From e38960ff845bddbd463c43801ad01834f77474f2 Mon Sep 17 00:00:00 2001
From: Iván Ávalos <avalos@disroot.org>
Date: Mon, 17 Jan 2022 02:06:41 -0600
Subject: Implemented timer that fetches units every 10 seconds, and updated
 map to work with timer

---
 .../TrackerMap/controllers/UnitsController.kt      | 45 +++++++++++++++-------
 .../mx/trackermap/TrackerMap/utils/Coroutines.kt   | 20 ++++++++++
 2 files changed, 51 insertions(+), 14 deletions(-)
 create mode 100644 shared/src/commonMain/kotlin/mx/trackermap/TrackerMap/utils/Coroutines.kt

(limited to 'shared')

diff --git a/shared/src/commonMain/kotlin/mx/trackermap/TrackerMap/controllers/UnitsController.kt b/shared/src/commonMain/kotlin/mx/trackermap/TrackerMap/controllers/UnitsController.kt
index 584f656..21692e7 100644
--- a/shared/src/commonMain/kotlin/mx/trackermap/TrackerMap/controllers/UnitsController.kt
+++ b/shared/src/commonMain/kotlin/mx/trackermap/TrackerMap/controllers/UnitsController.kt
@@ -1,17 +1,23 @@
 package mx.trackermap.TrackerMap.controllers
 
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.DelicateCoroutinesApi
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.*
 import kotlinx.coroutines.launch
 import mx.trackermap.TrackerMap.client.apis.DevicesApi
 import mx.trackermap.TrackerMap.client.apis.PositionsApi
 import mx.trackermap.TrackerMap.client.models.Position
 import mx.trackermap.TrackerMap.client.models.UnitInformation
+import mx.trackermap.TrackerMap.utils.Coroutines
+import kotlin.time.Duration.Companion.seconds
+import kotlin.time.ExperimentalTime
 
 @DelicateCoroutinesApi
+@ExperimentalTime
 class UnitsController(
     private val devicesApi: DevicesApi,
     private val positionsApi: PositionsApi
@@ -23,28 +29,39 @@ class UnitsController(
 
     init {
         GlobalScope.launch {
-            fetchUnits()
+            fetchUnits(this)
         }
         GlobalScope.launch {
             setupFlows()
         }
     }
 
-    private suspend fun fetchUnits() {
-        val devices = devicesApi.devicesGet()
-        val positions = positionsApi.positionsGet()
-        val positionsMap: MutableMap<Int, Position> = mutableMapOf()
-
-        positions.forEach { position ->
-            position.deviceId?.let {
-                positionsMap[it] = position
+    private suspend fun fetchUnits(scope: CoroutineScope) {
+        Coroutines.tickerFlow(10.seconds)
+            .map {
+                print("Fetching new positions...\n")
+                positionsApi.positionsGet()
             }
-        }
+            .distinctUntilChanged { old, new ->
+                old.contentEquals(new)
+            }
+            .onEach { positions ->
+                print("Position(s) changed! Reloading data...\n")
+                val devices = devicesApi.devicesGet()
+                val positionsMap: MutableMap<Int, Position> = mutableMapOf()
 
-        val units = devices.map {
-            UnitInformation(it, positionsMap[it.id])
-        }
-        unitsFlow.value = units
+                positions.forEach { position ->
+                    position.deviceId?.let {
+                        positionsMap[it] = position
+                    }
+                }
+
+                val units = devices.map {
+                    UnitInformation(it, positionsMap[it.id])
+                }
+                unitsFlow.value = units
+            }
+            .launchIn(scope)
     }
 
     fun search(query: String) {
diff --git a/shared/src/commonMain/kotlin/mx/trackermap/TrackerMap/utils/Coroutines.kt b/shared/src/commonMain/kotlin/mx/trackermap/TrackerMap/utils/Coroutines.kt
new file mode 100644
index 0000000..c953887
--- /dev/null
+++ b/shared/src/commonMain/kotlin/mx/trackermap/TrackerMap/utils/Coroutines.kt
@@ -0,0 +1,20 @@
+package mx.trackermap.TrackerMap.utils
+
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.flow
+import kotlin.time.Duration
+import kotlin.time.ExperimentalTime
+
+class Coroutines {
+    companion object {
+        // Source: https://stackoverflow.com/questions/54827455/how-to-implement-timer-with-kotlin-coroutines/54828055#54828055
+        @ExperimentalTime
+        fun tickerFlow(period: Duration, initialDelay: Duration = Duration.ZERO) = flow {
+            delay(initialDelay)
+            while (true) {
+                emit(Unit)
+                delay(period)
+            }
+        }
+    }
+}
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