"""
Shape Worker Module

Worker thread for async shape classification.
"""

from typing import Optional
import logging

from PyQt5.QtCore import pyqtSignal
from PyQt5.QtGui import QImage

from workers.base_worker import BaseWorker, WorkerSignals
from models.shape_model import ShapeModel
from utils.config import get_device

logger = logging.getLogger(__name__)


class ShapeWorkerSignals(WorkerSignals):
    """
    Signals specific to shape classification.
    
    Signals:
        result_ready: Emitted when classification is complete
            (annotated_image: QImage, shape_class: str, class_id: int, confidence: float)
    """
    result_ready = pyqtSignal(QImage, str, int, float)


class ShapeWorker(BaseWorker):
    """
    Worker for processing images and classifying durian shape.
    
    Runs ShapeModel inference in a background thread without blocking UI.
    
    Attributes:
        image_path: Path to image file
        model: ShapeModel instance
        signals: ShapeWorkerSignals for emitting results
    """
    
    def __init__(self, image_path: str, model: Optional[ShapeModel] = None):
        """
        Initialize the shape worker.
        
        Args:
            image_path: Path to image file to process
            model: ShapeModel instance (if None, creates new one)
        """
        super().__init__()
        self.image_path = image_path
        self.model = model
        
        # Replace base signals with shape-specific signals
        self.signals = ShapeWorkerSignals()
        
        # If no model provided, create and load one
        if self.model is None:
            device = get_device()
            # Shape model must be provided with explicit path
            # This will fail if model doesn't exist - that's expected
            from utils.config import PROJECT_ROOT
            shape_model_path = PROJECT_ROOT / "model_files" / "shape.pt"
            self.model = ShapeModel(str(shape_model_path), device=device)
            self.model.load()
        
        logger.info(f"ShapeWorker created for: {image_path}")
    
    def process(self):
        """
        Process the image and classify shape.
        
        Emits result_ready signal with classification results.
        """
        if self.is_cancelled():
            logger.info("ShapeWorker cancelled before processing")
            return
        
        # Update progress
        self.emit_progress(10, "Loading image...")
        
        if not self.model.is_loaded:
            logger.warning("Model not loaded, loading now...")
            self.emit_progress(30, "Loading model...")
            if not self.model.load():
                raise RuntimeError("Failed to load shape model")
        
        # Process image
        self.emit_progress(50, "Classifying shape...")
        
        result = self.model.predict(self.image_path)
        
        if self.is_cancelled():
            logger.info("ShapeWorker cancelled during processing")
            return
        
        if not result['success']:
            raise RuntimeError(result['error'])
        
        self.emit_progress(90, "Finalizing results...")
        
        # Make a copy of the QImage to ensure thread safety
        annotated_image_copy = result['annotated_image'].copy() if result['annotated_image'] else None
        
        # Emit results with annotated image if available
        self.signals.result_ready.emit(
            annotated_image_copy,
            result['shape_class'],
            result['class_id'],
            result['confidence']
        )
        
        self.emit_progress(100, "Complete!")
        
        logger.info(
            f"ShapeWorker completed: {result['shape_class']} "
            f"(confidence: {result['confidence']:.3f})"
        )