# Booking Integrity

This ExecPlan follows `docs/PLANS.md`.

## Purpose / Big Picture
Reject invalid booking windows and staff double-booking; accept only schedule-valid requests.

## Progress
- [x] (2026-02-28 13:05Z) Plan created.
- [x] (2026-02-28 13:30Z) Validation service implemented (duration/availability/overlap).
- [x] (2026-02-28 13:45Z) Tests added.
- [x] (2026-02-28 13:50Z) Risks updated.

## Surprises & Discoveries
- Observation: `makemigrations` unavailable in one environment due missing Django.
  Evidence: import error during initial migration step.

## Decision Log
- Decision: require `staff` on booking creation.
  Rationale: no deterministic schedule validation without staff.
  Date/Author: 2026-02-28/Codex
- Decision: no-availability-records => open schedule.
  Rationale: backward compatibility while enabling stricter config when data exists.
  Date/Author: 2026-02-28/Codex

## Outcomes & Retrospective
Completed. Booking integrity checks are active with tests for core failure modes.

## Context and Orientation
- Validation entrypoint: `backend/apps/bookings/services.py`
- Create serializer: `backend/apps/bookings/serializers.py`
- Staff availability model: `backend/apps/salons/models.py`

## Plan of Work
Completed; remaining future policy work is timezone/business-hours specifics.

## Validation and Acceptance
From `backend/`:
- `python3 -m pytest backend/apps/bookings/tests`
Acceptance:
- Invalid duration/availability/overlap cases return 400.
- Valid windows return 201.

## Idempotence and Recovery
Validation is stateless; schema change is additive and reversible by standard migrations.