#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Stegano - Stegano is a pure Python steganography module.
# Copyright (C) 2010-2022  Cédric Bonhomme - https://www.cedricbonhomme.org
#
# For more information : https://git.sr.ht/~cedric/stegano
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>

__author__ = "Cedric Bonhomme"
__version__ = "$Revision: 0.6 $"
__date__ = "$Date: 2016/04/13 $"
__revision__ = "$Date: 2022/01/04 $"
__license__ = "GPLv3"

import io
import os
import unittest
from unittest.mock import patch

from stegano import lsb
from stegano.lsb import generators


class TestLSB(unittest.TestCase):
    def test_hide_empty_message(self):
        """
        Test hiding the empty string.
        """
        with self.assertRaises(AssertionError):
            lsb.hide("./tests/sample-files/Lenna.png", "", generators.eratosthenes())

    def test_hide_and_reveal_without_generator(self):
        messages_to_hide = ["a", "foo", "Hello World!", ":Python:"]
        for message in messages_to_hide:
            secret = lsb.hide("./tests/sample-files/Lenna.png", message)
            secret.save("./image.png")

            clear_message = lsb.reveal("./image.png")

            self.assertEqual(message, clear_message)

    def test_hide_and_reveal_with_eratosthenes(self):
        messages_to_hide = ["a", "foo", "Hello World!", ":Python:"]
        for message in messages_to_hide:
            secret = lsb.hide(
                "./tests/sample-files/Lenna.png", message, generators.eratosthenes()
            )
            secret.save("./image.png")

            clear_message = lsb.reveal("./image.png", generators.eratosthenes())

            self.assertEqual(message, clear_message)

    def test_hide_and_reveal_with_ackermann(self):
        messages_to_hide = ["foo"]
        for message in messages_to_hide:
            secret = lsb.hide(
                "./tests/sample-files/Lenna.png", message, generators.ackermann(m=3)
            )
            secret.save("./image.png")

            clear_message = lsb.reveal("./image.png", generators.ackermann(m=3))

            self.assertEqual(message, clear_message)

    def test_hide_and_reveal_with_ackermann_naive(self):
        messages_to_hide = ["foo"]
        for message in messages_to_hide:
            secret = lsb.hide(
                "./tests/sample-files/Lenna.png",
                message,
                generators.ackermann_naive(m=2),
            )
            secret.save("./image.png")

            clear_message = lsb.reveal("./image.png", generators.ackermann_naive(m=2))

            self.assertEqual(message, clear_message)

    def test_hide_and_reveal_with_mersenne(self):
        messages_to_hide = ["f"]
        for message in messages_to_hide:
            secret = lsb.hide(
                "./tests/sample-files/Lenna.png",
                message,
                generators.mersenne(),
            )
            secret.save("./image.png")

            clear_message = lsb.reveal("./image.png", generators.mersenne())

            self.assertEqual(message, clear_message)

    def test_hide_and_reveal_with_shi_tomashi(self):
        messages_to_hide = ["foo bar"]
        for message in messages_to_hide:
            secret = lsb.hide(
                "./tests/sample-files/Lenna.png",
                message,
                generators.shi_tomashi("./tests/sample-files/Lenna.png"),
            )
            secret.save("./image.png")

            clear_message = lsb.reveal(
                "./image.png", generators.shi_tomashi("./tests/sample-files/Lenna.png")
            )

            self.assertEqual(message, clear_message)

    def test_hide_and_reveal_with_shift(self):
        messages_to_hide = ["a", "foo", "Hello World!", ":Python:"]
        for message in messages_to_hide:
            secret = lsb.hide(
                "./tests/sample-files/Lenna.png", message, generators.eratosthenes(), 4
            )
            secret.save("./image.png")

            clear_message = lsb.reveal("./image.png", generators.eratosthenes(), 4)

            self.assertEqual(message, clear_message)

    def test_hide_and_reveal_UTF32LE(self):
        messages_to_hide = "I love 🍕 and 🍫!"
        secret = lsb.hide(
            "./tests/sample-files/Lenna.png",
            messages_to_hide,
            generators.eratosthenes(),
            encoding="UTF-32LE",
        )
        secret.save("./image.png")

        clear_message = lsb.reveal(
            "./image.png", generators.eratosthenes(), encoding="UTF-32LE"
        )
        self.assertEqual(messages_to_hide, clear_message)

    def test_with_transparent_png(self):
        messages_to_hide = ["a", "foo", "Hello World!", ":Python:"]
        for message in messages_to_hide:
            secret = lsb.hide(
                "./tests/sample-files/transparent.png",
                message,
                generators.eratosthenes(),
            )
            secret.save("./image.png")

            clear_message = lsb.reveal("./image.png", generators.eratosthenes())

            self.assertEqual(message, clear_message)

    @patch("builtins.input", return_value="y")
    def test_manual_convert_rgb(self, input):
        message_to_hide = "Hello World!"
        lsb.hide(
            "./tests/sample-files/Lenna-grayscale.png",
            message_to_hide,
            generators.eratosthenes(),
        )

    @patch("builtins.input", return_value="n")
    def test_refuse_convert_rgb(self, input):
        message_to_hide = "Hello World!"
        with self.assertRaises(Exception):
            lsb.hide(
                "./tests/sample-files/Lenna-grayscale.png",
                message_to_hide,
                generators.eratosthenes(),
            )

    def test_with_location_of_image_as_argument(self):
        messages_to_hide = ["Hello World!"]

        for message in messages_to_hide:
            outputBytes = io.BytesIO()
            bytes_image = lsb.hide(
                "./tests/sample-files/20160505T130442.jpg",
                message,
                generators.identity(),
            )
            bytes_image.save(outputBytes, "PNG")
            outputBytes.seek(0)

            clear_message = lsb.reveal(outputBytes, generators.identity())

            self.assertEqual(message, clear_message)

    def test_auto_convert_rgb(self):
        message_to_hide = "Hello World!"
        lsb.hide(
            "./tests/sample-files/Lenna-grayscale.png",
            message_to_hide,
            generators.eratosthenes(),
            auto_convert_rgb=True,
        )

    def test_with_too_long_message(self):
        with open("./tests/sample-files/lorem_ipsum.txt") as f:
            message = f.read()
        message += message * 2
        with self.assertRaises(Exception):
            lsb.hide("./tests/sample-files/Lenna.png", message, generators.identity())

    def test_hide_and_reveal_with_bad_generator(self):
        message_to_hide = "Hello World!"
        secret = lsb.hide(
            "./tests/sample-files/Lenna.png", message_to_hide, generators.eratosthenes()
        )
        secret.save("./image.png")

        with self.assertRaises(IndexError):
            lsb.reveal("./image.png", generators.identity())

    def test_with_unknown_generator(self):
        message_to_hide = "Hello World!"
        with self.assertRaises(AttributeError):
            lsb.hide(
                "./tests/sample-files/Lenna.png",
                message_to_hide,
                generators.unknown_generator(),
            )

    def tearDown(self):
        try:
            os.unlink("./image.png")
        except Exception:
            pass


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