misc: move Models & Helpers into Common & Avalonia projects

src/Ryujinx/Utilities/AppLibrary/ApplicationMetadata.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Text.Json.Serialization;
+
+namespace Ryujinx.Ava.Utilities.AppLibrary
+{
+    public class ApplicationMetadata
+    {
+        public string Title { get; set; }
+        public bool Favorite { get; set; }
+
+        [JsonPropertyName("timespan_played")]
+        public TimeSpan TimePlayed { get; set; } = TimeSpan.Zero;
+
+        [JsonPropertyName("last_played_utc")]
+        public DateTime? LastPlayed { get; set; } = null;
+
+        [JsonPropertyName("time_played")]
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+        public double TimePlayedOld { get; set; }
+
+        [JsonPropertyName("last_played")]
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+        public string LastPlayedOld { get; set; }
+
+        /// <summary>
+        /// Updates <see cref="LastPlayed"/>. Call this before launching a game.
+        /// </summary>
+        public void UpdatePreGame()
+        {
+            LastPlayed = DateTime.UtcNow;
+        }
+
+        /// <summary>
+        /// Updates <see cref="LastPlayed"/> and <see cref="TimePlayed"/>. Call this after a game ends.
+        /// </summary>
+        public void UpdatePostGame()
+        {
+            DateTime? prevLastPlayed = LastPlayed;
+            UpdatePreGame();
+
+            if (!prevLastPlayed.HasValue)
+            {
+                return;
+            }
+
+            TimeSpan diff = DateTime.UtcNow - prevLastPlayed.Value;
+            double newTotalSeconds = TimePlayed.Add(diff).TotalSeconds;
+            TimePlayed = TimeSpan.FromSeconds(Math.Round(newTotalSeconds, MidpointRounding.AwayFromZero));
+        }
+    }
+}