"""

Part of the bsie test suite.
A copy of the license is provided with the project.
Author: Matthias Baumgartner, 2022
"""
# standard imports
from functools import partial
import importlib
import os
import unittest

# external imports
import PIL.Image

# bsie imports
from bsie.utils import errors

# objects to test
from bsie.reader.preview import Preview


## code ##

class TestPreview(unittest.TestCase):
    def setUp(self):
        if __package__ is None or __package__ == '': # direct call or local discovery
            importlib.import_module('load_nef', __package__).get()
        else: # parent discovery
            importlib.import_module('.load_nef', __package__).get()

    def test_construct(self):
        preview = Preview()
        self.assertIsInstance(preview, Preview)
        self.assertEqual(len(preview._children), 3)

    def test_call(self):
        preview = Preview()
        # call raises error if file cannot be read
        self.assertRaises(errors.ReaderError, preview,
            os.path.join(os.path.dirname(__file__), 'missing.jpg'))
        self.assertRaises(errors.ReaderError, preview(
            os.path.join(os.path.dirname(__file__), 'invalid.jpg')), 10)
        self.assertRaises(errors.UnsupportedFileFormatError, preview,
            os.path.join(os.path.dirname(__file__), 'invalid.foo'))

        # call returns raw preview
        gen = preview(os.path.join(os.path.dirname(__file__), 'testimage.nef'))
        img = gen(10)
        self.assertIsInstance(img, PIL.Image.Image)
        self.assertEqual(img.size, (10, 8))
        self.assertEqual(sum(band for pix in img.getdata() for band in pix), 25287)
        img.close()

        # call returns jpeg image
        gen = preview(os.path.join(os.path.dirname(__file__), 'testimage.jpg'))
        img = gen(10)
        self.assertIsInstance(img, PIL.Image.Image)
        self.assertEqual(img.size, (10, 10))
        self.assertEqual(sum(band for pix in img.getdata() for band in pix), 0)
        img.close()

        # preview generator can also extract data from non-image files
        gen = preview(os.path.join(os.path.dirname(__file__), 'testfile.pdf'))
        img = gen(10)
        self.assertIsInstance(img, PIL.Image.Image)
        self.assertEqual(img.size, (8, 10))
        self.assertEqual(sum(img.getdata()), 20258)
        img.close()


## main ##

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

## EOF ##