feat(vat-allocation): group SI rows by customer+template with multi tax articles

Sales Invoice moved its single tax_article (Link) to a multi-select child table,
which inflated VAT Allocation: one line citing N articles produced N rows of the
full amount (e.g. 1500 -> 6000), so a 1500 payment only covered one article.

Group sales-invoice rows by (customer, item_tax_template) and union the cited
articles into a JSON tax_articles list, summing the amount once (the article
aggregation is computed separately so the JOIN can no longer multiply amounts).
The tax-articles report parses the list and replicates each row's amount/odenis
into every cited maddE column (same turnover under several articles, as on e-taxes).

The grid shows a translatable "N articles" cell that opens a read-only pill popup.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

taxes_az/taxes_az/doctype/vat_allocation/vat_allocation.js

@@ -23,6 +23,9 @@ frappe.ui.form.on('VAT allocation', {
         // Setup filter for Payment Entry
         setup_payment_entry_query(frm);
 
+        // Tax Articles: grid labels + click-to-view popup
+        setup_tax_articles_viewer(frm);
+
     }
 });
 
@@ -225,6 +228,100 @@ function setup_payment_entry_query(frm) {
     };
 }
 
+// ---- Tax Articles helpers (stored as a JSON list of Tax Article names) ----
+
+// Parse the stored tax_articles value into an array of names.
+function parse_tax_articles_value(value) {
+    if (!value) return [];
+    if (Array.isArray(value)) return value.filter(Boolean);
+    if (typeof value === 'string') {
+        try {
+            let parsed = JSON.parse(value);
+            if (Array.isArray(parsed)) return parsed.filter(Boolean);
+            return parsed ? [parsed] : [];
+        } catch (e) {
+            return [value];
+        }
+    }
+    return [String(value)];
+}
+
+// Comma-separated label (used inside the allocation dialog).
+function format_tax_articles(value) {
+    let articles = parse_tax_articles_value(value);
+    return articles.length ? frappe.utils.escape_html(articles.join(', ')) : '-';
+}
+
+// Short label shown in the grid cell, e.g. "3 articles" (translatable).
+function format_tax_articles_count(value) {
+    let n = parse_tax_articles_value(value).length;
+    return n ? __('{0} articles', [n]) : '';
+}
+
+// Read-only popup showing the articles as pills (same look as the Sales Invoice
+// "Tax Articles" control). Rendered as plain styled chips so it does not depend on
+// the Sales Invoice Tax Article meta being loaded on this form, and cannot be edited.
+function show_tax_articles_view(value) {
+    let items = parse_tax_articles_value(value);
+    let pills = items.length
+        ? items.map(function(a) {
+            return '<span class="tax-article-pill">' + frappe.utils.escape_html(a) + '</span>';
+          }).join('')
+        : '<div class="text-muted">' + __('No tax articles') + '</div>';
+    let d = new frappe.ui.Dialog({
+        title: __('Tax Articles'),
+        fields: [{
+            fieldtype: 'HTML',
+            fieldname: 'body',
+            options: '<div class="tax-article-pills">' + pills + '</div>'
+        }],
+        primary_action_label: __('Close'),
+        primary_action() { d.hide(); }
+    });
+    d.show();
+}
+
+// Recompute grid labels for loaded rows and bind the click-to-view handler.
+function setup_tax_articles_viewer(frm) {
+    ['sales_invoice_table', 'sales_invoice_previous_table'].forEach(function(tbl) {
+        (frm.doc[tbl] || []).forEach(function(row) {
+            let label = format_tax_articles_count(row.tax_articles);
+            if (row.tax_articles_display !== label) {
+                row.tax_articles_display = label; // direct set: cosmetic, must not dirty the form
+            }
+        });
+        frm.refresh_field(tbl);
+    });
+
+    if (frm.__tax_articles_viewer_bound) return;
+    frm.__tax_articles_viewer_bound = true;
+
+    if (!document.getElementById('vat-tax-articles-style')) {
+        let style = document.createElement('style');
+        style.id = 'vat-tax-articles-style';
+        style.textContent =
+            '.grid-row [data-fieldname="tax_articles_display"]{cursor:pointer;}' +
+            '.grid-row [data-fieldname="tax_articles_display"] input,' +
+            '.grid-row [data-fieldname="tax_articles_display"] .like-disabled-input{pointer-events:none;}' +
+            // read-only pill chips (same look as the SI Tax Articles control)
+            '.tax-article-pills{display:flex;flex-wrap:wrap;gap:6px;padding:4px 0;}' +
+            '.tax-article-pill{display:inline-block;background:var(--control-bg,#f4f5f6);' +
+            'border:1px solid var(--border-color,#d1d8dd);border-radius:10px;' +
+            'padding:4px 10px;font-size:12px;line-height:1.5;color:var(--text-color,#1f272e);}';
+        document.head.appendChild(style);
+    }
+
+    $(document)
+        .off('mousedown.vataa')
+        .on('mousedown.vataa', '[data-fieldname="tax_articles_display"]', function(ev) {
+            let grid_row = $(this).closest('.grid-row').data('grid_row');
+            if (grid_row && grid_row.doc) {
+                ev.stopPropagation();
+                show_tax_articles_view(grid_row.doc.tax_articles);
+            }
+        });
+}
+
 // Function to fill Sales Invoice Items with filters - UPDATED to fill both tables
 function fill_sales_invoice_items(frm, filters) {
     // Call both server methods - current month and previous months
@@ -247,7 +344,8 @@ function fill_sales_invoice_items(frm, filters) {
                     let row = frm.add_child('sales_invoice_table');
                     row.customer = item.customer;
                     row.item_tax_template = item.item_tax_template;
-                    row.tax_article = item.tax_article;
+                    row.tax_articles = item.tax_articles;
+                    row.tax_articles_display = format_tax_articles_count(item.tax_articles);
                     row.amount = item.amount;
                     row.unallocated_amount = item.amount; // Default: all amount is unallocated
                 });
@@ -285,7 +383,8 @@ function load_previous_months_items(frm, filters) {
                     let row = frm.add_child('sales_invoice_previous_table');
                     row.customer = item.customer;
                     row.item_tax_template = item.item_tax_template;
-                    row.tax_article = item.tax_article;
+                    row.tax_articles = item.tax_articles;
+                    row.tax_articles_display = format_tax_articles_count(item.tax_articles);
                     row.amount = item.amount;
                     row.unallocated_amount = item.unallocated_amount;
                     row.allocated_amount = item.allocated_amount;
@@ -707,7 +806,7 @@ function show_allocation_dialog(frm, payment_row_idx, customer) {
         let item_data = {
             name: item.name,
             item_tax_template: item.item_tax_template || '',
-            tax_article: item.tax_article || '',
+            tax_articles: item.tax_articles || '',
             amount: item.amount || 0,
             unallocated_amount: item.unallocated_amount || 0,
             allocated_amount: item.allocated_amount || 0,
@@ -742,7 +841,7 @@ function show_allocation_dialog(frm, payment_row_idx, customer) {
         let item_data = {
             name: item.name,
             item_tax_template: item.item_tax_template || '',
-            tax_article: item.tax_article || '',
+            tax_articles: item.tax_articles || '',
             amount: item.amount || 0,
             unallocated_amount: item.unallocated_amount || 0,
             allocated_amount: item.allocated_amount || 0,
@@ -1099,7 +1198,7 @@ function build_allocation_html(vat_free_items, vat_items, allocation_data, tab_t
         html += '<table class="table table-bordered" style="margin-bottom: 20px;">';
         html += '<thead><tr>';
         html += '<th>Item Tax Template</th>';
-        html += '<th>Tax Article</th>';
+        html += '<th>Tax Articles</th>';
         html += '<th>Total Amount</th>';
         html += '<th>Unallocated</th>';
         html += '<th>Current Alloc</th>';
@@ -1110,7 +1209,7 @@ function build_allocation_html(vat_free_items, vat_items, allocation_data, tab_t
             allocation_data[item.name] = { value: item.current_allocation || 0, type: 'vat_free' };
             html += '<tr>';
             html += '<td>' + (item.item_tax_template || '-') + '</td>';
-            html += '<td>' + (item.tax_article || '-') + '</td>';
+            html += '<td>' + format_tax_articles(item.tax_articles) + '</td>';
             html += '<td>' + format_currency(item.amount) + '</td>';
             html += '<td>' + format_currency(item.unallocated_amount) + '</td>';
             html += '<td style="background-color: #fff3cd;">' + format_currency(item.current_allocation || 0) + '</td>';
@@ -1127,7 +1226,7 @@ function build_allocation_html(vat_free_items, vat_items, allocation_data, tab_t
         html += '<table class="table table-bordered">';
         html += '<thead><tr>';
         html += '<th>Item Tax Template</th>';
-        html += '<th>Tax Article</th>';
+        html += '<th>Tax Articles</th>';
         html += '<th>Total Amount</th>';
         html += '<th>Unallocated</th>';
         html += '<th>Current Alloc</th>';
@@ -1138,7 +1237,7 @@ function build_allocation_html(vat_free_items, vat_items, allocation_data, tab_t
             allocation_data[item.name] = { value: item.current_allocation || 0, type: 'vat_allocated' };
             html += '<tr>';
             html += '<td>' + (item.item_tax_template || '-') + '</td>';
-            html += '<td>' + (item.tax_article || '-') + '</td>';
+            html += '<td>' + format_tax_articles(item.tax_articles) + '</td>';
             html += '<td>' + format_currency(item.amount) + '</td>';
             html += '<td>' + format_currency(item.unallocated_amount) + '</td>';
             html += '<td style="background-color: #fff3cd;">' + format_currency(item.current_allocation || 0) + '</td>';

taxes_az/taxes_az/doctype/vat_allocation/vat_allocation.py

@@ -7,6 +7,26 @@ import json
 # Константа для tolerance округления
 ROUNDING_TOLERANCE = Decimal('0.01')
 
+
+def parse_tax_articles(value):
+    """Parse the stored ``tax_articles`` value into a list of Tax Article names.
+
+    Rows store the set of articles as a JSON list (e.g. ``["A", "B"]``). This
+    tolerates empty values and a legacy single-article string.
+    """
+    if not value:
+        return []
+    if isinstance(value, (list, tuple, set)):
+        return [a for a in value if a]
+    try:
+        parsed = json.loads(value)
+    except (ValueError, TypeError):
+        return [value]
+    if isinstance(parsed, list):
+        return [a for a in parsed if a]
+    return [parsed] if parsed else []
+
+
 class VATallocation(Document):
     def autoname(self):
         """
@@ -430,8 +450,9 @@ def get_journal_entry_query(doctype, txt, searchfield, start, page_len, filters)
 @frappe.whitelist()
 def get_sales_invoice_items(year, month, customers=None, min_amount=None, max_amount=None):
     """
-    Get Sales Invoice items for specified month and year, grouped by customer, item_tax_template, and tax_article
-    Includes all items, even those without tax_article
+    Get Sales Invoice items for specified month and year, grouped by customer and
+    item_tax_template. Only lines that carry at least one tax article are included;
+    their articles are unioned into a JSON ``tax_articles`` list per group.
     customers can be a JSON string of customer list
     """
     # Convert month name to number
@@ -484,12 +505,15 @@ def get_sales_invoice_items(year, month, customers=None, min_amount=None, max_am
     if having_conditions:
         having_clause = " HAVING " + " AND ".join(having_conditions)
     
-    # SQL query to get Sales Invoice items grouped by customer, item_tax_template, and tax_article
+    # Amounts grouped by (customer, item_tax_template). We deliberately do NOT
+    # join the tax-article child table here: a line carrying N articles would be
+    # multiplied into N joined rows and SUM(amount) would inflate N-fold. Only
+    # lines that carry at least one tax article participate (EXISTS), matching the
+    # previous behaviour where article-less lines were excluded.
     invoice_items = frappe.db.sql(f"""
         SELECT
             si.customer,
             sii.item_tax_template,
-            sita.tax_article,
             SUM(sii.amount) as amount,
             SUM(sii.net_amount) as net_amount,
             SUM(sii.qty) as total_qty
@@ -497,24 +521,56 @@ def get_sales_invoice_items(year, month, customers=None, min_amount=None, max_am
             `tabSales Invoice` si
         INNER JOIN
             `tabSales Invoice Item` sii ON si.name = sii.parent
+        WHERE
+            {conditions}
+            AND EXISTS (
+                SELECT 1 FROM `tabSales Invoice Tax Article` sita
+                WHERE sita.parent = sii.parent
+                  AND sita.parentfield = 'custom_item_tax_articles'
+                  AND sita.parent_row = sii.custom_si_row_key
+            )
+        GROUP BY
+            si.customer, sii.item_tax_template
+        {having_clause}
+        ORDER BY
+            si.customer, sii.item_tax_template
+    """, params, as_dict=1)
+
+    # Distinct tax articles per (customer, item_tax_template), aggregated
+    # separately so the JOIN cannot inflate amounts, then unioned in Python.
+    article_rows = frappe.db.sql(f"""
+        SELECT DISTINCT
+            si.customer,
+            sii.item_tax_template,
+            sita.tax_article
+        FROM
+            `tabSales Invoice` si
+        INNER JOIN
+            `tabSales Invoice Item` sii ON si.name = sii.parent
         INNER JOIN
             `tabSales Invoice Tax Article` sita ON sita.parent = sii.parent AND sita.parentfield = 'custom_item_tax_articles' AND sita.parent_row = sii.custom_si_row_key
         WHERE
             {conditions}
-        GROUP BY 
-            si.customer, sii.item_tax_template, sita.tax_article
-        {having_clause}
-        ORDER BY 
-            si.customer, sii.item_tax_template, sita.tax_article
     """, params, as_dict=1)
 
+    articles_by_group = {}
+    for row in article_rows:
+        if not row.tax_article:
+            continue
+        key = (row.customer, row.item_tax_template or '')
+        articles_by_group.setdefault(key, set()).add(row.tax_article)
+
+    for item in invoice_items:
+        key = (item.customer, item.item_tax_template or '')
+        item['tax_articles'] = json.dumps(sorted(articles_by_group.get(key, set())), ensure_ascii=False)
+
     return invoice_items
 
 @frappe.whitelist()
 def get_sales_invoice_items_previous_months(year, month, customers=None, min_amount=None, max_amount=None):
     """
     Get Sales Invoice items from previous VAT Allocation documents where unallocated_amount > 0
-    Grouped by customer, item_tax_template, and tax_article
+    Grouped by customer and item_tax_template, unioning their tax_articles lists
     """
     # Convert month name to number
     months = {
@@ -583,7 +639,7 @@ def get_sales_invoice_items_previous_months(year, month, customers=None, min_amo
             SELECT
                 customer,
                 item_tax_template,
-                tax_article,
+                tax_articles,
                 unallocated_amount
             FROM `tabVAT allocation sales invoice`
             WHERE parent = %(parent)s
@@ -594,7 +650,8 @@ def get_sales_invoice_items_previous_months(year, month, customers=None, min_amo
 
         all_items.extend(items)
 
-    # Group by customer, item_tax_template, tax_article and sum unallocated amounts
+    # Group by customer, item_tax_template and sum unallocated amounts,
+    # unioning the tax-article sets across rows.
     grouped_items = {}
 
     for item in all_items:
@@ -602,17 +659,18 @@ def get_sales_invoice_items_previous_months(year, month, customers=None, min_amo
         if customer_list and item.customer not in customer_list:
             continue
 
-        key = (item.customer, item.item_tax_template or '', item.tax_article or '')
+        key = (item.customer, item.item_tax_template or '')
 
         if key not in grouped_items:
             grouped_items[key] = {
                 'customer': item.customer,
                 'item_tax_template': item.item_tax_template,
-                'tax_article': item.tax_article,
+                'tax_articles': set(),
                 'amount': Decimal('0')
             }
 
         grouped_items[key]['amount'] += Decimal(str(item.unallocated_amount))
+        grouped_items[key]['tax_articles'].update(parse_tax_articles(item.get('tax_articles')))
 
     # Convert to list and apply amount filters
     result = []
@@ -628,14 +686,14 @@ def get_sales_invoice_items_previous_months(year, month, customers=None, min_amo
         result.append({
             'customer': item['customer'],
             'item_tax_template': item['item_tax_template'],
-            'tax_article': item['tax_article'],
+            'tax_articles': json.dumps(sorted(item['tax_articles']), ensure_ascii=False),
             'amount': amount,
             'unallocated_amount': amount,  # Initially all is unallocated
             'allocated_amount': 0
         })
 
-    # Sort by customer, item_tax_template, tax_article
-    result.sort(key=lambda x: (x['customer'], x['item_tax_template'] or '', x['tax_article'] or ''))
+    # Sort by customer, item_tax_template
+    result.sort(key=lambda x: (x['customer'], x['item_tax_template'] or ''))
     
     return result
 
@@ -705,7 +763,7 @@ def get_allocation_data(vat_allocation_name, payment_entry_row_name, customer):
             item_data = {
                 'name': item.name,
                 'item_tax_template': item.item_tax_template or '',
-                'tax_article': item.tax_article or '',
+                'tax_articles': item.tax_articles or '',
                 'amount': item.amount,
                 'unallocated_amount': item.unallocated_amount,
                 'allocated_amount': item.allocated_amount or 0,
@@ -730,7 +788,7 @@ def get_allocation_data(vat_allocation_name, payment_entry_row_name, customer):
             item_data = {
                 'name': item.name,
                 'item_tax_template': item.item_tax_template or '',
-                'tax_article': item.tax_article or '',
+                'tax_articles': item.tax_articles or '',
                 'amount': item.amount,
                 'unallocated_amount': item.unallocated_amount,
                 'allocated_amount': item.allocated_amount or 0,

taxes_az/taxes_az/doctype/vat_allocation_sales_invoice/vat_allocation_sales_invoice.json

@@ -9,7 +9,8 @@
   "customer",
   "payment_entry",
   "item_tax_template",
-  "tax_article",
+  "tax_articles_display",
+  "tax_articles",
   "amount",
   "allocated_amount",
   "unallocated_amount"
@@ -57,12 +58,17 @@
    "read_only": 1
   },
   {
-   "fieldname": "tax_article",
-   "fieldtype": "Link",
+   "fieldname": "tax_articles_display",
+   "fieldtype": "Data",
    "in_list_view": 1,
-   "label": "Tax Article",
-   "options": "Tax Article",
-   "precision": "2",
+   "label": "Tax Articles",
+   "read_only": 1
+  },
+  {
+   "fieldname": "tax_articles",
+   "fieldtype": "Small Text",
+   "hidden": 1,
+   "label": "Tax Articles (raw)",
    "read_only": 1
   },
   {

taxes_az/taxes_az/report/vat_allocation_tax_articles_report/vat_allocation_tax_articles_report.py

@@ -1,6 +1,8 @@
 # Copyright (c) 2026, Your Company and contributors
 # For license information, please see license.txt
 
+import json
+
 import frappe
 from frappe import _
 from frappe.utils import flt
@@ -11,6 +13,19 @@ def execute(filters=None):
 	return columns, data
 
 
+def _parse_tax_articles(value):
+	"""Parse the stored ``tax_articles`` JSON list; tolerate empty/legacy values."""
+	if not value:
+		return []
+	try:
+		parsed = json.loads(value)
+	except (ValueError, TypeError):
+		return [value]
+	if isinstance(parsed, list):
+		return [a for a in parsed if a]
+	return [parsed] if parsed else []
+
+
 def get_data(filters):
 	"""Получаем данные по VAT Allocation с распределением по налоговым статьям"""
 
@@ -45,9 +60,13 @@ def get_data(filters):
 				allocations_data[allocation_name][field_key] = 0
 				allocations_data[allocation_name][f"{field_key}_odenis"] = 0
 
-		# Получаем полное название статьи по сокращенному name
-		tax_article_name = item['tax_article']
-		if tax_article_name and tax_article_name in tax_article_names_mapping:
+		# Каждая строка несёт JSON-список статей; одна и та же сумма строки
+		# попадает в КАЖДУЮ статью из списка (как на ФНО, где один оборот может
+		# стоять под несколькими maddə).
+		for tax_article_name in _parse_tax_articles(item.get('tax_articles')):
+			if tax_article_name not in tax_article_names_mapping:
+				continue
+
 			full_article_name = tax_article_names_mapping[tax_article_name]
 
 			# Проверяем есть ли маппинг для полного названия
@@ -100,8 +119,8 @@ def get_vat_allocation_items(filters):
 	# Только строки с amount > 0 или allocated_amount > 0
 	conditions.append("(vasi.amount > 0 OR vasi.allocated_amount > 0)")
 
-	# Только строки с tax_article
-	conditions.append("vasi.tax_article IS NOT NULL AND vasi.tax_article != ''")
+	# Только строки с tax_articles (непустой JSON-список)
+	conditions.append("vasi.tax_articles IS NOT NULL AND vasi.tax_articles != '' AND vasi.tax_articles != '[]'")
 
 	where_clause = "WHERE " + " AND ".join(conditions) if conditions else ""
 
@@ -112,7 +131,7 @@ def get_vat_allocation_items(filters):
 			va.month,
 			STR_TO_DATE(CONCAT('01 ', va.month, ' ', va.year), '%%d %%M %%Y') as posting_date,
 			vasi.customer,
-			vasi.tax_article,
+			vasi.tax_articles,
 			vasi.amount,
 			vasi.allocated_amount
 		FROM