refactor: make exporting consistent

2025-02-06 19:14:36 +11:00
parent f946f3250c
commit 67f1c2a5d1
69 changed files with 908 additions and 921 deletions
@@ -0,0 +1,131 @@
+using ClosedXML.Excel;
+using Disco.Data.Repository;
+using Disco.Models.Exporting;
+using Disco.Models.Services.Exporting;
+using Disco.Services.Tasks;
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace Disco.Services.Exporting
+{
+    public static class Exporter
+    {
+        public static ExportResult Export<T, R>(DiscoDataContext database, IExportContext<T, R> context, IScheduledTaskStatus status)
+            where T : IExportOptions, new()
+            where R : IExportRecord
+        {
+            MemoryStream stream;
+            string mimeType;
+
+            status.UpdateStatus(1, $"Exporting {context.Name}", "Gathering data");
+
+            var records = context.BuildRecords(database, status);
+
+            status.UpdateStatus(70, "Building metadata");
+
+            var metadata = context.BuildMetadata(database, records, status);
+
+            if (metadata.Count == 0)
+                throw new ArgumentException("At least one export field must be specified", nameof(context.Options));
+
+            var filenameBuilder = new StringBuilder();
+            filenameBuilder.Append(context.SuggestedFilenamePrefix);
+            if (context.TimestampSuffix)
+            {
+                filenameBuilder.Append('-');
+                filenameBuilder.Append(status.StartedTimestamp.Value.ToString("yyyyMMdd-HHmmss"));
+            }
+
+            status.UpdateStatus(80, $"Rendering {records.Count} records for export");
+
+            switch (context.Options.Format)
+            {
+                case ExportFormat.Csv:
+                    filenameBuilder.Append(".csv");
+                    mimeType = "text/csv";
+                    stream = WriteCSV(metadata, records);
+                    break;
+                case ExportFormat.Xlsx:
+                    filenameBuilder.Append(".xlsx");
+                    mimeType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
+                    stream = WriteXlsx(context.ExcelWorksheetName, context.ExcelTableName, metadata, records);
+                    break;
+                default:
+                    throw new NotSupportedException($"Unsupported export format: {context.Options.Format}");
+            }
+
+            return new ExportResult()
+            {
+                Result = stream,
+                RecordCount = records.Count,
+                Filename = filenameBuilder.ToString(),
+                MimeType = mimeType,
+            };
+        }
+
+        private static MemoryStream WriteCSV<T>(List<ExportFieldMetadata<T>> metadata, List<T> records) where T : IExportRecord
+        {
+            var stream = new MemoryStream();
+
+            using (StreamWriter writer = new StreamWriter(stream, Encoding.Default, 0x400, true))
+            {
+                // Header
+                writer.Write('"');
+                writer.Write(string.Join("\",\"", metadata.Select(m => m.ColumnName)));
+                writer.Write('"');
+
+                // Records
+                foreach (var record in records)
+                {
+                    writer.WriteLine();
+                    for (int i = 0; i < metadata.Count; i++)
+                    {
+                        if (i != 0)
+                        {
+                            writer.Write(',');
+                        }
+                        var value = metadata[i].Accessor(record);
+                        writer.Write(metadata[i].CsvEncoder(value));
+                    }
+                }
+            }
+
+            stream.Position = 0;
+            return stream;
+        }
+
+        private static MemoryStream WriteXlsx<T>(string worksheetName, string tableName, List<ExportFieldMetadata<T>> metadata, List<T> records) where T : IExportRecord
+        {
+            var stream = new MemoryStream();
+
+            // Create DataTable
+            var dataTable = new DataTable();
+            foreach (var field in metadata)
+            {
+                dataTable.Columns.Add(field.ColumnName, field.ValueType);
+            }
+            foreach (var record in records)
+            {
+                dataTable.Rows.Add(metadata.Select(m => m.Accessor(record)).ToArray());
+            }
+
+            using (var xlWorkbook = new XLWorkbook())
+            {
+                var sheet = xlWorkbook.AddWorksheet(worksheetName);
+                var table = sheet.Cell(1, 1).InsertTable(dataTable, tableName);
+                table.Theme = XLTableTheme.TableStyleMedium2;
+
+                table.Columns().ForEach(c => c.WorksheetColumn().AdjustToContents(2, 15, 30));
+
+                xlWorkbook.SaveAs(stream);
+            }
+
+            stream.Position = 0;
+            return stream;
+        }
+    }
+}