Move source code into "Source" folder

Source/AaxDecrypter/AaxcDownloadMultiConverter.cs

@@ -0,0 +1,141 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using AAXClean;
+using AAXClean.Codecs;
+using Dinah.Core.StepRunner;
+using FileManager;
+
+namespace AaxDecrypter
+{
+	public class AaxcDownloadMultiConverter : AaxcDownloadConvertBase
+	{
+		protected override StepSequence Steps { get; }
+
+        private Func<MultiConvertFileProperties, string> multipartFileNameCallback { get; }
+
+        private static TimeSpan minChapterLength { get; } = TimeSpan.FromSeconds(3);
+		private List<string> multiPartFilePaths { get; } = new List<string>();
+
+        public AaxcDownloadMultiConverter(string outFileName, string cacheDirectory, DownloadOptions dlLic,
+            Func<MultiConvertFileProperties, string> multipartFileNameCallback = null)
+			: base(outFileName, cacheDirectory, dlLic)
+        {
+            Steps = new StepSequence
+            {
+                Name = "Download and Convert Aaxc To " + DownloadOptions.OutputFormat,
+
+                ["Step 1: Get Aaxc Metadata"] = Step_GetMetadata,
+                ["Step 2: Download Decrypted Audiobook"] = Step_DownloadAudiobookAsMultipleFilesPerChapter,
+                ["Step 3: Cleanup"] = Step_Cleanup,
+            };
+            this.multipartFileNameCallback = multipartFileNameCallback ?? MultiConvertFileProperties.DefaultMultipartFilename;
+        }
+
+        /*
+https://github.com/rmcrackan/Libation/pull/127#issuecomment-939088489
+
+If the chapter truly is empty, that is, 0 audio frames in length, then yes it is ignored.
+If the chapter is shorter than 3 seconds long but still has some audio frames, those frames are combined with the following chapter and not split into a new file.
+
+I also implemented file naming by chapter title. When 2 or more consecutive chapters are combined, the first of the combined chapter's title is used in the file name. For example, given an audiobook with the following chapters:
+
+00:00:00 - 00:00:02 | Part 1
+00:00:02 - 00:35:00 | Chapter 1
+00:35:02 - 01:02:00 | Chapter 2
+01:02:00 - 01:02:02 | Part 2
+01:02:02 - 01:41:00 | Chapter 3
+01:41:00 - 02:05:00 | Chapter 4
+
+The book will be split into the following files:
+
+00:00:00 - 00:35:00 | Book - 01 - Part 1.m4b
+00:35:00 - 01:02:00 | Book - 02 - Chapter 2.m4b
+01:02:00 - 01:41:00 | Book - 03 - Part 2.m4b
+01:41:00 - 02:05:00 | Book - 04 - Chapter 4.m4b
+
+That naming may not be desirable for everyone, but it's an easy change to instead use the last of the combined chapter's title in the file name.
+         */
+        private bool Step_DownloadAudiobookAsMultipleFilesPerChapter()
+        {
+            var zeroProgress = Step_DownloadAudiobook_Start();
+
+            var chapters = DownloadOptions.ChapterInfo.Chapters.ToList();
+
+            // Ensure split files are at least minChapterLength in duration.
+            var splitChapters = new ChapterInfo(DownloadOptions.ChapterInfo.StartOffset);
+
+            var runningTotal = TimeSpan.Zero;
+            string title = "";
+
+            for (int i = 0; i < chapters.Count; i++)
+            {
+                if (runningTotal == TimeSpan.Zero)
+                    title = chapters[i].Title;
+
+                runningTotal += chapters[i].Duration;
+
+                if (runningTotal >= minChapterLength)
+                {
+                    splitChapters.AddChapter(title, runningTotal);
+                    runningTotal = TimeSpan.Zero;
+                }
+            }
+
+            // reset, just in case
+            multiPartFilePaths.Clear();
+
+            ConversionResult result;
+
+            AaxFile.ConversionProgressUpdate += AaxFile_ConversionProgressUpdate;
+            if (DownloadOptions.OutputFormat == OutputFormat.M4b)
+                result = ConvertToMultiMp4a(splitChapters);
+            else
+                result = ConvertToMultiMp3(splitChapters);
+            AaxFile.ConversionProgressUpdate -= AaxFile_ConversionProgressUpdate;
+
+            Step_DownloadAudiobook_End(zeroProgress);
+
+            return result == ConversionResult.NoErrorsDetected;
+        }
+
+        private ConversionResult ConvertToMultiMp4a(ChapterInfo splitChapters)
+        {
+            var chapterCount = 0;
+            return AaxFile.ConvertToMultiMp4a(splitChapters, newSplitCallback =>
+                createOutputFileStream(++chapterCount, splitChapters, newSplitCallback),
+            DownloadOptions.TrimOutputToChapterLength);
+        }
+
+        private ConversionResult ConvertToMultiMp3(ChapterInfo splitChapters)
+        {
+            var chapterCount = 0;
+            return AaxFile.ConvertToMultiMp3(splitChapters, newSplitCallback =>
+            {
+                createOutputFileStream(++chapterCount, splitChapters, newSplitCallback);
+                ((NAudio.Lame.LameConfig)newSplitCallback.UserState).ID3.Track = chapterCount.ToString();
+            }, DownloadOptions.LameConfig, DownloadOptions.TrimOutputToChapterLength);
+        }
+
+        private void createOutputFileStream(int currentChapter, ChapterInfo splitChapters, NewSplitCallback newSplitCallback)
+        {
+            var fileName = multipartFileNameCallback(new()
+            {
+                OutputFileName = OutputFileName,
+                PartsPosition = currentChapter,
+                PartsTotal = splitChapters.Count,
+                Title = newSplitCallback?.Chapter?.Title
+            });
+            fileName = FileUtility.GetValidFilename(fileName);
+
+            multiPartFilePaths.Add(fileName);
+
+            FileUtility.SaferDelete(fileName);
+
+            newSplitCallback.OutputFile = File.Open(fileName, FileMode.OpenOrCreate);
+
+            OnFileCreated(fileName);
+        }
+    }
+}