From b5389c67ea3794a587b0d7956d2574d7f22ca05e Mon Sep 17 00:00:00 2001
From: Michael Bucari-Tovo <mbucari1@gmail.com>
Date: Mon, 28 Jun 2021 12:51:28 -0600
Subject: [PATCH] Get chapter infor from file is no downloaded chapters were
 supplied.

---
 AaxDecrypter/AaxcDownloadConverter.cs | 10 ++++++--
 AaxDecrypter/Chapters.cs              | 34 +++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/AaxDecrypter/AaxcDownloadConverter.cs b/AaxDecrypter/AaxcDownloadConverter.cs
index 7ba1f3a3..89d624c8 100644
--- a/AaxDecrypter/AaxcDownloadConverter.cs
+++ b/AaxDecrypter/AaxcDownloadConverter.cs
@@ -135,9 +135,11 @@ namespace AaxDecrypter
             var aaxcProcesser = new FFMpegAaxcProcesser(downloadLicense);
             aaxcProcesser.ProgressUpdate += AaxcProcesser_ProgressUpdate;
 
+            bool userSuppliedChapters = chapters != null;
+
             string metadataPath = null;
 
-            if (chapters != null)
+            if (userSuppliedChapters)
             {
                 //Only write chaopters to the metadata file. All other aaxc metadata will be
                 //wiped out but is restored in Step 3.
@@ -151,7 +153,10 @@ namespace AaxDecrypter
                 .GetAwaiter()
                 .GetResult();
 
-            if (chapters != null)
+            if (!userSuppliedChapters && aaxcProcesser.Succeeded)
+                chapters = new ChapterInfo(outputFileName);
+
+            if (userSuppliedChapters)
                 FileExt.SafeDelete(metadataPath);
 
             DecryptProgressUpdate?.Invoke(this, 0);
@@ -187,6 +192,7 @@ namespace AaxDecrypter
                 destTags.SetData(stag.BoxType, stag.Children.Cast<TagLib.Mpeg4.AppleDataBox>().ToArray());
             }
             outFile.Save();
+
             return true;
         }
 
diff --git a/AaxDecrypter/Chapters.cs b/AaxDecrypter/Chapters.cs
index 07ff0202..83d0f117 100644
--- a/AaxDecrypter/Chapters.cs
+++ b/AaxDecrypter/Chapters.cs
@@ -1,5 +1,8 @@
 using Dinah.Core;
+using Dinah.Core.Diagnostics;
 using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
 using System.Linq;
 using System.Text;
 
@@ -10,6 +13,37 @@ namespace AaxDecrypter
         private List<Chapter> _chapterList = new List<Chapter>();
         public IEnumerable<Chapter> Chapters => _chapterList.AsEnumerable();
         public int Count => _chapterList.Count;
+
+        public ChapterInfo() { }
+        public ChapterInfo(string audiobookFile) 
+        {
+            var info = new ProcessStartInfo
+            {
+                FileName = DecryptSupportLibraries.ffprobePath,
+                Arguments = "-loglevel panic -show_chapters -print_format xml \"" + audiobookFile + "\""
+            };
+            var xml = info.RunHidden().Output;
+
+            var xmlDocument = new System.Xml.XmlDocument();
+            xmlDocument.LoadXml(xml);
+            var chaptersXml = xmlDocument.SelectNodes("/ffprobe/chapters/chapter")
+                .Cast<System.Xml.XmlNode>()
+                .Where(n => n.Name == "chapter");
+
+            foreach (var cnode in chaptersXml)
+            {
+                double startTime = double.Parse(cnode.Attributes["start_time"].Value.Replace(",", "."), CultureInfo.InvariantCulture);
+                double endTime = double.Parse(cnode.Attributes["end_time"].Value.Replace(",", "."), CultureInfo.InvariantCulture);
+
+                string chapterTitle = cnode.ChildNodes
+                    .Cast<System.Xml.XmlNode>()
+                    .Where(childnode => childnode.Attributes["key"].Value == "title")
+                    .Select(childnode => childnode.Attributes["value"].Value)
+                    .FirstOrDefault();
+
+                AddChapter(new Chapter(chapterTitle, (long)(startTime * 1000), (long)((endTime - startTime) * 1000)));
+            }
+        }
         public void AddChapter(Chapter chapter)
         {
             ArgumentValidator.EnsureNotNull(chapter, nameof(chapter));