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New structure.
[plomrogue2-experiments] / new / plomrogue2.py
diff --git a/new/plomrogue2.py b/new/plomrogue2.py
new file mode 100755 (executable)
index 0000000..2b8f762
--- /dev/null
@@ -0,0 +1,926 @@
+#!/usr/bin/env python3
+import socketserver
+import threading
+import queue
+import sys
+import parser
+
+
+class GameError(Exception):
+    pass
+
+
+# Avoid "Address already in use" errors.
+socketserver.TCPServer.allow_reuse_address = True
+
+
+class Server(socketserver.ThreadingTCPServer):
+    """Bind together threaded IO handling server and message queue."""
+
+    def __init__(self, queue, port, *args, **kwargs):
+        super().__init__(('localhost', port), IO_Handler, *args, **kwargs)
+        self.queue_out = queue
+        self.daemon_threads = True  # Else, server's threads have daemon=False.
+
+
+class IO_Handler(socketserver.BaseRequestHandler):
+
+    def handle(self):
+        """Move messages between network socket and game IO loop via queues.
+
+        On start (a new connection from client to server), sets up a
+        new queue, sends it via self.server.queue_out to the game IO
+        loop thread, and from then on receives messages to send back
+        from the game IO loop via that new queue.
+
+        At the same time, loops over socket's recv to get messages
+        from the outside into the game IO loop by way of
+        self.server.queue_out into the game IO. Ends connection once a
+        'QUIT' message is received from socket, and then also calls
+        for a kill of its own queue.
+
+        All messages to the game IO loop are tuples, with the first
+        element a meta command ('ADD_QUEUE' for queue creation,
+        'KILL_QUEUE' for queue deletion, and 'COMMAND' for everything
+        else), the second element a UUID that uniquely identifies the
+        thread (so that the game IO loop knows whom to send replies
+        back to), and optionally a third element for further
+        instructions.
+
+        """
+
+        def send_queue_messages(plom_socket, queue_in, thread_alive):
+            """Send messages via socket from queue_in while thread_alive[0]."""
+            while thread_alive[0]:
+                try:
+                    msg = queue_in.get(timeout=1)
+                except queue.Empty:
+                    continue
+                plom_socket.send(msg, True)
+
+        import uuid
+        import plom_socket
+        plom_socket = plom_socket.PlomSocket(self.request)
+        print('CONNECTION FROM:', str(self.client_address))
+        connection_id = uuid.uuid4()
+        queue_in = queue.Queue()
+        self.server.queue_out.put(('ADD_QUEUE', connection_id, queue_in))
+        thread_alive = [True]
+        t = threading.Thread(target=send_queue_messages,
+                             args=(plom_socket, queue_in, thread_alive))
+        t.start()
+        for message in plom_socket.recv():
+            if message is None:
+                plom_socket.send('BAD MESSAGE', True)
+            elif 'QUIT' == message:
+                plom_socket.send('BYE', True)
+                break
+            else:
+                self.server.queue_out.put(('COMMAND', connection_id, message))
+        self.server.queue_out.put(('KILL_QUEUE', connection_id))
+        thread_alive[0] = False
+        print('CONNECTION CLOSED FROM:', str(self.client_address))
+        plom_socket.socket.close()
+
+
+class GameIO():
+
+    def __init__(self, game_file_name, game):
+        self.game_file_name = game_file_name
+        self.queues_out = {}
+        self.parser = parser.Parser(game)
+
+    def loop(self, q):
+        """Handle commands coming through queue q, send results back.
+
+        Commands from q are expected to be tuples, with the first element
+        either 'ADD_QUEUE', 'COMMAND', or 'KILL_QUEUE', the second element
+        a UUID, and an optional third element of arbitrary type. The UUID
+        identifies a receiver for replies.
+
+        An 'ADD_QUEUE' command should contain as third element a queue
+        through which to send messages back to the sender of the
+        command. A 'KILL_QUEUE' command removes the queue for that
+        receiver from the list of queues through which to send replies.
+
+        A 'COMMAND' command is specified in greater detail by a string
+        that is the tuple's third element. The game_command_handler takes
+        care of processing this and sending out replies.
+
+        """
+        while True:
+            x = q.get()
+            command_type = x[0]
+            connection_id = x[1]
+            content = None if len(x) == 2 else x[2]
+            if command_type == 'ADD_QUEUE':
+                self.queues_out[connection_id] = content
+            elif command_type == 'KILL_QUEUE':
+                del self.queues_out[connection_id]
+            elif command_type == 'COMMAND':
+                self.handle_input(content, connection_id)
+
+    def run_loop_with_server(self):
+        """Run connection of server talking to clients and game IO loop.
+
+        We have the TCP server (an instance of Server) and we have the
+        game IO loop, a thread running self.loop. Both communicate with
+        each other via a queue.Queue. While the TCP server may spawn
+        parallel threads to many clients, the IO loop works sequentially
+        through game commands received from the TCP server's threads (=
+        client connections to the TCP server). A processed command may
+        trigger messages to the commanding client or to all clients,
+        delivered from the IO loop to the TCP server via the queue.
+
+        """
+        q = queue.Queue()
+        c = threading.Thread(target=self.loop, daemon=True, args=(q,))
+        c.start()
+        server = Server(q, 5000)
+        try:
+            server.serve_forever()
+        except KeyboardInterrupt:
+            pass
+        finally:
+            print('Killing server')
+            server.server_close()
+
+    def handle_input(self, input_, connection_id=None, store=True):
+        """Process input_ to command grammar, call command handler if found."""
+        from inspect import signature
+
+        def answer(connection_id, msg):
+            if connection_id:
+                self.send(msg, connection_id)
+            else:
+                print(msg)
+
+        try:
+            command, args = self.parser.parse(input_)
+            if command is None:
+                answer(connection_id, 'UNHANDLED_INPUT')
+            else:
+                if 'connection_id' in list(signature(command).parameters):
+                    command(*args, connection_id=connection_id)
+                else:
+                    command(*args)
+                    if store and not hasattr(command, 'dont_save'):
+                        with open(self.game_file_name, 'a') as f:
+                            f.write(input_ + '\n')
+        except parser.ArgError as e:
+            answer(connection_id, 'ARGUMENT_ERROR ' + quote(str(e)))
+        except GameError as e:
+            answer(connection_id, 'GAME_ERROR ' + quote(str(e)))
+
+    def send(self, msg, connection_id=None):
+        """Send message msg to server's client(s) via self.queues_out.
+
+        If a specific client is identified by connection_id, only
+        sends msg to that one. Else, sends it to all clients
+        identified in self.queues_out.
+
+        """
+        if connection_id:
+            self.queues_out[connection_id].put(msg)
+        else:
+            for connection_id in self.queues_out:
+                self.queues_out[connection_id].put(msg)
+
+
+class MapBase:
+
+    def __init__(self, size=(0, 0)):
+        self.size = size
+        self.terrain = '?'*self.size_i
+
+    @property
+    def size_i(self):
+        return self.size[0] * self.size[1]
+
+    def set_line(self, y, line):
+        height_map = self.size[0]
+        width_map = self.size[1]
+        if y >= height_map:
+            raise ArgError('too large row number %s' % y)
+        width_line = len(line)
+        if width_line > width_map:
+            raise ArgError('too large map line width %s' % width_line)
+        self.terrain = self.terrain[:y * width_map] + line +\
+                       self.terrain[(y + 1) * width_map:]
+
+    def get_position_index(self, yx):
+        return yx[0] * self.size[1] + yx[1]
+
+
+class Map(MapBase):
+
+    def __getitem__(self, yx):
+        return self.terrain[self.get_position_index(yx)]
+
+    def __setitem__(self, yx, c):
+        pos_i = self.get_position_index(yx)
+        if type(c) == str:
+            self.terrain = self.terrain[:pos_i] + c + self.terrain[pos_i + 1:]
+        else:
+            self.terrain[pos_i] = c
+
+    def __iter__(self):
+        """Iterate over YX position coordinates."""
+        for y in range(self.size[0]):
+            for x in range(self.size[1]):
+                yield [y, x]
+
+    def lines(self):
+        width = self.size[1]
+        for y in range(self.size[0]):
+            yield (y, self.terrain[y * width:(y + 1) * width])
+
+    def get_fov_map(self, yx):
+        return self.fov_map_type(self, yx)
+
+    def get_directions(self):
+        directions = []
+        for name in dir(self):
+            if name[:5] == 'move_':
+                directions += [name[5:]]
+        return directions
+
+    def get_neighbors(self, pos):
+        neighbors = {}
+        if not hasattr(self, 'neighbors_to'):
+            self.neighbors_to = {}
+        if pos in self.neighbors_to:
+            return self.neighbors_to[pos]
+        for direction in self.get_directions():
+            neighbors[direction] = None
+            try:
+                neighbors[direction] = self.move(pos, direction)
+            except GameError:
+                pass
+        self.neighbors_to[pos] = neighbors
+        return neighbors
+
+    def new_from_shape(self, init_char):
+        import copy
+        new_map = copy.deepcopy(self)
+        for pos in new_map:
+            new_map[pos] = init_char
+        return new_map
+
+    def move(self, start_pos, direction):
+        mover = getattr(self, 'move_' + direction)
+        new_pos = mover(start_pos)
+        if new_pos[0] < 0 or new_pos[1] < 0 or \
+                new_pos[0] >= self.size[0] or new_pos[1] >= self.size[1]:
+            raise GameError('would move outside map bounds')
+        return new_pos
+
+    def move_LEFT(self, start_pos):
+        return [start_pos[0], start_pos[1] - 1]
+
+    def move_RIGHT(self, start_pos):
+        return [start_pos[0], start_pos[1] + 1]
+
+
+
+class MapHex(Map):
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fov_map_type = FovMapHex
+
+    def move_UPLEFT(self, start_pos):
+        if start_pos[0] % 2 == 1:
+            return [start_pos[0] - 1, start_pos[1] - 1]
+        else:
+            return [start_pos[0] - 1, start_pos[1]]
+
+    def move_UPRIGHT(self, start_pos):
+        if start_pos[0] % 2 == 1:
+            return [start_pos[0] - 1, start_pos[1]]
+        else:
+            return [start_pos[0] - 1, start_pos[1] + 1]
+
+    def move_DOWNLEFT(self, start_pos):
+        if start_pos[0] % 2 == 1:
+             return [start_pos[0] + 1, start_pos[1] - 1]
+        else:
+               return [start_pos[0] + 1, start_pos[1]]
+
+    def move_DOWNRIGHT(self, start_pos):
+        if start_pos[0] % 2 == 1:
+            return [start_pos[0] + 1, start_pos[1]]
+        else:
+            return [start_pos[0] + 1, start_pos[1] + 1]
+
+
+
+class FovMap:
+
+    def __init__(self, source_map, yx):
+        self.source_map = source_map
+        self.size = self.source_map.size
+        self.terrain = '?' * self.size_i
+        self[yx] = '.'
+        self.shadow_cones = []
+        self.circle_out(yx, self.shadow_process_hex)
+
+    def shadow_process_hex(self, yx, distance_to_center, dir_i, dir_progress):
+        # Possible optimization: If no shadow_cones yet and self[yx] == '.',
+        # skip all.
+        CIRCLE = 360  # Since we'll float anyways, number is actually arbitrary.
+
+        def correct_arm(arm):
+            if arm < 0:
+                arm += CIRCLE
+            return arm
+
+        def in_shadow_cone(new_cone):
+            for old_cone in self.shadow_cones:
+                if old_cone[0] >= new_cone[0] and \
+                    new_cone[1] >= old_cone[1]:
+                    #print('DEBUG shadowed by:', old_cone)
+                    return True
+                # We might want to also shade hexes whose middle arm is inside a
+                # shadow cone for a darker FOV. Note that we then could not for
+                # optimization purposes rely anymore on the assumption that a
+                # shaded hex cannot add growth to existing shadow cones.
+            return False
+
+        def merge_cone(new_cone):
+            import math
+            for old_cone in self.shadow_cones:
+                if new_cone[0] > old_cone[0] and \
+                    (new_cone[1] < old_cone[0] or
+                     math.isclose(new_cone[1], old_cone[0])):
+                    #print('DEBUG merging to', old_cone)
+                    old_cone[0] = new_cone[0]
+                    #print('DEBUG merged cone:', old_cone)
+                    return True
+                if new_cone[1] < old_cone[1] and \
+                    (new_cone[0] > old_cone[1] or
+                     math.isclose(new_cone[0], old_cone[1])):
+                    #print('DEBUG merging to', old_cone)
+                    old_cone[1] = new_cone[1]
+                    #print('DEBUG merged cone:', old_cone)
+                    return True
+            return False
+
+        def eval_cone(cone):
+            #print('DEBUG CONE', cone, '(', step_size, distance_to_center, number_steps, ')')
+            if in_shadow_cone(cone):
+                return
+            self[yx] = '.'
+            if self.source_map[yx] != '.':
+                #print('DEBUG throws shadow', cone)
+                unmerged = True
+                while merge_cone(cone):
+                    unmerged = False
+                if unmerged:
+                    self.shadow_cones += [cone]
+
+        #print('DEBUG', yx)
+        step_size = (CIRCLE/len(self.circle_out_directions)) / distance_to_center
+        number_steps = dir_i * distance_to_center + dir_progress
+        left_arm = correct_arm(-(step_size/2) - step_size*number_steps)
+        right_arm = correct_arm(left_arm - step_size)
+        # Optimization potential: left cone could be derived from previous
+        # right cone. Better even: Precalculate all cones.
+        if right_arm > left_arm:
+            eval_cone([left_arm, 0])
+            eval_cone([CIRCLE, right_arm])
+        else:
+            eval_cone([left_arm, right_arm])
+
+    def basic_circle_out_move(self, pos, direction):
+        """Move position pos into direction. Return whether still in map."""
+        mover = getattr(self, 'move_' + direction)
+        pos[:] = mover(pos)
+        if pos[0] < 0 or pos[1] < 0 or \
+            pos[0] >= self.size[0] or pos[1] >= self.size[1]:
+            return False
+        return True
+
+    def circle_out(self, yx, f):
+        # Optimization potential: Precalculate movement positions. (How to check
+        # circle_in_map then?)
+        # Optimization potential: Precalculate what hexes are shaded by what hex
+        # and skip evaluation of already shaded hexes. (This only works if hex
+        # shading implies they completely lie in existing shades; otherwise we
+        # would lose shade growth through hexes at shade borders.)
+
+        # TODO: Start circling only in earliest obstacle distance.
+        circle_in_map = True
+        distance = 1
+        yx = yx[:]
+        #print('DEBUG CIRCLE_OUT', yx)
+        while circle_in_map:
+            circle_in_map = False
+            self.basic_circle_out_move(yx, 'RIGHT')
+            for dir_i in range(len(self.circle_out_directions)):
+                for dir_progress in range(distance):
+                    direction = self.circle_out_directions[dir_i]
+                    if self.circle_out_move(yx, direction):
+                        f(yx, distance, dir_i, dir_progress)
+                        circle_in_map = True
+            distance += 1
+
+
+
+class FovMapHex(FovMap, MapHex):
+    circle_out_directions = ('DOWNLEFT', 'LEFT', 'UPLEFT',
+                             'UPRIGHT', 'RIGHT', 'DOWNRIGHT')
+
+    def circle_out_move(self, yx, direction):
+        return self.basic_circle_out_move(yx, direction)
+
+
+
+class ThingBase:
+
+    def __init__(self, world, id_, type_='?', position=[0,0]):
+        self.world = world
+        self.id_ = id_
+        self.type_ = type_
+        self.position = position
+
+
+class Thing(ThingBase):
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.set_task('WAIT')
+        self._last_task_result = None
+        self._stencil = None
+
+    def move_towards_target(self, target):
+        dijkstra_map = type(self.world.map_)(self.world.map_.size)
+        n_max = 256
+        dijkstra_map.terrain = [n_max for i in range(dijkstra_map.size_i)]
+        dijkstra_map[target] = 0
+        shrunk = True
+        visible_map = self.get_visible_map()
+        while shrunk:
+            shrunk = False
+            for pos in dijkstra_map:
+                if visible_map[pos] != '.':
+                    continue
+                neighbors = dijkstra_map.get_neighbors(tuple(pos))
+                for direction in neighbors:
+                    yx = neighbors[direction]
+                    if yx is not None and dijkstra_map[yx] < dijkstra_map[pos] - 1:
+                        dijkstra_map[pos] = dijkstra_map[yx] + 1
+                        shrunk = True
+        #with open('log', 'a') as f:
+        #    f.write('---------------------------------\n')
+        #    for y, line in dijkstra_map.lines():
+        #        for val in line:
+        #            if val < 10:
+        #                f.write(str(val))
+        #            elif val == 256:
+        #                f.write('x')
+        #            else:
+        #                f.write('~')
+        #        f.write('\n')
+        neighbors = dijkstra_map.get_neighbors(tuple(self.position))
+        n = n_max
+        #print('DEBUG', self.position, neighbors)
+        #dirs = dijkstra_map.get_directions()
+        #print('DEBUG dirs', dirs)
+        #print('DEBUG neighbors', neighbors)
+        #debug_scores = []
+        #for pos in neighbors:
+        #    if pos is None:
+        #        debug_scores += [9000]
+        #    else:
+        #        debug_scores += [dijkstra_map[pos]]
+        #print('DEBUG debug_scores', debug_scores)
+        target_direction = None
+        for direction in neighbors:
+            yx = neighbors[direction]
+            if yx is not None:
+                n_new = dijkstra_map[yx]
+                if n_new < n:
+                    n = n_new
+                    target_direction = direction
+        #print('DEBUG result', direction)
+        if target_direction:
+            self.set_task('MOVE', (target_direction,))
+
+    def decide_task(self):
+        # TODO: Check if monster can follow player too well (even when they should lose them)
+        visible_things = self.get_visible_things()
+        target = None
+        for t in visible_things:
+            if t.type_ == 'human':
+                target = t.position
+                break
+        if target is not None:
+            try:
+                self.move_towards_target(target)
+                return
+            except GameError:
+                pass
+        self.set_task('WAIT')
+
+    def set_task(self, task_name, args=()):
+        task_class = self.world.game.tasks[task_name]
+        self.task = task_class(self, args)
+        self.task.check()  # will throw GameError if necessary
+
+    def proceed(self, is_AI=True):
+        """Further the thing in its tasks.
+
+        Decrements .task.todo; if it thus falls to <= 0, enacts method
+        whose name is 'task_' + self.task.name and sets .task =
+        None. If is_AI, calls .decide_task to decide a self.task.
+
+        Before doing anything, ensures an empty map visibility stencil
+        and checks that task is still possible, and aborts it
+        otherwise (for AI things, decides a new task).
+
+        """
+        self._stencil = None
+        try:
+            self.task.check()
+        except GameError as e:
+            self.task = None
+            self._last_task_result = e
+            if is_AI:
+                try:
+                    self.decide_task()
+                except GameError:
+                    self.set_task('WAIT')
+            return
+        self.task.todo -= 1
+        if self.task.todo <= 0:
+            self._last_task_result = self.task.do()
+            self.task = None
+        if is_AI and self.task is None:
+            try:
+                self.decide_task()
+            except GameError:
+                self.set_task('WAIT')
+
+    def get_stencil(self):
+        if self._stencil is not None:
+            return self._stencil
+        self._stencil = self.world.map_.get_fov_map(self.position)
+        return self._stencil
+
+    def get_visible_map(self):
+        stencil = self.get_stencil()
+        m = self.world.map_.new_from_shape(' ')
+        for pos in m:
+            if stencil[pos] == '.':
+                m[pos] = self.world.map_[pos]
+        return m
+
+    def get_visible_things(self):
+        stencil = self.get_stencil()
+        visible_things = []
+        for thing in self.world.things:
+            if stencil[thing.position] == '.':
+                visible_things += [thing]
+        return visible_things
+
+
+
+class Task:
+    argtypes = ''
+
+    def __init__(self, thing, args=()):
+        self.thing = thing
+        self.args = args
+        self.todo = 3
+
+    @property
+    def name(self):
+        prefix = 'Task_'
+        class_name = self.__class__.__name__
+        return class_name[len(prefix):]
+
+    def check(self):
+        pass
+
+    def get_args_string(self):
+        stringed_args = []
+        for arg in self.args:
+            if type(arg) == str:
+                stringed_args += [quote(arg)]
+            else:
+                raise GameError('stringifying arg type not implemented')
+        return ' '.join(stringed_args)
+
+
+
+class Task_WAIT(Task):
+
+    def do(self):
+        return 'success'
+
+
+
+class Task_MOVE(Task):
+    argtypes = 'string:direction'
+
+    def check(self):
+        test_pos = self.thing.world.map_.move(self.thing.position, self.args[0])
+        if self.thing.world.map_[test_pos] != '.':
+            raise GameError('%s would move into illegal terrain' % self.thing.id_)
+        for t in self.thing.world.things:
+            if t.position == test_pos:
+                raise GameError('%s would move into other thing' % self.thing.id_)
+
+    def do(self):
+        self.thing.position = self.thing.world.map_.move(self.thing.position,
+                                                         self.args[0])
+
+
+
+class WorldBase:
+
+    def __init__(self, game):
+        self.turn = 0
+        self.things = []
+        self.game = game
+
+    def get_thing(self, id_, create_unfound=True):
+        for thing in self.things:
+            if id_ == thing.id_:
+                return thing
+        if create_unfound:
+            t = self.game.thing_type(self, id_)
+            self.things += [t]
+            return t
+        return None
+
+
+class World(WorldBase):
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.player_id = 0
+
+    def new_map(self, yx):
+        self.map_ = self.game.map_type(yx)
+
+    def proceed_to_next_player_turn(self):
+        """Run game world turns until player can decide their next step.
+
+        Iterates through all non-player things, on each step
+        furthering them in their tasks (and letting them decide new
+        ones if they finish). The iteration order is: first all things
+        that come after the player in the world things list, then
+        (after incrementing the world turn) all that come before the
+        player; then the player's .proceed() is run, and if it does
+        not finish his task, the loop starts at the beginning. Once
+        the player's task is finished, the loop breaks.
+        """
+        while True:
+            player = self.get_player()
+            player_i = self.things.index(player)
+            for thing in self.things[player_i+1:]:
+                thing.proceed()
+            self.turn += 1
+            for thing in self.things[:player_i]:
+                thing.proceed()
+            player.proceed(is_AI=False)
+            if player.task is None:
+                break
+
+    def get_player(self):
+        return self.get_thing(self.player_id)
+
+    def make_new(self, yx, seed):
+        import random
+        random.seed(seed)
+        self.turn = 0
+        self.new_map(yx)
+        for pos in self.map_:
+            if 0 in pos or (yx[0] - 1) == pos[0] or (yx[1] - 1) == pos[1]:
+                self.map_[pos] = '#'
+                continue
+            self.map_[pos] = random.choice(('.', '.', '.', '.', 'x'))
+        player = self.game.thing_type(self, 0)
+        player.type_ = 'human'
+        player.position = [random.randint(0, yx[0] -1),
+                           random.randint(0, yx[1] - 1)]
+        npc = self.game.thing_type(self, 1)
+        npc.type_ = 'monster'
+        npc.position = [random.randint(0, yx[0] -1),
+                        random.randint(0, yx[1] -1)]
+        self.things = [player, npc]
+        return 'success'
+
+
+
+def cmd_GEN_WORLD(self, yx, seed):
+    self.world.make_new(yx, seed)
+cmd_GEN_WORLD.argtypes = 'yx_tuple:pos string'
+
+def cmd_GET_GAMESTATE(self, connection_id):
+    """Send game state to caller."""
+    self.send_gamestate(connection_id)
+
+def cmd_MAP(self, yx):
+    """Create new map of size yx and only '?' cells."""
+    self.world.new_map(yx)
+cmd_MAP.argtypes = 'yx_tuple:pos'
+
+def cmd_THING_TYPE(self, i, type_):
+    t = self.world.get_thing(i)
+    t.type_ = type_
+cmd_THING_TYPE.argtypes = 'int:nonneg string'
+
+def cmd_THING_POS(self, i, yx):
+    t = self.world.get_thing(i)
+    t.position = list(yx)
+cmd_THING_POS.argtypes = 'int:nonneg yx_tuple:nonneg'
+
+def cmd_TERRAIN_LINE(self, y, terrain_line):
+    self.world.map_.set_line(y, terrain_line)
+cmd_TERRAIN_LINE.argtypes = 'int:nonneg string'
+
+def cmd_PLAYER_ID(self, id_):
+    # TODO: test whether valid thing ID
+    self.world.player_id = id_
+cmd_PLAYER_ID.argtypes = 'int:nonneg'
+
+def cmd_TURN(self, n):
+    self.world.turn = n
+cmd_TURN.argtypes = 'int:nonneg'
+
+def cmd_SWITCH_PLAYER(self):
+    player = self.world.get_player()
+    player.set_task('WAIT')
+    thing_ids = [t.id_ for t in self.world.things]
+    player_index = thing_ids.index(player.id_)
+    if player_index == len(thing_ids) - 1:
+        self.world.player_id = thing_ids[0]
+    else:
+        self.world.player_id = thing_ids[player_index + 1]
+    self.proceed()
+
+def cmd_SAVE(self):
+
+    def write(f, msg):
+        f.write(msg + '\n')
+
+    save_file_name = self.io.game_file_name + '.save'
+    with open(save_file_name, 'w') as f:
+        write(f, 'TURN %s' % self.world.turn)
+        write(f, 'MAP ' + stringify_yx(self.world.map_.size))
+        for y, line in self.world.map_.lines():
+            write(f, 'TERRAIN_LINE %5s %s' % (y, quote(line)))
+        for thing in self.world.things:
+            write(f, 'THING_TYPE %s %s' % (thing.id_, thing.type_))
+            write(f, 'THING_POS %s %s' % (thing.id_,
+                                          stringify_yx(thing.position)))
+            task = thing.task
+            if task is not None:
+                task_args = task.get_args_string()
+                write(f, 'SET_TASK:%s %s %s %s' % (task.name, thing.id_,
+                                                   task.todo, task_args))
+        write(f, 'PLAYER_ID %s' % self.world.player_id)
+cmd_SAVE.dont_save = True
+
+
+class Game:
+
+    def __init__(self, game_file_name):
+        self.io = GameIO(game_file_name, self)
+        self.map_type = MapHex
+        self.tasks = {'WAIT': Task_WAIT, 'MOVE': Task_MOVE}
+        self.commands = {'GEN_WORLD': cmd_GEN_WORLD,
+                         'GET_GAMESTATE': cmd_GET_GAMESTATE,
+                         'MAP': cmd_MAP,
+                         'THING_TYPE': cmd_THING_TYPE,
+                         'THING_POS': cmd_THING_POS,
+                         'TERRAIN_LINE': cmd_TERRAIN_LINE,
+                         'PLAYER_ID': cmd_PLAYER_ID,
+                         'TURN': cmd_TURN,
+                         'SWITCH_PLAYER': cmd_SWITCH_PLAYER,
+                         'SAVE': cmd_SAVE}
+        self.world_type = World
+        self.world = self.world_type(self)
+        self.thing_type = Thing
+
+    def get_string_options(self, string_option_type):
+        if string_option_type == 'direction':
+            return self.world.map_.get_directions()
+        return None
+
+    def send_gamestate(self, connection_id=None):
+        """Send out game state data relevant to clients."""
+
+        self.io.send('TURN ' + str(self.world.turn))
+        self.io.send('MAP ' + stringify_yx(self.world.map_.size))
+        visible_map = self.world.get_player().get_visible_map()
+        for y, line in visible_map.lines():
+            self.io.send('VISIBLE_MAP_LINE %5s %s' % (y, quote(line)))
+        visible_things = self.world.get_player().get_visible_things()
+        for thing in visible_things:
+            self.io.send('THING_TYPE %s %s' % (thing.id_, thing.type_))
+            self.io.send('THING_POS %s %s' % (thing.id_,
+                                              stringify_yx(thing.position)))
+        player = self.world.get_player()
+        self.io.send('PLAYER_POS %s' % (stringify_yx(player.position)))
+        self.io.send('GAME_STATE_COMPLETE')
+
+    def proceed(self):
+        """Send turn finish signal, run game world, send new world data.
+
+        First sends 'TURN_FINISHED' message, then runs game world
+        until new player input is needed, then sends game state.
+        """
+        self.io.send('TURN_FINISHED ' + str(self.world.turn))
+        self.world.proceed_to_next_player_turn()
+        msg = str(self.world.get_player()._last_task_result)
+        self.io.send('LAST_PLAYER_TASK_RESULT ' + quote(msg))
+        self.send_gamestate()
+
+    def get_command(self, command_name):
+        from functools import partial
+
+        def cmd_TASK_colon(task_name, game, *args):
+            game.world.get_player().set_task(task_name, args)
+            game.proceed()
+
+        def cmd_SET_TASK_colon(task_name, game, thing_id, todo, *args):
+            t = game.world.get_thing(thing_id, False)
+            if t is None:
+                raiseArgError('No such Thing.')
+            task_class = game.tasks[task_name]
+            t.task = task_class(t, args)
+            t.task.todo = todo
+
+        def task_prefixed(command_name, task_prefix, task_command,
+                          argtypes_prefix=None):
+            if command_name[:len(task_prefix)] == task_prefix:
+                task_name = command_name[len(task_prefix):]
+                if task_name in self.tasks:
+                    f = partial(task_command, task_name, self)
+                    task = self.tasks[task_name]
+                    if argtypes_prefix:
+                        f.argtypes = argtypes_prefix + ' ' + task.argtypes
+                    else:
+                        f.argtypes = task.argtypes
+                    return f
+            return None
+
+        command = task_prefixed(command_name, 'TASK:', cmd_TASK_colon)
+        if command:
+            return command
+        command = task_prefixed(command_name, 'SET_TASK:', cmd_SET_TASK_colon,
+                                'int:nonneg int:nonneg ')
+        if command:
+            return command
+        if command_name in self.commands:
+            f = partial(self.commands[command_name], self)
+            if hasattr(self.commands[command_name], 'argtypes'):
+                f.argtypes = self.commands[command_name].argtypes
+            return f
+        return None
+
+
+
+def quote(string):
+    """Quote & escape string so client interprets it as single token."""
+    quoted = []
+    quoted += ['"']
+    for c in string:
+        if c in {'"', '\\'}:
+            quoted += ['\\']
+        quoted += [c]
+    quoted += ['"']
+    return ''.join(quoted)
+
+
+def stringify_yx(tuple_):
+    """Transform tuple (y,x) into string 'Y:'+str(y)+',X:'+str(x)."""
+    return 'Y:' + str(tuple_[0]) + ',X:' + str(tuple_[1])
+
+
+
+if __name__ == "__main__":
+    import sys
+    import os
+    if len(sys.argv) != 2:
+        print('wrong number of arguments, expected one (game file)')
+        exit(1)
+    game_file_name = sys.argv[1]
+    game = Game(game_file_name)
+    if os.path.exists(game_file_name):
+        if not os.path.isfile(game_file_name):
+            print('game file name does not refer to a valid game file')
+        else:
+            with open(game_file_name, 'r') as f:
+                lines = f.readlines()
+            for i in range(len(lines)):
+                line = lines[i]
+                print("FILE INPUT LINE %5s: %s" % (i, line), end='')
+                game.io.handle_input(line, store=False)
+    else:
+        game.io.handle_input('GEN_WORLD Y:16,X:16 bar')
+    game.io.run_loop_with_server()