"""
QR Code generation utilities
"""

import os
import qrcode
from qrcode.image.styledpil import StyledPilImage
from qrcode.image.styles.moduledrawers import RoundedModuleDrawer, CircleModuleDrawer, SquareModuleDrawer
from qrcode.image.svg import SvgPathImage, SvgFragmentImage, SvgFillImage
from PIL import Image
import io

class QRCodeGenerator:
    def __init__(self):
        self.default_settings = {
            'size': 10,
            'border': 4,
            'error_correction': qrcode.constants.ERROR_CORRECT_M,
            'foreground_color': '#000000',
            'background_color': '#FFFFFF',
            'style': 'square'
        }
    
    def generate_qr_code(self, data, settings=None, format='PNG'):
        """Generate QR code with custom settings in PNG or SVG format"""
        if settings is None:
            settings = self.default_settings.copy()
        else:
            merged_settings = self.default_settings.copy()
            merged_settings.update(settings)
            settings = merged_settings
        
        if format.upper() == 'SVG':
            return self._generate_svg_qr_code(data, settings)
        else:
            return self._generate_png_qr_code(data, settings)
    
    def _generate_png_qr_code(self, data, settings):
        """Generate PNG QR code (existing functionality)"""
        # Create QR code instance
        qr = qrcode.QRCode(
            version=1,
            error_correction=settings['error_correction'],
            box_size=settings['size'],
            border=settings['border'],
        )
        
        qr.add_data(data)
        qr.make(fit=True)
        
        # For styled QR codes with custom module drawer
        if settings['style'] != 'square':
            # Choose module drawer based on style
            module_drawer = None
            if settings['style'] == 'rounded':
                module_drawer = RoundedModuleDrawer()
            elif settings['style'] == 'circle':
                module_drawer = CircleModuleDrawer()
            
            # Generate the styled image
            img = qr.make_image(
                image_factory=StyledPilImage,
                module_drawer=module_drawer,
                fill_color=settings['foreground_color'],
                back_color=settings['background_color']
            )
        else:
            # Generate standard image with custom colors
            img = qr.make_image(
                fill_color=settings['foreground_color'],
                back_color=settings['background_color']
            )
        
        return img
    
    def _generate_svg_qr_code(self, data, settings):
        """Generate SVG QR code"""
        # Create QR code instance
        qr = qrcode.QRCode(
            version=1,
            error_correction=settings['error_correction'],
            box_size=settings['size'],
            border=settings['border'],
        )
        
        qr.add_data(data)
        qr.make(fit=True)
        
        # Choose SVG image factory based on style
        if settings['style'] == 'circle':
            # Use SvgFillImage for better circle support
            factory = SvgFillImage
        else:
            # Use SvgPathImage for square and rounded styles
            factory = SvgPathImage
        
        # Generate SVG image
        img = qr.make_image(
            image_factory=factory,
            fill_color=settings['foreground_color'],
            back_color=settings['background_color']
        )
        
        return img
    
    def generate_qr_code_svg_string(self, data, settings=None):
        """Generate QR code as SVG string"""
        svg_img = self.generate_qr_code(data, settings, format='SVG')
        
        # Convert SVG image to string
        svg_buffer = io.BytesIO()
        svg_img.save(svg_buffer)
        svg_buffer.seek(0)
        
        return svg_buffer.getvalue().decode('utf-8')
    
    def add_logo(self, qr_img, logo_path, logo_size_ratio=0.2):
        """Add logo to QR code"""
        try:
            logo = Image.open(logo_path)
            
            # Calculate logo size
            qr_width, qr_height = qr_img.size
            logo_size = int(min(qr_width, qr_height) * logo_size_ratio)
            
            # Resize logo
            logo = logo.resize((logo_size, logo_size), Image.Resampling.LANCZOS)
            
            # Create a white background for the logo
            logo_bg = Image.new('RGB', (logo_size + 20, logo_size + 20), 'white')
            logo_bg.paste(logo, (10, 10))
            
            # Calculate position to center the logo
            logo_pos = (
                (qr_width - logo_bg.width) // 2,
                (qr_height - logo_bg.height) // 2
            )
            
            # Paste logo onto QR code
            qr_img.paste(logo_bg, logo_pos)
            
            return qr_img
        except Exception as e:
            print(f"Error adding logo: {e}")
            return qr_img