from __future__ import absolute_import, division, print_function

import unittest

import six
from PIL import Image

import imagehash

from .utils import TestImageHash


class TestBasic(TestImageHash):

	def setUp(self):
		self.image = self.get_data_image()
		self.func = imagehash.whash

	def test_whash(self):
		self.check_hash_algorithm(self.func, self.image)

	def test_whash_length(self):
		self.check_hash_length(self.func, self.image, sizes=[2, 4, 8, 16, 32, 64])

	def test_whash_stored(self):
		self.check_hash_stored(self.func, self.image, sizes=[2, 4, 8, 16, 32, 64])


class Test(unittest.TestCase):
	def setUp(self):
		self.image = self._get_white_image()

	def _get_white_image(self, size=None):
		if size is None:
			size = (512, 512)
		return Image.new('RGB', size, 'white')

	def test_hash_size_2power(self):
		for hash_size in [4, 8, 16]:
			hash = imagehash.whash(self.image, hash_size=hash_size)
			self.assertEqual(hash.hash.size, hash_size**2)

	def test_hash_size_for_small_images(self):
		default_hash_size = 8
		for image_size in [(1, 25), (7, 5)]:
			image = self._get_white_image(image_size)
			hash = imagehash.whash(image)
			self.assertEqual(hash.hash.size, default_hash_size**2)

	def test_hash_size_not_2power(self):
		emsg = 'hash_size is not power of 2'
		for hash_size in [3, 7, 12]:
			with six.assertRaisesRegex(self, AssertionError, emsg):
				imagehash.whash(self.image, hash_size=hash_size)

	def test_hash_size_is_less_than_image_scale(self):
		image = self._get_white_image((120, 200))
		emsg = 'hash_size in a wrong range'
		for hash_size in [128, 512]:
			with six.assertRaisesRegex(self, AssertionError, emsg):
				imagehash.whash(image, hash_size=hash_size, image_scale=64)

	def test_custom_hash_size_and_scale(self):
		hash_size = 16
		hash = imagehash.whash(self.image, hash_size=hash_size, image_scale=64)
		self.assertEqual(hash.hash.size, hash_size**2)

	def test_hash_size_more_than_scale(self):
		emsg = 'hash_size in a wrong range'
		with six.assertRaisesRegex(self, AssertionError, emsg):
			imagehash.whash(self.image, hash_size=32, image_scale=16)

	def test_image_scale_not_2power(self):
		emsg = 'image_scale is not power of 2'
		for image_scale in [4, 8, 16]:
			with six.assertRaisesRegex(self, AssertionError, emsg):
				imagehash.whash(self.image, image_scale=image_scale + 1)


if __name__ == '__main__':
	unittest.main()