Helpers/Export: Code cleanup

Elwig/Helpers/Export/CsvFile.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Elwig.Helpers.Export {
+    public abstract class CsvFile<T> : IExporter<T> {
+
+        public static string FileExtension => "csv";
+
+        private readonly StreamWriter _writer;
+        protected readonly char Separator;
+        protected string? Header;
+
+        public CsvFile(string filename, char separator = ';') :
+            this(filename, separator, Utils.UTF8) {
+        }
+
+        public CsvFile(string filename, char separator, Encoding encoding) {
+            _writer = new StreamWriter(filename, false, encoding);
+            Separator = separator;
+        }
+
+        public void Dispose() {
+            GC.SuppressFinalize(this);
+            _writer.Dispose();
+        }
+
+        public ValueTask DisposeAsync() {
+            GC.SuppressFinalize(this);
+            return _writer.DisposeAsync();
+        }
+
+        public async Task ExportAsync(IEnumerable<T> data, IProgress<double>? progress = null) {
+            progress?.Report(0.0);
+            int count = data.Count() + 2, i = 0;
+
+            if (Header != null) await _writer.WriteLineAsync(Header);
+            progress?.Report(100.0 * ++i / count);
+
+            foreach (var row in data) {
+                await _writer.WriteLineAsync(FormatRow(row));
+                progress?.Report(100.0 * ++i / count);
+            }
+
+            await _writer.FlushAsync();
+            progress?.Report(100.0);
+        }
+
+        public void Export(IEnumerable<T> data, IProgress<double>? progress = null) {
+            ExportAsync(data, progress).GetAwaiter().GetResult();
+        }
+
+        public string FormatRow(IEnumerable row) {
+            return string.Join(Separator, row);
+        }
+
+        public abstract string FormatRow(T row);
+    }
+
+    public class CsvSimple : CsvFile<IEnumerable<object?>> {
+
+        public CsvSimple(string filename, char separator, Encoding encoding) :
+            base(filename, separator, encoding) {
+        }
+
+        public CsvSimple(string filename, char separator = ';') :
+            base(filename, separator) {
+        }
+
+        public override string FormatRow(IEnumerable<object?> row) {
+            return string.Join(Separator, row.Select(i => {
+                var str = $"{i}";
+                return str.Contains(Separator) || str.Contains('\n') ? $"\"{str.Replace("\"", "\"\"")}\"" : str;
+            }));
+        }
+    }
+}