class Right:

  def __init__(self, row):

    self.user_id = int(row['user_id'])

    self.target_type = str(row['target_type'])

    self.target_id = int(row['target_id'])

    self.mode = str(row['mode'])

class MyRights:

  def __init__(self, internal):

    self.internal = internal

    self.user_id = self.internal.user_id

  def issuperuser(self):

    return self.internal.issuperuser()

  def isallowed(self, target_type, target_id, mode):

    return self.internal.isallowed(target_type, target_id, mode)

  def isallowed_root(self, mode):

    return self.internal.isallowed_root(mode)

class InternalRights:

  TABLE = 'rights'

  ROOT = 'root'

  def __init__(self, connection, user_id = 0, superuser = False):

    assert(type(user_id) is int)

    assert(type(superuser) is bool)

    self.connection = connection

    self.user_id = user_id

    self.superuser = superuser

  def issuperuser(self):

    if self.superuser:

      return True

    if self.user_id and self.get(self.user_id, self.ROOT, 0, self.ROOT):

      return True

  def isallowed(self, target_type, target_id, mode):

    if self.issuperuser():

      return True

    if self.user_id and self.get(self.user_id, target_type, target_id, mode):

      return True

    return False

  def build_where(self, user_id = None, target_type = None, target_id = None, mode = None):

    where = list()

    args = list()

    if user_id:

      assert(type(user_id) is int)

      where.append("`user_id`=%d")

      args.append(user_id)

    if target_type:

      assert(type(target_type) is str)

      where.append("`target_type`=%s")

      args.append(target_type)

    if target_id:

      assert(type(target_id) is int)

      where.append("`target_id`=%d")

      args.append(target_id)

    if mode:

      assert(type(mode) is str)

      where.append("`mode`=%s")

      args.append(mode)

    if not where:

      return '', list()

    return ' WHERE ' + ' AND '.join(where), args

  def get_list(self, user_id = None, target_type = None, target_id = None, mode = None):

    where, args = self.build_where(user_id, target_type, target_id, mode)

    rows = connection.query_dict('SELECT * FROM %T' + where, self.TABLE, *args)

    rights = list()

    for row in rows:

      rights.append( Right(row) )

    return rights

  def delete_list(self, user_id = None, target_type = None, target_id = None, mode = None):

    where, args = self.build_where(user_id, target_type, target_id, mode)

    self.connection.execute('DELETE FROM %T' + where, self.TABLE, *args)

    self.connection.cache.reset(self.TABLE)

  def reset_cache(self, user_id, target_type, target_id, mode):

    assert(type(user_id) is int)

    assert(type(target_type) is str)

    assert(type(target_id) is int)

    assert(type(mode) is str)

    self.connection.cache.reset(

      self.TABLE,

      { 'user_id': user_id,

        'target_type': target_type,

        'target_id': target_id,

        'mode': mode })

  def get(self, user_id, target_type, target_id, mode):

    assert(type(user_id) is int)

    assert(type(target_type) is str)

    assert(type(target_id) is int)

    assert(type(mode) is str)

    rows = self.connection.cache.select(

      self.TABLE,

      { 'user_id': user_id,

        'target_type': target_type,

        'target_id': target_id,

        'mode': mode })

    return bool(rows)

  def set(self, user_id, target_type, target_id, mode, allowed):

    assert(type(user_id) is int)

    assert(type(target_type) is str)

    assert(type(target_id) is int)

    assert(type(mode) is str)

    if not allowed:

      self.connection.execute(

        '''DELETE FROM %T WHERE

                `user_id`=%d

            AND `target_type`=%s

            AND `target_id`=%d

            AND `mode`=%s''',

        self.TABLE, user_id, target_type, target_id, mode )

      self.reset_cache(user_id, target_type, target_id, mode)

    elif not self.get(user_id, target_type, target_id, mode):

      self.connection.execute(

        '''INSERT INTO %T SET

                `user_id`=%d,

                `target_type`=%s,

                `target_id`=%d,

                `mode`=%s''',

        self.TABLE, user_id, target_type, target_id, mode )

      self.reset_cache(user_id, target_type, target_id, mode)

  def isallowed_root(self, mode):

    return self.isallowed(self.ROOT, 0, mode)

  def get_list_root(self, user_id = None, mode = None):

    return self.get_list(user_id, self.ROOT, 0, mode)

  def delete_list_root(self, user_id = None, mode = None):

    return self.delete_list_root(user_id, self.ROOT, 0, mode)

  def get_root(self, user_id, mode):

    return self.get(user_id, self.ROOT, 0, mode)

  def set_root(self, user_id, mode, allowed):

    return self.set(user_id, self.ROOT, 0, mode, allowed)

  def get_superuser(self, user_id):

    return self.get_root(user_id, self.ROOT)

  def set_superuser(self, user_id, allowed):

    return self.set_root(user_id, self.ROOT, allowed)