Proof of concept

build.gradle

@@ -59,6 +59,7 @@ plugins {
     id "com.ncorti.ktfmt.gradle" version "0.11.0"
     id "com.google.dagger.hilt.android" version "$hiltVersion" apply false
     id "io.gitlab.arturbosch.detekt" version "1.23.0"
+    id "com.google.protobuf" version "0.9.4" apply false
 }
 
 allprojects {

ground/build.gradle

@@ -21,7 +21,7 @@ apply plugin: 'kotlinx-serialization'
 apply plugin: 'com.google.dagger.hilt.android'
 apply plugin: 'com.google.firebase.firebase-perf'
 apply plugin: 'com.google.firebase.crashlytics'
-
+apply plugin: 'com.google.protobuf'
 apply from: '../config/checkstyle/checkstyle.gradle'
 apply from: '../config/lint/lint.gradle'
 apply from: '../config/jacoco/jacoco.gradle'
@@ -321,6 +321,11 @@ dependencies {
     stagingImplementation "androidx.fragment:fragment-testing:$fragmentVersion"
 
     implementation "com.google.guava:guava:31.1-android"
+
+    api("com.google.protobuf:protobuf-kotlin-lite:3.25.0")
+    // TODO: Move protos into shared module and set correct path here.
+//    testProtobuf(files("lib/protos-test.tar.gz"))
+//    implementation("com.google.protobuf:protobuf-java-util:3.25.0")
 }
 
 // Allow references to generated code.
@@ -337,3 +342,28 @@ apply plugin: 'com.google.gms.google-services'
 kotlin {
     jvmToolchain rootProject.jvmToolchainVersion
 }
+
+protobuf {
+    protoc {
+        artifact = "com.google.protobuf:protoc:3.25.0"
+    }
+    plugins {
+        create("java") {
+            artifact = "io.grpc:protoc-gen-grpc-java:1.59.0"
+        }
+    }
+    generateProtoTasks {
+        all().each {
+            it.plugins {
+                create("java") {
+                    option("lite")
+                }
+            }
+            it.builtins {
+                create("kotlin") {
+                    option("lite")
+                }
+            }
+        }
+    }
+}

ground/src/main/java/com/google/android/ground/persistence/remote/firebase/FirestoreProtoExt.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * 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
+ *
+ *     https://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.google.android.ground.persistence.remote.firebase
+
+import com.google.firebase.firestore.DocumentSnapshot
+import com.google.protobuf.GeneratedMessageLite
+import timber.log.Timber
+
+fun <T : GeneratedMessageLite<*, *>> DocumentSnapshot.copyInto(proto: T?): T? {
+  val o = proto ?: return null
+  val map = data
+  // TODO: Replace `id` with `uuid`?
+  map?.set("id", id)
+  map?.forEach { (key, value) ->
+    try {
+      val field = o::class.java.getDeclaredField(key + "_")
+      field.isAccessible = true
+      // TODO: Handle maps, arrays, GeoPoint, and other types.
+      field.set(proto, value)
+      field.isAccessible = false
+    } catch (e: NoSuchFieldException) {
+      Timber.v("Skipping unknown field: $key")
+    } catch (e: IllegalArgumentException) {
+      // TODO: Add expected and actual
+      Timber.v("Skipping field with wrong type: $key")
+    }
+  }
+  return proto
+}

ground/src/main/java/com/google/android/ground/persistence/remote/firebase/schema/SurveyConverter.kt

@@ -20,16 +20,22 @@ import com.google.android.ground.model.Survey
 import com.google.android.ground.model.imagery.TileSource
 import com.google.android.ground.model.job.Job
 import com.google.android.ground.persistence.remote.DataStoreException
+import com.google.android.ground.persistence.remote.firebase.proto.copyInto
 import com.google.android.ground.persistence.remote.firebase.schema.JobConverter.toJob
+import com.google.android.ground.proto.survey
 import com.google.firebase.firestore.DocumentSnapshot
 import kotlinx.collections.immutable.toPersistentList
 import kotlinx.collections.immutable.toPersistentMap
+import timber.log.Timber
 
 /** Converts between Firestore documents and [Survey] instances. */
 internal object SurveyConverter {
 
   @Throws(DataStoreException::class)
   fun toSurvey(doc: DocumentSnapshot): Survey {
+
+    Timber.e("!!! Survey: " + doc.copyInto(survey {}))
+
     if (!doc.exists()) throw DataStoreException("Missing survey")
 
     val pd =

ground/src/main/proto/com/google/ground/survey.proto

@@ -0,0 +1,13 @@
+syntax = "proto3";
+
+option java_package = "com.google.android.ground.proto";
+option java_multiple_files = true;
+
+message Survey {
+    string id = 1;
+    string title = 2;
+    string description = 3;
+//    val jobMap: Map<String, Job>,
+//    val tileSources: List<TileSource> = listOf(),
+//    val acl: Map<String, String> = mapOf()
+}