Fixing timestamp conversion bug (#9)

* Fixing timestamp conversion bug

* Implementing new date formatter to fix timezone bug.

app/build.gradle

@@ -31,5 +31,7 @@ dependencies {
 
     implementation 'com.github.PhilJay:MPAndroidChart:v3.1.0'
 
+    implementation 'com.jakewharton.threetenabp:threetenabp:1.2.1'
+
     implementation project(path: ':core')
 }

app/src/main/java/com/oxeanbits/forecastchart/ui/MainExample.kt

@@ -3,6 +3,7 @@ package com.oxeanbits.forecastchart.ui
 import android.os.Bundle
 import android.view.View
 import androidx.appcompat.app.AppCompatActivity
+import com.jakewharton.threetenabp.AndroidThreeTen
 import com.oxeanbits.forecastchart.core.ui.component.forecastChartComponent
 import com.oxeanbits.forecastchart.util.SetupChartExample
 import trikita.anvil.BaseDSL.MATCH
@@ -13,6 +14,7 @@ class MainExample : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        AndroidThreeTen.init(this)
         setContentView(getView())
     }
 

app/src/main/java/com/oxeanbits/forecastchart/util/SetupChartExample.kt

@@ -4,22 +4,19 @@ import android.graphics.Color
 import com.github.mikephil.charting.data.Entry
 import com.github.mikephil.charting.utils.ColorTemplate
 import com.oxeanbits.forecastchart.core.model.Line
-import java.text.SimpleDateFormat
+import com.oxeanbits.forecastchart.core.util.DateFormatter
 
 object SetupChartExample{
-    const val THOUS = 1000f
 
-    val dateFormat = SimpleDateFormat("yyyy-MM-dd")
-
-    val timestamp1 = (dateFormat.parse("2019-01-01").time)/THOUS
+    val timestamp1 = DateFormatter.stringToTimestamp("2019-01-01")
     val progress1 = 25f
-    val timestamp2 = (dateFormat.parse("2019-01-02").time)/THOUS
+    val timestamp2 = DateFormatter.stringToTimestamp("2019-01-02")
     val progress2 = 25f + progress1
-    val timestamp3 = (dateFormat.parse("2019-01-03").time)/THOUS
+    val timestamp3 = DateFormatter.stringToTimestamp("2019-01-03")
     val progress3 = 25f + progress2
-    val timestamp4 = (dateFormat.parse("2019-01-04").time)/THOUS
+    val timestamp4 = DateFormatter.stringToTimestamp("2019-01-04")
     val progress4 = 0f + progress3
-    val timestamp5 = (dateFormat.parse("2019-01-05").time)/THOUS
+    val timestamp5 = DateFormatter.stringToTimestamp("2019-01-05")
     val progress5 = 25f + progress4
 
     fun getExpectedObj(): Line{

core/build.gradle

@@ -33,4 +33,6 @@ dependencies {
     implementation 'co.trikita:anvil-design:0.5.2'
 
     implementation 'com.github.PhilJay:MPAndroidChart:v3.1.0'
+
+    implementation 'com.jakewharton.threetenabp:threetenabp:1.2.1'
 }

core/src/main/java/com/oxeanbits/forecastchart/core/util/DateFormatter.kt

@@ -1,12 +1,22 @@
 package com.oxeanbits.forecastchart.core.util
 
-import java.text.SimpleDateFormat
-import java.util.Date
+import org.threeten.bp.Instant
+import org.threeten.bp.LocalDate
+import org.threeten.bp.LocalDateTime
+import org.threeten.bp.ZoneOffset
+import org.threeten.bp.format.DateTimeFormatter
+
 
 object DateFormatter{
+
+    fun stringToTimestamp(date: String): Float{
+        return LocalDate.parse(date).atStartOfDay()
+            .toInstant(ZoneOffset.UTC).epochSecond.toFloat()
+    }
+
     fun timestampToDate(timestamp: Long): String{
-        val mDate = Date()
-        mDate.time = (timestamp.times(1000))
-        return SimpleDateFormat("yyyy-MM-dd").format(mDate)
+        val mDate = LocalDateTime.ofInstant(Instant.ofEpochSecond(timestamp), ZoneOffset.UTC)
+        val formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd")
+        return mDate.format(formatter)
     }
 }