# 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 import transaction
from django.db.models import Sum

from note.models import RecurrentTransaction, TransactionTemplate


class Command(BaseCommand):
    help = """
    Syntax of inventory file:
        DATE_START=YYYY-MM-DD HH:MM:SS
        button_id=quantity
        "button_name"=quantity
        'button_name'=quantity
        # some comment
        ...
        DATE_END=YYYY-MM-DD
        button_id=quantity
        ...
        GROCERY
        button_id=quantity
        ...
    Syntax of price file:
        button_id;price_ht;TVA
        "button_name";price_ht;TVA
        'button_name';price_ht;TVA
        # some comment
        button_name
    You don't need to escape internal " or ' in button_name
    "=" and ";" aren't allowed in button_name
    TVA in % (i.e 5.5, 20)
    price_ht in € (i.e 0.928, 1.045)
    """

    def add_arguments(self, parser):
        parser.add_argument('file', type=str)
        parser.add_argument('-t', '--type', choices=["weekend", "weekdays"],
                            default="", help='Type of prices')
        parser.add_argument('-d', '--doit', action='store_true',
                            help='Actually do it')

    def handle(self, *args, **kwargs):
        prices_csv = '/var/inventory/prices.csv'
        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)

        file.close()

        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))

        change = False
        if kwargs['type']:
            change = True
            prices_dict = {}
            prices = open(prices_csv, 'r', encoding='utf-8')
            for line in prices:
                if line[0] == '#':
                    continue
                b, p, tva = line.split(';')
                if b[0] == "\"" or b[0] == "'":
                    b = TransactionTemplate.objects.get(name=b[1:-1])
                else:
                    b = TransactionTemplate.objects.get(pk=int(b))
                prices_dict[b] = float(p) * (1 + float(tva) / 100)
            prices.close()

        if kwargs['type'] == 'weekdays':
            for b in prices_dict:
                # people steal on weekdays
                prices_dict[b] = prices_dict[b] * (1 + steal_dict[b] / 100)

        if change:
            with transaction.atomic():
                for b in prices_dict:
                    # dizaine de centime supérieures
                    # sauf si les pertes sont inférieures à 1 centimes
                    # 1.299€ -> 1.30€ | 1.2100€ -> 1.30€ | 1.20999€ -> 1.20€
                    amount = round(int(100*(prices_dict[b] + 0.05)), -1)
                    if kwargs['verbosity'] > 0:
                        self.stdout.write(f"""{b.name}:
                        -Old amount: {b.amount}c€
                        -New amount: {amount}c€""")
                    b.amount = amount
                    # we don't want to flood price history each week
                    b._no_signal = True
                    if kwargs['doit']:
                        b.save()
        return 0


def add_to_dict(line, d):
    b, quantity = line.split('=')
    if b[0] == "\"" or b[0] == "'":
        button = TransactionTemplate.objects.get(name=b[1:-1])
    else:
        button = TransactionTemplate.objects.get(pk=int(b))
    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