Add view holder for accounts

app/build.gradle

@@ -37,6 +37,9 @@ dependencies {
 
     testImplementation 'junit:junit:4.12'
     testImplementation 'com.natpryce:hamkrest:1.5.0.0'
+    testImplementation "androidx.arch.core:core-testing:$lifecycle_version"
+    testImplementation "com.nhaarman.mockitokotlin2:mockito-kotlin:2.0.0-RC1"
+    testImplementation "org.mockito:mockito-inline:2.19.0"
 
     androidTestImplementation "androidx.test:runner:$support_version"
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha4'

app/src/main/java/com/chameth/yaotp/accounts/Accounts.kt

@@ -1,8 +1,15 @@
 package com.chameth.yaotp.accounts
 
-import com.chameth.yaotp.algos.HotpParams
-import com.chameth.yaotp.algos.TotpParams
+import com.chameth.yaotp.algos.*
 
-sealed class Account(val label: String, val issuer: String? = null)
-class HotpAccount(label: String, issuer: String?, val counter: Long, val params: HotpParams) : Account(label, issuer)
-class TotpAccount(label: String, issuer: String?, val params: TotpParams) : Account(label, issuer)
+sealed class Account(val label: String, val issuer: String? = null, val timeBased: Boolean) {
+    abstract fun generateOtp(): Otp
+}
+
+class HotpAccount(label: String, issuer: String?, var counter: Long, val params: HotpParams) : Account(label, issuer, false) {
+    override fun generateOtp() = hotp(params, counter.toByteArray()).also { counter++ }
+}
+
+class TotpAccount(label: String, issuer: String?, val params: TotpParams) : Account(label, issuer, true) {
+    override fun generateOtp() = totp(params)
+}

app/src/main/java/com/chameth/yaotp/viewmodel/OtpItemViewModel.kt

@@ -0,0 +1,29 @@
+package com.chameth.yaotp.viewmodel
+
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import com.chameth.yaotp.accounts.Account
+import com.chameth.yaotp.algos.Otp
+import com.chameth.yaotp.algos.currentTime
+import kotlin.math.max
+
+class OtpItemViewModel : ViewModel() {
+
+    var account: Account? = null
+    set(value) {
+        value?.let {
+            label.value = it.label
+            otp.value = it.generateOtp()
+            showTime.value = it.timeBased
+            timeLeft.value = if (it.timeBased) "${calculateTimeLeft(otp.value?.expiresAt ?: 0)}s" else ""
+        }
+    }
+
+    val label = MutableLiveData<String>()
+    val otp = MutableLiveData<Otp>()
+    val showTime = MutableLiveData<Boolean>()
+    val timeLeft = MutableLiveData<String>()
+
+    internal fun calculateTimeLeft(expiry: Long, currentTime: Long = currentTime())= max(0, expiry - currentTime)
+
+}

app/src/main/res/layout/item_otp.xml

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
+        xmlns:tools="http://schemas.android.com/tools">
+
+    <data>
+        <import type="android.view.View"/>
+        <variable
+                name="viewmodel"
+                type="com.chameth.yaotp.viewmodel.OtpItemViewModel"/>
+    </data>
+
+    <RelativeLayout
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_margin="16dp">
+
+        <TextView
+                android:id="@+id/otpLabel"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_alignParentStart="true"
+                android:layout_toStartOf="@id/otpTimeLeft"
+                android:textSize="16sp"
+                android:text="@{viewmodel.label}"
+                tools:text="Label" />
+
+        <TextView
+                android:id="@+id/otpValue"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_below="@id/otpLabel"
+                android:layout_alignParentStart="true"
+                android:layout_toStartOf="@id/otpTimeLeft"
+                android:textSize="32sp"
+                android:text="@{viewmodel.otp.otp}"
+                tools:text="012345" />
+
+        <TextView
+                android:id="@+id/otpTimeLeft"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_alignParentEnd="true"
+                android:textSize="24sp"
+                android:layout_margin="16dp"
+                android:visibility="@{viewmodel.showTime ? View.VISIBLE : View.GONE}"
+                android:text="@{viewmodel.timeLeft}"
+                tools:text="20s"/>
+
+    </RelativeLayout>
+</layout>

app/src/test/java/com/chameth/yaotp/viewmodel/OtpItemViewModelTest.kt

@@ -0,0 +1,86 @@
+package com.chameth.yaotp.viewmodel
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import androidx.lifecycle.Observer
+import com.chameth.yaotp.algos.Otp
+import com.nhaarman.mockitokotlin2.argThat
+import com.nhaarman.mockitokotlin2.doReturn
+import com.nhaarman.mockitokotlin2.mock
+import com.nhaarman.mockitokotlin2.verify
+import org.junit.Assert.assertEquals
+import org.junit.Rule
+import org.junit.Test
+
+class OtpItemViewModelTest {
+
+    @get:Rule
+    val instantTaskExecutorRule = InstantTaskExecutorRule()
+
+    private val viewModel = OtpItemViewModel()
+
+    @Test
+    fun testCalculateTimeLeft_withFutureTimes() {
+        assertEquals(1, viewModel.calculateTimeLeft(100L, 99L))
+        assertEquals(1000, viewModel.calculateTimeLeft(1000L, 0L))
+        assertEquals(1000, viewModel.calculateTimeLeft(99999991000L, 99999990000L))
+    }
+
+    @Test
+    fun testCalculateTimeLeft_withPastTimes() {
+        assertEquals(0, viewModel.calculateTimeLeft(100L, 100L))
+        assertEquals(0, viewModel.calculateTimeLeft(100L, 1000L))
+        assertEquals(0, viewModel.calculateTimeLeft(100L, 100000000000L))
+    }
+
+    @Test
+    fun testSetAccount_updatesLabel() {
+        val observer = mock<Observer<String>>()
+        viewModel.label.observeForever(observer)
+        viewModel.account = mock { on { label } doReturn "My label" }
+        verify(observer).onChanged("My label")
+    }
+
+    @Test
+    fun testSetAccount_updatesOtp() {
+        val otp = mock<Otp>()
+        val observer = mock<Observer<Otp>>()
+        viewModel.otp.observeForever(observer)
+        viewModel.account = mock { on { generateOtp() } doReturn otp }
+        verify(observer).onChanged(otp)
+    }
+
+    @Test
+    fun testSetAccount_updatesShowTime_withTimeBasedAccount() {
+        val observer = mock<Observer<Boolean>>()
+        viewModel.showTime.observeForever(observer)
+        viewModel.account = mock { on { timeBased } doReturn true }
+        verify(observer).onChanged(true)
+    }
+
+    @Test
+    fun testSetAccount_updatesShowTime_withNonTimeBasedAccount() {
+        val observer = mock<Observer<Boolean>>()
+        viewModel.showTime.observeForever(observer)
+        viewModel.account = mock { on { timeBased } doReturn false }
+        verify(observer).onChanged(false)
+    }
+
+    @Test
+    fun testSetAccount_updatesTimeLeft_withTimeBasedAccount() {
+        val otp = mock<Otp> { on { expiresAt } doReturn (System.currentTimeMillis() / 1000) + 10 }
+        val observer = mock<Observer<String>>()
+        viewModel.timeLeft.observeForever(observer)
+        viewModel.account = mock { on { generateOtp() } doReturn otp; on { timeBased } doReturn true }
+        verify(observer).onChanged(argThat { matches(Regex("(9|10)s")) })
+    }
+
+    @Test
+    fun testSetAccount_updatesTimeLeft_withNonTimeBasedAccount() {
+        val otp = mock<Otp>()
+        val observer = mock<Observer<String>>()
+        viewModel.timeLeft.observeForever(observer)
+        viewModel.account = mock { on { generateOtp() } doReturn otp; on { timeBased } doReturn false }
+        verify(observer).onChanged("")
+    }
+
+}