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 _
from django.core.cache import cache

from orgs.mixins import OrgModelMixin
from orgs.utils import set_current_org, get_current_org
from orgs.models import Organization

__all__ = ['Node']


class Node(OrgModelMixin):
    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
    _assets_amount = None
    _full_value_cache_key = '_NODE_VALUE_{}'
    _assets_amount_cache_key = '_NODE_ASSETS_AMOUNT_{}'

    class Meta:
        verbose_name = _("Node")

    def __str__(self):
        return self.full_value

    def __eq__(self, other):
        if not other:
            return False
        return self.key == other.key

    def __gt__(self, other):
        if self.is_root():
            return True
        self_key = [int(k) for k in self.key.split(':')]
        other_key = [int(k) for k in other.key.split(':')]
        return self_key.__lt__(other_key)

    def __lt__(self, other):
        return not self.__gt__(other)

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

    @property
    def assets_amount(self):
        """
        获取节点下所有资产数量速度太慢，所以需要重写，使用cache等方案
        :return:
        """
        if self._assets_amount is not None:
            return self._assets_amount
        cache_key = self._assets_amount_cache_key.format(self.key)
        cached = cache.get(cache_key)
        if cached is not None:
            return cached
        assets_amount = self.get_all_assets().count()
        cache.set(cache_key, assets_amount, 3600)
        return assets_amount

    @assets_amount.setter
    def assets_amount(self, value):
        self._assets_amount = value

    def expire_assets_amount(self):
        ancestor_keys = self.get_ancestor_keys(with_self=True)
        cache_keys = [self._assets_amount_cache_key.format(k) for k in ancestor_keys]
        cache.delete_many(cache_keys)

    @classmethod
    def expire_nodes_assets_amount(cls, nodes=None):
        if nodes:
            for node in nodes:
                node.expire_assets_amount()
            return
        key = cls._assets_amount_cache_key.format('*')
        cache.delete_pattern(key)

    @property
    def full_value(self):
        key = self._full_value_cache_key.format(self.key)
        cached = cache.get(key)
        if cached:
            return cached
        if self.is_root():
            return self.value
        parent_full_value = self.parent.full_value
        value = parent_full_value + ' / ' + self.value
        key = self._full_value_cache_key.format(self.key)
        cache.set(key, value, 3600)
        return value

    def expire_full_value(self):
        key = self._full_value_cache_key.format(self.key)
        cache.delete_pattern(key+'*')

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

    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}$|^{0}:[0-9]+$' if with_self else r'^{0}:[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_default_node():
            assets = Asset.objects.filter(Q(nodes__id=self.id) | Q(nodes__isnull=True))
        else:
            assets = Asset.objects.filter(nodes__id=self.id)
        return assets.distinct()

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

    def get_all_assets(self):
        from .asset import Asset
        pattern = r'^{0}$|^{0}:'.format(self.key)
        args = []
        kwargs = {}
        if self.is_default_node():
            args.append(Q(nodes__key__regex=pattern) | Q(nodes=None))
        else:
            kwargs['nodes__key__regex'] = pattern
        assets = Asset.objects.filter(*args, **kwargs).distinct()
        return assets

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

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

    def is_root(self):
        if self.key.isdigit():
            return True
        else:
            return False

    @property
    def parent_key(self):
        parent_key = ":".join(self.key.split(":")[:-1])
        return parent_key

    @property
    def parent(self):
        if self.is_root():
            return self
        try:
            parent = self.__class__.objects.get(key=self.parent_key)
            return parent
        except Node.DoesNotExist:
            return self.__class__.root()

    @parent.setter
    def parent(self, parent):
        if not self.is_node:
            self.key = parent.key + ':fake'
            return
        children = self.get_all_children()
        old_key = self.key
        with transaction.atomic():
            self.key = parent.get_next_child_key()
            for child in children:
                child.key = child.key.replace(old_key, self.key, 1)
                child.save()
            self.save()

    def get_ancestor_keys(self, with_self=False):
        parent_keys = []
        key_list = self.key.split(":")
        if not with_self:
            key_list.pop()
        for i in range(len(key_list)):
            parent_keys.append(":".join(key_list))
            key_list.pop()
        return parent_keys

    def get_ancestor(self, with_self=False):
        ancestor_keys = self.get_ancestor_keys(with_self=with_self)
        ancestor = self.__class__.objects.filter(
            key__in=ancestor_keys
        ).order_by('key')
        return ancestor

    @classmethod
    def create_root_node(cls):
        # 如果使用current_org 在set_current_org时会死循环
        _current_org = get_current_org()
        with transaction.atomic():
            if not _current_org.is_real():
                return cls.default_node()
            set_current_org(Organization.root())
            org_nodes_roots = cls.objects.filter(key__regex=r'^[0-9]+$')
            org_nodes_roots_keys = org_nodes_roots.values_list('key', flat=True) or ['1']
            key = max([int(k) for k in org_nodes_roots_keys])
            key = str(key + 1) if key != 0 else '2'
            set_current_org(_current_org)
            root = cls.objects.create(key=key, value=_current_org.name)
            return root

    @classmethod
    def root(cls):
        root = cls.objects.filter(key__regex=r'^[0-9]+$')
        if root:
            return root[0]
        else:
            return cls.create_root_node()

    @classmethod
    def default_node(cls):
        defaults = {'value': 'Default'}
        return cls.objects.get_or_create(defaults=defaults, key='1')

    @classmethod
    def generate_fake(cls, count=100):
        import random
        for i in range(count):
            node = random.choice(cls.objects.all())
            node.create_child('Node {}'.format(i))