[dzid26]

Summary

Bases the discharge projection on the parked drain only, using the DriveState odometer (#149) to tell parked stretches from drives. One commit on top of main.

What counts as parked

• A pair of consecutive battery samples is parked when neither is charging and the odometer did not move between them.
• Each sample takes its odometer from the drive sample nearest to it in time, within 2 minutes. A drive read follows every charge read, both on the car's clock.
• A sample with no drive sample in that window (or one without an odometer) isn't known to be parked, so its pairs are left out.
• A long unobserved gap still counts when the odometer is unchanged across it. That keeps the overnight drop up to the wake-up read when the door opens. A drive no phone saw shows up as an odometer change and is left out.
• The rate is the summed signed percent change over the summed parked time, so a parked rounding blip cancels instead of inflating the drop.

Horizon and chart

• The projection looks half the selected range ahead (6 h → 3 h, 24 h → 12 h, 7 d → 3.5 d, All → half the span).
• The chart's x-axis expands by that horizon, so the dashed line keeps its slope.

Sparse samples (#161). Battery reads now come every 20 min while parked and awake, and not at all while asleep. I checked the two rules:

• Under 10 minutes of parked time: unchanged. It applies to the summed parked time, which hour-long gaps easily clear.
• Last sample stale: changed. The old bound (a quarter of the range, 30 min to 6 h) hid the projection for most of a night parked, since a sleeping car produces no reads. The projection now stays until its whole line lies in the past, i.e. the last sample is older than the horizon. A 24 h chart keeps it for 12 h after the last read.

Wiring.

• The car screen feeds the selected car's drive samples into the projection.
• MainScreen takes battery and drive samples as one HistorySamples value. That keeps it at 14 parameters, under detekt's limit, without raising the threshold.
• The demo history now seeds a DriveState next to each charge record. Its odometer moves only across the seeded drives and ends at the simulated car's live odometer, so the demo still shows the parked drain.

Type

• Bug fix
• Feature
• Protocol / crypto change
• Docs / CI / tooling
• Refactor (no behavior change)

Testing

• ./gradlew :core:test. DischargeProjectionTest (kotlin.test, 13 cases) covers:
  • a long overnight gap with an unchanged odometer counts;
  • a gap with an odometer change doesn't;
  • a charging pair doesn't;
  • a missing drive sample excludes its pairs (including one just past the 2-minute tolerance, and none at all);
  • a rounding blip cancels;
  • the horizon is half the range;
  • a sleeping car keeps its projection until the horizon passes;
  • the null cases.
• ./gradlew :app:testDebugUnitTest
• ./gradlew :app:lintDebug
• ./gradlew :app:assembleDebug, ktlintCheck, detekt. The full build from the brief is green locally.
• Real car: not tested. Worth checking on the car that the overnight drop shows up after the morning wake-up read.

Checklist

• Protocol changes ship test vectors; expected.txt regenerated, not hand-edited (n/a: no protocol change)
• No VINs, keys, or decrypted payloads in logs
• Docs/master-plan updated where relevant: README, master-plan projection and drive-detection lines
• New source files carry SPDX-License-Identifier: AGPL-3.0-only

🤖 Generated with Claude Code

https://claude.ai/code/session_0129RzhbEE2cboMcYyZMuxqX

[github-actions]

Projection fix on the phone — 24 h chart, real data.

The x-axis now spans 05 Oct 12:29 → 07 Oct 00:29 (24 h back + the 12 h horizon) and the dashed line drops 72 → 68 % over 12 h instead of the old near-vertical stub at the right edge. Caption: Discharging · projected 68% by 06 Oct 22:17.

The 6 h chart shows no projection right now: the newest sample is 2 h 11 m old, past the 6 h range's freshness bound (1.5 h).

[dzid26]

Actually we should only project based on Parked slope. Waiting for #94 and getDriveState to land first.

[github-actions]

Screenshots

Captured from the demo build at 2a1b34a.

Debug APK: zip from Android CI (GitHub sign-in needed)

[github-actions]

Screenshots

Captured from the demo build at 7aadccf.

Debug APK: zip from Android CI (GitHub sign-in needed)

[github-actions]

Screenshots

Captured from the demo build at e7cc97a.

Debug APK: zip from Android CI (GitHub sign-in needed)

[github-actions]

Screenshots

Light

Dark

Captured from the demo build at a47c909.

Debug APK: zip from Android CI (GitHub sign-in needed)

[github-actions]

Screenshots

Light

Dark

Captured from the demo build at 91efc11.

Debug APK: zip from Android CI (GitHub sign-in needed)