"""
Images to PDF Converter Module

This module provides functionality to convert multiple images into a single PDF file.
"""

import os
from PIL import Image
from pathlib import Path
from custom_logger import logger_config


class ImagesToPDF:
    """
    Convert multiple images into a single PDF file.
    """
    
    def __init__(self):
        self.current_path = os.path.abspath(os.path.join(os.path.dirname(__file__)))
        self.input_dir = os.path.join(self.current_path, "input")
        self.output_dir = os.path.join(self.current_path, "output")
        self.supported_formats = ['jpg', 'jpeg', 'png', 'webp', 'bmp', 'gif', 'tiff', 'tif']
        
        # Create directories if they don't exist
        os.makedirs(self.input_dir, exist_ok=True)
        os.makedirs(self.output_dir, exist_ok=True)
    
    def _validate_image(self, filename: str) -> bool:
        """Check if file is a supported image format."""
        ext = Path(filename).suffix.lower().lstrip('.')
        return ext in self.supported_formats
    
    def convert_to_pdf(self, image_ids: list, output_name: str = "output.pdf") -> str:
        """
        Convert multiple images to a single PDF.
        
        Args:
            image_ids: List of image file IDs in the input directory
            output_name: Name for the output PDF file
            
        Returns:
            Path to the generated PDF file, or None on failure
        """
        try:
            if not image_ids:
                raise ValueError("No images provided for conversion")
            
            images = []
            first_image = None
            
            for img_id in image_ids:
                img_path = os.path.join(self.input_dir, img_id)
                
                if not os.path.exists(img_path):
                    logger_config.warning(f"Image not found: {img_path}")
                    continue
                
                # Open and convert image to RGB (PDF requires RGB)
                img = Image.open(img_path)
                
                # Handle transparency by converting to RGB with white background
                if img.mode in ('RGBA', 'LA', 'P'):
                    # Create white background
                    background = Image.new('RGB', img.size, (255, 255, 255))
                    if img.mode == 'P':
                        img = img.convert('RGBA')
                    background.paste(img, mask=img.split()[-1] if img.mode == 'RGBA' else None)
                    img = background
                elif img.mode != 'RGB':
                    img = img.convert('RGB')
                
                if first_image is None:
                    first_image = img
                else:
                    images.append(img)
            
            if first_image is None:
                raise ValueError("No valid images found for conversion")
            
            # Generate output path
            output_path = os.path.join(self.output_dir, output_name)
            
            # Save as PDF
            if images:
                first_image.save(
                    output_path,
                    save_all=True,
                    append_images=images,
                    resolution=100.0
                )
            else:
                first_image.save(output_path, resolution=100.0)
            
            logger_config.success(f"PDF created successfully: {output_path}")
            
            # Cleanup input files
            for img_id in image_ids:
                img_path = os.path.join(self.input_dir, img_id)
                if os.path.exists(img_path):
                    os.unlink(img_path)
            
            return output_path
            
        except Exception as e:
            logger_config.error(f"PDF conversion failed: {str(e)}")
            return None
    
    def upload(self, file_id: str, file_content: bytes):
        """Save uploaded file to input directory."""
        file_path = os.path.join(self.input_dir, file_id)
        with open(file_path, 'wb') as f:
            f.write(file_content)
        logger_config.info(f"File uploaded: {file_path}")