from typing import List

from opendevin.exceptions import PlanInvalidStateError
from opendevin.logger import opendevin_logger as logger

OPEN_STATE = 'open'
COMPLETED_STATE = 'completed'
ABANDONED_STATE = 'abandoned'
IN_PROGRESS_STATE = 'in_progress'
VERIFIED_STATE = 'verified'
STATES = [OPEN_STATE, COMPLETED_STATE,
          ABANDONED_STATE, IN_PROGRESS_STATE, VERIFIED_STATE]


class Task:
    id: str
    goal: str
    parent: 'Task | None'
    subtasks: List['Task']

    def __init__(self, parent: 'Task | None', goal: str, state: str = OPEN_STATE, subtasks: List = []):
        """Initializes a new instance of the Task class.

        Args:
            parent: The parent task, or None if it is the root task.
            goal: The goal of the task.
            state: The initial state of the task.
            subtasks: A list of subtasks associated with this task.
        """
        if parent is None:
            self.id = '0'
        else:
            self.id = parent.id + '.' + str(len(parent.subtasks))
        self.parent = parent
        self.goal = goal
        self.subtasks = []
        for subtask in (subtasks or []):
            if isinstance(subtask, Task):
                self.subtasks.append(subtask)
            else:
                goal = subtask.get('goal')
                state = subtask.get('state')
                subtasks = subtask.get('subtasks')
                self.subtasks.append(Task(self, goal, state, subtasks))

        self.state = OPEN_STATE

    def to_string(self, indent=''):
        """Returns a string representation of the task and its subtasks.

        Args:
            indent: The indentation string for formatting the output.

        Returns:
            A string representation of the task and its subtasks.
        """
        emoji = ''
        if self.state == VERIFIED_STATE:
            emoji = '✅'
        elif self.state == COMPLETED_STATE:
            emoji = '🟢'
        elif self.state == ABANDONED_STATE:
            emoji = '❌'
        elif self.state == IN_PROGRESS_STATE:
            emoji = '💪'
        elif self.state == OPEN_STATE:
            emoji = '🔵'
        result = indent + emoji + ' ' + self.id + ' ' + self.goal + '\n'
        for subtask in self.subtasks:
            result += subtask.to_string(indent + '    ')
        return result

    def to_dict(self):
        """Returns a dictionary representation of the task.

        Returns:
            A dictionary containing the task's attributes.
        """
        return {
            'id': self.id,
            'goal': self.goal,
            'state': self.state,
            'subtasks': [t.to_dict() for t in self.subtasks]
        }

    def set_state(self, state):
        """Sets the state of the task and its subtasks.

        Args:            state: The new state of the task.

        Raises:
            PlanInvalidStateError: If the provided state is invalid.
        """
        if state not in STATES:
            logger.error('Invalid state: %s', state)
            raise PlanInvalidStateError(state)
        self.state = state
        if state == COMPLETED_STATE or state == ABANDONED_STATE or state == VERIFIED_STATE:
            for subtask in self.subtasks:
                if subtask.state != ABANDONED_STATE:
                    subtask.set_state(state)
        elif state == IN_PROGRESS_STATE:
            if self.parent is not None:
                self.parent.set_state(state)

    def get_current_task(self) -> 'Task | None':
        """Retrieves the current task in progress.

        Returns:
            The current task in progress, or None if no task is in progress.
        """
        for subtask in self.subtasks:
            if subtask.state == IN_PROGRESS_STATE:
                return subtask.get_current_task()
        if self.state == IN_PROGRESS_STATE:
            return self
        return None


class Plan:
    """Represents a plan consisting of tasks.

    Attributes:
        main_goal: The main goal of the plan.
        task: The root task of the plan.
    """
    main_goal: str
    task: Task

    def __init__(self, task: str):
        """Initializes a new instance of the Plan class.

        Args:
            task: The main goal of the plan.
        """
        self.main_goal = task
        self.task = Task(parent=None, goal=task, subtasks=[])

    def __str__(self):
        """Returns a string representation of the plan.

        Returns:
            A string representation of the plan.
        """
        return self.task.to_string()

    def get_task_by_id(self, id: str) -> Task:
        """Retrieves a task by its ID.

        Args:
            id: The ID of the task.

        Returns:
            The task with the specified ID.

        Raises:
            ValueError: If the provided task ID is invalid or does not exist.
        """
        try:
            parts = [int(p) for p in id.split('.')]
        except ValueError:
            raise ValueError('Invalid task id, non-integer:' + id)
        if parts[0] != 0:
            raise ValueError('Invalid task id, must start with 0:' + id)
        parts = parts[1:]
        task = self.task
        for part in parts:
            if part >= len(task.subtasks):
                raise ValueError('Task does not exist:' + id)
            task = task.subtasks[part]
        return task

    def add_subtask(self, parent_id: str, goal: str, subtasks: List = []):
        """Adds a subtask to a parent task.

        Args:
            parent_id: The ID of the parent task.
            goal: The goal of the subtask.
            subtasks: A list of subtasks associated with the new subtask.
        """
        parent = self.get_task_by_id(parent_id)
        child = Task(parent=parent, goal=goal, subtasks=subtasks)
        parent.subtasks.append(child)

    def set_subtask_state(self, id: str, state: str):
        """Sets the state of a subtask.

        Args:
            id: The ID of the subtask.
            state: The new state of the subtask.
        """
        task = self.get_task_by_id(id)
        task.set_state(state)

    def get_current_task(self):
        """Retrieves the current task in progress.

        Returns:
            The current task in progress, or None if no task is in progress.
        """
        return self.task.get_current_task()