# Backend — Föräldraledigplannerare

FastAPI + Python 3.14, packages managed with `uv`. Layered architecture
(entities → repositories → services → routers) with dependency injection.
**Postgres is a partial stub, not a working swap today:** only
`repositories_impl/postgres/vacation_days_repository.py` exists; every other
`app/dependencies.py` repository factory raises `ValueError` for any
`database_type` other than `"sqlite"`. SQLite is the only usable backend
until the remaining Postgres repositories land.

## Setup

```bash
uv sync                 # install deps (incl. dev group)
# --reload-exclude keeps the dev SQLite file (and its -wal/-shm/-journal
# siblings) out of the watched tree — a write-heavy request otherwise
# self-triggers a reload mid-request and drops the connection, returning a
# 503 *after* the write already committed (see frontend/package.json's
# dev:backend/login:backend for the same flags).
uv run uvicorn app.main:app --reload --reload-exclude '*.db' --reload-exclude '*.db-shm' --reload-exclude '*.db-wal' --reload-exclude '*.db-journal'   # run dev server on :8000
uv run pytest           # run tests with coverage
uv run ruff check .     # lint
```

`uv run pytest` alone does not enforce a coverage floor (`pyproject.toml`'s
`addopts` only requests a report). CI additionally passes
`--cov-fail-under=80` (see the root `CLAUDE.md`) — a locally green run can
still fail in CI if coverage dropped.

## Configuration

Env vars (prefix `APP_`, nested via `__`; see `.env.example`). `Settings`
lives in `app/config.py` — that file's module docstring mentions a
`HMAC_PEPPER` setting; **no such setting exists**, so do not look for it here
or set it expecting an effect.

- `APP_ENV` — `development` (default) | `test` | `production`. In production,
  `Settings` refuses to start unless `APP_JWT_SECRET` is a random value of at
  least 32 characters (the shipped dev default is rejected). Production also
  disables `/docs`, `/redoc`, and `/openapi.json`.
- `APP_DATABASE_TYPE` — `sqlite` (default) | `postgres` (not usable yet — see above).
- `APP_SQLITE_PATH` — default `./foraldraledig.db`.
- `APP_CORS_ORIGINS` — JSON list; default `["http://localhost:5173"]`.
- `APP_JWT_SECRET` — required to be a strong, random secret in production.
- `APP_JWT_ALGORITHM` — default `HS256`.
- `APP_JWT_ACCESS_TOKEN_EXPIRE_MINUTES` — default `15`.
- `APP_JWT_REFRESH_TOKEN_EXPIRE_DAYS` — default `7`.
- `APP_LOG_LEVEL` — default `INFO`.
- `APP_SCRAPER_ENABLED` — **defaults to `true`.** Legal/ToS review of FK scraping + BankID
  automation completed 2026-06; the scraper is cleared for use. Set to `false` in any
  environment without Playwright's Chromium installed (`uv run playwright install chromium`).
- `APP_SCRAPER_HEADLESS` — default `true`.
- `APP_SCRAPER_SESSION_TTL_SECONDS` — default `180`; auto-cancels a stalled scraper session.
- `APP_SCRAPER_DEBUG_ENABLED` — default `false`. **When enabled, writes personal data to disk**
  (an HTML dump + full-page screenshot of the logged-in FK page — name, balances, payout
  amounts). Requires `APP_SCRAPER_DEBUG_DIR` to also be set. Local debugging only; never enable
  in a shared or production environment.
- `APP_SCRAPER_DEBUG_DIR` — where debug artifacts are written when the above is enabled.
- `APP_SCRAPER_DEBUG_DUMP_ON_SUCCESS` — default `false`. Also writes the same debug artifacts
  (HTML + full-page screenshot) after a **successful** extraction, not just on error — a capture
  aid for confirming FK's real DOM (e.g. the family panel structure `app/scrapers/fk_scraper.py`
  currently assumes). Same personal-data warning as `APP_SCRAPER_DEBUG_ENABLED` applies; only
  takes effect when both `APP_SCRAPER_DEBUG_ENABLED` and `APP_SCRAPER_DEBUG_DIR` are also set.
- `APP_SCRAPER_RESULT_RETENTION_SECONDS` — default `300`; how long a finished scraper session's
  result stays in memory before being purged.
- `APP_RULES__*` — the Swedish parental-leave rule constants (`LeaveRules`, nested under `rules`),
  overridable per field, e.g. `APP_RULES__MAX_SAVABLE_DAYS_AT_AGE_4=96`. Defaults: 390
  sjukpenning days, 90 lägstanivå days, 90 reserved days/parent, 60 max dubbeldagar over the
  first 15 months, 96 max savable at age 4 (48 per parent when the child has two or more
  parents — see `resolve_age4_savable_cap`), age-12 hard expiry, 6 preschool planning days/year,
  25 statutory vacation days/year, 20 minimum vacation days/year that must be taken. These are
  common-case figures only — children born before 2014, multiples, and single custody differ and
  are not modeled.

## Layout

```
app/
  config.py            # pydantic-settings (app config + frozen LeaveRules)
  dependencies.py      # DI factories (pick repo impl by settings.database_type)
  entities/            # plain dataclasses (domain)
  models/              # pydantic API schemas
  repositories/        # abstract interfaces
  repositories_impl/   # concrete impls per backend (sqlite/, postgres/)
  services/            # business logic
  routers/             # FastAPI routes
  db/connection.py     # connection + (dev) schema bootstrap
  utils/               # errors, logger
```

## Demo data (manual/browser testing)

`scripts/seed_demo.py` seeds a realistic, ready-to-explore workspace through the
normal service/repository layers (no raw SQL) — a couple workspace with a
partner, a child born ~6 months ago, vacation rows for only some years (so the
`is_assumed` badge is visible), day overrides, and a spread of leave wishes
(fixed, flexible, and one deliberately underfunded to show a shortfall +
remedies + surplus advice). Login credentials are fixed and printed at the end.

```bash
uv run python scripts/seed_demo.py            # create once; re-running is a no-op
uv run python scripts/seed_demo.py --reset     # wipe the demo workspace and rebuild
```

Then open `http://localhost:5173` and log in with the printed `demo@example.com`
credentials. Safe to re-run: without `--reset` it detects the existing demo
user and changes nothing; `--reset` only ever deletes the one demo workspace.

## Reference vertical slice

`VacationDays` is implemented end-to-end (entity → schema → repo interface →
SQLite impl → service → router → tests). **Copy this slice** when adding a new
entity.

> The inline schema in `db/connection.py` exists only so dev/tests are
> self-contained. Production schema is owned by Alembic migrations (a senior task).