Add bitrate to Book

Source/DataLayer/EfClasses/AudioFormat.cs

@@ -0,0 +1,62 @@
+using System;
+
+namespace DataLayer
+{
+    internal enum AudioFormatEnum : long
+    {
+        //Defining the enum this way ensures that when comparing:
+        //LC_128_44100_stereo > LC_64_44100_stereo > LC_64_22050_stereo > LC_64_22050_stereo
+        //This matches how audible interprets these codecs when specifying quality using AudibleApi.DownloadQuality
+        //I've never seen mono formats.
+        Unknown = 0,
+        LC_32_22050_stereo = (32L << 18) | (22050 << 2) | 2,
+        LC_64_22050_stereo = (64L << 18) | (22050 << 2) | 2,
+        LC_64_44100_stereo = (64L << 18) | (44100 << 2) | 2,
+        LC_128_44100_stereo = (128L << 18) | (44100 << 2) | 2,
+    }
+
+    public class AudioFormat : IComparable<AudioFormat>, IComparable
+    {
+
+        internal int AudioFormatID { get; private set; }
+        public int Bitrate { get; private init; }
+        public int SampleRate { get; private init; }
+        public int Channels { get; private init; }
+        public bool IsValid => Bitrate != 0 && SampleRate != 0 && Channels != 0;
+
+        public static AudioFormat FromString(string formatStr)
+        {
+            if (Enum.TryParse(formatStr, ignoreCase: true, out AudioFormatEnum enumVal))
+                return FromEnum(enumVal);
+            return FromEnum(AudioFormatEnum.Unknown);
+        }
+
+        internal static AudioFormat FromEnum(AudioFormatEnum enumVal)
+        {
+            var val = (long)enumVal;
+
+            return new()
+            {
+                Bitrate = (int)(val >> 18),
+                SampleRate = (int)(val >> 2) & ushort.MaxValue,
+                Channels = (int)(val & 3)
+            };
+        }
+        internal AudioFormatEnum ToEnum()
+        {
+            var val = (AudioFormatEnum)(((long)Bitrate << 18) | ((long)SampleRate << 2) | (long)Channels);
+
+            return Enum.IsDefined(val) ?
+                val : AudioFormatEnum.Unknown;
+        }
+
+        public override string ToString()
+            => IsValid ?
+            $"{Bitrate} Kbps, {SampleRate / 1000d:F1} kHz, {(Channels == 2 ? "Stereo" : Channels)}" :
+            "Unknown";
+
+        public int CompareTo(AudioFormat other) => ToEnum().CompareTo(other.ToEnum());
+
+        public int CompareTo(object obj) => CompareTo(obj as AudioFormat);
+    }
+}

Source/DataLayer/EfClasses/Book.cs

@@ -25,6 +25,7 @@ namespace DataLayer
         Parent = 4,
     }
 
+
     public class Book
     {
         // implementation detail. set by db only. only used by data layer
@@ -38,6 +39,10 @@ namespace DataLayer
         public ContentType ContentType { get; private set; }
         public string Locale { get; private set; }
 
+        internal AudioFormatEnum _audioFormat;
+
+        public AudioFormat AudioFormat { get => AudioFormat.FromEnum(_audioFormat); set => _audioFormat = value.ToEnum(); }
+
         // mutable
         public string PictureId { get; set; }
         public string PictureLarge { get; set; }