issue-8: adding samreader

.vscode/launch.json

@@ -12,12 +12,23 @@
       // If you have changed target frameworks, make sure to update the program path.
       "program": "${workspaceFolder}/bin/Debug/net6.0/Ovation.FasterQC.Net.dll",
       "args": [
-        "-p", "-i", "/tmp/zr6254_1/zr6254_1.sorted.bam", "-o", "/tmp/bob.json", "-m", "BasicStatistics", "NCountsAtPosition"
+        "-v",
+        "-d",
+        "-f",
+        "sam",
+        "-i",
+        "./tmp/in3257_2_S1.sorted.sam",
+        "-o",
+        "./tmp/bob.json",
+        "-m",
+        "BasicStatistics",
+        "NCountsAtPosition"
       ],
       "cwd": "${workspaceFolder}",
       // For more information about the 'console' field, see https://aka.ms/VSCode-CS-LaunchJson-Console
       "console": "internalConsole",
-      "stopAtEntry": false
+      "stopAtEntry": false,
+      "requireExactSource": false
     },
     {
       "name": ".NET Core Attach",

Models/ReadFlag.cs

@@ -0,0 +1,57 @@
+using System;
+
+namespace Ovation.FasterQC.Net
+{
+    [Flags]
+    public enum ReadFlag : ushort
+    {
+        /// <summary>
+        /// template having multiple templates in sequencing (read is paired)
+        /// </summary>
+        Paired = 1,
+
+        /// <summary>
+        /// </summary>
+        Aligned = 2,
+
+        /// <summary>
+        /// </summary>
+        SegmentUnmapped = 4,
+
+        /// <summary>
+        /// </summary>
+        NextSegmentUnmapped = 8,
+
+        /// <summary>
+        /// </summary>
+        ReverseComplemented = 16,
+
+        /// <summary>
+        /// </summary>
+        NextSegmentReverseComplemented = 32,
+
+        /// <summary>
+        /// </summary>
+        FirstSegment = 64,
+
+        /// <summary>
+        /// </summary>
+        LastSegment = 128,
+
+        /// <summary>
+        /// </summary>
+        NotPrimaryAlignment = 256,
+
+        /// <summary>
+        /// </summary>
+        FailedQualityChecks = 512,
+
+        /// <summary>
+        /// </summary>
+        OpticalDuplicate = 1024,
+
+        /// <summary>
+        /// </summary>
+        SupplementaryAlignment = 2048
+    }
+}

Models/Sequence.cs

@@ -5,6 +5,8 @@ namespace Ovation.FasterQC.Net
 {
     public class Sequence
     {
+        public ReadFlag ReadFlag { get; }
+
         public byte[] Identifier { get; }
 
         public byte[] Read { get; }
@@ -21,8 +23,9 @@ public Sequence(byte[] lines, int[] endOfLines)
             Quality = new ReadOnlyMemory<byte>(lines, endOfLines[2], endOfLines[3] - endOfLines[2]).ToArray();
         }
 
-        public Sequence(byte[] identifer, byte[] read, byte[] blank, byte[] quality)
+        public Sequence(ushort readFlag, byte[] identifer, byte[] read, byte[] blank, byte[] quality)
         {
+            ReadFlag = (ReadFlag)readFlag;
             Identifier = new ReadOnlyMemory<byte>(identifer).ToArray();
             Read = new ReadOnlyMemory<byte>(read).ToArray();
             Blank = new ReadOnlyMemory<byte>(blank).ToArray();
@@ -31,6 +34,7 @@ public Sequence(byte[] identifer, byte[] read, byte[] blank, byte[] quality)
 
         public Sequence(BamAlignment bamAlignment)
         {
+            ReadFlag = (ReadFlag)bamAlignment.flag;
             Identifier = new ReadOnlyMemory<byte>(bamAlignment.read_name).ToArray();
             Read = new ReadOnlyMemory<byte>(bamAlignment.seq).ToArray();
             Quality = new ReadOnlyMemory<byte>(bamAlignment.qual).ToArray();
@@ -41,6 +45,7 @@ public override string ToString()
         {
             var sb = new StringBuilder("sequence: \n");
 
+            sb.AppendLine(ReadFlag.ToString());
             sb.AppendLine(new string(Encoding.ASCII.GetChars(Identifier)));
             sb.AppendLine(new string(Encoding.ASCII.GetChars(Read)));
             sb.AppendLine(new string(Encoding.ASCII.GetChars(Blank)));

Program.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Text.Json;
 using CommandLine;
 using Ovation.FasterQC.Net.Modules;
@@ -23,13 +24,20 @@ class Program
 
         static void Main(string[] args)
         {
-            Parser.Default.ParseArguments<CliOptions>(args)
-                .WithParsed(o =>
+            var parser = new Parser(config =>
                 {
-                    o.Validate();
-                    Settings = o;
-                    new Program().Run();
-                });
+                    config.AutoHelp = true;
+                    config.AutoVersion = true;
+                    config.CaseInsensitiveEnumValues = true;
+                }
+            );
+
+            parser.ParseArguments<CliOptions>(args)
+                .WithParsed(o =>
+                    {
+                        Settings = o;
+                        new Program().Run();
+                    });
         }
 
         private void Run()

Readers/FastqLineReader.cs

@@ -66,7 +66,7 @@ public bool ReadSequence(out Sequence? sequence)
                 var blank = Encoding.ASCII.GetBytes(streamReader.ReadLine() ?? "");
                 var quality = Encoding.ASCII.GetBytes(streamReader.ReadLine() ?? "");
 
-                sequence = new Sequence(identifier, read, blank, quality);
+                sequence = new Sequence(0, identifier, read, blank, quality);
                 sequencesRead++;
                 return true;
             }

Readers/ReaderFactory.cs

@@ -7,10 +7,19 @@ public static class ReaderFactory
     {
         public static ISequenceReader Create(CliOptions settings)
         {
-            return settings switch
+            return settings.Format switch
             {
-                { Fastq: true } => new FastqLineReader(settings.InputFilename, settings.Zipped),
-                { Bam: true } => new BamReader(settings.InputFilename),
+                ReaderType.Fastq => new FastqReader(settings.InputFilename, false),
+                ReaderType.FastqGz => new FastqReader(settings.InputFilename, true),
+
+                ReaderType.FastqLine => new FastqLineReader(settings.InputFilename, false),
+                ReaderType.FastqLineGz => new FastqLineReader(settings.InputFilename, true),
+
+                ReaderType.Sam => new SamReader(settings.InputFilename, false),
+                ReaderType.SamGz => new SamReader(settings.InputFilename, true),
+
+                ReaderType.Bam => new BamReader(settings.InputFilename),
+
                 _ => throw new InvalidOperationException($"could not determine file type of {settings.InputFilename}")
             };
         }

Readers/ReaderType.cs

@@ -0,0 +1,19 @@
+namespace Ovation.FasterQC.Net
+{
+    public enum ReaderType
+    {
+        Fastq,
+
+        FastqGz,
+
+        FastqLine,
+
+        FastqLineGz,
+
+        Sam,
+
+        SamGz,
+
+        Bam
+    }
+}

Readers/SamReader.cs

@@ -0,0 +1,136 @@
+using System;
+using System.Globalization;
+using System.IO;
+using System.IO.Compression;
+using System.Text;
+using static Ovation.FasterQC.Net.Utils.CliOptions;
+
+namespace Ovation.FasterQC.Net
+{
+    public class SamReader : ISequenceReader
+    {
+        private readonly FileStream inputStream;
+
+        private readonly GZipStream? gzipStream;
+
+        private readonly BufferedStream bufferedStream;
+
+        private readonly StreamReader streamReader;
+
+        private bool disposedValue;
+
+        private int sequencesRead = 0;
+
+        public int SequencesRead => sequencesRead;
+
+        public SamReader(string sam, bool gzipped = true)
+        {
+            var bufferSize = 128 * 1024;
+
+            var fileStreamOptions = new FileStreamOptions()
+            {
+                Mode = FileMode.Open,
+                BufferSize = bufferSize,
+            };
+
+            if (gzipped == true)
+            {
+                inputStream = File.Open(sam, fileStreamOptions);
+                gzipStream = new GZipStream(inputStream, CompressionMode.Decompress);
+                bufferedStream = new BufferedStream(gzipStream, bufferSize);
+                streamReader = new StreamReader(bufferedStream, Encoding.ASCII, false, bufferSize);
+            }
+            else
+            {
+                inputStream = File.Open(sam, fileStreamOptions);
+                bufferedStream = new BufferedStream(inputStream, bufferSize);
+                streamReader = new StreamReader(bufferedStream, Encoding.ASCII, false, bufferSize);
+            }
+
+            ConsumeHeader();
+        }
+
+        private void ConsumeHeader()
+        {
+            try
+            {
+                while (streamReader.Peek() == '@')
+                {
+                    var header = streamReader.ReadLine();
+                    On(Settings.Debug, () => Console.Error.WriteLine(header));
+                }
+            }
+            catch (EndOfStreamException)
+            {
+                // swallow this, we've run out of file and a call
+                // into ReadSequence will handle the EOF case
+            }
+        }
+
+        public bool ReadSequence(out Sequence? sequence)
+        {
+            try
+            {
+                if (streamReader.EndOfStream == true)
+                {
+                    goto endofstream;
+                }
+
+                var entry = streamReader.ReadLine();
+                if (entry == null)
+                {
+                    goto endofstream;
+                }
+
+                // this is clearly a bad approach, we're going to be allocating a
+                // ton of small strings here, probably better to read the line,
+                // find the tabs ourselves, then pull the bytes out of the components
+                var parts = entry.Split('\t', StringSplitOptions.TrimEntries);
+
+                var identifier = Encoding.ASCII.GetBytes(parts[0]);
+                var flag = ushort.Parse(parts[1], CultureInfo.InvariantCulture);
+                var read = Encoding.ASCII.GetBytes(parts[9]);
+                var blank = Encoding.ASCII.GetBytes("");
+                var quality = Encoding.ASCII.GetBytes(parts[10]);
+
+                sequence = new Sequence(flag, identifier, read, blank, quality);
+                sequencesRead++;
+                return true;
+            }
+            catch (EndOfStreamException)
+            {
+                goto endofstream;
+            }
+
+        endofstream:
+            On(Settings.Verbose, () => Console.Error.WriteLine("End of stream"));
+            sequence = null;
+            return false;
+        }
+
+        public double ApproximateCompletion =>
+            100.0 * inputStream.Position / inputStream.Length;
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!disposedValue)
+            {
+                if (disposing)
+                {
+                    streamReader?.Dispose();
+                    bufferedStream?.Dispose();
+                    gzipStream?.Dispose();
+                    inputStream?.Dispose();
+                }
+
+                disposedValue = true;
+            }
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+    }
+}