Backend: Kalendar zauzetosti

GitHub Issue: #190

Backend task for the Kalendar zauzetosti (GET /drivepark/calendar) – check the API spec and DB structure, return all vehicles (archived only with bookings in the month) with their reservations and event bookings for a month, implement, and verify against the spec.

Docs: Kalendar zauzetosti Spec: GET /drivepark/calendar (getDriveParkCalendar), DriveParkCalendar, DriveParkCalendarVehicle (allOf Vehicle), DriveParkCalendarEntry in api-docs/openapi.yaml DB: Vehicles, VehicleReservations, DriveParkReservations, Events in api/database/pending_schema.sql (-- DRIVE PARK --) and create_schema.sql

1. Double check API spec and DB structure

• Vehicles shown: all non-deleted vehicles; archived ones only when they have an entry in the month (the docs show archived vehicles so past reservations stay visible). Confirm this with the docs comment (“Recommended: only in months where they have a reservation or an event”).
• Groups: Vozni park = IsForDrive, grouped by Purpose (frontend values it, after-sales, vip, press); Događaji = IsForEvent. Grouping and counts (“1 vozilo”, “2 vozila”) are done by the frontend. Check every vehicle has exactly one of the two flags, or decide where a vehicle with both / neither goes.
• Entries: VehicleReservations rows overlapping the month, reservation (blue, label = company – fullName) or event (green, event name). Check past event bookings are kept when an event is archived (only future bookings are released) so past green bars stay.
• Neispravno: not an entry; the frontend shows grey from today when isActive is false. Check the docs agree (based on the current status, from today on).
• Brand filter: brandCode (nice-to-have “SVE MARKE”). No limitedBrandCodes restriction: Vozni park shows all brands.
• Not shown: pickup/return records (Zapisnici).
• Event dates: green bars span the event’s StartTime–EndTime from its VehicleReservations row. The docs comment (“Recommended: the event’s start to end date”) matches; confirm.
• Roles and permissions: drivepark.access.
• DB: IX_VehicleReservations_VehicleId is enough for one month of data. If the query is slow, add an index on (StartTime, EndTime) with a migration.

2. Implementation

• Roles and permissions: require drivepark.access → 403.
• Validate month (YYYY-MM) and brandCode → 400 validation_error.
• One query for the vehicles and one for the entries of the month (StartTime < first day of next month AND EndTime > first day of month), LEFT JOIN DriveParkReservations and Events for the label; group entries per vehicle in code. No query per vehicle.
• Order vehicles: Vozni park (by purpose) first, then Događaji; then brandCode, name, plate. Entries by start.
• Map to DriveParkCalendarVehicle (Vehicle fields, isOccupied / canVehicleBeDeleted omitted) and DriveParkCalendarEntry (startDate / startTime / endDate / endTime, HH:mm).

3. Verify implementation against spec

• Route, method, query parameters and response shape match getDriveParkCalendar.
• 400 (bad month) / 401 / 403 / 500 can be produced; no undocumented status codes.
• A reservation from 28.11. to 3.12. shows in both November and December.
• An archived vehicle with a reservation in the month is included; without one it isn’t. A deleted vehicle is never included.
• A vehicle with IsActive = 0 is returned with isActive: false and its existing entries.
• brandCode=A returns only Audi vehicles.

Done when

The calendar shows every vehicle of the month with its blue reservation bars, green event bars and Neispravno state.