Extract grouping logic into shared function (#19)

Add group_rows_by_project_and_version() to report_builder.py and replace
the duplicated inline grouping in both html.py and odt.py with a single
call to the shared function. This ensures consistent grouping behavior
across formatters and removes a maintenance burden — any change to
grouping logic now happens in one place.

Closes #19

redmine_reporter/formatters/html.py

@@ -1,6 +1,7 @@
 from html import escape
-from typing import Dict, List
+from typing import List
 
+from ..report_builder import group_rows_by_project_and_version
 from ..types import ReportRow
 from .base import Formatter
 
@@ -12,16 +13,7 @@ class HTMLFormatter(Formatter):
         super().__init__()
 
     def format(self, rows: List[ReportRow]) -> str:
-        # Сгруппируем данные
-        projects: Dict[str, Dict[str, List[ReportRow]]] = {}
-        for r in rows:
-            proj = r["project"]
-            ver = r["version"]
-            if proj not in projects:
-                projects[proj] = {}
-            if ver not in projects[proj]:
-                projects[proj][ver] = []
-            projects[proj][ver].append(r)
+        projects = group_rows_by_project_and_version(rows)
 
         lines = [
             '<table border="1" cellpadding="6" cellspacing="0" style="border-collapse: collapse; font-family: Arial, sans-serif;">',

redmine_reporter/formatters/odt.py

@@ -1,11 +1,12 @@
 from importlib import resources
-from typing import Dict, List
+from typing import List
 
 from odf.opendocument import OpenDocument, load
 from odf.style import Style, TableCellProperties, TableColumnProperties
 from odf.table import Table, TableCell, TableColumn, TableRow
 from odf.text import P
 
+from ..report_builder import group_rows_by_project_and_version
 from ..types import ReportRow
 from ..utils import get_month_name_from_range
 from .base import Formatter
@@ -69,18 +70,7 @@ class ODTFormatter(Formatter):
             header_row.addElement(cell)
         table.addElement(header_row)
 
-        projects: Dict[str, Dict[str, List[ReportRow]]] = {}
-        for r in rows:
-            project = r["project"]
-            version = r["version"]
-
-            if project not in projects:
-                projects[project] = {}
-
-            if version not in projects[project]:
-                projects[project][version] = []
-
-            projects[project][version].append(r)
+        projects = group_rows_by_project_and_version(rows)
 
         # Данные с двухуровневой группировкой и объединением ячеек
         for project, versions in projects.items():

redmine_reporter/report_builder.py

@@ -1,4 +1,4 @@
-from typing import List, Tuple, cast
+from typing import Dict, List, Tuple, cast
 
 from redminelib.resources import Issue
 
@@ -71,3 +71,28 @@ def build_grouped_report(
         prev_version = version
 
     return rows
+
+
+def group_rows_by_project_and_version(
+    rows: List[ReportRow],
+) -> Dict[str, Dict[str, List[ReportRow]]]:
+    """
+    Группирует плоский список строк отчёта в иерархию project → version → [rows].
+
+    Предполагается, что rows уже отсортирован (build_grouped_report это гарантирует).
+    Возвращает обычный dict, сохраняющий порядок вставки (Python 3.7+).
+    Используется форматтерами HTML и ODT для объединения ячеек.
+    """
+    projects: Dict[str, Dict[str, List[ReportRow]]] = {}
+    for r in rows:
+        project = r["project"]
+        version = r["version"]
+
+        if project not in projects:
+            projects[project] = {}
+        if version not in projects[project]:
+            projects[project][version] = []
+
+        projects[project][version].append(r)
+
+    return projects