import re from django.core.exceptions import ValidationError from django.db import models, connection from django.urls import reverse from django.db.models import F from django.db.models.signals import pre_save from django.dispatch.dispatcher import receiver from reversion import revisions as reversion from reversion.models import Version from RIGS.models import RevisionMixin class AssetCategory(models.Model): class Meta: verbose_name = 'Asset Category' verbose_name_plural = 'Asset Categories' ordering = ['name'] name = models.CharField(max_length=80) def __str__(self): return self.name class AssetStatus(models.Model): class Meta: verbose_name = 'Asset Status' verbose_name_plural = 'Asset Statuses' ordering = ['name'] name = models.CharField(max_length=80) should_show = models.BooleanField( default=True, help_text="Should this be shown by default in the asset list.") display_class = models.CharField(max_length=80, blank=True, null=True, help_text="HTML class to be appended to alter display of assets with this status, such as in the list.") def __str__(self): return self.name @reversion.register class Supplier(models.Model, RevisionMixin): name = models.CharField(max_length=80) class Meta: ordering = ['name'] permissions = ( ('view_supplier', 'Can view a supplier'), ) def get_absolute_url(self): return reverse('supplier_list') def __str__(self): return self.name class Connector(models.Model): description = models.CharField(max_length=80) current_rating = models.DecimalField(decimal_places=2, max_digits=10, help_text='Amps') voltage_rating = models.IntegerField(help_text='Volts') num_pins = models.IntegerField(blank=True, null=True) def __str__(self): return self.description class CableType(models.Model): class Meta: ordering = ['plug', 'socket', '-circuits'] circuits = models.IntegerField(blank=True, null=True) cores = models.IntegerField(blank=True, null=True) plug = models.ForeignKey(Connector, on_delete=models.SET_NULL, related_name='plug', blank=True, null=True) socket = models.ForeignKey(Connector, on_delete=models.SET_NULL, related_name='socket', blank=True, null=True) def __str__(self): return "%s → %s" % (self.plug.description, self.socket.description) @reversion.register class Asset(models.Model, RevisionMixin): class Meta: ordering = ['asset_id_prefix', 'asset_id_number'] permissions = ( ('asset_finance', 'Can see financial data for assets'), ('view_asset', 'Can view an asset') ) parent = models.ForeignKey(to='self', related_name='asset_parent', blank=True, null=True, on_delete=models.SET_NULL) asset_id = models.CharField(max_length=15, unique=True) description = models.CharField(max_length=120) category = models.ForeignKey(to=AssetCategory, on_delete=models.CASCADE) status = models.ForeignKey(to=AssetStatus, on_delete=models.CASCADE) serial_number = models.CharField(max_length=150, blank=True) purchased_from = models.ForeignKey(to=Supplier, on_delete=models.CASCADE, blank=True, null=True, related_name="assets") date_acquired = models.DateField() date_sold = models.DateField(blank=True, null=True) purchase_price = models.DecimalField(blank=True, null=True, decimal_places=2, max_digits=10) salvage_value = models.DecimalField(blank=True, null=True, decimal_places=2, max_digits=10) comments = models.TextField(blank=True) next_sched_maint = models.DateField(blank=True, null=True) # Cable assets is_cable = models.BooleanField(default=False) cable_type = models.ForeignKey(to=CableType, blank=True, null=True, on_delete=models.SET_NULL) length = models.DecimalField(decimal_places=1, max_digits=10, blank=True, null=True, help_text='m') csa = models.DecimalField(decimal_places=2, max_digits=10, blank=True, null=True, help_text='mm^2') # Hidden asset_id components # For example, if asset_id was "C1001" then asset_id_prefix would be "C" and number "1001" asset_id_prefix = models.CharField(max_length=8, default="") asset_id_number = models.IntegerField(default=1) def get_available_asset_id(wanted_prefix=""): sql = """ SELECT a.asset_id_number+1 FROM assets_asset a LEFT OUTER JOIN assets_asset b ON (a.asset_id_number + 1 = b.asset_id_number AND a.asset_id_prefix = b.asset_id_prefix) WHERE b.asset_id IS NULL AND a.asset_id_number >= %s AND a.asset_id_prefix = %s; """ with connection.cursor() as cursor: cursor.execute(sql, [9000, wanted_prefix]) row = cursor.fetchone() if row is None or row[0] is None: return 9000 else: return row[0] def get_absolute_url(self): return reverse('asset_detail', kwargs={'pk': self.asset_id}) def __str__(self): out = str(self.asset_id) + ' - ' + self.description if self.is_cable: out += '{} - {}m - {}'.format(self.cable_type.plug, self.length, self.cable_type.socket) return out def clean(self): errdict = {} if self.date_sold and self.date_acquired > self.date_sold: errdict["date_sold"] = ["Cannot sell an item before it is acquired"] self.asset_id = self.asset_id.upper() asset_search = re.search("^([a-zA-Z0-9]*?[a-zA-Z]?)([0-9]+)$", self.asset_id) if asset_search is None: errdict["asset_id"] = [ "An Asset ID can only consist of letters and numbers, with a final number"] if self.purchase_price and self.purchase_price < 0: errdict["purchase_price"] = ["A price cannot be negative"] if self.salvage_value and self.salvage_value < 0: errdict["salvage_value"] = ["A price cannot be negative"] if self.is_cable: if not self.length or self.length <= 0: errdict["length"] = ["The length of a cable must be more than 0"] if not self.csa or self.csa <= 0: errdict["csa"] = ["The CSA of a cable must be more than 0"] if not self.cable_type: errdict["cable_type"] = ["A cable must have a type"] # if not self.circuits or self.circuits <= 0: # errdict["circuits"] = ["There must be at least one circuit in a cable"] # if not self.cores or self.cores <= 0: # errdict["cores"] = ["There must be at least one core in a cable"] # if self.socket is None: # errdict["socket"] = ["A cable must have a socket"] # if self.plug is None: # errdict["plug"] = ["A cable must have a plug"] if errdict != {}: # If there was an error when validation raise ValidationError(errdict) @receiver(pre_save, sender=Asset) def pre_save_asset(sender, instance, **kwargs): """Automatically fills in hidden members on database access""" asset_search = re.search("^([a-zA-Z0-9]*?[a-zA-Z]?)([0-9]+)$", instance.asset_id) if asset_search is None: instance.asset_id += "1" asset_search = re.search("^([a-zA-Z0-9]*?[a-zA-Z]?)([0-9]+)$", instance.asset_id) instance.asset_id_prefix = asset_search.group(1) instance.asset_id_number = int(asset_search.group(2))