# Copyright 2017-present Open Networking Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import absolute_import
from __future__ import print_function
import unittest
from xosgenx.generator import XOSProcessor, XOSProcessorArgs
from helpers import XProtoTestHelpers, FakeObject


def output_security_check(x, y):
    """
    This function eliminates warnings arising due to the missing
    output_security_check, which is generated and loaded dynamically. This is
    defined in the global namespace, and in python3 the globals() namespace has
    to be passed to calls to "exec()" for the xproto-generated version to
    redefine this function.
    """

    raise Exception("Security enforcer not generated. Test failed.")
    return False


class XProtoSecurityTest(unittest.TestCase):
    """
    Use the Python code target to generate Python security policies, set up an
    appropriate environment and execute the Python.
    """

    def setUp(self):
        self.target = XProtoTestHelpers.write_tmp_target(
            """
{% for name, policy in proto.policies.items() %}
{{ xproto_fol_to_python_test(name, policy, None, '0') }}
{% endfor %}
"""
        )

    def test_constant(self):
        xproto = """
    policy output < True >
"""
        args = XOSProcessorArgs(inputs=xproto, target=self.target)
        output = XOSProcessor.process(args)
        exec(output, globals())  # This loads the generated function, which should look like this:

        """
        def output_security_check(obj, ctx):
            i1 = True
            return i1
        """

        verdict = output_security_check({}, {})
        self.assertTrue(verdict)

    def test_equal(self):
        xproto = """
    policy output < ctx.user = obj.user >
"""

        args = XOSProcessorArgs(inputs=xproto, target=self.target)
        output = XOSProcessor.process(args)
        exec(output, globals())  # This loads the generated function, which should look like this:

        """
        def output_security_check(obj, ctx):
            i1 = (ctx.user == obj.user)
            return i1
        """

        obj = FakeObject()
        obj.user = 1
        ctx = FakeObject()
        ctx.user = 1

        verdict = output_security_check(obj, ctx)

    def test_call_policy(self):
        xproto = """
    policy sub_policy < ctx.user = obj.user >
    policy output < *sub_policy(child) >
"""

        args = XOSProcessorArgs(inputs=xproto, target=self.target)
        output = XOSProcessor.process(args)
        exec(output, globals())  # This loads the generated function, which should look like this:

        """
        def sub_policy_security_check(obj, ctx):
            i1 = (ctx.user == obj.user)
            return i1

        def output_security_check(obj, ctx):
            if obj.child:
                i1 = sub_policy_security_check(obj.child, ctx)
            else:
                i1 = True
            return i1
        """

        obj = FakeObject()
        obj.child = FakeObject()
        obj.child.user = 1

        ctx = FakeObject()
        ctx.user = 1

        verdict = output_security_check(obj, ctx)
        self.assertTrue(verdict)

    def test_call_policy_child_none(self):
        xproto = """
    policy sub_policy < ctx.user = obj.user >
    policy output < *sub_policy(child) >
"""

        args = XOSProcessorArgs(inputs=xproto, target=self.target)
        output = XOSProcessor.process(args)
        exec(output, globals())  # This loads the generated function, which should look like this:

        """
        def sub_policy_security_check(obj, ctx):
            i1 = (ctx.user == obj.user)
            return i1

        def output_security_check(obj, ctx):
            if obj.child:
                i1 = sub_policy_security_check(obj.child, ctx)
            else:
                i1 = True
            return i1
        """

        obj = FakeObject()
        obj.child = None

        ctx = FakeObject()
        ctx.user = 1

        verdict = output_security_check(obj, ctx)
        self.assertTrue(verdict)

    def test_bin(self):
        xproto = """
    policy output < ctx.is_admin = True | obj.empty = True>
"""

        args = XOSProcessorArgs(inputs=xproto, target=self.target)
        output = XOSProcessor.process(args)
        exec(output, globals())  # This loads the generated function, which should look like this:

        """
        def output_security_check(obj, ctx):
            i2 = (ctx.is_admin == True)
            i3 = (obj.empty == True)
            i1 = (i2 or i3)
            return i1
        """

        obj = FakeObject()
        obj.empty = True

        ctx = FakeObject()
        ctx.is_admin = True

        verdict = output_security_check(obj, ctx)

        self.assertTrue(verdict)

    def test_exists(self):
        xproto = """
    policy output < exists Privilege: Privilege.object_id = obj.id >
"""
        args = XOSProcessorArgs(inputs=xproto, target=self.target)
        output = XOSProcessor.process(args)
        exec(output, globals())  # This loads the generated function, which should look like this:

        """
        def output_security_check(obj, ctx):
            i1 = Privilege.objects.filter(object_id=obj.id)
                return i1
        """

        self.assertTrue(output_security_check is not None)

    def test_python(self):
        xproto = """
    policy output < {{ "jack" in ["the", "box"] }} = False >
"""
        args = XOSProcessorArgs(inputs=xproto, target=self.target)
        output = XOSProcessor.process(args)
        exec(output, globals())  # This loads the generated function, which should look like this:

        """
        def output_security_check(obj, ctx):
            i2 = ('jack' in ['the', 'box'])
            i1 = (i2 == False)
            return i1
        """

        self.assertTrue(output_security_check({}, {}) is True)

    def test_forall(self):
        # This one we only parse
        xproto = """
    policy output < forall Credential: Credential.obj_id = obj_id >
"""

        args = XOSProcessorArgs(inputs=xproto, target=self.target)
        output = XOSProcessor.process(args)
        exec(output, globals())

        """
        def output_security_check(obj, ctx):
            i2 = Credential.objects.filter((~ Q(obj_id=obj_id)))[0]
            i1 = (not i2)
            return i1
        """


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