Handle mutiple files. use strings in article fields

Records.cs

@@ -1,7 +1,9 @@
 using System;
+using System.CodeDom;
 using System.Configuration;
 using System.Linq;
 using System.Text.RegularExpressions;
+using System.Windows.Media.Converters;
 using System.Windows.Navigation;
 
 namespace Txt2Bib.Records
@@ -15,8 +17,8 @@ namespace Txt2Bib.Records
         public string Title { get; set; } = "";
         public string Journal { get; set; } = "";
         public ushort Year { get; set; } = 1950;
-        public ushort Volume { get; set; } = 1;
+        public string Volume { get; set; } = "";
-        public byte? Issue { get; set; } = null;
+        public string? Issue { get; set; } = null;
         public ushort FirstPage { get; set; } = 1;
         public ushort LastPage { get; set; } = 1;
         public string Doi { get; set; } = "";
@@ -32,21 +34,24 @@ namespace Txt2Bib.Records
                 return $"{s[1]} {s[0]}";
             };
             var checkVol = (string v) =>
-            {
+                v.Split(',').Length == 2 ? v.Split(',')[0] : v;
-                if (v.Length == 0) return byte.MinValue;
+
-                return v.Split(',').Length == 2 ?
-                    byte.Parse(v.Split(',')[0]) :
-                    byte.Parse(v);
-            };
             Author = temp.Select(a => rearrange(a)).ToArray();
             Year = ushort.Parse(entryLines[2]);
             Title = entryLines[3];
             Journal = entryLines[4];
-            Volume = checkVol(entryLines[5]);
+            Volume = entryLines[5] != string.Empty ? checkVol(entryLines[5]) : Volume;
             Issue = entryLines[5].Split(',').Length == 2 ?
-               byte.Parse(entryLines[5].Split(',')[1]) : null;
+               entryLines[5].Split(',')[1] : Issue;
+            try
+            {
                 FirstPage = ushort.Parse(entryLines[6].Split('-')[0]);
                 LastPage = ushort.Parse(entryLines[6].Split('-')[1]);
+            }
+            catch (Exception)
+            {
+                throw;
+            }
             Doi = entryLines.Length > 7 ? entryLines[7] : "";
 
             return ToString();
@@ -82,7 +87,7 @@ namespace Txt2Bib.Records
 
         public override string ToString()
         {
-            return $"@{Type}" + "{" +$"{Author[0][..5]}_{Year},\n" +
+            return $"@{Type}{{{Author[0][..5]}_{Year},\n" +
                 $"\tauthor = \"{string.Join(" and", Author)}\",\n" +
                 $"\ttitle = {{{Title}}},\n" +
                 $"\tpublisher = \"{Publisher}\",\n" +

Text2Bib.cs

@@ -16,6 +16,7 @@ namespace Txt2Bib
     public class Text2Bib
     {
         private string[] _citTypes = { "J", "B", "C", "P", "?" };
+        
         /// <summary>
         /// Generate single .bib file from input text files
         /// </summary>
@@ -24,33 +25,43 @@ namespace Txt2Bib
         public string Generate(string filenames)
         {
             var paths = filenames.Trim().Split('\n');
-            string result = "";
+            var output = "";
-            string output = "";
 
             foreach (var path in paths)
+            {
+                output += CreateBibTeX(path);
+            }
+
+            return output;
+        }
+        /// <summary>
+        /// Create a BibTeX string from an input file path
+        /// </summary>
+        /// <param name="path"></param>
+        /// <returns></returns>
+        public string CreateBibTeX(string path)
         {
             var reader = File.OpenText(path);
             byte[] contentBytes = File.ReadAllBytes(path);
-
+            var content = Encoding.Latin1.GetString(contentBytes);
-                result += Encoding.Latin1.GetString(contentBytes);
-            }
 
             IEnumerable<string> entries = new List<string>();
             try
             {
-                entries = result.Split('%').ToList().Select(entry => Process(entry));
+                entries = content.Split('%').ToList().Select(entry => Process(entry));
             }
             catch (Exception)
             {
                 throw;
             }
 
+            var bibtex = "";
             foreach (var entry in entries)
             {
-                output += entry;
+                bibtex += entry;
             }
 
-            return output;
+            return bibtex;
         }
         /// <summary>
         /// Creates a bib entry from source text 
@@ -66,7 +77,11 @@ namespace Txt2Bib
 
             if (!IsValidEntry(type)) throw new Exception($"Invalid entry type '{type}'");
 
-            string citation = type switch
+            string citation = "";
+
+            try
+            {
+                citation = type switch
                 {
                     "J" => (new ArticleBib()).Convert(lines),
                     //"B" => new BookBib(),
@@ -74,6 +89,11 @@ namespace Txt2Bib
                     //"P" => new ConferenceBib(),
                     _ => (new ArticleBib()).Convert(lines)
                 };
+            }
+            catch (Exception)
+            {
+                throw new Exception("Faulty string in " + lines);
+            }
 
             return citation;
         }
@@ -95,7 +115,6 @@ namespace Txt2Bib
         {
             var cp = "UTF-8";
             return Encoding.GetEncoding(cp);
-
         }
     }
 }