools the agent are limited to use for this task.", default=[]
    )

    @root_validator(pre=False)
    def _set_tools(_cls, values):
        if (values.get("agent")) and not (values.get("tools")):
            values["tools"] = values.get("agent").tools
        return values

    def execute(self, context: str = None) -> str:
        """
        Execute the task.
                Returns:
                        output (str): Output of the task.
        """
        if self.agent:
            return self.agent.execute_task(
                task=self.description, context=context, tools=self.tools
            )
        else:
            raise Exception(
                f"The task '{self.description}' has no agent assigned, therefore it can't be executed directly and should be executed in a Crew using a specific process that support that, either consensual or hierarchical."
            )