JensKrumsieck/ChemSharp

using System.Text;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.Text;

namespace ChemSharp.Molecules.Generator;

[Generator]
public class MoleculeCreateGenerator : ISourceGenerator
{
    public void Initialize(GeneratorInitializationContext context) { }

    public void Execute(GeneratorExecutionContext context)
    {
        var formats = context.GetClassesImplementing("IAtomFileFormat").ToList();
        var sb = new StringBuilder(@"
        using System.IO;
        using ChemSharp.Extensions;
        using ChemSharp.Molecules.Formats;

        namespace ChemSharp.Molecules{

            public partial class Molecule
            {
                public static Molecule FromFile(string path){
                    var mol = ReadFile(path);
                    if (mol == null) throw new IOException(""Could not open file! Are you sure it is a supported format?"");
                            return mol;
                }
                public static Molecule FromStream(Stream stream, string ext){
                    var mol = ReadStream(stream, ext);
                    if (mol == null) throw new IOException(""Could not open file! Are you sure it is a supported format?"");
                            return mol;
                }

                private static Molecule? ReadFile(string path) => FileUtil.GetExtension(path) switch
                {
        ");
        foreach (var format in formats)
        {
            var ext = format.Identifier.ValueText.Split(new[] {"Format"}, StringSplitOptions.RemoveEmptyEntries)[0]
                            .ToLower();
            sb.AppendLine($@"""{ext}"" => {format.Identifier.ValueText}.Read(path),");
        }

        sb.Append(@"
                _ => null
                };

                private static Molecule? ReadStream(Stream stream, string extension) => extension switch
                {
        ");
        foreach (var format in formats)
        {
            var ext = format.Identifier.ValueText.Split(new[] {"Format"}, StringSplitOptions.RemoveEmptyEntries)[0]
                            .ToLower();
            sb.AppendLine($@"""{ext}"" => {format.Identifier.ValueText}.ReadFromStream(stream),");
        }

        sb.Append(@"
                _ => null
                };
            }
        }");
        context.AddSource("Molecule_Create", SourceText.From(sb.ToString(), Encoding.UTF8));
    }
}