node.py

# -*- coding: utf-8 -*-
#
import uuid

from django.db import models, transaction
from django.db.models import Q
from django.utils.translation import ugettext_lazy as _


__all__ = ['Node']


class Node(models.Model):
    id = models.UUIDField(default=uuid.uuid4, primary_key=True)
    key = models.CharField(unique=True, max_length=64, verbose_name=_("Key"))  # '1:1:1:1'
    value = models.CharField(max_length=128, verbose_name=_("Value"))
    child_mark = models.IntegerField(default=0)
    date_create = models.DateTimeField(auto_now_add=True)

    is_node = True

    def __str__(self):
        return self.full_value

    @property
    def name(self):
        return self.value

    @property
    def full_value(self):
        ancestor = [a.value for a in self.get_ancestor(with_self=True)]
        if self.is_root():
            return self.value
        return ' / '.join(ancestor)

    @property
    def level(self):
        return len(self.key.split(':'))

    def set_parent(self, instance):
        children = self.get_all_children()
        old_key = self.key
        with transaction.atomic():
            self.parent = instance
            for child in children:
                child.key = child.key.replace(old_key, self.key, 1)
                child.save()
            self.save()

    def get_next_child_key(self):
        mark = self.child_mark
        self.child_mark += 1
        self.save()
        return "{}:{}".format(self.key, mark)

    def create_child(self, value):
        with transaction.atomic():
            child_key = self.get_next_child_key()
            child = self.__class__.objects.create(key=child_key, value=value)
            return child

    def get_children(self, with_self=False):
        pattern = r'^{0}$|^{}:[0-9]+$' if with_self else r'^{}:[0-9]+$'
        return self.__class__.objects.filter(
            key__regex=pattern.format(self.key)
        )

    def get_all_children(self, with_self=False):
        pattern = r'^{0}$|^{0}:' if with_self else r'^{0}'
        return self.__class__.objects.filter(
            key__regex=pattern.format(self.key)
        )

    def get_sibling(self, with_self=False):
        key = ':'.join(self.key.split(':')[:-1])
        pattern = r'^{}:[0-9]+$'.format(key)
        sibling = self.__class__.objects.filter(
            key__regex=pattern.format(self.key)
        )
        if not with_self:
            sibling = sibling.exclude(key=self.key)
        return sibling

    def get_family(self):
        ancestor = self.get_ancestor()
        children = self.get_all_children()
        return [*tuple(ancestor), self, *tuple(children)]

    def get_assets(self):
        from .asset import Asset
        if self.is_root():
            assets = Asset.objects.filter(
                Q(nodes__id=self.id) | Q(nodes__isnull=True)
            )
        else:
            assets = Asset.objects.filter(nodes__id=self.id)
        return assets

    def get_valid_assets(self):
        return self.get_assets().valid()

    def get_all_assets(self):
        from .asset import Asset
        if self.is_root():
            assets = Asset.objects.all()
        else:
            nodes = self.get_all_children(with_self=True)
            assets = Asset.objects.filter(nodes__in=nodes).distinct()
        return assets

    def get_all_valid_assets(self):
        return self.get_all_assets().valid()

    def is_root(self):
        return self.key == '0'

    @property
    def parent(self):
        if self.key == "0" or not self.key.startswith("0"):
            return self.__class__.root()
        parent_key = ":".join(self.key.split(":")[:-1])
        try:
            parent = self.__class__.objects.get(key=parent_key)
            return parent
        except Node.DoesNotExist:
            return self.__class__.root()

    @parent.setter
    def parent(self, parent):
        self.key = parent.get_next_child_key()

    def get_ancestor(self, with_self=False):
        if self.is_root():
            ancestor = self.__class__.objects.filter(key='0')
            return ancestor

        _key = self.key.split(':')
        if not with_self:
            _key.pop()
        ancestor_keys = []
        for i in range(len(_key)):
            ancestor_keys.append(':'.join(_key))
            _key.pop()
        ancestor = self.__class__.objects.filter(
            key__in=ancestor_keys
        ).order_by('key')
        return ancestor

    @classmethod
    def root(cls):
        obj, created = cls.objects.get_or_create(
            key='0', defaults={"key": '0', 'value': "ROOT"}
        )
        return obj


class Tree:
    def __init__(self, root):
        self.root = root
        self.nodes = []

    def add_node(self, node):
        pass