text: import json
  from sqlalchemy import and_, or_
  from sqlalchemy.orm.exc import NoResultFound
  
  from .models import get_sessionmaker, Item, ItemSimilarityRelation, ValidTime, Box, Property
  from .logger import logger
  from .word_model import WordModel
  from . import config
  
  class KnowledgeGraph:
      def __init__(self):
          self.Sessionmaker = get_sessionmaker()
          self.session = self.Sessionmaker()
          self.word_model = WordModel()
  
      def get_all_items(self):
          return self.session.query(Item).all()
  
      def get_all_valid_times(self):
          return self.session.query(ValidTime).all()
  
      def get_all_boxes(self):
          return self.session.query(Box).all()
  
      def get_all_properties(self):
          return self.session.query(Property).all()
  
      def get_all_similarities(self):
          return self.session.query(ItemSimilarityRelation).all()
  
      def set_item_similarities(self):
          rows = self.session.execute('''
              SELECT   MIN(a.id) a, a.classname a, b.id b, b.classname b
              FROM     item a JOIN item b ON a.id <> b.id AND b.ID > a.ID
              GROUP BY b.ID
          ''')
          batch_count = 0
  
          def sanitize(word):
              return word.lower().replace('-', ' ').replace('_', ' ')
          
          for id1, classname1, id2, classname2 in rows:
              similarity = self.word_model.get_word_similarity(
                  sanitize(classname1), 
                  sanitize(classname2),
              )
              if similarity is not None:
                  self.session.add(ItemSimilarityRelation(
                      similarity=similarity,
                      item_id=id1,
                      another_item_id=id2,
                  ))
                  batch_count += 1
                  if batch_count >= 100:
                      self.session.commit()
                      batch_count = 0
          self.session.commit()
      
      def get_overlapped_items_by_coordinate(self, coordinate, seconds):
          x_start, y_start, x_end, y_end = coordinate
          time_start = seconds - config.MERGE_TIME_WINDOW
          time_end = seconds + config.MERGE_TIME_WINDOW
          rows = self.session.query(Item, ValidTime, Box).filter(and_(
              Item.id == ValidTime.item_id,
              Item.id == Box.item_id,
              or_(
                  and_(
                      ValidTime.time_start >= time_start,
                      ValidTime.time_start <= time_end
                  ),
                  and_(
                      ValidTime.time_end >= time_start,
                      ValidTime.time_end <= time_end
                  )
              ),
              Box.time >= time_start,
              Box.time <= time_end,
              or_(
                  and_(
                      Box.x_start >= x_start,
                      Box.x_start <= x_end
                  ),
                  and_(
                      Box.x_end >= x_start,
                      Box.x_end <= x_end
                  )
              ),
              or_(
                  and_(
                      Box.y_start >= y_start,
                      Box.y_start <= y_end
                  ),
                  and_(
                      Box.y_end >= y_start,
                      Box.y_end <= y_end
                  )
              )
          ))
          return rows
  
      def is_coordinates_mergeable(self, coordinate1, coordinate2):
          c1_x_start, c1_y_start, c1_x_end, c1_y_end = coordinate1
          c2_x_start, c2_y_start, c2_x_end, c2_y_end = coordinate2
          overlap_width = max(
              0, 
              min(c1_x_end, c2_x_end) - max(c1_x_start, c2_x_start)
          )
          overlap_height = max(
              0, 
              min(c1_y_end, c2_y_end) - max(c1_y_start, c2_y_start)
          )
          c1_area = (c1_x_end - c1_x_start) * (c1_y_end - c1_y_start)
          c2_area = (c2_x_end - c2_x_start) * (c2_y_end - c2_y_start)
          overlap_area = overlap_width * overlap_height
          return (
              (overlap_area > c1_area * config.MERGE_OVERLAP_THRESHOLD) and
              (overlap_area > c2_area * config.MERGE_OVERLAP_THRESHOLD)
          )
  
      def get_item_by_id_str(self, id_str):
          try:
              return self.session.query(Item).filter_by(id_str=id_str).one()
          except NoResultFound:
              return None
  
      def get_abstract_item(self, classname, label):
          try:
              return self.session.query(Item).filter_by(
                  classname=classname,
                  label=label,
                  is_abstract=True,
              ).one()
          except NoResultFound:
              return None
  
      def get_or_create_video_item(self):
          item = self.get_item_by_id_str('_video')
          if item is None:
              item = Item(
                  id_str='_video',
                  classname='video',
                  label='video',
                  is_abstract=True,
              )
              self.session.add(item)
              self.session.commit()
          return item
  
      def get_or_create_abstract_item(self, classname, label):
          item = self.get_abstract_item(classname, label)
          if item is None:
              item = Item(
                  classname=classname,
                  label=label,
                  is_abstract=True
              )
              self.session.add(item)
              self.session.commit()
          return item
  
      def create_item_with_coordinate(self, coordinate, seconds):
          item = Item(
              classname='unknown',
              label='unknown',
          )
          self.session.add(item)
          box = Box(
              time=seconds,
              x_start=coordinate[0],
              x_end=coordinate[2],
              y_start=coordinate[1],
              y_end=coordinate[3],
              item=item,
          )
          self.session.add(box)
          valid_time = ValidTime(
              time_start=seconds,
              time_end=seconds,
              item=item,
          )
          self.session.add(valid_time)
          self.session.commit()
          return item
  
      def create_item_with_id_str(self, id_str, seconds):
          item = Item(
              classname='item',
              label=id_str,
              id_str=id_str,
          )
          self.session.add(item)
          valid_time = ValidTime(
              time_start=seconds,
              time_end=seconds,
              item=item,
          )
          self.session.add(valid_time)
          self.session.commit()
          return item
  
      def get_item_by_coordinate(self, coordinate, seconds):
          rows = self.get_overlapped_items_by_coordinate(coordinate, seconds)
          for item, valid_time, box in rows:
              box_coordinate = (
                  box.x_start,
                  box.y_start,
                  box.x_end,
                  box.y_end,
              )
              if self.is_coordinates_mergeable(coordinate, box_coordinate):
                  return item
          return None
  
      def get_absolute_coordinate(self, coordinate):
          x, y, width, height = coordinate
          return x, y, x + width, y + height
  
      def get_item_by_indicator(self, indicator, seconds):
          if 'id' in indicator:
              item = self.get_item_by_id_str(indicator['id'])
              if item is None:
                  item = self.create_item_with_id_str(indicator['id'], seconds)
              return item
          elif 'coordinates' in indicator:
              abs_coord = self.get_absolute_coordinate(
                  indicator['coordinates']
              )
              item = self.get_item_by_coordinate(abs_coord, seconds)
              if item is None:
                  item = self.create_item_with_coordinate(abs_coord, seconds)
              return item
          else:
              logger.error(
                  'Failed to find an object with object indicator "%s"' 
                  % json.dumps(indicator)
              )
              return None
  
      def get_or_create_valid_time(self, seconds, item):
          seconds_lb = seconds - config.MERGE_TIME_WINDOW
          seconds_ub = seconds + config.MERGE_TIME_WINDOW
          valid_time = self.session.query(ValidTime).filter(
              and_(
                  or_(
                      and_(
                          ValidTime.time_start <= seconds,
                          ValidTime.time_end >= seconds,
                      ),
                      and_(
                          ValidTime.time_start <= seconds,
                          ValidTime.time_end >= seconds_lb,
                      ),
                      and_(
                          ValidTime.time_start <= seconds_ub,
                          ValidTime.time_end >= seconds,
                      ),
                  ),
                  ValidTime.item_id == item.id,
              )
          ).first()
          if valid_time is not None:
              if valid_time.time_start <= seconds and valid_time.time_end >= seconds:
                  return valid_time
              elif valid_time.time_start <= seconds and valid_time.time_end >= seconds_lb:
                  if valid_time.time_end < seconds:
                      valid_time.time_end = seconds  
              elif valid_time.time_start <= seconds_ub and valid_time.time_end >= seconds:
                  if valid_time.time_start > seconds:
                      valid_time.time_start = seconds
              return valid_time
          else:
              return ValidTime(
                  time_start=seconds,
                  time_end=seconds,
                  item=item,
              )
  
      def get_or_create_property(self, classname, seconds, source, target, relation=None, id_str=None, value=None):
          seconds_lb = seconds - config.MERGE_TIME_WINDOW
          seconds_ub = seconds + config.MERGE_TIME_WINDOW
          query_filter = and_(
              or_(
                  and_(
                      Property.time_start <= seconds,
                      Property.time_end >= seconds,
                  ),
                  and_(
                      Property.time_start <= seconds,
                      Property.time_end >= seconds_lb,
                  ),
                  and_(
                      Property.time_start <= seconds_ub,
                      Property.time_end >= seconds,
                  ),
              ),
              Property.classname == classname,
              Property.source_item_id == source.id,
              Property.target_item_id == target.id,
          )
          if relation is not None:
              query_filter = and_(
                  query_filter,
                  Property.relation_item_id == relation.id,
              )
          if value is not None:
              query_filter = and_(
                  query_filter,
                  Property.value == value,
              )
          if id_str is not None:
              query_filter = and_(
                  query_filter,
                  Property.id_str == id_str,
              )
          prop = self.session.query(Property).filter(query_filter).first()
          if prop is not None:
              if prop.time_start <= seconds and prop.time_end >= seconds:
                  return prop
              elif prop.time_start <= seconds and prop.time_end >= seconds_lb:
                  if prop.time_end < seconds:
                      prop.time_end = seconds
              elif prop.time_start <= seconds_ub and prop.time_end >= seconds:
                  if prop.time_start > seconds:
                      prop.time_start = seconds
          else:
              prop = Property(
                  id_str=id_str,
                  classname=classname,
                  time_start=seconds,
                  time_end=seconds,
                  source=source,
                  target=target,
                  relation=relation,
              )
          self.session.add(prop)
          self.session.commit()
          return prop
  
      def add_object_label(self, label):
          abs_coord = self.get_absolute_coordinate(label['coordinates'])
          item = None
          if 'id' in label:
              item = self.get_item_by_id_str(label['id']) 
          if item is None:
              item = self.get_item_by_coordinate(abs_coord, label['seconds'])
          if item is None:
              item = Item()
          item.classname = label['class']
          item.label = label['label']
          if 'id' in label and not item.id_str:
              item.id_str = label['id']
          self.session.add(item)
          valid_time = self.get_or_create_valid_time(label['seconds'], item)
          self.session.add(valid_time)
          box = Box(
              time=label['seconds'],
              x_start=abs_coord[0],
              x_end=abs_coord[2],
              y_start=abs_coord[1],
              y_end=abs_coord[3],
              item=item,
          )
          self.session.add(box)
          self.session.commit()
  
      def add_behavior_label(self, label):
          item = self.get_item_by_indicator(
              label['object'], 
              label['seconds'],
          )
          abstract_item = self.get_or_create_abstract_item(
              'behavior', 
              label['class'],
          )
          self.get_or_create_property('do', label['seconds'], item, abstract_item)
  
      def add_emotion_label(self, label):
          item = self.get_item_by_indicator(
              label['object'],
              label['seconds'],
          )
          abstract_item = self.get_or_create_abstract_item(
              'emotion',
              label['class'],
          )
          self.get_or_create_property('feel', label['seconds'], item, abstract_item)
  
      def add_relation_label(self, label):
          relation_item = self.get_or_create_abstract_item(
              label['class'],
              label['subclass'],
          )
          source_item = self.get_item_by_indicator(
              label['source'],
              label['seconds'],
          )
          target_item = self.get_item_by_indicator(
              label['target'],
              label['seconds'],
          )
          self.get_or_create_property(
              'related_to',
              label['seconds'],
              source_item,
              target_item,
              relation_item,
          )
  
      def add_location_label(self, label):
          item = self.get_or_create_abstract_item(
              'location',
              label['class'],
          )
          self.get_or_create_property(
              'location_of',
              label['seconds'],
              item,
              self.get_or_create_video_item(),
          )
  
      def add_sound_label(self, label):
          item = self.get_or_create_abstract_item(
              'sound',
              label['class'],
          )
          self.get_or_create_property(
              'sound_of',
              label['seconds'],
              item,
              self.get_or_create_video_item(),
          )
  
      def add_label(self, label):
          if label['type'] == 'object':
              self.add_object_label(label)
          elif label['type'] == 'behavior':
              self.add_behavior_label(label)
          elif label['type'] == 'emotion':
              self.add_emotion_label(label)
          elif label['type'] == 'relation':
              self.add_relation_label(label)
          elif label['type'] == 'location':
              self.add_location_label(label)
          elif label['type'] == 'sound':
              self.add_sound_label(label)
  
      def dump_to_dict_iter(self):
          for item in self.get_all_items():
              yield item.as_dict()
          for valid_time in self.get_all_valid_times():
              yield valid_time.as_dict()
          for box in self.get_all_boxes():
              yield box.as_dict()
          for prop in self.get_all_properties():
              yield prop.as_dict()
          for similarity in self.get_all_similarities():
              if similarity.similarity > config.ITEM_MERGE_THRESHOLD:
                  yield similarity.as_dict()
  
      def dump_to_json_iter(self):
          for d in self.dump_to_dict_iter():
              yield json.dumps(d)
  