import os, tempfile, unittest
from path_sandbox import PathEscapeError, safe_join, safe_resolve, is_within, realpath_root


class TestPathSandbox(unittest.TestCase):
    def setUp(self):
        self.d = tempfile.mkdtemp()
        self.root = os.path.join(self.d, "root")
        os.makedirs(self.root)
        self.rr = os.path.realpath(self.root)
        # a file inside
        with open(os.path.join(self.root, "a.txt"), "w") as f:
            f.write("x")
        # subdir
        os.makedirs(os.path.join(self.root, "sub"))
        # symlink escaping root
        os.symlink("/etc", os.path.join(self.root, "escape"))

    def test_basic_join(self):
        self.assertEqual(safe_join(self.root, "a.txt"), os.path.join(self.rr, "a.txt"))

    def test_nested(self):
        self.assertEqual(safe_join(self.root, "sub", "b.txt"), os.path.join(self.rr, "sub", "b.txt"))

    def test_traversal_rejected(self):
        with self.assertRaises(PathEscapeError):
            safe_join(self.root, "..", "etc", "passwd")

    def test_absolute_rejected(self):
        with self.assertRaises(PathEscapeError):
            safe_join(self.root, "/etc/passwd")

    def test_backslash_rejected(self):
        with self.assertRaises(PathEscapeError):
            safe_join(self.root, "a\\..\\..\\etc")

    def test_nul_rejected(self):
        with self.assertRaises(PathEscapeError):
            safe_join(self.root, "a\x00b")

    def test_symlink_escape_rejected(self):
        with self.assertRaises(PathEscapeError):
            safe_join(self.root, "escape", "passwd")

    def test_empty_root_error(self):
        with self.assertRaises(PathEscapeError):
            realpath_root("")

    def test_nonexistent_root_error(self):
        with self.assertRaises(PathEscapeError):
            realpath_root(os.path.join(self.d, "nope"))

    def test_is_within_true(self):
        self.assertTrue(is_within(self.root, os.path.join(self.root, "a.txt")))

    def test_is_within_false(self):
        self.assertFalse(is_within(self.root, "/etc/passwd"))

    def test_safe_resolve_list(self):
        self.assertEqual(safe_resolve(self.root, ["sub", "x"]), os.path.join(self.rr, "sub", "x"))

    def test_dot_components_ok(self):
        # single "." components collapse
        p = safe_join(self.root, ".", "a.txt")
        self.assertEqual(p, os.path.join(self.rr, "a.txt"))

    def test_double_slash_ok(self):
        p = safe_join(self.root, "sub//b.txt")
        self.assertEqual(p, os.path.join(self.rr, "sub", "b.txt"))


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