Part pricing cache (#3710)

* Create new model for storing Part pricing data

Currently this model does not "do" anything but will be used for caching pre-calculated pricing information

* Define function for accessing pricing information for a specific part

* Adds admin site support for new PartPricing model

* Specify role for PartPricing model

* Allow blank values for PartPricing model fields

* Add some TODO entries

* Update migration files to sync with latest master

* Expose API endpoint for viewing part pricing information

* Update migration file

* Improvements:

- Updated model with new fields
- Code for calculating BOM price
- Code for calculating internal price
- Code for calculating supplier price
- Updated unit testing

* Fix (and test) for API serializer

* Including min/max pricing data in part serializer

* Bump API version

* Add pricing overview information in part table

- Adds helper function for formatting currency data
- No longer pre-render "price strings" on the server

* Overhaul of BOM API

- Pricing data no longer calculated "on the fly"
- Remove expensive annotation operations
- Display cached price range information in BOM table

* Filter BOM items by "has pricing"

* Part API endpoint can be filtered by price range

* Updpated API version notes

* Improvements for price caching calculations

- Handle null price values
- Handle case where conversion rates are missing
- Allow manual update via API

* Button to manually refresh pricing

* Improve rendering of price-break table

* Update supplier part pricing table

* Updated js functions

* Adds background task to update assembly pricing whenever a part price cache is changed

* Updates for task offloading

* HTML tweaks

* Implement calculation of historical purchase cost

- take supplier part pack size into account
- improve unit tests

* Improvements for pricing tab rendering

* Refactor of pricing page

- Move javascript functions out into separate files
- Change price-break tables to use bar graphs
- Display part pricing history table and chart
- Remove server-side rendering for price history data
- Fix rendering of supplier pricing table
- Adds extra filtering options to the SupplierPriceBreak API endpoint

* Refactor BOM pricing chart / table

- Display as bar chart with min/max pricing
- Display simplified BOM table

* Update page anchors

* Improvements for BOM pricing table display

* Refactoring sales data tables

- Add extra data and filter options to sales order API endpoints
- Display sales order history table and chart

* Add extra fields to PartPricing model:

- sale_price_min
- sale_price_max
- sale_history_min
- sale_history_max

* Calculate and cache sale price data

* Update part pricing when PurchaseOrder is completed

* Update part pricing when sales order is completed

* Signals for updating part pricing cache

- Whenever an internal price break is created / edited / deleted
- Whenever a sale price break is created / edited / deleted

* Also trigger part pricing update when BomItem is created  / edited / deleted

* Update part pricing whenever a supplier price break is updated

* Remove has_complete_bom_pricing method

* Export min/max pricing data in BOM file

* Fix pricing data in BOM export

- Calculate total line cost
- Use more than two digits

* Add pricing information to part export

Also some improvements to part exporting

* Allow download of part category table

* Allow export of stock location data to file

* Improved exporting of StockItem data

* Add cached variant pricing data

- New fields in part pricing model
- Display variant pricing overview in "pricing" tab

* Remove outdated "PART_SHOW_PRICE_HISTORY" setting

* Adds scheduled background task to periodically update part pricing

* Internal prices can optionally override other pricing

* Update js file checks

* Update price breaks to use 6 decimal places

* Fix for InvenTreeMoneySerializer class

- Allow 6 decimal places through the API

* Update for supplier price break table

* javascript linting fix

* Further js fixes

* Unit test updates

* Improve rendering of currency in templates

- Do not artificially limit to 2 decimal places

* Unit test fixes

* Add pricing information to part "details" tab

* Tweak for money formatting

* Enable sort-by-price in BOM table

* More unit test tweaks

* Update BOM exporting

* Fixes for background worker process

- To determine if worker is running, look for *any* successful task, not just heartbeat
- Heartbeat rate increased to 5 minute intervals
- Small adjustments to django_q settings

Ref: https://github.com/inventree/InvenTree/issues/3921
(cherry picked from commit cb26003b92)

* Force background processing of heartbeat task when server is started

- Removes the ~5 minute window in which the server "thinks" that the worker is not actually running

* Adjust strategy for preventing recursion

- Rather than looking for duplicate parts, simply increment a counter
- Add a "scheduled_for_update" flag to prevent multiple updates being scheduled
- Consolidate migration files

* Adds helper function for rendering a range of prices

* Include variant cost in calculations

* Fixes for "has_pricing" API filters

* Ensure part pricing status flags are reset when the server restarts

* Bug fix for BOM API filter

* Include BOM quantity in BOM pricing chart

* Small tweaks to pricing tab

* Prevent caching when looking up settings in background worker

- Caching across mnultiple processes causes issues
- Need to move to something like redis to solve this
- Ref: https://github.com/inventree/InvenTree/issues/3921

* Fixes for /part/pricing/ detail API endpoint

* Update pricing tab

- Consistent naming

* Unit test fixes

* Prevent pricing updates when loading test fixtures

* Fix for Part.pricing

* Updates for "check_missing_pricing"

* Change to pie chart for BOM pricing

* Unit test fix

* Updates

- Sort BOM pie chart correctly
- Simplify PartPricing.is_valid
- Pass "limit" through to check_missing_pricing
- Improved logic for update scheduling

* Add option for changing how many decimals to use when displaying pricing data

* remove old unused setting

* Consolidate settings tabs for pricing and currencies

* Fix CI after changing settings page

* Fix rendering for "Supplier Pricing"

- Take unit pricing / pack size into account

* Extra filtering / ordering options for the SupplierPriceBreak API endpoint

* Fix for purchase price history graph

- Use unit pricing (take pack size into account)

* JS fixes

InvenTree/templates/js/translated/company.js

@@ -22,6 +22,7 @@
     loadManufacturerPartTable,
     loadManufacturerPartParameterTable,
     loadSupplierPartTable,
+    loadSupplierPriceBreakTable,
 */
 
 
@@ -1092,3 +1093,97 @@ function loadSupplierPartTable(table, url, options) {
         }
     });
 }
+
+
+/*
+ * Load a table of supplier price break data
+ */
+function loadSupplierPriceBreakTable(options={}) {
+
+    var table = options.table || $('#price-break-table');
+
+    // Setup button callbacks once table is loaded
+    function setupCallbacks() {
+        table.find('.button-price-break-delete').click(function() {
+            var pk = $(this).attr('pk');
+
+            constructForm(`/api/company/price-break/${pk}/`, {
+                method: 'DELETE',
+                title: '{% trans "Delete Price Break" %}',
+                onSuccess: function() {
+                    table.bootstrapTable('refresh');
+                },
+            });
+        });
+
+        table.find('.button-price-break-edit').click(function() {
+            var pk = $(this).attr('pk');
+
+            constructForm(`/api/company/price-break/${pk}/`, {
+                fields: {
+                    quantity: {},
+                    price: {},
+                    price_currency: {},
+                },
+                title: '{% trans "Edit Price Break" %}',
+                onSuccess: function() {
+                    table.bootstrapTable('refresh');
+                }
+            });
+        });
+    }
+
+    setupFilterList('supplierpricebreak', table, '#filter-list-supplierpricebreak');
+
+    table.inventreeTable({
+        name: 'buypricebreaks',
+        url: '{% url "api-part-supplier-price-list" %}',
+        queryParams: {
+            part: options.part,
+        },
+        formatNoMatches: function() {
+            return '{% trans "No price break information found" %}';
+        },
+        onPostBody: function() {
+            setupCallbacks();
+        },
+        columns: [
+            {
+                field: 'pk',
+                title: 'ID',
+                visible: false,
+                switchable: false,
+            },
+            {
+                field: 'quantity',
+                title: '{% trans "Quantity" %}',
+                sortable: true,
+            },
+            {
+                field: 'price',
+                title: '{% trans "Price" %}',
+                sortable: true,
+                formatter: function(value, row, index) {
+                    return formatCurrency(value, {
+                        currency: row.price_currency
+                    });
+                }
+            },
+            {
+                field: 'updated',
+                title: '{% trans "Last updated" %}',
+                sortable: true,
+                formatter: function(value, row) {
+                    var html = renderDate(value);
+
+                    html += `<div class='btn-group float-right' role='group'>`;
+                    html += makeIconButton('fa-edit icon-blue', 'button-price-break-edit', row.pk, '{% trans "Edit price break" %}');
+                    html += makeIconButton('fa-trash-alt icon-red', 'button-price-break-delete', row.pk, '{% trans "Delete price break" %}');
+                    html += `</div>`;
+
+                    return html;
+                }
+            },
+        ]
+    });
+}