Integrating ColorContrast in Picker

This CL aims at adding changes for integrating ColorContrast
functionality in WallpaperPicker App.

Bug: b/326108993
Test: Tested by building and installing picker on local and checking if
option appears or not, and testing dark/light theme
Flag: N/A

Change-Id: I8a9ec55d4aef621d2ea74be5373fc5137aa49b3b
diff --git a/tests/robotests/Android.bp b/tests/robotests/Android.bp
index 4fecaef..1377e22 100644
--- a/tests/robotests/Android.bp
+++ b/tests/robotests/Android.bp
@@ -27,6 +27,8 @@
         "truth",
         "SystemUICustomizationTestUtils",
         "ThemePickerApplicationLib",
+        "mockito-robolectric-prebuilt",
+        "mockito-kotlin2",
     ],
 
     libs: [
diff --git a/tests/robotests/src/com/android/customization/model/picker/settings/data/repository/ColorContrastSectionRepositoryTest.kt b/tests/robotests/src/com/android/customization/model/picker/settings/data/repository/ColorContrastSectionRepositoryTest.kt
new file mode 100644
index 0000000..01c0a62
--- /dev/null
+++ b/tests/robotests/src/com/android/customization/model/picker/settings/data/repository/ColorContrastSectionRepositoryTest.kt
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.customization.model.picker.settings.data.repository
+
+import android.app.UiModeManager
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.filters.SmallTest
+import com.android.customization.picker.settings.data.repository.ColorContrastSectionRepository
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.TestCoroutineDispatcher
+import kotlinx.coroutines.test.runBlockingTest
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.mock
+import org.mockito.Mockito.verify
+import org.mockito.Mockito.`when`
+import org.mockito.kotlin.any
+import org.mockito.kotlin.argumentCaptor
+import org.robolectric.RobolectricTestRunner
+
+@SmallTest
+@RunWith(RobolectricTestRunner::class)
+class ColorContrastSectionRepositoryTest {
+    private lateinit var underTest: ColorContrastSectionRepository
+
+    private lateinit var context: Context
+    private lateinit var bgDispatcher: TestCoroutineDispatcher
+
+    @Before
+    fun setUp() {
+        context = ApplicationProvider.getApplicationContext<Context>()
+        bgDispatcher = TestCoroutineDispatcher()
+        underTest = ColorContrastSectionRepository(context, bgDispatcher)
+    }
+
+    @Test
+    fun creationSucceeds() {
+        assertThat(underTest).isNotNull()
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun contrastFlowEmitsValues() = runBlockingTest {
+        val mockUiModeManager = mock(UiModeManager::class.java)
+        val contrastValues = listOf(0.5f, 0.7f, 0.8f)
+
+        // Stub the initial contrast value before the flow starts collecting
+        `when`(mockUiModeManager.contrast).thenReturn(contrastValues[0])
+
+        // Assign the mockUiModeManager to the repository's uiModeManager
+        underTest.uiModeManager = mockUiModeManager
+
+        // Create a collector for the flow
+        val flowCollector = mutableListOf<Float>()
+
+        // Start collecting values from the flow
+        val job = launch { underTest.contrast.collect { flowCollector.add(it) } }
+
+        // Capture the ContrastChangeListener
+        val listenerCaptor = argumentCaptor<UiModeManager.ContrastChangeListener>()
+        verify(mockUiModeManager).addContrastChangeListener(any(), listenerCaptor.capture())
+
+        // Simulate contrast changes after the initial value has been emitted
+        contrastValues.drop(1).forEach { newValue ->
+            listenerCaptor.firstValue.onContrastChanged(newValue)
+        }
+
+        assertThat(flowCollector).containsExactlyElementsIn(contrastValues)
+
+        job.cancel()
+    }
+
+    @After
+    fun tearDown() {
+        bgDispatcher.cleanupTestCoroutines()
+    }
+}