# Copyright (C) 2018-2025 by BDE ENS-Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later

from django.core.management.base import BaseCommand
from django.db.models import Sum

from note.models import RecurrentTransaction, TransactionTemplate


class Command(BaseCommand):
    help = """
    Syntax of inventory file:\n
        DATE_START=YYYY-MM-DD HH:MM:SS\n
        button_id=quantity\n
        # some comment\n
        ...\n
        DATE_END=YYYY-MM-DD\n
        button_id=quantity\n
        ...\n
        GROCERY\n
        button_id=quantity\n
        ...\n
    """

    def add_arguments(self, parser):
        parser.add_argument('file', type=str)

    def handle(self, *args, **kwargs):
        if not kwargs['file']:
            kwargs['file'] = '/var/inventory/current.inv'
        file = open(kwargs['file'], 'r', encoding='utf-8')

        inv_start, inv_end, inv_grocery = {}, {}, {}
        start = True
        grocery = False

        for line in file:
            if line[0] == '#':
                continue
            if start:
                if 'DATE_START' in line:
                    date_start = line.split('=')[1]
                elif 'DATE_END' in line:
                    date_end = line.split('=')[1]
                    start = False
                else:
                    add_to_dict(line, inv_start)
            elif not grocery:
                if 'GROCERY' in line:
                    grocery = True
                else:
                    add_to_dict(line, inv_end)
            else:
                add_to_dict(line, inv_grocery)

        delta_real = delta_from_inv(inv_start, inv_end, inv_grocery)
        delta_th = delta_from_note(date_start, date_end, delta_real.keys())

        steal_dict = steal(delta_real, delta_th)

        if kwargs['verbosity'] > 0:
            for button in steal_dict:
                text = "%.2f" % steal_dict[button] + \
                        f"% of steal on button: {button.name} (pk={button.pk})"
                if steal_dict[button] > 20:
                    self.stdout.write(self.style.ERROR(text))
                elif steal_dict[button] > 0:
                    self.stdout.write(self.style.WARNING(text))
                else:
                    self.stdout.write(self.style.SUCCESS(text))

        return 0


def add_to_dict(line, d):
    pk, quantity = line.split('=')
    button = TransactionTemplate.objects.get(pk=pk)
    d[button] = int(quantity)
    return


def delta_from_note(date_start, date_end, keys):
    d = {}
    for button in keys:
        quantity = RecurrentTransaction.objects.filter(
            valid=True,
            created_at__gte=date_start,
            created_at__lte=date_end,
            template__pk=button.pk).aggregate(total=Sum('quantity'))['total']
        d[button] = quantity
    return d


def delta_from_inv(s, e, g):
    d = {}
    for button in s:
        if button in g:
            if button in e:
                d[button] = s[button] + g[button] - e[button]
            else:
                d[button] = s[button] + g[button]
        else:
            if button in e:
                d[button] = s[button] - e[button]
            else:
                d[button] = s[button]
    return d


def steal(real, th):
    s = {}
    for b in real:
        s[b] = 100 * (real[b] - th[b]) / real[b]
    return s