Bluetooth device connections (#147)

# *Bluetooth device connections*

## ♻️ Current situation & Problem
- Fixes last connected (seen) timestamp to be formatted to current time
zone
- Fixes double paring request. I was able to reproduce the issue and
from different stack overflow posts it seems to be an android bug. This
[suggestion](PhilipsHue/flutter_reactive_ble#507 (comment))
to create the bond request manually before connecting seems to work.

## ⚙️ Release Notes 
*Add a bullet point list summary of the feature and possible migration
guides if this is a breaking change so this section can be added to the
release notes.*
*Include code snippets that provide examples of the feature implemented
or links to the documentation if it appends or changes the public
interface.*


## 📚 Documentation
*Please ensure that you properly document any additions in conformance
to [Spezi Documentation
Guide](https://github.com/StanfordSpezi/.github/blob/main/DOCUMENTATIONGUIDE.md).*
*You can use this section to describe your solution, but we encourage
contributors to document your reasoning and changes using in-line
documentation.*


## ✅ Testing
*Please ensure that the PR meets the testing requirements set by CodeCov
and that new functionality is appropriately tested.*
*This section describes important information about the tests and why
some elements might not be testable.*


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of
Conduct](https://github.com/StanfordSpezi/.github/blob/main/CODE_OF_CONDUCT.md)
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---------

Co-authored-by: Paul Schmiedmayer <[email protected]>

app/src/main/kotlin/edu/stanford/bdh/engagehf/bluetooth/data/mapper/BluetoothUiStateMapper.kt

@@ -33,6 +33,10 @@ class BluetoothUiStateMapper @Inject constructor(
         )
     }
 
+    private val systemDefaultDateFormatter by lazy {
+        dateFormatter.withZone(ZoneId.systemDefault())
+    }
+
     fun mapBleServiceState(state: EngageBLEServiceState): BluetoothUiState {
         return when (state) {
             EngageBLEServiceState.Idle -> {
@@ -81,7 +85,7 @@ class BluetoothUiStateMapper @Inject constructor(
                         name = it.device.name,
                         summary = summary,
                         connected = it.device.connected,
-                        lastSeen = StringResource(R.string.last_seen_on, dateFormatter.format(time))
+                        lastSeen = StringResource(R.string.last_seen_on, systemDefaultDateFormatter.format(time))
                     )
                 }
                 val header = if (devices.isEmpty()) {

core/bluetooth/src/main/kotlin/edu/stanford/spezi/core/bluetooth/domain/BLEDeviceConnector.kt

@@ -95,6 +95,7 @@ internal class BLEDeviceConnector @AssistedInject constructor(
     fun connect() {
         val currentGatt = bluetoothGatt
         if (currentGatt != null || isDestroyed.get()) return
+        device.createBond()
         bluetoothGatt = device.connectGatt(context, false, gattCallback)
     }
 

core/bluetooth/src/test/kotlin/edu/stanford/spezi/core/bluetooth/domain/BLEDeviceConnectorTest.kt

@@ -46,6 +46,7 @@ class BLEDeviceConnectorTest {
 
     @Before
     fun setup() {
+        every { device.createBond() } returns true
         every { device.connectGatt(context, false, any()) } returns bluetoothGatt
         every { bluetoothGatt.disconnect() } just Runs
     }
@@ -59,6 +60,7 @@ class BLEDeviceConnectorTest {
         repeat(10) { sut.connect() }
 
         // then
+        verify(exactly = 1) { device.createBond() }
         verify(exactly = 1) { device.connectGatt(context, false, any()) }
     }
 

core/utils/src/main/kotlin/edu/stanford/spezi/core/utils/TimeProvider.kt

@@ -1,7 +1,8 @@
 package edu.stanford.spezi.core.utils
 
+import java.time.Instant
 import javax.inject.Inject
 
 class TimeProvider @Inject constructor() {
-    fun currentTimeMillis(): Long = System.currentTimeMillis()
+    fun currentTimeMillis(): Long = Instant.now().toEpochMilli()
 }

core/utils/src/test/kotlin/edu/stanford/spezi/core/utils/TimeProviderTest.kt

@@ -2,14 +2,15 @@ package edu.stanford.spezi.core.utils
 
 import com.google.common.truth.Truth.assertThat
 import org.junit.Test
+import java.time.Instant
 
 class TimeProviderTest {
     private val provider = TimeProvider()
 
     @Test
-    fun `it should indicate system currentTimeMillis`() {
+    fun `it should indicate now instant epoch millis`() {
         // given
-        val current = System.currentTimeMillis()
+        val current = Instant.now().toEpochMilli()
         val threshold = 1000L
 
         // when