feat: Space Booking System - MVP complet

Sistem web pentru rezervarea de birouri și săli de ședință
cu flux de aprobare administrativă.

Stack: FastAPI + Vue.js 3 + SQLite + TypeScript

Features implementate:
- Autentificare JWT + Self-registration cu email verification
- CRUD Spații, Utilizatori, Settings (Admin)
- Calendar interactiv (FullCalendar) cu drag-and-drop
- Creare rezervări cu validare (durată, program, overlap, max/zi)
- Rezervări recurente (săptămânal)
- Admin: aprobare/respingere/anulare cereri
- Admin: creare directă rezervări (bypass approval)
- Admin: editare orice rezervare
- User: editare/anulare rezervări proprii
- Notificări in-app (bell icon + dropdown)
- Notificări email (async SMTP cu BackgroundTasks)
- Jurnal acțiuni administrative (audit log)
- Rapoarte avansate (utilizare, top users, approval rate)
- Șabloane rezervări (booking templates)
- Atașamente fișiere (upload/download)
- Conflict warnings (verificare disponibilitate real-time)
- Integrare Google Calendar (OAuth2)
- Suport timezone (UTC storage + user preference)
- 225+ teste backend

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/services/booking_service.py

@@ -0,0 +1,112 @@
+"""Booking validation service."""
+from datetime import datetime
+
+from sqlalchemy import and_
+from sqlalchemy.orm import Session
+
+from app.models.booking import Booking
+from app.models.settings import Settings
+
+
+def validate_booking_rules(
+    db: Session,
+    space_id: int,
+    user_id: int,
+    start_datetime: datetime,
+    end_datetime: datetime,
+    exclude_booking_id: int | None = None,
+) -> list[str]:
+    """
+    Validate booking against global settings rules.
+
+    Args:
+        db: Database session
+        space_id: ID of the space to book
+        user_id: ID of the user making the booking
+        start_datetime: Booking start time
+        end_datetime: Booking end time
+        exclude_booking_id: Optional booking ID to exclude from overlap check
+                           (used when re-validating an existing booking)
+
+    Returns:
+        List of validation error messages (empty list = validation OK)
+    """
+    errors = []
+
+    # Fetch settings (create default if not exists)
+    settings = db.query(Settings).filter(Settings.id == 1).first()
+    if not settings:
+        settings = Settings(
+            id=1,
+            min_duration_minutes=30,
+            max_duration_minutes=480,
+            working_hours_start=8,
+            working_hours_end=20,
+            max_bookings_per_day_per_user=3,
+            min_hours_before_cancel=2,
+        )
+        db.add(settings)
+        db.commit()
+        db.refresh(settings)
+
+    # a) Validate duration in range
+    duration_minutes = (end_datetime - start_datetime).total_seconds() / 60
+    if (
+        duration_minutes < settings.min_duration_minutes
+        or duration_minutes > settings.max_duration_minutes
+    ):
+        errors.append(
+            f"Durata rezervării trebuie să fie între {settings.min_duration_minutes} "
+            f"și {settings.max_duration_minutes} minute"
+        )
+
+    # b) Validate working hours
+    if (
+        start_datetime.hour < settings.working_hours_start
+        or end_datetime.hour > settings.working_hours_end
+    ):
+        errors.append(
+            f"Rezervările sunt permise doar între {settings.working_hours_start}:00 "
+            f"și {settings.working_hours_end}:00"
+        )
+
+    # c) Check for overlapping bookings
+    query = db.query(Booking).filter(
+        Booking.space_id == space_id,
+        Booking.status.in_(["approved", "pending"]),
+        and_(
+            Booking.start_datetime < end_datetime,
+            Booking.end_datetime > start_datetime,
+        ),
+    )
+
+    # Exclude current booking if re-validating
+    if exclude_booking_id is not None:
+        query = query.filter(Booking.id != exclude_booking_id)
+
+    overlapping_bookings = query.first()
+    if overlapping_bookings:
+        errors.append("Spațiul este deja rezervat în acest interval")
+
+    # d) Check max bookings per day per user
+    booking_date = start_datetime.date()
+    start_of_day = datetime.combine(booking_date, datetime.min.time())
+    end_of_day = datetime.combine(booking_date, datetime.max.time())
+
+    user_bookings_count = (
+        db.query(Booking)
+        .filter(
+            Booking.user_id == user_id,
+            Booking.status.in_(["approved", "pending"]),
+            Booking.start_datetime >= start_of_day,
+            Booking.start_datetime <= end_of_day,
+        )
+        .count()
+    )
+
+    if user_bookings_count >= settings.max_bookings_per_day_per_user:
+        errors.append(
+            f"Ai atins limita de {settings.max_bookings_per_day_per_user} rezervări pe zi"
+        )
+
+    return errors