# This class has the method by which we manage the Tasks
# It's a printing queue, so we need to add, remove and get information on where
# the queue is

from collections import deque

# Because actually printing and adding new print job requests happen at
# diffrent times, the print queue is managed by it's own thread.
import threading

from datetime import datetime
from task import TaskType, CutTask

class PrintQueue:
    """
    A Double-ended Queue to manage the printing Tasks
    """
    def __init__(self, app):
        self.app = app
        self._queue = deque()
        self._lock = threading.Lock()
        self._completed_tasks = {}  # Store completed task info
        self._task_counter = 0
        self.app.logger.debug("Created a new PrintQueue")

    def __len__(self) -> int:
        return len(self._queue)

    def enqueue(self, task):
        """Add task to right of the queue and return position"""
        with self._lock:
            try:
                self.app.logger.info("Add task %s to queue ", task.task_id)
                self._queue.append(task)
                position = self._queue.index(task)
                # We return the current position of the task if it was added
                self.app.logger.debug("Added a new task %s to the queue at position %s", task.task_id, position)
                return position
            except Exception as e:
                self.app.logger.error("Could not add a task to the queue : %s ", e)
                raise e

    def dequeue(self):
        """Remove and return next task ( from the left of the queue ) (thread-safe)"""
        with self._lock:
            return self._queue.popleft() if len(self._queue) > 0 else None

    def get_position(self, task):
        """Get current position of task in queue (1-indexed)"""
        with self._lock:
            if task.task_id in self._completed_tasks:
                return None  # Task already completed

        try:
            # Try to get the position of a Task
            return self._queue.index(task)
        except ValueError as e:
            raise e
        # end try

    def is_empty(self):
        """Check if queue is empty"""
        with self._lock:
            self.app.logger.debug("Checking if queue is empty")
            return len(self._queue) == 0

    def get_queue_state(self):
        """Return current queue state"""
        with self._lock:
            self.app.logger.debug("Return current queue state")
            return [{"task_id": t.task_id, "status": t.status} for t in self._queue]

    def get_status(self, task_id):
        """Get full status info for a task"""
        with self._lock:

            if task_id in self._completed_tasks:
                return self._completed_tasks[task_id]

            # Check in queue if it exists
            for index, task in enumerate(self._queue):
                if task.task_id == task_id:
                    # Depending on it's type, we return more info
                    if task.task_type == TaskType.IMAGE:
                        return {
                            "task_id": task_id,
                            "status": task.status,
                            "type" : task.task_type,
                            "position": index,
                            "in_queue": True,
                            "content" : task.content,
                            "signature": task.signature
                        }

                    if task.task_type == TaskType.TEXT:
                        return {
                            "task_id": task_id,
                            "status": task.status,
                            "type" : task.task_type,
                            "position": index,
                            "in_queue": True,
                            "image_path" : str(task.image_path),
                            "signature" : task.signature,
                            "process" : str(task.process)
                        }

                    if task.task_type == TaskType.CUT:
                        return {
                            "task_id": task_id,
                            "status": task.status,
                            "type" : task.task_type,
                            "position": index,
                            "in_queue": True
                        }

            return None

    def mark_completed(self, task_id, task_status):
        """Mark task as completed and remove from queue"""
        with self._lock:
            self._completed_tasks[task_id] = {
                "task_id": task_id,
                "status": task_status,
                "position": None,
                "in_queue": False,
                "completed_at": datetime.now().isoformat()
            }