# Med det samme

A local-first Android medication reminder. *«Med det samme»* — "right away" — is
the design brief in three words: it nags you to take the dose **now**.

The name tips its hat to Arve Opsahl's 1962 classic
[*«Medisin, medisin med det samme!»*](https://sonichits.com/video/Arve_Opsahl/Medisin%2C_Medisin_Med_Det_Samme!)
— a man demanding his medicine *right away*, which is exactly what this app
does on his behalf.

Built as a personal replacement for MyTherapy: no ads, no account, no
analytics, no cloud service. Single user, single device. Reminders are the
entire point, so reliability beats polish wherever the two trade off.

## Features

- **Escalating reminders** — a due dose posts a notification and re-nags every
  10 minutes (capped at ~6) until you tap *Tatt* or *Utsett*. Snooze defers
  15 minutes and keeps nagging. The nag counter lives in the database, so a
  reboot mid-escalation resumes where it left off.
- **Flexible schedules** — time-of-day + weekday mask (different times on
  different days) or every-N-days from an anchor date. All schedule math is a
  pure, unit-tested engine.
- **Inventory** — physical stock is its own entity with one-tap package
  restock. Taking a dose decrements stock; refill warnings are *derived* from
  stock ÷ scheduled consumption, never manually scheduled. Prescription
  renewal (expiry, reiterutleveringer) is tracked separately from stock — you
  can have pills and a dead e-resept, or vice versa.
- **Offline drug autocomplete** — a slim extract of
  [FEST](https://www.dmp.no/om-oss/distribusjon-av-legemiddeldata/fest)
  (the open national dataset from DMP) is bundled in the APK and searched
  offline. Release builds auto-refresh the bundle when it's >30 days old.
- **Encrypted backups you can leave with** — versioned JSON, encrypted as a
  standard [age](https://age-encryption.org) v1 file (scrypt/passphrase mode),
  uploaded nightly to a self-hosted S3-compatible bucket
  ([Garage](https://garagehq.deuxfleurs.fr/)) with a hand-rolled SigV4 signer.
  Any backup decrypts on any machine with plain `age -d` — no app lock-in.
- **Doctor summary** — a one-page PDF (current meds, schedules, supply, rx
  status, 30-day adherence) generated with the platform `PdfDocument` and
  shared via the system sheet. Human-readable, distinct from the
  machine-readable backup.

## Reliability design

Android actively fights background work; a medication app has to fight back:

- **Exact alarms** (`USE_EXACT_ALARM`, plus `SCHEDULE_EXACT_ALARM` on API
  31–32) with `setExactAndAllowWhileIdle`, always gated on
  `canScheduleExactAlarms()` with an inexact fallback.
- **Re-arm on boot and app update** (`BOOT_COMPLETED`, `MY_PACKAGE_REPLACED`)
  — AlarmManager state is wiped on both; every alarm is rebuilt from the DB.
- **No alarm drift by construction** — the alarm layer holds at most one
  pending alarm per dose-time and always *recomputes* from the database via
  the pure engine. Reboot, update and "Taken" all just re-ask. PendingIntent
  identity (stable requestCode + `FLAG_UPDATE_CURRENT`) makes stacking
  impossible at the OS level.
- **One-time battery-optimisation exemption prompt** — the biggest cause of
  dropped reminders on aggressive OEMs.
- **One implementation of Taken/Snooze/Skip** (`DoseActions`), shared by the
  notification actions and the UI, so the two can never disagree about
  inventory or escalation state.

## Data model

```
InventoryItem  — physical stock: name, strength, unit, form, ATC,
                 package size, stock, low-stock lead, rx expiry/refills
Medication     — a dosing regimen referencing an item (RESTRICT FK:
                 deleting stock can never erase adherence history)
DoseTime       — minute-of-day + weekday mask (bit 0 = Sunday) or
                 every-N-days from an anchor epoch day
DoseLog        — one scheduled occurrence and its outcome
                 (PENDING/TAKEN/SKIPPED/SNOOZED), amount snapshotted
ScheduleEngine — pure: next occurrence, daily consumption,
                 days-of-supply, needs-refill, needs-renewal, adherence
```

Room with exported schemas committed under `app/schemas/`; migrations are
proven by instrumented `MigrationTestHelper` tests before they touch real
data. Google Auto Backup carries exactly one file: the app's own
age-encrypted export (written only while a backup passphrase is set) —
include-rules keep the database and settings out, and restoring on a new
device requires typing the passphrase, since Keystore keys never migrate.

## Backup format

`{"version": 2, "inventoryItems": [...], "medications": [...], "doseTimes":
[...], "doseLogs": [...]}` — pretty-printed JSON, then encrypted. Decrypt
anywhere:

```sh
age -d backup-20260610T020000Z.json.age | jq .
```

Version 1 files (pre inventory split) still import. The JCE baseline format
(`MDS1` header, PBKDF2-HMAC-SHA256 → AES-256-GCM) remains readable; new
backups are always age. The age implementation
([kage](https://github.com/android-password-store/kage)) is verified in unit
tests against the [C2SP CCTV](https://github.com/C2SP/CCTV) scrypt vectors.

## FEST dataset

`tools/fest_flatten.py` (stdlib Python) downloads DMP's M30 Rekvirent extract,
streams the ~115 MB XML, and flattens ~9 000 active human-use preparations
into `app/src/main/assets/fest/slim.json`. `assembleRelease` runs it
automatically: fresh file → fast skip; download failure → keep the old file
(an offline release build never breaks). See `docs/fest-dataset.md` for the
JSON contract. Felleskatalogen is deliberately not used: licensed editorial
content, no open API.

## Building

Requirements: JDK 17 and an Android SDK with platform 37.

```sh
./gradlew assembleDebug          # debug build
./gradlew test                   # unit tests (engine, crypto, SigV4, FEST search)
./gradlew connectedDebugAndroidTest   # migration tests (needs an emulator/device)
./gradlew assembleRelease        # signed if keystore.properties exists, else unsigned
```

Release signing reads a gitignored `keystore.properties` at the repo root
(`storeFile`/`storePassword`/`keyAlias`/`keyPassword`); without it the release
build is unsigned rather than failing.

- minSdk 26, targetSdk 35, compileSdk 37
- Kotlin + Jetpack Compose (Material3), Room (+KSP), WorkManager, OkHttp,
  kotlinx-serialization, kage — Gradle Kotlin DSL with a version catalog,
  no DI framework, no AWS SDK.

## Out of scope

Caregiver alerts, multi-profile, Health Connect, streaks/gamification,
symptom diary. This is one person's medication reminder, not a platform.

## License

[MIT](LICENSE) © Ole-Morten Duesund.

The bundled FEST extract (`app/src/main/assets/fest/slim.json`) is derived from
DMP's openly published drug data and remains subject to DMP's own terms, not
the MIT license above.