import os
import pickle
from collections import OrderedDict

import numpy as np
from django.conf import settings

from c3nav.mapdata.models import Level
from c3nav.mapdata.models.geometry import LevelConnector
from c3nav.routing.level import GraphLevel
from c3nav.routing.point import GraphPoint


class Graph:
    graph_cached = None
    graph_cached_date = None
    default_filename = os.path.join(settings.DATA_DIR, 'graph.pickle')

    def __init__(self):
        self.levels = OrderedDict()
        for level in Level.objects.all():
            self.levels[level.name] = GraphLevel(self, level)

        self.points = []
        self.level_transfer_points = None

    # Building the Graph
    def build(self):
        self._built_level_transfer_points = []
        self._built_levelconnector_points = {}

        for level in self.levels.values():
            level.build()

        # collect rooms and points
        rooms = sum((level.rooms for level in self.levels.values()), [])
        self.points = sum((level._built_points for level in self.levels.values()), [])

        # create connections between levels
        print()
        self.connect_levelconnectors()

        # finishing build: creating numpy arrays and convert everything else to tuples
        self.points = tuple(set(self.points))

        for i, room in enumerate(rooms):
            room.i = i

        for i, point in enumerate(self.points):
            point.i = i

        self.level_transfer_points = np.array(tuple(point.i for point in self._built_level_transfer_points))

        for level in self.levels.values():
            level.finish_build()

        print()
        print('Total:')
        self.print_stats()

        print()
        print('Points per room:')
        for name, level in self.levels.items():
            print(('Level %s:' % name), *(sorted((len(room.points) for room in level.rooms), reverse=True)))

    def print_stats(self):
        print('%d points' % len(self.points))
        print('%d rooms' % sum(len(level.rooms) for level in self.levels.values()))
        print('%d level transfer points' % len(self.level_transfer_points))
        print('%d connections' % sum(level.connection_count() for level in self.levels.values()))

    def add_levelconnector_point(self, levelconnector, point):
        self._built_levelconnector_points.setdefault(levelconnector.name, []).append(point)

    def connect_levelconnectors(self):
        for levelconnector in LevelConnector.objects.all():
            center = levelconnector.geometry.centroid
            points = self._built_levelconnector_points.get(levelconnector.name, [])
            rooms = set(point.room for point in points if point.room is not None)
            connected_levels = set(room.level for room in rooms)

            should_levels = tuple(level.name for level in levelconnector.levels.all())
            missing_levels = set(should_levels) - set(level.level.name for level in connected_levels)

            if missing_levels:
                print('levelconnector %s on levels %s at (%.2f, %.2f) is not connected to levels %s!' %
                      (levelconnector.name, ', '.join(should_levels), center.x, center.y, ', '.join(missing_levels)))
                continue

            center_point = GraphPoint(center.x, center.y, None)
            self.points.append(center_point)
            self._built_level_transfer_points.append(center_point)

            for level in connected_levels:
                level._built_room_transfer_points.append(center_point)
                level._built_points.append(center_point)

            for room in rooms:
                room._built_points.append(center_point)

            for point in points:
                center_point.connect_to(point)
                point.connect_to(center_point)

    # Loading/Saving the Graph
    def serialize(self):
        return (
            {name: level.serialize() for name, level in self.levels.items()},
            [point.serialize() for point in self.points],
            self.level_transfer_points,
        )

    def save(self, filename=None):
        if filename is None:
            filename = self.default_filename
        with open(filename, 'wb') as f:
            pickle.dump(self.serialize(), f)

    @classmethod
    def unserialize(cls, data):
        levels, points, level_transfer_points = data

        graph = cls()

        for name, level in levels.items():
            graph.levels[name].unserialize(level)

        rooms = sum((level.rooms for level in graph.levels.values()), ())

        graph.points = tuple(GraphPoint(x, y, None if room is None else rooms[room]) for x, y, room in points)
        graph.level_transfer_points = level_transfer_points

        return graph

    @classmethod
    def load(cls, filename=None):
        do_cache = False
        if filename is None:
            do_cache = True
            filename = cls.default_filename

        graph_mtime = None
        if do_cache:
            graph_mtime = os.path.getmtime(filename)
            if cls.graph_cached is not None:
                if cls.graph_cached_date == graph_mtime:
                    return cls.graph_cached

        with open(filename, 'rb') as f:
            graph = cls.unserialize(pickle.load(f))

        if do_cache:
            cls.graph_cached_date = graph_mtime
            cls.graph_cached = graph
            print(cls.graph_cached, cls.graph_cached_date)

        graph.print_stats()
        return graph

    # Drawing
    def draw_pngs(self, points=True, lines=True):
        for level in self.levels.values():
            level.draw_png(points, lines)

    # Router
    def build_router(self):
        for level in self.levels.values():
            level.build_router()