utils: add a proper reverseModes() with tests

Closes #107.

tests/test_utils.py

@@ -101,19 +101,43 @@ class TestUtils(unittest.TestCase):
                                ('+b', '*!*@*.badisp.net')])
         self.assertEqual(res, '-o+l-nm+kb 9PYAAAAAA 50 hello *!*@*.badisp.net')
 
-    @unittest.skip('Wait, we need to work out the kinks first! (reversing changes of modes with arguments)')
+    def _reverseModes(self, query, expected, target='#test'):
+        res = utils.reverseModes(self.irc, target, query)
+        self.assertEqual(res, expected)
+
     def testReverseModes(self):
-        f = lambda x: utils.reverseModes(self.irc, '#test', x)
+        test = lambda x, y: self.assertEqual(utils.reverseModes(self.irc, '#test', x), y)
         # Strings.
-        self.assertEqual(f("+nt-lk"), "-nt+lk")
-        self.assertEqual(f("nt-k"), "-nt+k")
+        self._reverseModes("+mi-lk test", "-mi+lk test")
+        self._reverseModes("mi-k test", "-mi+k test")
         # Lists.
-        self.assertEqual(f([('+m', None), ('+t', None), ('+l', '3'), ('-o', 'person')]),
-            [('-m', None), ('-t', None), ('-l', '3'), ('+o', 'person')])
+        self._reverseModes([('+m', None), ('+r', None), ('+l', '3'), ('-o', 'person')],
+                           {('-m', None), ('-r', None), ('-l', None), ('+o', 'person')})
         # Sets.
-        self.assertEqual(f({('s', None), ('+o', 'whoever')}), {('-s', None), ('-o', 'whoever')})
+        self._reverseModes({('s', None), ('+o', 'whoever')}, {('-s', None), ('-o', 'whoever')})
         # Combining modes with an initial + and those without
-        self.assertEqual(f({('s', None), ('+n', None)}), {('-s', None), ('-n', None)})
+        self._reverseModes({('s', None), ('+R', None)}, {('-s', None), ('-R', None)})
+
+    def testReverseModesUser(self):
+        self._reverseModes({('+i', None), ('l', 'asfasd')}, {('-i', None), ('-l', 'asfasd')},
+                           target=self.irc.pseudoclient.uid)
+
+    def testReverseModesExisting(self):
+        utils.applyModes(self.irc, '#test', [('+m', None), ('+l', '50'), ('+k', 'supersecret'),
+                                             ('+o', '9PYAAAAAA')])
+
+        self._reverseModes({('+i', None), ('+l', '3')}, {('-i', None), ('+l', '50')})
+        self._reverseModes('-n', '+n')
+        self._reverseModes('-l', '+l 50')
+        self._reverseModes('+k derp', '+k supersecret')
+        self._reverseModes('-mk *', '+mk supersecret')
+
+        # Existing modes are ignored.
+        self._reverseModes([('+t', None)], set())
+        self._reverseModes('+n', '+')
+        self._reverseModes('+oo GLolol 9PYAAAAAA', '-o GLolol')
+        self._reverseModes('+o 9PYAAAAAA', '+')
+        self._reverseModes('+vvvvM test abcde atat abcd', '-vvvvM test abcde atat abcd')
 
 if __name__ == '__main__':
     unittest.main()

utils.py

@@ -326,10 +326,20 @@ def joinModes(modes):
         modelist += ' %s' % ' '.join(args)
     return modelist
 
-def reverseModes(irc, target, modes):
-    """<mode string/mode list>
+def _flip(mode):
+    """Flips a mode character."""
+    # Make it a list first, strings don't support item assignment
+    mode = list(mode)
+    if mode[0] == '-':  # Query is something like "-n"
+        mode[0] = '+'  # Change it to "+n"
+    elif mode[0] == '+':
+        mode[0] = '-'
+    else:  # No prefix given, assume +
+        mode.insert(0, '-')
+    return ''.join(mode)
 
-    Reverses/Inverts the mode string or mode list given.
+def reverseModes(irc, target, modes):
+    """Reverses/Inverts the mode string or mode list given.
 
     "+nt-lk" => "-nt+lk"
     "nt-k" => "-nt+k"
@@ -338,21 +348,56 @@ def reverseModes(irc, target, modes):
     [('s', None), ('+n', None)] => [('-s', None), ('-n', None)]
     """
     origtype = type(modes)
-    # Operate on joined modestrings only; it's easier.
-    if origtype != str:
-        modes = joinModes(modes)
-    # Swap the +'s and -'s by replacing one with a dummy character, and then changing it back.
-    assert '\x00' not in modes, 'NUL cannot be in the mode list (it is a reserved character)!'
-    if not modes.startswith(('+', '-')):
-        modes = '+' + modes
-    newmodes = modes.replace('+', '\x00')
-    newmodes = newmodes.replace('-', '+')
-    newmodes = newmodes.replace('\x00', '-')
-    if origtype != str:
-        # If the original query isn't a string, send back the parseModes() output.
-        return parseModes(irc, target, newmodes.split(" "))
+    # If the query is a string, we have to parse it first.
+    if origtype == str:
+        modes = parseModes(irc, target, modes.split(" "))
+    # Get the current mode list first.
+    if isChannel(target):
+        oldmodes = irc.channels[target].modes.copy()
+        possible_modes = irc.cmodes.copy()
+        # For channels, this also includes the list of prefix modes.
+        possible_modes['*A'] += ''.join(irc.prefixmodes)
+        for name, userlist in irc.channels[target].prefixmodes.items():
+            try:
+                oldmodes.update([(irc.cmodes[name[:-1]], u) for u in userlist])
+            except KeyError:
+                continue
     else:
-        return newmodes
+        oldmodes = irc.users[target].modes
+        possible_modes = irc.umodes
+    newmodes = []
+    for char, arg in modes:
+        # Mode types:
+        # A = Mode that adds or removes a nick or address to a list. Always has a parameter.
+        # B = Mode that changes a setting and always has a parameter.
+        # C = Mode that changes a setting and only has a parameter when set.
+        # D = Mode that changes a setting and never has a parameter.
+        mchar = char[-1]
+        if mchar in possible_modes['*B'] + possible_modes['*C']:
+            # We need to find the current mode list, so we can reset arguments
+            # for modes that have arguments. For example, setting +l 30 on a channel
+            # that had +l 50 set should give "+l 30", not "-l".
+            oldarg = [m for m in oldmodes if m[0] == mchar]
+            if oldarg:  # Old mode argument for this mode existed, use that.
+                oldarg = oldarg[0]
+                mpair = ('+%s' % oldarg[0], oldarg[1])
+            else:  # Not found, flip the mode then.
+                # Mode takes no arguments when unsetting.
+                if mchar in possible_modes['*C'] and char[0] != '-':
+                    arg = None
+                mpair = (_flip(char), arg)
+        else:
+            mpair = (_flip(char), arg)
+        if char[0] != '-' and (mchar, arg) in oldmodes:
+            # Mode is already set.
+            continue
+        newmodes.append(mpair)
+
+    if origtype == str:
+        # If the original query is a string, send it back as a string.
+        return joinModes(newmodes)
+    else:
+        return set(newmodes)
 
 def isInternalClient(irc, numeric):
     """