[Feature] Stocktake reports (#4345)

* Add settings to control upcoming stocktake features

* Adds migration for "cost range" when performing stocktake

* Add cost data to PartStocktakeSerializer

Implement a new custom serializer for currency data type

* Refactor existing currency serializers

* Update stocktake table and forms

* Prevent trailing zeroes in forms

* Calculate cost range when adding manual stocktake entry

* Display interactive chart for part stocktake history

* Ensure chart data are converted to common currency

* Adds new model for building stocktake reports

* Add admin integration for new model

* Adds API endpoint to expose list of stocktake reports available for download

- No ability to edit or delete via API

* Add setting to control automated deletion of old stocktake reports

* Updates for settings page

- Load part stocktake report table
- Refactor function to render a downloadable media file
- Fix bug with forcing files to be downloaded
- Split js code into separate templates
- Make use of onPanelLoad functionalitty

* Fix conflicting migration files

* Adds API endpoint for manual generation of stocktake report

* Offload task to generate new stocktake report

* Adds python function to perform stocktake on a single part instance

* Small bug fixes

* Various tweaks

- Prevent new stocktake models from triggering plugin events when created
- Construct a simple csv dataset

* Generate new report

* Updates for report generation

- Prefetch related data
- Add extra columns
- Keep track of stocktake instances (for saving to database later on)

* Updates:

- Add confirmation message
- Serializer validation checks

* Ensure that background worker is running before manually scheduling a new stocktake report

* Add extra fields to stocktake models

Also move code from part/models.py to part/tasks.py

* Add 'part_count' to PartStocktakeReport table

* Updates for stocktake generation

- remove old performStocktake javascript code
- Now handled by automated server-side calculation
- Generate report for a single part

* Add a new "role" for stocktake

- Allows fine-grained control on viewing / creating / deleting stocktake data
- More in-line with existing permission controls
- Remove STOCKTAKE_OWNER setting

* Add serializer field to limit stocktake report to particular locations

* Use location restriction when generating a stocktake report

* Add UI buttons to perform stocktake for a whole category tree

* Add button to perform stocktake report for a location tree

* Adds a background tasks to handle periodic generation of stocktake reports

- Reports are generated at fixed intervals
- Deletes old reports after certain number of days

* Implement notifications for new stocktake reports

- If manually requested by a user, notify that user
- Cleanup notification table
- Amend PartStocktakeModel for better notification rendering

* Hide buttons on location and category page if stocktake is not enabled

* Cleanup log messages during server start

* Extend functionality of RoleRequired permission mixin

- Allow 'role_required' attribute to be added to an API view
- Useful when using a serializer class that does not have a model defined

* Add boolean option to toggle whether a report will be generated

* Update generateStocktake function

* Improve location filtering

- Don't limit the actual stock items
- Instead, select only parts which exist within a given location tree

* Update API version

* String tweaks

* Fix permissions for PartStocktake API

* More unit testing for stocktake functionality

* QoL fix

* Fix for assigning inherited permissions

InvenTree/stock/serializers.py

@@ -19,10 +19,10 @@ import InvenTree.helpers
 import InvenTree.serializers
 import part.models as part_models
 import stock.filters
-from common.settings import currency_code_default, currency_code_mappings
 from company.serializers import SupplierPartSerializer
 from InvenTree.models import extract_int
-from InvenTree.serializers import InvenTreeDecimalField
+from InvenTree.serializers import (InvenTreeCurrencySerializer,
+                                   InvenTreeDecimalField)
 from part.serializers import PartBriefSerializer
 
 from .models import (StockItem, StockItemAttachment, StockItemTestResult,
@@ -171,17 +171,11 @@ class StockItemSerializer(InvenTree.serializers.InvenTreeModelSerializer):
 
     purchase_price = InvenTree.serializers.InvenTreeMoneySerializer(
         label=_('Purchase Price'),
-        max_digits=19, decimal_places=6,
         allow_null=True,
         help_text=_('Purchase price of this stock item'),
     )
 
-    purchase_price_currency = serializers.ChoiceField(
-        choices=currency_code_mappings(),
-        default=currency_code_default,
-        label=_('Currency'),
-        help_text=_('Purchase currency of this stock item'),
-    )
+    purchase_price_currency = InvenTreeCurrencySerializer(help_text=_('Purchase currency of this stock item'))
 
     purchase_order_reference = serializers.CharField(source='purchase_order.reference', read_only=True)
     sales_order_reference = serializers.CharField(source='sales_order.reference', read_only=True)

InvenTree/stock/templates/stock/location.html

@@ -32,6 +32,12 @@
 {% url 'admin:stock_stocklocation_change' location.pk as url %}
 {% include "admin_button.html" with url=url %}
 {% endif %}
+{% settings_value "STOCKTAKE_ENABLE" as stocktake_enable %}
+{% if stocktake_enable and roles.stocktake.add %}
+<button type='button' class='btn btn-outline-secondary' id='location-stocktake' title='{% trans "Perform stocktake for this stock location" %}'>
+    <span class='fas fa-clipboard-check'></span>
+</button>
+{% endif %}
 
 {% mixin_available "locate" as locate_available %}
 {% if location and plugins_enabled and locate_available %}
@@ -246,6 +252,20 @@
 {% block js_ready %}
 {{ block.super }}
 
+    {% settings_value "STOCKTAKE_ENABLE" as stocktake_enable %}
+    {% if stocktake_enable and roles.stocktake.add %}
+    $('#location-stocktake').click(function() {
+        generateStocktakeReport({
+            category: {},
+            location: {
+                {% if location %}value: {{ location.pk }},{% endif %}
+            },
+            generate_report: {},
+            update_parts: {},
+        });
+    });
+    {% endif %}
+
     {% if plugins_enabled and location %}
     $('#locate-location-button').click(function() {
         locateItemOrLocation({