backend for watch history

app/src/main/java/com/github/libretube/fragments/PlayerFragment.kt

@@ -455,6 +455,7 @@ class PlayerFragment : Fragment() {
                     if (!relatedStreamsEnabled) toggleComments()
                     // prepare for autoplay
                     initAutoPlay()
+                    PreferenceHelper.addToWatchHistory(requireContext(), videoId!!, response)
                 }
             }
         }

app/src/main/java/com/github/libretube/obj/WatchHistoryItem.kt

@@ -0,0 +1,11 @@
+package com.github.libretube.obj
+
+data class WatchHistoryItem(
+    val videoId: String?,
+    val title: String?,
+    val uploadDate: String?,
+    val uploader: String?,
+    val uploaderUrl: String?,
+    val thumbnailUrl: String?,
+    val duration: Int?
+)

app/src/main/java/com/github/libretube/util/PreferenceHelper.kt

@@ -2,13 +2,18 @@ package com.github.libretube.util
 
 import android.content.Context
 import android.content.SharedPreferences
+import android.util.Log
 import androidx.preference.PreferenceManager
 import com.github.libretube.obj.CustomInstance
+import com.github.libretube.obj.Streams
+import com.github.libretube.obj.WatchHistoryItem
 import com.google.common.reflect.TypeToken
 import com.google.gson.Gson
 import java.lang.reflect.Type
 
 object PreferenceHelper {
+    private val TAG = "PreferenceHelper"
+
     fun setString(context: Context, key: String?, value: String?) {
         val editor = getDefaultSharedPreferencesEditor(context)
         editor.putString(key, value)
@@ -122,6 +127,39 @@ object PreferenceHelper {
         editor.putStringSet("search_history", set).apply()
     }
 
+    fun addToWatchHistory(context: Context, videoId: String, streams: Streams) {
+        val editor = getDefaultSharedPreferencesEditor(context)
+        val gson = Gson()
+
+        val watchHistoryItem = WatchHistoryItem(
+            videoId,
+            streams.title,
+            streams.uploadDate,
+            streams.uploader,
+            streams.uploaderUrl?.replace("/channel/", ""),
+            streams.thumbnailUrl,
+            streams.duration
+        )
+
+        val watchHistory = getWatchHistory(context)
+        watchHistory += watchHistoryItem
+
+        val json = gson.toJson(watchHistory)
+        editor.putString("watch_history", json).apply()
+    }
+
+    fun getWatchHistory(context: Context): ArrayList<WatchHistoryItem> {
+        val settings = getDefaultSharedPreferences(context)
+        val gson = Gson()
+        val json: String = settings.getString("watch_history", "")!!
+        val type: Type = object : TypeToken<List<WatchHistoryItem?>?>() {}.type
+        return try {
+            gson.fromJson(json, type)
+        } catch (e: Exception) {
+            arrayListOf()
+        }
+    }
+
     private fun getDefaultSharedPreferences(context: Context): SharedPreferences {
         return PreferenceManager.getDefaultSharedPreferences(context)
     }