from typing import Awaitable, Callable

from playwright.async_api import Page

from skyvern.exceptions import StepUnableToExecuteError
from skyvern.forge import app
from skyvern.forge.async_operations import AsyncOperation
from skyvern.forge.sdk.models import Organization, Step, StepStatus
from skyvern.forge.sdk.schemas.tasks import Task, TaskStatus
from skyvern.webeye.browser_factory import BrowserState

CleanupElementTreeFunc = Callable[[str, list[dict]], Awaitable[list[dict]]]


def _remove_rect(element: dict) -> None:
    if "rect" in element:
        del element["rect"]


class AgentFunction:
    async def validate_step_execution(
        self,
        task: Task,
        step: Step,
    ) -> None:
        """
        Checks if the step can be executed. It is called before the step is executed.
        :return: A tuple of whether the step can be executed and a list of reasons why it can't be executed.
        """
        reasons = []
        # can't execute if task status is not running
        has_valid_task_status = task.status == TaskStatus.running
        if not has_valid_task_status:
            reasons.append(f"invalid_task_status:{task.status}")
        # can't execute if the step is already running or completed
        has_valid_step_status = step.status in [StepStatus.created, StepStatus.failed]
        if not has_valid_step_status:
            reasons.append(f"invalid_step_status:{step.status}")
        # can't execute if the task has another step that is running
        steps = await app.DATABASE.get_task_steps(task_id=task.task_id, organization_id=task.organization_id)
        has_no_running_steps = not any(step.status == StepStatus.running for step in steps)
        if not has_no_running_steps:
            reasons.append(f"another_step_is_running_for_task:{task.task_id}")

        can_execute = has_valid_task_status and has_valid_step_status and has_no_running_steps
        if not can_execute:
            raise StepUnableToExecuteError(step_id=step.step_id, reason=f"Cannot execute step. Reasons: {reasons}")

    async def prepare_step_execution(
        self,
        organization: Organization | None,
        task: Task,
        step: Step,
        browser_state: BrowserState,
    ) -> None:
        """
        Get prepared for the step execution. It's called at the first beginning when step running.
        """
        return

    def generate_async_operations(
        self,
        organization: Organization,
        task: Task,
        page: Page,
    ) -> list[AsyncOperation]:
        return []

    def cleanup_element_tree_factory(
        self,
        task: Task,
        step: Step,
        organization: Organization | None = None,
    ) -> CleanupElementTreeFunc:
        async def cleanup_element_tree_func(url: str, element_tree: list[dict]) -> list[dict]:
            """
            Remove rect and attribute.unique_id from the elements.
            The reason we're doing it is to
            1. reduce unnecessary data so that llm get less distrction
            TODO later: 2. reduce tokens sent to llm to save money
            :param elements: List of elements to remove xpaths from.
            :return: List of elements without xpaths.
            """
            queue = []
            for element in element_tree:
                queue.append(element)
            while queue:
                queue_ele = queue.pop(0)
                _remove_rect(queue_ele)
                # TODO: we can come back to test removing the unique_id
                # from element attributes to make sure this won't increase hallucination
                # _remove_unique_id(queue_ele)
                if "children" in queue_ele:
                    queue.extend(queue_ele["children"])
            return element_tree

        return cleanup_element_tree_func