Compose migration (#26)

* Modify configuration files to support Kotlin & Jetpack Compose

As discussed this morning, we plan on moving to Kotlin and Jetpack compose. This commit marks the beginning of the modification to make it.

* Update minSdk to comply with firebase requirement

Changes:
* Change from minSdk:24 to minSdk:28 to comply with the firebase
  realtime database requirements

* Delete old java activity file and write basic test

Changes:
* Remove `GreetingActivity.java` and `MainActivity.java` and
  dependencies
* Write simple `ComposeActvitityTest.kt`

* fix: Support for coverage with Kotlin

* Added Mockito

* Fixed the build.gradle with proper versions

* 🔥 💯 :triump: base 😡

---------

Co-authored-by: BoyeGuillaume <guillaume.boye@epfl.ch>

app/build.gradle

@@ -62,22 +62,18 @@ dependencies {
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
     implementation 'androidx.core:core-ktx:1.9.0'
     implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.5.1'
+    implementation 'androidx.navigation:navigation-compose:2.5.3'
+
+    // Add compose dependencies
     implementation 'androidx.activity:activity-compose:1.6.1'
     implementation "androidx.compose.ui:ui:$compose_ui_version"
     implementation "androidx.compose.ui:ui-tooling-preview:$compose_ui_version"
     implementation 'androidx.compose.material:material:1.3.1'
-    implementation 'androidx.core:core-ktx:+'
-    debugImplementation "androidx.compose.ui:ui-tooling:$compose_ui_version"
-    debugImplementation "androidx.compose.ui:ui-test-manifest:$compose_ui_version"
+    implementation 'com.google.android.gms:play-services-location:19.0.1'
 
     // Firebase
     implementation platform('com.google.firebase:firebase-bom:31.2.3')
 
-    // Authentication
-    implementation 'com.google.firebase:firebase-auth-ktx'
-    implementation 'com.google.firebase:firebase-firestore-ktx'
-    implementation 'com.firebaseui:firebase-ui-auth:7.2.0'
-
     // Tests
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
@@ -86,6 +82,8 @@ dependencies {
     androidTestImplementation 'androidx.test:rules:1.5.0'
     androidTestImplementation 'androidx.test.espresso:espresso-intents:3.5.1'
     androidTestImplementation "androidx.compose.ui:ui-test-junit4:$compose_ui_version"
+    debugImplementation "androidx.compose.ui:ui-tooling:$compose_ui_version"
+    debugImplementation "androidx.compose.ui:ui-test-manifest:$compose_ui_version"
     testImplementation "org.mockito.kotlin:mockito-kotlin:4.1.0"
     testImplementation "org.mockito:mockito-inline:4.1.0"
 }
@@ -110,7 +108,7 @@ task jacocoTestReport(type: JacocoReport, dependsOn: ['testDebugUnitTest', 'crea
             'android/**/*.*',
     ]
 
-    def debugTree = fileTree(dir: "$project.buildDir/intermediates/javac/debug/classes", excludes: fileFilter)
+    def debugTree = fileTree(dir: "$project.buildDir/tmp/kotlin-classes/debug", excludes: fileFilter)
     def mainSrc = "$project.projectDir/src/main/java"
 
     sourceDirectories.setFrom(files([mainSrc]))

app/src/main/java/com/github/geohunt/app/model/database/Database.kt

@@ -0,0 +1,34 @@
+package com.github.geohunt.app.model.database
+
+import android.app.Activity
+import android.graphics.Bitmap
+import com.github.geohunt.app.model.database.api.Challenge
+import com.github.geohunt.app.model.database.api.Location
+import java.util.concurrent.CompletableFuture
+
+
+interface Database {
+    fun createChallenge(bitmap: Bitmap, location: Location) : CompletableFuture<Challenge>
+
+    fun getChallengeById(cid: String) : CompletableFuture<Challenge>
+
+    fun getNearbyChallenge(location: Location) : CompletableFuture<List<Challenge>>
+
+    // fun getProfileById(uid: String) : CompletableFuture<Profile>
+
+}
+
+/**
+ * Utility class to create a new database handle (this is used for testing purpose
+ * to replace the database instance with a mock one using mockito)
+ */
+object DatabaseFactory  {
+
+    /**
+     * Create a new instance of a database
+     */
+    fun createDatabaseHandle(activity: Activity) : Database {
+        TODO("Not implemented")
+    }
+}
+

app/src/main/java/com/github/geohunt/app/model/database/api/Challenge.kt

@@ -0,0 +1,41 @@
+package com.github.geohunt.app.model.database.api
+
+import java.time.LocalDateTime
+
+interface Challenge
+{
+    /**
+     * The challenge's id.
+     */
+    val cid: String
+
+    /**
+     * The author's id
+     */
+    val uid: String
+
+    /**
+     * Publication date
+     */
+    val published: LocalDateTime
+
+    /**
+     * Expiration date
+     */
+    val expirationDate: LocalDateTime?
+
+    val thumbnail: PictureImage
+
+    /**
+     * The approximate location of the challenge
+     */
+    val coarseLocation: Location
+
+    /**
+     * The true position of the challenge
+     */
+    val correctLocation: Location
+
+    val claims: List<String>
+}
+

app/src/main/java/com/github/geohunt/app/model/database/api/Claim.kt

@@ -0,0 +1,12 @@
+package com.github.geohunt.app.model.database.api
+
+import java.time.LocalDateTime
+
+interface Claim {
+    val id: String
+    val cid: String
+    val uid: String
+
+    val time: LocalDateTime
+    val location: Location
+}

app/src/main/java/com/github/geohunt/app/model/database/api/Location.kt

@@ -0,0 +1,42 @@
+package com.github.geohunt.app.model.database.api
+
+import java.nio.ByteBuffer
+import java.util.zip.CRC32
+import kotlin.math.absoluteValue
+import kotlin.math.roundToLong
+
+data class Location(var latitude: Double,
+                    var longitude: Double) {
+    override fun toString(): String {
+        return "${getDMS(latitude, 'N', 'S')}, ${getDMS(longitude, 'E', 'W')}"
+    }
+
+    private fun getDMS(v: Double, positive: Char, negative: Char) : String {
+        var value = v.absoluteValue
+
+        val degree = value.toInt()
+
+        value = (value - degree) * 60.0
+        val minutes = value.toInt()
+
+        value = (value - minutes) * 60.0
+
+        return "$degree° $minutes' ${String.format("%.2f", value)}'' ${if (v > 0.0) positive else negative}"
+    }
+
+    companion object {
+        fun getCoarseHash(location: Location) : String {
+            val crc32 = CRC32()
+
+            // Define a ~11.1km lattice (at the equator)
+            var coarseLatitude = (location.latitude * 10.0).roundToLong()
+            var coarseLongitude = (location.longitude * 10.0).roundToLong()
+
+            val byteBuffer = ByteBuffer.allocate(2 * Long.SIZE_BYTES)
+                    .putLong(0, coarseLatitude)
+                    .putLong(Double.SIZE_BYTES, coarseLongitude)
+            crc32.update(byteBuffer)
+            return crc32.value.toString(36)
+        }
+    }
+}

app/src/main/java/com/github/geohunt/app/model/database/api/PictureImage.kt

@@ -0,0 +1,13 @@
+package com.github.geohunt.app.model.database.api
+
+import android.graphics.Bitmap
+import java.util.concurrent.CompletableFuture
+
+interface PictureImage {
+    val iid : String
+    val bitmap : Bitmap?
+
+    fun load() : CompletableFuture<Bitmap>
+
+    fun save() : CompletableFuture<Void>
+}

app/src/main/java/com/github/geohunt/app/model/database/api/User.kt

@@ -0,0 +1,16 @@
+package com.github.geohunt.app.model.database.api
+
+import com.github.geohunt.app.model.database.api.PictureImage
+
+interface User {
+    var displayName: String?
+
+    val uid: String
+
+    val profilePicture: PictureImage?
+
+    val challenges: List<String>
+    val hunts: List<String>
+
+    var score: Number
+}