Initial support code for beatmap loading

osu.Desktop/Beatmaps/IO/LegacyFilesystemReader.cs

@@ -0,0 +1,51 @@
+using System;
+using System.IO;
+using System.Collections.Generic;
+using System.Linq;
+using osu.Game.Beatmaps.Formats;
+using osu.Game.Beatmaps.IO;
+using osu.Game.Beatmaps;
+
+namespace osu.Desktop.Beatmaps.IO
+{
+    /// <summary>
+    /// Reads an extracted legacy beatmap from disk.
+    /// </summary>
+    public class LegacyFilesystemReader : ArchiveReader
+    {
+        static LegacyFilesystemReader()
+        {
+            AddReader<LegacyFilesystemReader>((storage, path) => Directory.Exists(path));
+        }
+    
+        private string BasePath { get; set; }
+        private Beatmap FirstMap { get; set; }
+    
+        public LegacyFilesystemReader(string path)
+        {
+            BasePath = path;
+            var maps = ReadBeatmaps();
+            if (maps.Length == 0)
+                throw new FileNotFoundException("This directory contains no beatmaps");
+            using (var stream = new StreamReader(ReadFile(maps[0])))
+            {
+                var decoder = BeatmapDecoder.GetDecoder(stream);
+                FirstMap = decoder.Decode(stream);
+            }
+        }
+
+        public override string[] ReadBeatmaps()
+        {
+            return Directory.GetFiles(BasePath, "*.osu").Select(f => Path.GetFileName(f)).ToArray();
+        }
+
+        public override Stream ReadFile(string name)
+        {
+            return File.OpenRead(Path.Combine(BasePath, name));
+        }
+
+        public override Metadata ReadMetadata()
+        {
+            return FirstMap.Metadata;
+        }
    }
+}

osu.Desktop/osu.Desktop.csproj

@@ -135,8 +135,13 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Program.cs" />
+    <Compile Include="Beatmaps\IO\LegacyFilesystemReader.cs" />
   </ItemGroup>
   <ItemGroup />
+  <ItemGroup>
+    <Folder Include="Beatmaps\" />
+    <Folder Include="Beatmaps\IO\" />
+  </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
        Other similar extension points exist, see Microsoft.Common.targets.

osu.Game/Beatmaps/Beatmap.cs

@@ -10,11 +10,12 @@ namespace osu.Game.Beatmaps
 {
     public class Beatmap
     {
-        public List<HitObject> HitObjects;
+        public int BeatmapID;
         
+        public List<HitObject> HitObjects;
         public List<ControlPoint> ControlPoints;
         
-        public string Difficulty;
+        public string Version;
-        public User Creator;
+        public Metadata Metadata;
     }
 }

osu.Game/Beatmaps/BeatmapSet.cs

@@ -11,6 +11,8 @@ namespace osu.Game.Beatmaps
     /// </summary>
     public class BeatmapSet
     {
+        public int BeatmapSetID;
+        
         public List<Beatmap> Beatmaps { get; protected set; }
 
         public Metadata Metadata;

osu.Game/Beatmaps/Formats/BeatmapDecoder.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+namespace osu.Game.Beatmaps.Formats
+{
+    public abstract class BeatmapDecoder
+    {
+        private static Dictionary<string, Type> Decoders { get; set; } = new Dictionary<string, Type>();
+    
+        public static BeatmapDecoder GetDecoder(TextReader stream)
+        {
+            var line = stream.ReadLine().Trim();
+            if (!Decoders.ContainsKey(line))
+                throw new IOException("Unknown file format");
+            return (BeatmapDecoder)Activator.CreateInstance(Decoders[line]);
+        }
+
        protected static void AddDecoder<T>(string magic) where T : BeatmapDecoder
+        {
+            Decoders[magic] = typeof(T);
+        }
+    
+        public abstract Beatmap Decode(TextReader stream);
+    }
+}

osu.Game/Beatmaps/Formats/OsuLegacyDecoder.cs

@@ -0,0 +1,34 @@
+using System;
+using System.IO;
+
+namespace osu.Game.Beatmaps.Formats
+{
+    public class OsuLegacyDecoder : BeatmapDecoder
+    {
+        static OsuLegacyDecoder()
+        {
+            AddDecoder<OsuLegacyDecoder>("osu file format v14");
+            AddDecoder<OsuLegacyDecoder>("osu file format v13");
+            AddDecoder<OsuLegacyDecoder>("osu file format v12");
+            AddDecoder<OsuLegacyDecoder>("osu file format v11");
+            AddDecoder<OsuLegacyDecoder>("osu file format v10");
+            // TODO: Not sure how far back to go, or differences between versions
+        }
+
        private enum Section
+        {
+            General,
+            Editor,
+            Metadata,
+            Difficulty,
+            Events,
+            TimingPoints,
+            Colours,
+            HitObjects,
+        }
+
+        public override Beatmap Decode(TextReader stream)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

osu.Game/Beatmaps/IO/ArchiveReader.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using osu.Framework.OS;
+
+namespace osu.Game.Beatmaps.IO
+{
+    public abstract class ArchiveReader
+    {
+        private class Reader
+        {
+            public Func<BasicStorage, string, bool> Test { get; set; }
+            public Type Type { get; set; }
+        }
+    
+        private static List<Reader> Readers { get; set; } = new List<Reader>();
+    
+        public static ArchiveReader GetReader(BasicStorage storage, string path)
+        {
+            foreach (var reader in Readers)
+            {
+                if (reader.Test(storage, path))
+                    return (ArchiveReader)Activator.CreateInstance(reader.Type);
+            }
+            throw new IOException("Unknown file format");
+        }
+        
+        protected static void AddReader<T>(Func<BasicStorage, string, bool> test) where T : ArchiveReader
+        {
+            Readers.Add(new Reader { Test = test, Type = typeof(T) });
+        }
+    
+        /// <summary>
+        /// Reads the beatmap metadata from this archive.
+        /// </summary>
+        public abstract Metadata ReadMetadata();
+        /// <summary>
+        /// Gets a list of beatmap file names.
+        /// </summary>
+        public abstract string[] ReadBeatmaps();
+        /// <summary>
+        /// Opens a stream for reading a specific file from this archive.
+        /// </summary>
+        public abstract Stream ReadFile(string name);
+    }
+}

osu.Game/Beatmaps/IO/OszArchiveReader.cs

@@ -0,0 +1,42 @@
+using System;
+using System.IO;
+
+namespace osu.Game.Beatmaps.IO
+{
+    public class OszArchiveReader : ArchiveReader
+    {
+        static OszArchiveReader()
+        {
+            AddReader<OszArchiveReader>((storage, path) =>
+            {
+                using (var stream = storage.GetStream(path))
+                {
+                    // TODO: detect if osz
+                    return false;
+                }
+            });
+        }
+    
+        private Stream Archive { get; set; }
+    
+        public OszArchiveReader(Stream archive)
+        {
+            Archive = archive;
+        }
+
+        public override string[] ReadBeatmaps()
+        {
+            throw new NotImplementedException();
+        }
+
+        public override Stream ReadFile(string name)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override Metadata ReadMetadata()
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

osu.Game/Beatmaps/Metadata.cs

@@ -1,11 +1,23 @@
 //Copyright (c) 2007-2016 ppy Pty Ltd <contact@ppy.sh>.
 //Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using osu.Game.GameModes.Play;
+
 namespace osu.Game.Beatmaps
 {
     public class Metadata
     {
-        public string Artist;
+        public int BeatmapSetID { get; set; }
-        public string Title;
+        public string Title { get; set; }
+        public string TitleUnicode { get; set; }
+        public string Artist { get; set; }
+        public string ArtistUnicode { get; set; }
+        public string Author { get; set; }
+        public string Source { get; set; }
+        public string Tags { get; set; }
+        public PlayMode Mode { get; set; }
+        public int PreviewTime { get; set; }
+        public string AudioFile { get; set; }
+        public string BackgroundFile { get; set; }
     }
 }

osu.Game/Database/BeatmapDatabase.cs

@@ -1,5 +1,9 @@
 using System;
+using System.Collections.Generic;
+using System.IO;
 using osu.Framework.OS;
+using osu.Game.Beatmaps.Formats;
+using osu.Game.Beatmaps.IO;
 using SQLite;
 
 namespace osu.Game.Database
@@ -18,5 +22,45 @@ namespace osu.Game.Database
                 Connection.CreateTable<Beatmap>();
             }
         }
+
        public void AddBeatmap(ArchiveReader input)
+        {
+            var metadata = input.ReadMetadata();
+            if (Connection.Table<BeatmapSet>().Count(b => b.BeatmapSetID == metadata.BeatmapSetID) != 0)
+                return;
+            string[] mapNames = input.ReadBeatmaps();
+            var beatmapSet = new BeatmapSet { BeatmapSetID = metadata.BeatmapSetID };
+            var beatmapMetadata = new BeatmapMetadata
+            {
+                Title = metadata.Title,
+                TitleUnicode = metadata.TitleUnicode,
+                Artist = metadata.Artist,
+                ArtistUnicode = metadata.ArtistUnicode,
+                Author = metadata.Author,
+                Source = metadata.Source,
+                Tags = metadata.Tags,
+                Mode = metadata.Mode,
+                PreviewTime = metadata.PreviewTime,
+                AudioFile = metadata.AudioFile,
+                BackgroundFile = metadata.BackgroundFile,
+            };
+            var maps = new List<Beatmap>();
+            foreach (var name in mapNames)
+            {
+                using (var stream = new StreamReader(input.ReadFile(name)))
+                {
+                    var decoder = BeatmapDecoder.GetDecoder(stream);
+                    var beatmap = decoder.Decode(stream);
+                    maps.Add(new Beatmap
+                    {
+                        ID = beatmap.BeatmapID,
+                        BeatmapSetID = metadata.BeatmapSetID,
+                        // TODO: Import more things
+                    });
+                }
+            }
+            beatmapSet.BeatmapMetadataID = Connection.Insert(beatmapMetadata);
+            Connection.Insert(beatmapSet);
+            Connection.InsertAll(maps);
+        }
     }
 }

osu.Game/osu.Game.csproj

@@ -149,6 +149,10 @@
     <Compile Include="Database\BeatmapSet.cs" />
     <Compile Include="Database\BeatmapMetadata.cs" />
     <Compile Include="Database\Beatmap.cs" />
+    <Compile Include="Beatmaps\IO\ArchiveReader.cs" />
+    <Compile Include="Beatmaps\Formats\BeatmapDecoder.cs" />
+    <Compile Include="Beatmaps\Formats\OsuLegacyDecoder.cs" />
+    <Compile Include="Beatmaps\IO\OszArchiveReader.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\osu-framework\osu.Framework\osu.Framework.csproj">
@@ -169,6 +173,8 @@
   <ItemGroup />
   <ItemGroup>
     <Folder Include="Database\" />
+    <Folder Include="Beatmaps\Formats\" />
+    <Folder Include="Beatmaps\IO\" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it.