Greptile Summary

This PR tunes the BATTERY_SAVER BLE power profile to improve device discovery reliability: it increases scan duration (5s → 8s) to guarantee more radio windows per scan, halves the advertising refresh interval (180s → 90s) for better peer visibility, switches the idle scan mode from LOW_POWER to BALANCED (avoiding LOW_POWER's ~10% duty cycle that starved discovery), and upgrades the global match mode from MATCH_MODE_STICKY to MATCH_MODE_AGGRESSIVE. A clarifying comment on the non-monotonic scanDurationMs values across profiles is also added.

Key observations from the review:

• The MATCH_MODE_AGGRESSIVE change in performScan() is applied globally to all power profiles (PERFORMANCE, BALANCED, BATTERY_SAVER), not just BATTERY_SAVER as the PR description implies. This is likely intentional given that aggressive matching improves discovery reliability in general, but it is an undocumented behavioural change for the other profiles and should be called out.
• After replacing SCAN_MODE_LOW_POWER with SCAN_MODE_BALANCED in the else branch, determineScanMode() now has two branches (scansWithoutNewDevices < IDLE_SCANS_THRESHOLD and else) that return the same value, leaving the second condition as effective dead code. The function should be simplified to a two-branch when.
• All profiles remain safely under Android's 5-scans-per-30s throttle limit with these new durations.

Confidence Score: 4/5

• Safe to merge with minor cleanup; the redundant when branch and unscoped MATCH_MODE_AGGRESSIVE change should be addressed.
• The core BLE tuning is sound — scan durations, idle intervals, and scan mode changes are all correct and keep every profile well under Android's throttle limit. Two issues reduce confidence: (1) MATCH_MODE_AGGRESSIVE silently affects all power profiles beyond the PR's stated BATTERY_SAVER scope, and (2) determineScanMode() has a redundant unreachable branch that is dead code. Neither is a runtime crash risk, but the global match-mode change is an undocumented behavioural regression path for BALANCED/PERFORMANCE.
• BleScanner.kt — both issues (global MATCH_MODE_AGGRESSIVE and redundant when-branch) are in this file.

Important Files Changed

Sequence Diagram

sequenceDiagram
    participant ScanLoop as Scan Loop
    participant PS as performScan()
    participant DSM as determineScanMode()
    participant BLE as BT LE Scanner (HW)
    participant HSR as handleScanResult()

    ScanLoop->>PS: performScan(minRssi)
    PS->>DSM: determineScanMode()
    alt newDevicesInLastScan > 3
        DSM-->>PS: SCAN_MODE_LOW_LATENCY
    else all other cases (was LOW_POWER for idle)
        DSM-->>PS: SCAN_MODE_BALANCED
    end
    PS->>BLE: startScan(filter, MATCH_MODE_AGGRESSIVE)
    Note over BLE: Previously MATCH_MODE_STICKY for all profiles
    BLE-->>HSR: onScanResult() callbacks
    HSR->>HSR: filter by MIN_RSSI, update devices map
    Note over PS: delay(scanDurationMs) — BATTERY_SAVER 8s (was 5s)
    PS->>BLE: stopScan()
    PS-->>ScanLoop: return
    ScanLoop->>ScanLoop: delay(currentScanInterval)
    Note over ScanLoop: BATTERY_SAVER active=15s, idle=120s
    ScanLoop->>ScanLoop: adjustScanInterval()

_{Last reviewed commit: 19f4219}

Codecov Report

✅ All modified and coverable lines are covered by tests.

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