import json
import random
from typing import Dict

from django.core.management.base import BaseCommand

from kfet.models import Account, Article, Operation


def gen_anonymisation_table() -> Dict[int, str]:
    random.seed()
    hashes = {}
    for account_id in Account.objects.values_list("id", flat=True):
        h = random.getrandbits(128)
        hashes[account_id] = "{:032x}".format(h)
    return hashes


def dump_articles(filename: str) -> None:
    articles = [
        {
            "id": article.id,
            "name": article.name,
            "price": str(article.price),
            "category": article.category.name,
            "box_type": article.box_type,
            "box_capacity": article.box_capacity,
        }
        for article in Article.objects.all()
    ]
    with open(filename, "w") as file:
        json.dump(articles, file, indent=4)


def dump_operations(filename: str, accounts_hashes: Dict[int, str]) -> None:
    not_canceled_purchases = (
        Operation.objects.filter(type=Operation.PURCHASE)
        .filter(canceled_at__isnull=True)
        .values_list(
            "amount",
            "article__id",
            "article_nb",
            "group__at",
            "group__is_cof",
            "group__on_acc__id",
        )
    )
    operations = [
        {
            "amount": str(amount),
            "article": article_id,
            "number": nb,
            "date": str(at),
            "is_cof": is_cof,
            "on_account": accounts_hashes[on_acc],
        }
        for amount, article_id, nb, at, is_cof, on_acc in not_canceled_purchases
    ]
    with open(filename, "w") as file:
        json.dump(operations, file, indent=4)


class Command(BaseCommand):
    help = 'Dump un historique "anonymisé".'

    def handle(self, *args, **options):
        # XXX. This is not great for privacy.
        accounts_hashes = gen_anonymisation_table()

        article_file = "article.dump.json"
        self.stdout.write('Dumping articles to "{}"'.format(article_file))
        dump_articles(article_file)

        operation_file = "operation.dump.json"
        self.stdout.write('Dumping operations to "{}"'.format(operation_file))
        dump_operations(operation_file, accounts_hashes)