import pickle
import codecs
import json

from django.db import models
from django.core import validators as django_validators

from pingcap_sso.exceptions import TypeUnsupportedError


class SiteSettingDB(models.Model):

    TYPE_STR = 'str'
    TYPE_INTEGER = 'integer'
    TYPE_STR_LIST = 'str_list'
    DATA_TYPE_CHOCES = (
        (TYPE_STR, 'str'),
        (TYPE_INTEGER, 'integer'),
        (TYPE_STR_LIST, 'str_list')
    )

    name = models.CharField(max_length=255)
    value = models.TextField()
    data_type = models.CharField(
        max_length=64, choices=DATA_TYPE_CHOCES, default=TYPE_STR)
    display_at_admin_frontend = models.BooleanField(default=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = 'site_settings'
        unique_together = ('name', 'data_type')


class SiteSettingValue:

    def __init__(self, name, data_type):
        self.name = name
        self.data_type = data_type


# SiteSetting.asktug_webhook_secret = 1
# a = SiteSetting.asktug_webhook_secret


class MetaSiteSetting(type):

    REGISTERED_SETTINGS = {
        'asktug_post_business_leads_key_words': SiteSettingDB.TYPE_STR_LIST,
        'metabase_secret_key': SiteSettingDB.TYPE_STR,
        'metabase_site_url': SiteSettingDB.TYPE_STR,
        'points_user_redeem_notify_lark_webhook': SiteSettingDB.TYPE_STR,
        'business_download_leads_lark_webhook': SiteSettingDB.TYPE_STR,
        'asktug_contact_us_lark_webhook': SiteSettingDB.TYPE_STR,
        'org_topic_urgency_alert_lark_webhook': SiteSettingDB.TYPE_STR,
        'org_topic_urgency_alert_email_address': SiteSettingDB.TYPE_STR,
        'asktug_user_action_last_sync_at': SiteSettingDB.TYPE_STR,
        'contact_us_emergency_lark_webhook': SiteSettingDB.TYPE_STR,
        'contact_us_cooperation_lark_webhook': SiteSettingDB.TYPE_STR,
        'contact_us_communication_lark_webhook': SiteSettingDB.TYPE_STR,
        'tug_new_application_notify_lark_webhook': SiteSettingDB.TYPE_STR,
        'official_new_contact_us_notify_lark_webhook': SiteSettingDB.TYPE_STR,
        'official_new_joint_solution_notify_lark_webhook': SiteSettingDB.TYPE_STR,
        'company_verification_notify_lark_webhook': SiteSettingDB.TYPE_STR,
        'asktug_user_action_for_behavior_track_last_sync_at': SiteSettingDB.TYPE_INTEGER,
        'pingcap_staff_resigned_notify_lark_webhook': SiteSettingDB.TYPE_STR,
        'community_new_contact_us_notify_lark_webhook': SiteSettingDB.TYPE_STR,
        'official_new_partner_compatibility_certification_notify_lark_webhook': SiteSettingDB.TYPE_STR,
    }

    def __setattr__(cls, attr, value):
        data_type = cls.REGISTERED_SETTINGS.get(attr)
        if not data_type:
            raise AttributeError(attr)

        setting, _ = SiteSettingDB.objects.get_or_create(name=attr)
        setting.value = cls._encode(value, data_type)
        setting.data_type = data_type
        setting.save()
        super(MetaSiteSetting, cls).__setattr__(attr, value)

    def __getattr__(cls, attr):
        data_type = cls.REGISTERED_SETTINGS.get(attr)
        if not data_type:
            raise AttributeError(attr)

        try:
            setting = SiteSettingDB.objects.get(
                name=attr, data_type=data_type)
            return cls._parse(setting.value, data_type)
        except SiteSettingDB.DoesNotExist:
            return cls._get_default_value_by_type(data_type)

    def _get_default_value_by_type(cls, data_type):
        if data_type == SiteSettingDB.TYPE_STR:
            return ''
        elif data_type == SiteSettingDB.TYPE_INTEGER:
            return 0
        elif data_type == SiteSettingDB.TYPE_STR_LIST:
            return []
        else:
            raise Exception('Unsupported data_type: {}'.format(data_type))

    def _parse(cls, raw_value, data_type):
        return json.loads(raw_value)

    def _encode(cls, raw_value, data_type):
        return json.dumps(raw_value)


class SiteSetting(metaclass=MetaSiteSetting):
    pass