feat: initial project structure

- GitLabClient: REST Events API z paginacją, pobieranie członków grupy
- Aggregator: zliczanie commitów, MR, komentarzy per użytkownik
- Exporter: generowanie pliku Excel (openpyxl) ze stylami
- main.py: CLI (click) + .env support
- README, .env.example, requirements.txt, .gitignore

exporter.py

@@ -0,0 +1,103 @@
+"""
+Eksporter — generuje plik Excel ze statystykami.
+"""
+
+from pathlib import Path
+from datetime import date
+
+from openpyxl import Workbook
+from openpyxl.styles import Font, PatternFill, Alignment, Border, Side
+from openpyxl.utils import get_column_letter
+
+from aggregator import UserStats
+
+
+HEADER_FILL = PatternFill(start_color="1F4E79", end_color="1F4E79", fill_type="solid")
+HEADER_FONT = Font(color="FFFFFF", bold=True, size=11)
+ALT_ROW_FILL = PatternFill(start_color="D6E4F0", end_color="D6E4F0", fill_type="solid")
+
+THIN_BORDER = Border(
+    left=Side(style="thin"),
+    right=Side(style="thin"),
+    top=Side(style="thin"),
+    bottom=Side(style="thin"),
+)
+
+
+def export_to_excel(
+    stats: list[UserStats],
+    output_path: str,
+    group: str,
+    date_from: date,
+    date_to: date,
+) -> None:
+    wb = Workbook()
+    ws = wb.active
+    ws.title = "Contributions"
+
+    # --- Tytuł ---
+    ws.merge_cells("A1:G1")
+    title_cell = ws["A1"]
+    title_cell.value = (
+        f"Raport aktywności GitLab — grupa: {group} "
+        f"({date_from} → {date_to})"
+    )
+    title_cell.font = Font(bold=True, size=13)
+    title_cell.alignment = Alignment(horizontal="center")
+    ws.row_dimensions[1].height = 24
+
+    # --- Nagłówki ---
+    headers = [
+        "Lp.",
+        "Imię i nazwisko",
+        "Username",
+        "Contributions (suma)",
+        "Commity",
+        "Merge Requesty",
+        "Komentarze",
+    ]
+    ws.append([])  # pusty wiersz 2
+    ws.append(headers)  # wiersz 3
+
+    header_row = 3
+    for col_idx, header in enumerate(headers, start=1):
+        cell = ws.cell(row=header_row, column=col_idx)
+        cell.font = HEADER_FONT
+        cell.fill = HEADER_FILL
+        cell.alignment = Alignment(horizontal="center", wrap_text=True)
+        cell.border = THIN_BORDER
+
+    # --- Dane ---
+    for i, user in enumerate(stats, start=1):
+        row_num = header_row + i
+        row_data = [
+            i,
+            user.name,
+            user.username,
+            user.total_contributions,
+            user.commits,
+            user.merge_requests,
+            user.comments,
+        ]
+        ws.append(row_data)
+
+        fill = ALT_ROW_FILL if i % 2 == 0 else None
+        for col_idx in range(1, len(headers) + 1):
+            cell = ws.cell(row=row_num, column=col_idx)
+            cell.border = THIN_BORDER
+            cell.alignment = Alignment(horizontal="center")
+            if fill:
+                cell.fill = fill
+            # Imię/username — wyrównaj do lewej
+            if col_idx == 2:
+                cell.alignment = Alignment(horizontal="left")
+
+    # --- Szerokości kolumn ---
+    col_widths = [6, 30, 20, 22, 12, 18, 14]
+    for col_idx, width in enumerate(col_widths, start=1):
+        ws.column_dimensions[get_column_letter(col_idx)].width = width
+
+    # --- Zapis ---
+    Path(output_path).parent.mkdir(parents=True, exist_ok=True)
+    wb.save(output_path)
+    print(f"✅ Zapisano: {output_path} ({len(stats)} użytkowników)")