#    This file is part of Korman.
#
#    Korman 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.
#
#    Korman 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 Korman.  If not, see <http://www.gnu.org/licenses/>.

import abc
import bpy
from PyHSPlasma import plMessage, plNotifyMsg

from ..exporter import ExportError

class PlasmaNodeBase:
    def generate_notify_msg(self, exporter, so, socket_id, idname=None):
        notify = plNotifyMsg()
        notify.BCastFlags = (plMessage.kNetPropagate | plMessage.kLocalPropagate)
        for i in self.find_outputs(socket_id, idname):
            key = i.get_key(exporter, so)
            if key is None:
                exporter.report.warn(" '{}' Node '{}' doesn't expose a key. It won't be triggered by '{}'!".format(i.bl_idname, i.name, self.name), indent=3)
            elif isinstance(key, tuple):
                for i in key:
                    notify.addReceiver(key)
            else:
                notify.addReceiver(key)
        return notify

    def get_key(self, exporter, so):
        return None

    def draw_label(self):
        if hasattr(self, "pl_label_attr") and self.hide:
            return str(getattr(self, self.pl_label_attrib, self.bl_label))
        return self.bl_label

    def export(self, exporter, bo, so):
        pass

    def find_input(self, key, idname=None):
        for i in self.inputs:
            if i.alias == key:
                if i.links:
                    node = i.links[0].from_node
                    if idname is not None and idname != node.bl_idname:
                        return None
                    return node
                else:
                    return None
        raise KeyError(key)

    def find_inputs(self, key, idname=None):
        for i in self.inputs:
            if i.alias == key:
                if i.links:
                    node = i.links[0].from_node
                    if idname is None or idname == node.bl_idname:
                        yield node

    def find_input_socket(self, key, spawn_empty=False):
        # In the case that this socket will be used to make new input linkage,
        # we might want to allow the spawning of a new input socket... :)
        # This will only be done if the node's socket definitions allow it.
        options = self._socket_defs[0].get(key, {})
        spawn_empty = spawn_empty and options.get("spawn_empty", False)

        for i in self.inputs:
            if i.alias == key:
                if spawn_empty and i.is_linked:
                    continue
                return i
        if spawn_empty:
            return self._spawn_socket(key, options, self.inputs)
        else:
            raise KeyError(key)

    def find_input_sockets(self, key, idname=None):
        for i in self.inputs:
            if i.alias == key:
                if idname is None:
                    yield i
                elif i.links:
                    node = i.links[0].from_node
                    if idname == node.bl_idname:
                        yield i

    def find_output(self, key, idname=None):
        for i in self.outputs:
            if i.alias == key:
                if i.links:
                    node = i.links[0].to_node
                    if idname is not None and idname != node.bl_idname:
                        return None
                    return node
                else:
                    return None
        raise KeyError(key)

    def find_outputs(self, key, idname=None):
        for i in self.outputs:
            if i.alias == key:
                for j in i.links:
                    node = j.to_node
                    if idname is not None and idname != node.bl_idname:
                        continue
                    yield node

    def find_output_socket(self, key, spawn_empty=False):
        # In the case that this socket will be used to make new output linkage,
        # we might want to allow the spawning of a new output socket... :)
        # This will only be done if the node's socket definitions allow it.
        options = self._socket_defs[1].get(key, {})
        spawn_empty = spawn_empty and options.get("spawn_empty", False)

        for i in self.outputs:
            if i.alias == key:
                if spawn_empty and i.is_linked:
                    continue
                return i
        if spawn_empty:
            return self._spawn_socket(key, options, self.outputs)
        raise KeyError(key)

    def find_output_sockets(self, key, idname=None):
        for i in self.outputs:
            if i.alias == key:
                if idname is None:
                    yield i
                elif i.links:
                    node = i.links[0].from_node
                    if idname == node.bl_idname:
                        yield i

    def harvest_actors(self):
        return set()

    @property
    def key_name(self):
        return "{}_{}".format(self.id_data.name, self.name)

    def link_input(self, node, out_key, in_key):
        """Links a given Node's output socket to a given input socket on this Node"""
        if isinstance(in_key, str):
            in_socket = self.find_input_socket(in_key, spawn_empty=True)
        else:
            in_socket = in_key
        if isinstance(out_key, str):
            out_socket = node.find_output_socket(out_key, spawn_empty=True)
        else:
            out_socket = out_key
        link = self.id_data.links.new(in_socket, out_socket)

    def link_output(self, node, out_key, in_key):
        """Links a given Node's input socket to a given output socket on this Node"""
        if isinstance(in_key, str):
            in_socket = node.find_input_socket(in_key, spawn_empty=True)
        else:
            in_socket = in_key
        if isinstance(out_key, str):
            out_socket = self.find_output_socket(out_key, spawn_empty=True)
        else:
            out_socket = out_key
        link = self.id_data.links.new(in_socket, out_socket)

    @property
    def node_path(self):
        """Returns an absolute path to this Node. Needed because repr() uses an elipsis..."""
        return "{}.{}".format(repr(self.id_data), self.path_from_id())

    @classmethod
    def poll(cls, context):
        return (context.bl_idname == "PlasmaNodeTree")

    def raise_error(self, message):
        final = "Plasma Node Tree '{}' Node '{}': {}".format(self.id_data.name, self.name, message)
        raise ExportError(final)

    @property
    def requires_actor(self):
        return False

    @property
    def _socket_defs(self):
        return (getattr(self.__class__, "input_sockets", {}),
                getattr(self.__class__, "output_sockets", {}))

    def _spawn_socket(self, key, options, sockets):
        socket = sockets.new(options["type"], options["text"], key)
        link_limit = options.get("link_limit", None)
        if link_limit is not None:
            socket.link_limit = link_limit
        socket.hide = options.get("hidden", False)
        socket.hide_value = options.get("hidden", False)
        return socket

    def _tattle(self, socket, link, reason):
        direction = "->" if socket.is_output else "<-"
        print("Removing {} {} {} {}".format(link.from_node.name, direction, link.to_node.name, reason))

    def unlink_outputs(self, alias, reason=None):
        links = self.id_data.links
        from_socket = next((i for i in self.outputs if i.alias == alias))
        i = 0
        while i < len(from_socket.links):
            link = from_socket.links[i]
            self._tattle(from_socket, link, reason if reason else "socket unlinked")
            links.remove(link)

    def update(self):
        """Ensures that sockets are linked appropriately and there are enough inputs"""
        input_defs, output_defs = self._socket_defs
        for defs, sockets in ((input_defs, self.inputs), (output_defs, self.outputs)):
            done = set()

            # Need to enumerate by hand because blendsucks has major (crashing) issues if we modify
            # this swhizzle while stuff is going down.
            i = 0
            while i < len(sockets):
                socket = sockets[i]
                node = socket.node

                options = defs.get(socket.alias, None)
                if options is None or socket.bl_idname != options["type"]:
                    sockets.remove(socket)
                    continue

                # Make sure the socket info is up to date
                socket.name = options["text"]
                link_limit = options.get("link_limit", None)
                if link_limit is not None:
                    socket.link_limit = link_limit
                socket.hide = options.get("hidden", False)
                socket.hide_value = options.get("hidden", False)

                # Make sure the link is good
                allowed_sockets = options.get("valid_link_sockets", None)
                allowed_nodes = options.get("valid_link_nodes", None)

                # The socket may decide it doesn't want anyone linked to it.
                can_link_attr = options.get("can_link", None)
                if can_link_attr is not None:
                    can_link = getattr(node, can_link_attr)
                    socket.enabled = can_link
                    if not can_link:
                        for link in socket.links:
                            try:
                                self._tattle(socket, link, "(socket refused link)")
                                self.id_data.links.remove(link)
                            except RuntimeError:
                                # was already removed by someone else
                                pass

                # Helpful default... If neither are set, require the link to be to the same socket type
                if allowed_nodes is None and allowed_sockets is None:
                    allowed_sockets = frozenset((options["type"],))
                if allowed_sockets or allowed_nodes:
                    for link in socket.links:
                        if allowed_nodes:
                            to_from_node = link.to_node if socket.is_output else link.from_node
                            if to_from_node.bl_idname not in allowed_nodes:
                                try:
                                    self._tattle(socket, link, "(bad node)")
                                    self.id_data.links.remove(link)
                                except RuntimeError:
                                    # was already removed by someone else
                                    pass
                                continue
                        if allowed_sockets:
                            to_from_socket = link.to_socket if socket.is_output else link.from_socket
                            if to_from_socket is None or to_from_socket.bl_idname not in allowed_sockets:
                                try:
                                    self._tattle(socket, link, "(bad socket)")
                                    self.id_data.links.remove(link)
                                except RuntimeError:
                                    # was already removed by someone else
                                    pass
                                continue

                # If this is a spawn empty socket, make sure we have exactly one empty socket
                if options.get("spawn_empty", False) and not socket.alias in done:
                    empty_sockets = [j for j in sockets if j.bl_idname == socket.bl_idname and not j.is_used]
                    if not empty_sockets:
                        idx = len(sockets)
                        dbg = sockets.new(socket.bl_idname, socket.name, socket.alias)
                        # don't even ask...
                        new_idx = i + 2
                        if idx != new_idx:
                            sockets.move(idx, new_idx)
                    else:
                        while len(empty_sockets) > 1:
                            sockets.remove(empty_sockets.pop())
                done.add(socket.alias)

                i += 1

            # Create any new sockets
            for alias in (j for j in defs if j not in done):
                self._spawn_socket(alias, defs[alias], sockets)

    def _whine(self, msg, *args):
        if args:
            msg = msg.format(*args)
        print("'{}' Node '{}': Whinging about {}".format(self.bl_idname, self.name, msg))


class PlasmaTreeOutputNodeBase(PlasmaNodeBase):
    """Represents the final output of a node tree"""
    def init(self, context):
        nodes = self.id_data.nodes

        # There can only be one of these nodes per tree, so let's make sure I'm the only one.
        for i in nodes:
            if isinstance(i, self.__class__) and i != self:
                nodes.remove(self)
                return


class PlasmaNodeSocketBase:
    @property
    def alias(self):
        """Blender appends .000 stuff if it's a dupe. We don't care about dupe identifiers..."""
        ident = self.identifier
        if ident.find('.') == -1:
            return ident
        return ident.rsplit('.', 1)[0]

    def draw(self, context, layout, node, text):
        layout.label(text)

    def draw_color(self, context, node):
        # It's so tempting to just do RGB sometimes... Let's be nice.
        if len(self.bl_color) == 3:
            return tuple(self.bl_color[0], self.bl_color[1], self.bl_color[2], 1.0)
        return self.bl_color

    @property
    def is_used(self):
        return bool(self.links)


class PlasmaNodeSocketInputGeneral(PlasmaNodeSocketBase, bpy.types.NodeSocket):
    """A general input socket that will steal the output's color"""
    def draw_color(self, context, node):
        if self.is_linked:
            return self.links[0].from_socket.draw_color(context, node)
        else:
            return (0.0, 0.0, 0.0, 0.0)


class PlasmaNodeTree(bpy.types.NodeTree):
    bl_idname = "PlasmaNodeTree"
    bl_label = "Plasma"
    bl_icon = "NODETREE"

    def export(self, exporter, bo, so):
        # just pass it off to each node
        for node in self.nodes:
            node.export(exporter, bo, so)

    def find_output(self, idname):
        for node in self.nodes:
            if node.bl_idname == idname:
                return node
        return None

    def harvest_actors(self):
        actors = set()
        for node in self.nodes:
            harvest_method = getattr(node, "harvest_actors", None)
            if harvest_method is not None:
                actors.update(harvest_method())
            elif not isinstance(node, PlasmaNodeBase):
                raise ExportError("Plasma Node Tree '{}' Node '{}': is not a valid node for this tree".format(self.id_data.name, node.name))
        return actors

    @classmethod
    def poll(cls, context):
        return (context.scene.render.engine == "PLASMA_GAME")