import json
from typing import List

from django.db import connection, models

# Create your models here.


class TruncatableMixin:
    @classmethod
    def truncate_table(cls):
        cursor = connection.cursor()
        cursor.execute('TRUNCATE TABLE "{0}"'.format(cls._meta.db_table))
        cursor.execute('ALTER SEQUENCE {0}_id_seq RESTART WITH 1'.format(cls._meta.db_table.lower()))


class ToJsonableMixin:
    def to_jsonable(self):
        internal_dict = self.__dict__.copy()
        if '_state' in internal_dict:
            del internal_dict['_state']
        return internal_dict

    NESTED_JSON_FIELDS: List[str] = []

    def to_jsonable_nested(self):
        data = self.to_jsonable()
        for nested_json_field in type(self).NESTED_JSON_FIELDS:
            field = data[nested_json_field]
            if field is not None:
                data[nested_json_field] = json.loads(data[nested_json_field])
        return data


class Job(models.Model, TruncatableMixin, ToJsonableMixin):
    NESTED_JSON_FIELDS = ['result']
    hsh = models.CharField(max_length=255, null=False, blank=False)
    file = models.TextField(null=False, blank=False)
    taken_at = models.DateTimeField(default=None, null=True, blank=True)
    result = models.TextField(default=None, null=True, blank=True)


class Log(models.Model, TruncatableMixin, ToJsonableMixin):
    NESTED_JSON_FIELDS = ['sender', 'content']
    sender = models.TextField(null=False, blank=False)
    content = models.TextField(null=False, blank=False)

    class Meta:
        abstract = True


class ErrorLog(Log):
    pass


class PerformanceLog(Log):
    pass