konova/compensation/models/eco_account.py

"""
Author: Michel Peltriaux
Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
Contact: michel.peltriaux@sgdnord.rlp.de
Created on: 16.11.21

"""
import shutil

from django.urls import reverse

from konova.utils.message_templates import DEDUCTION_REMOVED
from django.core.exceptions import ValidationError
from django.core.validators import MinValueValidator
from django.db import models
from django.db.models import Sum, QuerySet
from django.utils.translation import gettext_lazy as _

from compensation.managers import EcoAccountManager, EcoAccountDeductionManager
from compensation.models.compensation import AbstractCompensation
from compensation.utils.quality import EcoAccountQualityChecker
from konova.models import ShareableObjectMixin, RecordableObjectMixin, AbstractDocument, BaseResource, \
    generate_document_file_upload_path
from konova.settings import DEFAULT_SRID_RLP, LANIS_LINK_TEMPLATE


class EcoAccount(AbstractCompensation, ShareableObjectMixin, RecordableObjectMixin):
    """
    An eco account is a kind of 'prepaid' compensation. It can be compared to an account that already has been filled
    with some kind of currency. From this account one is able to deduct currency for current projects.
    """
    deductable_surface = models.FloatField(
        blank=True,
        null=True,
        help_text="Amount of deductable surface - can be lower than the total surface due to deduction limitations",
        default=0,
    )

    legal = models.OneToOneField(
        "intervention.Legal",
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        help_text="Holds data on legal dates or law"
    )

    objects = EcoAccountManager()

    def __str__(self):
        return f"{self.identifier} ({self.title})"

    def clean(self):
        # Deductable surface can not be larger than added states after surface
        after_state_sum = self.get_state_after_surface_sum()
        if self.deductable_surface > after_state_sum:
            raise ValidationError(_("Deductable surface can not be larger than existing surfaces in after states"))

        # Deductable surface can not be lower than amount of already deducted surfaces
        # User needs to contact deducting user in case of further problems
        deducted_sum = self.get_deductions_surface()
        if self.deductable_surface < deducted_sum:
            raise ValidationError(
                _("Deductable surface can not be smaller than the sum of already existing deductions. Please contact the responsible users for the deductions!")
            )

    def save(self, *args, **kwargs):
        if self.identifier is None or len(self.identifier) == 0:
            # Create new identifier if none was given
            self.identifier = self.generate_new_identifier()

        # Before saving, make sure the given identifier is not used, yet
        while EcoAccount.objects.filter(identifier=self.identifier).exclude(id=self.id).exists():
            self.identifier = self.generate_new_identifier()
        super().save(*args, **kwargs)

    @property
    def deductions_surface_sum(self) -> float:
        """ Shortcut for get_deductions_surface.

        Can be used in templates

        Returns:
            sum_surface (float)
        """
        return self.get_deductions_surface()

    def get_deductions_surface(self) -> float:
        """ Calculates the account's deductions surface sum

        Returns:
            sum_surface (float)
        """
        return self.deductions.all().aggregate(Sum("surface"))["surface__sum"] or 0

    def get_state_after_surface_sum(self) -> float:
        """ Calculates the account's after state surface sum

        Returns:
            sum_surface (float)
        """
        return self.after_states.all().aggregate(Sum("surface"))["surface__sum"] or 0

    def get_available_rest(self) -> (float, float):
        """ Calculates available rest surface of the eco account

        Args:

        Returns:
            ret_val_total (float): Total amount
            ret_val_relative (float): Amount as percentage (0-100)
        """
        deductions = self.deductions.filter(
            intervention__deleted=None,
        )
        deductions_surfaces = deductions.aggregate(Sum("surface"))["surface__sum"] or 0
        available_surfaces = self.deductable_surface or deductions_surfaces ## no division by zero
        ret_val_total = available_surfaces - deductions_surfaces

        if available_surfaces > 0:
            ret_val_relative = int((ret_val_total / available_surfaces) * 100)
        else:
            ret_val_relative = 0

        return ret_val_total, ret_val_relative

    def get_LANIS_link(self) -> str:
        """ Generates a link for LANIS depending on the geometry

        Returns:

        """
        try:
            geom = self.geometry.geom.transform(DEFAULT_SRID_RLP, clone=True)
            x = geom.centroid.x
            y = geom.centroid.y
            zoom_lvl = 16
        except AttributeError:
            # If no geometry has been added, yet.
            x = 1
            y = 1
            zoom_lvl = 6
        return LANIS_LINK_TEMPLATE.format(
            zoom_lvl,
            x,
            y,
        )

    def quality_check(self) -> EcoAccountQualityChecker:
        """ Quality check

        Returns:
            ret_msgs (EcoAccountQualityChecker): Holds validity and error messages
        """
        checker = EcoAccountQualityChecker(self)
        checker.run_check()
        return checker

    def get_documents(self) -> QuerySet:
        """ Getter for all documents of an EcoAccount

        Returns:
            docs (QuerySet): The queryset of all documents
        """
        docs = EcoAccountDocument.objects.filter(
            instance=self
        )
        return docs

    def is_ready_for_publish(self) -> bool:
        """ Checks whether the data passes all constraints for being publishable

        Returns:
            is_ready (bool) : True|False
        """
        is_recorded = self.recorded is not None
        is_ready = is_recorded
        return is_ready

    def get_share_link(self):
        """ Returns the share url for the object

        Returns:

        """
        return reverse("compensation:acc:share", args=(self.id, self.access_token))


class EcoAccountDocument(AbstractDocument):
    """
    Specializes document upload for revocations with certain path
    """
    instance = models.ForeignKey(
        EcoAccount,
        on_delete=models.CASCADE,
        related_name="documents",
    )
    file = models.FileField(
        upload_to=generate_document_file_upload_path,
        max_length=1000,
    )

    def delete(self, *args, **kwargs):
        """
        Custom delete functionality for EcoAccountDocuments.
        Removes the folder from the file system if there are no further documents for this entry.

        Args:
            *args ():
            **kwargs ():

        Returns:

        """
        acc_docs = self.instance.get_documents()

        folder_path = None
        if acc_docs.count() == 1:
            # The only file left for this eco account is the one which is currently processed and will be deleted
            # Make sure that the compensation folder itself is deleted as well, not only the file
            # Therefore take the folder path from the file path
            folder_path = self.file.path.split("/")[:-1]
            folder_path = "/".join(folder_path)

        # Remove the file itself
        super().delete(*args, **kwargs)

        # If a folder path has been set, we need to delete the whole folder!
        if folder_path is not None:
            try:
                shutil.rmtree(folder_path)
            except FileNotFoundError:
                # Folder seems to be missing already...
                pass


class EcoAccountDeduction(BaseResource):
    """
    A deduction object for eco accounts
    """
    account = models.ForeignKey(
        EcoAccount,
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        help_text="Deducted from",
        related_name="deductions",
    )
    surface = models.FloatField(
        null=True,
        blank=True,
        help_text="Amount deducted (m²)",
        validators=[
            MinValueValidator(limit_value=0.00),
        ]
    )
    intervention = models.ForeignKey(
        "intervention.Intervention",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        help_text="Deducted for",
        related_name="deductions",
    )

    objects = EcoAccountDeductionManager()

    def __str__(self):
        return "{} of {}".format(self.surface, self.account)

    def delete(self, user=None, *args, **kwargs):
        if user is not None:
            self.intervention.mark_as_edited(user, edit_comment=DEDUCTION_REMOVED)
            self.account.mark_as_edited(user, edit_comment=DEDUCTION_REMOVED, reset_recorded=False)
        super().delete(*args, **kwargs)