implement database for feed persistence

app/src/main/java/cc/sovellus/vrcaa/helper/DatabaseHelper.kt

@@ -0,0 +1,35 @@
+package cc.sovellus.vrcaa.helper
+
+import android.database.sqlite.SQLiteDatabase
+import android.database.sqlite.SQLiteOpenHelper
+import cc.sovellus.vrcaa.App
+
+class DatabaseHelper : SQLiteOpenHelper(App.getContext(),
+    Constants.DATABASE_NAME, null,
+    Constants.DATABASE_VERSION
+) {
+    override fun onCreate(database: SQLiteDatabase) {
+        database.execSQL(Queries.SQL_CREATE_FEED_TABLE)
+    }
+
+    override fun onUpgrade(database: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
+        onUpgrade(database, oldVersion, newVersion)
+    }
+
+    override fun onDowngrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
+        onDowngrade(db, oldVersion, newVersion)
+    }
+
+    object Constants {
+        const val DATABASE_NAME = "vrcaa.db"
+        const val DATABASE_VERSION = 1
+    }
+
+    object Queries {
+        const val SQL_CREATE_FEED_TABLE = "CREATE TABLE feed(type INTEGER, feedId TEXT, friendId TEXT, friendName TEXT, friendPictureUrl TEXT, friendStatus TEXT, travelDestination TEXT, feedTimestamp BIGINT)"
+    }
+
+    object Tables {
+        const val SQL_TABLE_FEED = "feed"
+    }
+}

app/src/main/java/cc/sovellus/vrcaa/helper/StatusHelper.kt

@@ -29,6 +29,10 @@ object StatusHelper {
                 else -> "Offline"
             }
         }
+
+        companion object {
+            fun fromInt(value: Int) = Status.entries.first { it.ordinal == value }
+        }
     }
 
     fun getStatusFromString(status: String?): Status {

app/src/main/java/cc/sovellus/vrcaa/manager/DatabaseManager.kt

@@ -0,0 +1,60 @@
+package cc.sovellus.vrcaa.manager
+
+import android.content.ContentValues
+import cc.sovellus.vrcaa.helper.DatabaseHelper
+import cc.sovellus.vrcaa.helper.StatusHelper
+import java.time.LocalDateTime
+import java.time.ZoneOffset
+import java.util.UUID
+
+object DatabaseManager {
+    private val dbHelper = DatabaseHelper()
+
+    fun writeFeed(feed: FeedManager.Feed) {
+        val values = ContentValues().apply {
+            put("type", feed.type.ordinal)
+            put("feedId", feed.feedId.toString())
+            put("friendId", feed.friendId)
+            put("friendName", feed.friendName)
+            put("friendPictureUrl", feed.friendPictureUrl)
+            put("friendStatus", feed.friendStatus.ordinal)
+            put("travelDestination", feed.travelDestination)
+            put("feedTimestamp", feed.feedTimestamp.toEpochSecond(ZoneOffset.UTC))
+        }
+
+        dbHelper.writableDatabase.insert(DatabaseHelper.Tables.SQL_TABLE_FEED, null, values)
+    }
+
+    fun readFeeds(): MutableList<FeedManager.Feed> {
+        val cursor = dbHelper.readableDatabase.query(
+            DatabaseHelper.Tables.SQL_TABLE_FEED,
+            arrayOf("type", "feedId", "friendId", "friendName", "friendPictureUrl", "friendStatus", "travelDestination", "feedTimestamp"),
+            null,
+            null,
+            null,
+            null,
+            null
+        )
+
+        val feeds = mutableListOf<FeedManager.Feed>()
+
+        with(cursor) {
+            while (moveToNext()) {
+                val feed = FeedManager.Feed(
+                    type = FeedManager.FeedType.fromInt(getInt(getColumnIndexOrThrow("type"))),
+                    feedId = UUID.fromString(getString(getColumnIndexOrThrow("feedId"))),
+                    friendId = getString(getColumnIndexOrThrow("friendId")),
+                    friendName = getString(getColumnIndexOrThrow("friendName")),
+                    friendPictureUrl = getString(getColumnIndexOrThrow("friendPictureUrl")),
+                    friendStatus = StatusHelper.Status.fromInt(getInt(getColumnIndexOrThrow("friendStatus"))),
+                    travelDestination = getString(getColumnIndexOrThrow("travelDestination")),
+                    feedTimestamp = LocalDateTime.ofEpochSecond(getLong(getColumnIndexOrThrow("feedTimestamp")), 0, ZoneOffset.UTC)
+                )
+                feeds.add(feed)
+            }
+        }
+
+        cursor.close()
+        return feeds
+    }
+}

app/src/main/java/cc/sovellus/vrcaa/manager/FeedManager.kt

@@ -10,14 +10,22 @@ object FeedManager {
     private var feedListener: FeedListener? = null
     private var feedList: MutableList<Feed> = ArrayList()
 
+    init {
+        feedList = DatabaseManager.readFeeds()
+    }
+
     enum class FeedType {
         FRIEND_FEED_ONLINE,
         FRIEND_FEED_OFFLINE,
         FRIEND_FEED_LOCATION,
         FRIEND_FEED_STATUS,
         FRIEND_FEED_FRIEND_REQUEST,
         FRIEND_FEED_REMOVED,
-        FRIEND_FEED_ADDED
+        FRIEND_FEED_ADDED;
+
+        companion object {
+            fun fromInt(value: Int) = entries.first { it.ordinal == value }
+        }
     }
 
     data class Feed(
@@ -37,6 +45,7 @@ object FeedManager {
 
     fun addFeed(feed: Feed) {
         feedList.add(feed)
+        DatabaseManager.writeFeed(feed)
         feedListener?.onReceiveUpdate(feedList)
     }