# -*- coding: utf-8 -*-
#
import io
import os
import uuid
from hashlib import md5

import sshpubkeys
from django.conf import settings
from django.core.cache import cache
from django.db import models
from django.db.models import QuerySet
from django.utils import timezone
from django.utils.translation import ugettext_lazy as _

from common.db import fields
from common.utils import random_string
from common.utils import (
    ssh_key_string_to_obj, ssh_key_gen, get_logger, lazyproperty
)
from common.utils.encode import parse_ssh_public_key_str
from orgs.mixins.models import OrgModelMixin

logger = get_logger(__file__)


class Connectivity(models.TextChoices):
    unknown = 'unknown', _('Unknown')
    ok = 'ok', _('Ok')
    failed = 'failed', _('Failed')


class AbsConnectivity(models.Model):
    connectivity = models.CharField(
        choices=Connectivity.choices, default=Connectivity.unknown,
        max_length=16, verbose_name=_('Connectivity')
    )
    date_verified = models.DateTimeField(null=True, verbose_name=_("Date verified"))

    def set_connectivity(self, val):
        self.connectivity = val
        self.date_verified = timezone.now()
        self.save(update_fields=['connectivity', 'date_verified'])

    @classmethod
    def bulk_set_connectivity(cls, queryset_or_id, connectivity):
        if not isinstance(queryset_or_id, QuerySet):
            queryset = cls.objects.filter(id__in=queryset_or_id)
        else:
            queryset = queryset_or_id
        queryset.update(connectivity=connectivity, date_verified=timezone.now())

    class Meta:
        abstract = True


class AuthMixin:
    private_key = ''
    password = ''
    public_key = ''
    username = ''

    @property
    def ssh_key_fingerprint(self):
        if self.public_key:
            public_key = self.public_key
        elif self.private_key:
            try:
                public_key = parse_ssh_public_key_str(private_key=self.private_key, password=self.password)
            except IOError as e:
                return str(e)
        else:
            return ''

        public_key_obj = sshpubkeys.SSHKey(public_key)
        fingerprint = public_key_obj.hash_md5()
        return fingerprint

    @property
    def private_key_obj(self):
        if self.private_key:
            key_obj = ssh_key_string_to_obj(self.private_key, password=self.password)
            return key_obj
        else:
            return None

    @property
    def private_key_file(self):
        if not self.private_key_obj:
            return None
        project_dir = settings.PROJECT_DIR
        tmp_dir = os.path.join(project_dir, 'tmp')
        key_name = '.' + md5(self.private_key.encode('utf-8')).hexdigest()
        key_path = os.path.join(tmp_dir, key_name)
        if not os.path.exists(key_path):
            self.private_key_obj.write_private_key_file(key_path)
            os.chmod(key_path, 0o400)
        return key_path

    def get_private_key(self):
        if not self.private_key_obj:
            return None
        string_io = io.StringIO()
        self.private_key_obj.write_private_key(string_io)
        private_key = string_io.getvalue()
        return private_key

    @property
    def public_key_obj(self):
        if self.public_key:
            try:
                return sshpubkeys.SSHKey(self.public_key)
            except TabError:
                pass
        return None

    def set_auth(self, password=None, private_key=None, public_key=None):
        update_fields = []
        if password:
            self.password = password
            update_fields.append('password')
        if private_key:
            self.private_key = private_key
            update_fields.append('private_key')
        if public_key:
            self.public_key = public_key
            update_fields.append('public_key')

        if update_fields:
            self.save(update_fields=update_fields)

    def _merge_auth(self, other):
        if other.password:
            self.password = other.password
        if other.public_key or other.private_key:
            self.private_key = other.private_key
            self.public_key = other.public_key

    def clear_auth(self):
        self.password = ''
        self.private_key = ''
        self.public_key = ''
        self.save()

    @staticmethod
    def gen_password(length=36):
        return random_string(length, special_char=True)

    @staticmethod
    def gen_key(username):
        private_key, public_key = ssh_key_gen(
            username=username
        )
        return private_key, public_key

    def auto_gen_auth(self, password=True, key=True):
        _password = None
        _private_key = None
        _public_key = None

        if password:
            _password = self.gen_password()
        if key:
            _private_key, _public_key = self.gen_key(self.username)
        self.set_auth(
            password=_password, private_key=_private_key,
            public_key=_public_key
        )


class BaseUser(OrgModelMixin, AuthMixin):
    id = models.UUIDField(default=uuid.uuid4, primary_key=True)
    name = models.CharField(max_length=128, verbose_name=_('Name'))
    username = models.CharField(max_length=128, blank=True, verbose_name=_('Username'), db_index=True)
    password = fields.EncryptCharField(max_length=256, blank=True, null=True, verbose_name=_('Password'))
    private_key = fields.EncryptTextField(blank=True, null=True, verbose_name=_('SSH private key'))
    public_key = fields.EncryptTextField(blank=True, null=True, verbose_name=_('SSH public key'))
    comment = models.TextField(blank=True, verbose_name=_('Comment'))
    date_created = models.DateTimeField(auto_now_add=True, verbose_name=_("Date created"))
    date_updated = models.DateTimeField(auto_now=True, verbose_name=_("Date updated"))
    created_by = models.CharField(max_length=128, null=True, verbose_name=_('Created by'))

    ASSETS_AMOUNT_CACHE_KEY = "ASSET_USER_{}_ASSETS_AMOUNT"
    ASSET_USER_CACHE_TIME = 600

    APPS_AMOUNT_CACHE_KEY = "APP_USER_{}_APPS_AMOUNT"
    APP_USER_CACHE_TIME = 600

    def get_related_assets(self):
        assets = self.assets.filter(org_id=self.org_id)
        return assets

    def get_related_apps(self):
        from applications.models import Account
        apps = Account.objects.filter(systemuser=self)
        return apps

    def get_username(self):
        return self.username

    @lazyproperty
    def assets_amount(self):
        cache_key = self.ASSETS_AMOUNT_CACHE_KEY.format(self.id)
        cached = cache.get(cache_key)
        if not cached:
            cached = self.get_related_assets().count()
            cache.set(cache_key, cached, self.ASSET_USER_CACHE_TIME)
        return cached

    @property
    def apps_amount(self):
        cache_key = self.APPS_AMOUNT_CACHE_KEY.format(self.id)
        cached = cache.get(cache_key)
        if not cached:
            cached = self.get_related_apps().count()
            cache.set(cache_key, cached, self.APP_USER_CACHE_TIME)
        return cached

    def expire_assets_amount(self):
        cache_key = self.ASSETS_AMOUNT_CACHE_KEY.format(self.id)
        cache.delete(cache_key)

    def _to_secret_json(self):
        """Push system user use it"""
        return {
            'name': self.name,
            'username': self.username,
            'password': self.password,
            'public_key': self.public_key,
            'private_key': self.private_key_file,
        }

    class Meta:
        abstract = True