feat: Enhance appointment booking interface with date and time selection features

Web/modules/terminplaner/backend_server.py

@@ -10,6 +10,135 @@ import Web.modules.database.settings as cfg
 from Web.tenant import get_tenant_context
 
 
+def _parse_date_value(value):
+    try:
+        return datetime.datetime.strptime(str(value), '%Y-%m-%d').date()
+    except Exception:
+        return None
+
+
+def _parse_time_span_entry(entry):
+    """Parse entries like '2026-06-01 08:00-12:00' into a date and time window."""
+    text = str(entry or '').strip()
+    if not text:
+        return None
+
+    match = None
+    import re
+    match = re.match(r'^(\d{4}-\d{2}-\d{2})\s+(\d{2}:\d{2})-(\d{2}:\d{2})$', text)
+    if match:
+        date_text, start_text, end_text = match.groups()
+        return {
+            'date': date_text,
+            'start_time': start_text,
+            'end_time': end_text,
+            'raw': text,
+        }
+
+    match = re.match(r'^(\d{2}:\d{2})-(\d{2}:\d{2})$', text)
+    if match:
+        start_text, end_text = match.groups()
+        return {
+            'date': None,
+            'start_time': start_text,
+            'end_time': end_text,
+            'raw': text,
+        }
+
+    return None
+
+
+def _iter_date_range(start_date, end_date):
+    if not start_date or not end_date:
+        return []
+    current = start_date
+    days = []
+    while current <= end_date:
+        days.append(current)
+        current += datetime.timedelta(days=1)
+    return days
+
+
+def _format_display_date(date_value):
+    if not date_value:
+        return ''
+    try:
+        return date_value.strftime('%d.%m.%Y')
+    except Exception:
+        return str(date_value)
+
+
+def _weekday_name(date_value):
+    names = ['Montag', 'Dienstag', 'Mittwoch', 'Donnerstag', 'Freitag', 'Samstag', 'Sonntag']
+    try:
+        return names[date_value.weekday()]
+    except Exception:
+        return ''
+
+
+def _build_slot_overview(termin_range):
+    start_date = _parse_date_value(termin_range.get('date_start'))
+    end_date = _parse_date_value(termin_range.get('date_end'))
+    slot_length = termin_range.get('slot_lenght')
+    try:
+        slot_length = int(slot_length or 0)
+    except Exception:
+        slot_length = 0
+
+    booked_entries = termin_range.get('slots_booked', []) or []
+    booked_starts = set()
+    for booked in booked_entries:
+        if isinstance(booked, (list, tuple)) and len(booked) >= 1:
+            booked_starts.add(str(booked[0]).strip())
+        elif isinstance(booked, dict):
+            booked_starts.add(str(booked.get('start') or booked.get('value') or '').strip())
+
+    windows_by_date = {}
+    fallback_windows = []
+    for entry in termin_range.get('time_span', []) or []:
+        parsed = _parse_time_span_entry(entry)
+        if not parsed:
+            continue
+        if parsed['date']:
+            windows_by_date.setdefault(parsed['date'], []).append(parsed)
+        else:
+            fallback_windows.append(parsed)
+
+    day_items = []
+    for day in _iter_date_range(start_date, end_date):
+        day_key = day.strftime('%Y-%m-%d')
+        day_windows = windows_by_date.get(day_key, []) or fallback_windows
+        slots = []
+
+        for window in day_windows:
+            try:
+                window_start = datetime.datetime.strptime(f"{day_key} {window['start_time']}", '%Y-%m-%d %H:%M')
+                window_end = datetime.datetime.strptime(f"{day_key} {window['end_time']}", '%Y-%m-%d %H:%M')
+            except Exception:
+                continue
+
+            current = window_start
+            while current + datetime.timedelta(minutes=max(1, slot_length)) <= window_end:
+                start_label = current.strftime('%Y-%m-%d %H:%M')
+                end_label = (current + datetime.timedelta(minutes=max(1, slot_length))).strftime('%H:%M')
+                slots.append({
+                    'value': start_label,
+                    'label': current.strftime('%H:%M') + ' - ' + end_label,
+                    'occupied': start_label in booked_starts,
+                })
+                current += datetime.timedelta(minutes=max(1, slot_length))
+
+        day_items.append({
+            'date': day_key,
+            'display_date': _format_display_date(day),
+            'weekday': _weekday_name(day),
+            'slots': slots,
+            'has_slots': bool(slots),
+        })
+
+    return day_items
+
+
 def _resolve_public_base_url() -> str:
     if has_request_context():
         try:
@@ -330,6 +459,7 @@ def get_available(id):
             'slots_total': total_slots,
             'slots_booked': normalized,
             'slots_left': slots_left,
+            'slot_days': _build_slot_overview(termin_range),
         }
     except Exception as e:
         print(f"Error getting available slots: {e}")