inabox/InABox.Poster.CSV/CSVPosterEngine.cs

using CsvHelper;
using InABox.Core;
using InABox.Core.Postable;
using InABox.Scripting;
using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace InABox.Poster.CSV
{
    public class CSVPosterEngine<TPostable> : PosterEngine<TPostable, ICSVPoster<TPostable>, CSVPosterSettings>
        where TPostable : Entity, IPostable, IRemotable, IPersistent, new()
    {
        protected override bool DoProcess(IEnumerable<TPostable> posts)
        {
            var settings = GetSettings();

            ICSVExport results;
            if(settings.ScriptEnabled && !string.IsNullOrWhiteSpace(settings.Script))
            {
                var document = new ScriptDocument(settings.Script);
                document.Properties.Add(new ScriptProperty("Results", null));
                if (!document.Compile())
                {
                    throw new Exception("Script failed to compile!");
                }
                if(!document.Execute(methodname: "Process", parameters: new object[] { posts }))
                {
                    return false;
                }

                var resultsObject = document.GetValue("Results");
                results = (resultsObject as ICSVExport)
                    ?? throw new Exception($"Script 'Results' property expected to be ICSVExport, got {resultsObject}");
            }
            else
            {
                results = Poster.Process(posts);
            }

            var dlg = new SaveFileDialog()
            {
                FileName = settings.DefaultOutputFile,
                Filter = "CSV Files (*.csv)|*.csv"
            };

            if(dlg.ShowDialog() == true)
            {
                using var writer = new StreamWriter(dlg.FileName);
                using var csv = new CsvWriter(writer, CultureInfo.InvariantCulture);
                csv.Context.RegisterClassMap(results.ClassMap.ClassMap);

                var method = typeof(CsvWriter).GetMethods()
                    .Where(x => x.Name == nameof(CsvWriter.WriteRecords) && x.GetGenericArguments().Length == 1).First()
                    .MakeGenericMethod(results.Type);
                method.Invoke(csv, new object?[] { results.Records });
                return true;
            }
            else
            {
                throw new PostCancelledException();
            }
        }
    }
}