From 5c8cc035a48c1880aa6ea811b514652e7541c31a Mon Sep 17 00:00:00 2001
From: Oliver Walters <oliver.henry.walters@gmail.com>
Date: Tue, 28 Mar 2017 21:24:00 +1100
Subject: [PATCH] Started work on cross-referencing - part admin now shows
 total quantity in stock - part model can return a list of projects it is
 associated with

---
 InvenTree/part/admin.py     |  2 +-
 InvenTree/part/models.py    | 38 +++++++++++++++++++++++++++++++++++++
 InvenTree/project/models.py | 12 +++++++++---
 InvenTree/stock/models.py   |  3 ++-
 4 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/InvenTree/part/admin.py b/InvenTree/part/admin.py
index fce0c2d257..3cc2ad10bb 100644
--- a/InvenTree/part/admin.py
+++ b/InvenTree/part/admin.py
@@ -4,7 +4,7 @@ from .models import PartCategory, Part
 
 class PartAdmin(admin.ModelAdmin):
     
-    list_display = ('name', 'IPN', 'category')
+    list_display = ('name', 'IPN', 'quantity', 'category')
 
 # Custom form for PartCategory
 class PartCategoryAdmin(admin.ModelAdmin):
diff --git a/InvenTree/part/models.py b/InvenTree/part/models.py
index 5fe39656bf..80d4728c93 100644
--- a/InvenTree/part/models.py
+++ b/InvenTree/part/models.py
@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 from django.db import models
+from django.db.models import Sum
 from django.core.exceptions import ObjectDoesNotExist
 
 from InvenTree.models import InvenTreeTree
@@ -35,6 +36,43 @@ class Part(models.Model):
     class Meta:
         verbose_name = "Part"
         verbose_name_plural = "Parts"
+        
+    @property
+    def stock_list(self):
+        """ Return a list of all stock objects associated with this part
+        """
+        
+        return self.stockitem_set.all()
+        
+    @property
+    def quantity(self):
+        """ Return the total stock quantity for this part.
+        Part may be stored in multiple locations
+        """
+        
+        stocks = self.stock_list
+        if len(stocks) == 0:
+            return 0
+            
+        result = stocks.aggregate(total=Sum('quantity'))
+        return result['total']
+        
+    @property
+    def projects(self):
+        """ Return a list of unique projects that this part is associated with
+        """
+        
+        project_ids = set()
+        project_parts = self.projectpart_set.all()
+        
+        projects = []
+        
+        for pp in project_parts:
+            if pp.project.id not in project_ids:
+                project_ids.add(pp.project.id)
+                projects.append(pp.project)
+                
+        return projects
 
 class PartRevision(models.Model):
     """ A PartRevision represents a change-notification to a Part
diff --git a/InvenTree/project/models.py b/InvenTree/project/models.py
index 18da1221f4..b7d0800fc1 100644
--- a/InvenTree/project/models.py
+++ b/InvenTree/project/models.py
@@ -26,7 +26,12 @@ class Project(models.Model):
     
     def __str__(self):
         return self.name
-    
+        
+    @property
+    def projectParts(self):
+        """ Return a list of all project parts associated with this project
+        """
+        return self.projectpart_set.all()
 
 class ProjectPart(models.Model):
     """ A project part associates a single part with a project
@@ -40,9 +45,10 @@ class ProjectPart(models.Model):
     
     part = models.ForeignKey(Part, on_delete=models.CASCADE)
     project = models.ForeignKey(Project, on_delete=models.CASCADE)
-    quantity = models.IntegerField()
-    overage = models.FloatField()
+    quantity = models.IntegerField(default=1)
+    overage = models.FloatField(default=0)
     overage_type = models.IntegerField(
+        default=1,
         choices=[
         (OVERAGE_PERCENT, "Percent"),
         (OVERAGE_ABSOLUTE, "Absolute")
diff --git a/InvenTree/stock/models.py b/InvenTree/stock/models.py
index a07308a435..2cc5e4c727 100644
--- a/InvenTree/stock/models.py
+++ b/InvenTree/stock/models.py
@@ -9,7 +9,8 @@ class Warehouse(InvenTreeTree):
     pass
     
 class StockItem(models.Model):
-    part = models.ForeignKey(Part, on_delete=models.CASCADE)
+    part = models.ForeignKey(Part,
+                             on_delete=models.CASCADE)
     location = models.ForeignKey(Warehouse, on_delete=models.CASCADE)
     quantity = models.IntegerField()
     updated = models.DateField(auto_now=True)