# coding: utf-8

from django.core.exceptions import ValidationError
from django.core.files.images import get_image_dimensions
from django.utils.translation import ugettext_lazy as _
from django.utils.deconstruct import deconstructible


@deconstructible
class ImageDimensionsValidator:
    """ImageField dimensions validator."""
    
    def __init__(self, width=None, height=None, min_width=None, max_width=None, 
        min_height=None, max_height=None):
        """
        Constructor
        
        Args:
            width (int): exact width
            height (int): exact height
            min_width (int): minimum width
            min_height (int): minimum height
            max_width (int): maximum width
            max_height (int): maximum height
        """
                        
        self.width = width
        self.height = height
        self.min_width = min_width
        self.max_width = max_width
        self.min_height = min_height
        self.max_height = max_height
        
    def __call__(self, image):
        w, h = get_image_dimensions(image)
        
        if self.width is not None and w != self.width:
            raise ValidationError(_('%s width must be %dpx.') % (image.field.verbose_name.title(), self.width, ))
        
        if self.height is not None and h != self.height:
            raise ValidationError(_('%s height must be %dpx.') % (image.field.verbose_name.title(), self.height, ))
        
        if self.min_width is not None and w < self.min_width:
            raise ValidationError(_('%s minimum width must be %dpx.') % (image.field.verbose_name.title(), self.min_width, ))
            
        if self.min_height is not None and h < self.min_height:
            raise ValidationError(_('%s minimum height must be %dpx.') % (image.field.verbose_name.title(), self.min_height, ))
            
        if self.max_width is not None and w > self.max_width:
            raise ValidationError(_('%s maximum width must be %dpx.') % (image.field.verbose_name.title(), self.max_width, ))
            
        if self.max_height is not None and h > self.max_height:
            raise ValidationError(_('%s maximum height must be %dpx.') % (image.field.verbose_name.title(), self.max_height, ))