Sith/accounting/models.py

# -*- coding:utf-8 -*
#
# Copyright 2016,2017
# - Skia <skia@libskia.so>
#
# Ce fichier fait partie du site de l'Association des Étudiants de l'UTBM,
# http://ae.utbm.fr.
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License a published by the Free Software
# Foundation; either version 3 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Sofware Foundation, Inc., 59 Temple
# Place - Suite 330, Boston, MA 02111-1307, USA.
#
#

from django.core.urlresolvers import reverse
from django.core.exceptions import ValidationError
from django.core import validators
from django.db import models
from django.conf import settings
from django.utils.translation import ugettext_lazy as _
from django.template import defaultfilters

from phonenumber_field.modelfields import PhoneNumberField

from decimal import Decimal
from core.models import User, SithFile
from club.models import Club


class CurrencyField(models.DecimalField):
    """
    This is a custom database field used for currency
    """

    def __init__(self, *args, **kwargs):
        kwargs["max_digits"] = 12
        kwargs["decimal_places"] = 2
        super(CurrencyField, self).__init__(*args, **kwargs)

    def to_python(self, value):
        try:
            return super(CurrencyField, self).to_python(value).quantize(Decimal("0.01"))
        except AttributeError:
            return None


# Accounting classes


class Company(models.Model):
    name = models.CharField(_("name"), max_length=60)
    street = models.CharField(_("street"), max_length=60, blank=True)
    city = models.CharField(_("city"), max_length=60, blank=True)
    postcode = models.CharField(_("postcode"), max_length=10, blank=True)
    country = models.CharField(_("country"), max_length=32, blank=True)
    phone = PhoneNumberField(_("phone"), blank=True)
    email = models.EmailField(_("email"), blank=True)
    website = models.CharField(_("website"), max_length=64, blank=True)

    class Meta:
        verbose_name = _("company")

    def is_owned_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        if user.is_in_group(settings.SITH_GROUP_ACCOUNTING_ADMIN_ID):
            return True
        return False

    def can_be_edited_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        for club in user.memberships.filter(end_date=None).all():
            if club and club.role == settings.SITH_CLUB_ROLES_ID["Treasurer"]:
                return True
        return False

    def can_be_viewed_by(self, user):
        """
        Method to see if that object can be viewed by the given user
        """
        for club in user.memberships.filter(end_date=None).all():
            if club and club.role >= settings.SITH_CLUB_ROLES_ID["Treasurer"]:
                return True
        return False

    def get_absolute_url(self):
        return reverse("accounting:co_edit", kwargs={"co_id": self.id})

    def get_display_name(self):
        return self.name

    def __str__(self):
        return self.name


class BankAccount(models.Model):
    name = models.CharField(_("name"), max_length=30)
    iban = models.CharField(_("iban"), max_length=255, blank=True)
    number = models.CharField(_("account number"), max_length=255, blank=True)
    club = models.ForeignKey(Club, related_name="bank_accounts", verbose_name=_("club"))

    class Meta:
        verbose_name = _("Bank account")
        ordering = ["club", "name"]

    def is_owned_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        if user.is_in_group(settings.SITH_GROUP_ACCOUNTING_ADMIN_ID):
            return True
        m = self.club.get_membership_for(user)
        if m is not None and m.role >= settings.SITH_CLUB_ROLES_ID["Treasurer"]:
            return True
        return False

    def get_absolute_url(self):
        return reverse("accounting:bank_details", kwargs={"b_account_id": self.id})

    def __str__(self):
        return self.name


class ClubAccount(models.Model):
    name = models.CharField(_("name"), max_length=30)
    club = models.ForeignKey(Club, related_name="club_account", verbose_name=_("club"))
    bank_account = models.ForeignKey(
        BankAccount, related_name="club_accounts", verbose_name=_("bank account")
    )

    class Meta:
        verbose_name = _("Club account")
        ordering = ["bank_account", "name"]

    def is_owned_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        if user.is_in_group(settings.SITH_GROUP_ACCOUNTING_ADMIN_ID):
            return True
        return False

    def can_be_edited_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        m = self.club.get_membership_for(user)
        if m and m.role == settings.SITH_CLUB_ROLES_ID["Treasurer"]:
            return True
        return False

    def can_be_viewed_by(self, user):
        """
        Method to see if that object can be viewed by the given user
        """
        m = self.club.get_membership_for(user)
        if m and m.role >= settings.SITH_CLUB_ROLES_ID["Treasurer"]:
            return True
        return False

    def has_open_journal(self):
        for j in self.journals.all():
            if not j.closed:
                return True
        return False

    def get_open_journal(self):
        return self.journals.filter(closed=False).first()

    def get_absolute_url(self):
        return reverse("accounting:club_details", kwargs={"c_account_id": self.id})

    def __str__(self):
        return self.name

    def get_display_name(self):
        return _("%(club_account)s on %(bank_account)s") % {
            "club_account": self.name,
            "bank_account": self.bank_account,
        }


class GeneralJournal(models.Model):
    """
    Class storing all the operations for a period of time
    """

    start_date = models.DateField(_("start date"))
    end_date = models.DateField(_("end date"), null=True, blank=True, default=None)
    name = models.CharField(_("name"), max_length=40)
    closed = models.BooleanField(_("is closed"), default=False)
    club_account = models.ForeignKey(
        ClubAccount, related_name="journals", null=False, verbose_name=_("club account")
    )
    amount = CurrencyField(_("amount"), default=0)
    effective_amount = CurrencyField(_("effective_amount"), default=0)

    class Meta:
        verbose_name = _("General journal")
        ordering = ["-start_date"]

    def is_owned_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        if user.is_in_group(settings.SITH_GROUP_ACCOUNTING_ADMIN_ID):
            return True
        if self.club_account.can_be_edited_by(user):
            return True
        return False

    def can_be_edited_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        if user.is_in_group(settings.SITH_GROUP_ACCOUNTING_ADMIN_ID):
            return True
        if self.club_account.can_be_edited_by(user):
            return True
        return False

    def can_be_viewed_by(self, user):
        return self.club_account.can_be_viewed_by(user)

    def get_absolute_url(self):
        return reverse("accounting:journal_details", kwargs={"j_id": self.id})

    def __str__(self):
        return self.name

    def update_amounts(self):
        self.amount = 0
        self.effective_amount = 0
        for o in self.operations.all():
            if o.accounting_type.movement_type == "CREDIT":
                if o.done:
                    self.effective_amount += o.amount
                self.amount += o.amount
            else:
                if o.done:
                    self.effective_amount -= o.amount
                self.amount -= o.amount
        self.save()


class Operation(models.Model):
    """
    An operation is a line in the journal, a debit or a credit
    """

    number = models.IntegerField(_("number"))
    journal = models.ForeignKey(
        GeneralJournal, related_name="operations", null=False, verbose_name=_("journal")
    )
    amount = CurrencyField(_("amount"))
    date = models.DateField(_("date"))
    remark = models.CharField(_("comment"), max_length=128, null=True, blank=True)
    mode = models.CharField(
        _("payment method"),
        max_length=255,
        choices=settings.SITH_ACCOUNTING_PAYMENT_METHOD,
    )
    cheque_number = models.CharField(
        _("cheque number"), max_length=32, default="", null=True, blank=True
    )
    invoice = models.ForeignKey(
        SithFile,
        related_name="operations",
        verbose_name=_("invoice"),
        null=True,
        blank=True,
    )
    done = models.BooleanField(_("is done"), default=False)
    simpleaccounting_type = models.ForeignKey(
        "SimplifiedAccountingType",
        related_name="operations",
        verbose_name=_("simple type"),
        null=True,
        blank=True,
    )
    accounting_type = models.ForeignKey(
        "AccountingType",
        related_name="operations",
        verbose_name=_("accounting type"),
        null=True,
        blank=True,
    )
    label = models.ForeignKey(
        "Label",
        related_name="operations",
        verbose_name=_("label"),
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
    )
    target_type = models.CharField(
        _("target type"),
        max_length=10,
        choices=[
            ("USER", _("User")),
            ("CLUB", _("Club")),
            ("ACCOUNT", _("Account")),
            ("COMPANY", _("Company")),
            ("OTHER", _("Other")),
        ],
    )
    target_id = models.IntegerField(_("target id"), null=True, blank=True)
    target_label = models.CharField(
        _("target label"), max_length=32, default="", blank=True
    )
    linked_operation = models.OneToOneField(
        "self",
        related_name="operation_linked_to",
        verbose_name=_("linked operation"),
        null=True,
        blank=True,
        default=None,
    )

    class Meta:
        unique_together = ("number", "journal")
        ordering = ["-number"]

    def __getattribute__(self, attr):
        if attr == "target":
            return self.get_target()
        else:
            return object.__getattribute__(self, attr)

    def clean(self):
        super(Operation, self).clean()
        if self.date is None:
            raise ValidationError(_("The date must be set."))
        elif self.date < self.journal.start_date:
            raise ValidationError(
                _(
                    """The date can not be before the start date of the journal, which is
%(start_date)s."""
                )
                % {
                    "start_date": defaultfilters.date(
                        self.journal.start_date, settings.DATE_FORMAT
                    )
                }
            )
        if self.target_type != "OTHER" and self.get_target() is None:
            raise ValidationError(_("Target does not exists"))
        if self.target_type == "OTHER" and self.target_label == "":
            raise ValidationError(
                _("Please add a target label if you set no existing target")
            )
        if not self.accounting_type and not self.simpleaccounting_type:
            raise ValidationError(
                _(
                    "You need to provide ether a simplified accounting type or a standard accounting type"
                )
            )
        if self.simpleaccounting_type:
            self.accounting_type = self.simpleaccounting_type.accounting_type

    @property
    def target(self):
        return self.get_target()

    def get_target(self):
        tar = None
        if self.target_type == "USER":
            tar = User.objects.filter(id=self.target_id).first()
        elif self.target_type == "CLUB":
            tar = Club.objects.filter(id=self.target_id).first()
        elif self.target_type == "ACCOUNT":
            tar = ClubAccount.objects.filter(id=self.target_id).first()
        elif self.target_type == "COMPANY":
            tar = Company.objects.filter(id=self.target_id).first()
        return tar

    def save(self):
        if self.number is None:
            self.number = self.journal.operations.count() + 1
        super(Operation, self).save()
        self.journal.update_amounts()

    def is_owned_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        if user.is_in_group(settings.SITH_GROUP_ACCOUNTING_ADMIN_ID):
            return True
        if self.journal.closed:
            return False
        m = self.journal.club_account.club.get_membership_for(user)
        if m is not None and m.role >= settings.SITH_CLUB_ROLES_ID["Treasurer"]:
            return True
        return False

    def can_be_edited_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        if user.is_in_group(settings.SITH_GROUP_ACCOUNTING_ADMIN_ID):
            return True
        if self.journal.closed:
            return False
        m = self.journal.club_account.club.get_membership_for(user)
        if m is not None and m.role == settings.SITH_CLUB_ROLES_ID["Treasurer"]:
            return True
        return False

    def get_absolute_url(self):
        return reverse("accounting:journal_details", kwargs={"j_id": self.journal.id})

    def __str__(self):
        return "%d € | %s | %s | %s" % (
            self.amount,
            self.date,
            self.accounting_type,
            self.done,
        )


class AccountingType(models.Model):
    """
    Class describing the accounting types.

    Thoses are numbers used in accounting to classify operations
    """

    code = models.CharField(
        _("code"),
        max_length=16,
        validators=[
            validators.RegexValidator(
                r"^[0-9]*$", _("An accounting type code contains only numbers")
            )
        ],
    )
    label = models.CharField(_("label"), max_length=128)
    movement_type = models.CharField(
        _("movement type"),
        choices=[
            ("CREDIT", _("Credit")),
            ("DEBIT", _("Debit")),
            ("NEUTRAL", _("Neutral")),
        ],
        max_length=12,
    )

    class Meta:
        verbose_name = _("accounting type")
        ordering = ["movement_type", "code"]

    def is_owned_by(self, user):
        """
        Method to see if that object can be edited by the given user
        """
        if user.is_in_group(settings.SITH_GROUP_ACCOUNTING_ADMIN_ID):
            return True
        return False

    def get_absolute_url(self):
        return reverse("accounting:type_list")

    def __str__(self):
        return self.code + " - " + self.get_movement_type_display() + " - " + self.label


class SimplifiedAccountingType(models.Model):
    """
    Class describing the simplified accounting types.
    """

    label = models.CharField(_("label"), max_length=128)
    accounting_type = models.ForeignKey(
        AccountingType,
        related_name="simplified_types",
        verbose_name=_("simplified accounting types"),
    )

    class Meta:
        verbose_name = _("simplified type")
        ordering = ["accounting_type__movement_type", "accounting_type__code"]

    @property
    def movement_type(self):
        return self.accounting_type.movement_type

    def get_movement_type_display(self):
        return self.accounting_type.get_movement_type_display()

    def get_absolute_url(self):
        return reverse("accounting:simple_type_list")

    def __str__(self):
        return (
            self.get_movement_type_display()
            + " - "
            + self.accounting_type.code
            + " - "
            + self.label
        )


class Label(models.Model):
    """Label allow a club to sort its operations"""

    name = models.CharField(_("label"), max_length=64)
    club_account = models.ForeignKey(
        ClubAccount, related_name="labels", verbose_name=_("club account")
    )

    class Meta:
        unique_together = ("name", "club_account")

    def __str__(self):
        return "%s (%s)" % (self.name, self.club_account.name)

    def get_absolute_url(self):
        return reverse(
            "accounting:label_list", kwargs={"clubaccount_id": self.club_account.id}
        )

    def is_owned_by(self, user):
        return self.club_account.is_owned_by(user)

    def can_be_edited_by(self, user):
        return self.club_account.can_be_edited_by(user)

    def can_be_viewed_by(self, user):
        return self.club_account.can_be_viewed_by(user)