Finished the Pandoc integration (#487)

app/MindWork AI Studio/Tools/PandocProcessBuilder.cs

@@ -0,0 +1,135 @@
+using System.Diagnostics;
+using System.Reflection;
+using System.Text;
+
+using AIStudio.Tools.Metadata;
+using AIStudio.Tools.Services;
+
+using SharedTools;
+
+namespace AIStudio.Tools;
+
+public sealed class PandocProcessBuilder
+{
+    private static readonly Assembly ASSEMBLY = Assembly.GetExecutingAssembly();
+    private static readonly MetaDataArchitectureAttribute META_DATA_ARCH = ASSEMBLY.GetCustomAttribute<MetaDataArchitectureAttribute>()!;
+    private static readonly RID CPU_ARCHITECTURE = META_DATA_ARCH.Architecture.ToRID();
+    
+    private string? providedInputFile;
+    private string? providedOutputFile;
+    private string? providedInputFormat;
+    private string? providedOutputFormat;
+    
+    private readonly List<string> additionalArguments = new();
+    
+    private PandocProcessBuilder()
+    {
+    }
+    
+    public static PandocProcessBuilder Create() => new();
+    
+    public PandocProcessBuilder WithInputFile(string inputFile)
+    {
+        this.providedInputFile = inputFile;
+        return this;
+    }
+    
+    public PandocProcessBuilder WithOutputFile(string outputFile)
+    {
+        this.providedOutputFile = outputFile;
+        return this;
+    }
+    
+    public PandocProcessBuilder WithInputFormat(string inputFormat)
+    {
+        this.providedInputFormat = inputFormat;
+        return this;
+    }
+    
+    public PandocProcessBuilder WithOutputFormat(string outputFormat)
+    {
+        this.providedOutputFormat = outputFormat;
+        return this;
+    }
+    
+    public PandocProcessBuilder AddArgument(string argument)
+    {
+        this.additionalArguments.Add(argument);
+        return this;
+    }
+    
+    public async Task<PandocPreparedProcess> BuildAsync(RustService rustService)
+    {
+        var sbArguments = new StringBuilder();
+        
+        if(!string.IsNullOrWhiteSpace(this.providedInputFile))
+            sbArguments.Append(this.providedInputFile);
+        
+        if(!string.IsNullOrWhiteSpace(this.providedInputFormat))
+            sbArguments.Append($" -f {this.providedInputFormat}");
+        
+        if(!string.IsNullOrWhiteSpace(this.providedOutputFormat))
+            sbArguments.Append($" -t {this.providedOutputFormat}");
+        
+        foreach (var additionalArgument in this.additionalArguments)
+            sbArguments.Append($" {additionalArgument}");
+        
+        if(!string.IsNullOrWhiteSpace(this.providedOutputFile))
+            sbArguments.Append($" -o {this.providedOutputFile}");
+        
+        var pandocExecutable = await PandocExecutablePath(rustService);
+        return new (new ProcessStartInfo
+        {
+            FileName = pandocExecutable.Executable,
+            Arguments = sbArguments.ToString(),
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            UseShellExecute = false,
+            CreateNoWindow = true
+        }, pandocExecutable.IsLocalInstallation);
+    }
+    
+    /// <summary>
+    /// Returns the path to the pandoc executable.
+    /// </summary>
+    /// <remarks>
+    /// Any local installation of pandoc will be preferred over the system-wide installation.
+    /// When a local installation is found, its absolute path will be returned. In case no local
+    /// installation is found, the name of the pandoc executable will be returned.
+    /// </remarks>
+    /// <param name="rustService">Global rust service to access file system and data dir.</param>
+    /// <returns>Path to the pandoc executable.</returns>
+    private static async Task<PandocExecutable> PandocExecutablePath(RustService rustService)
+    {
+        //
+        // First, we try to find the pandoc executable in the data directory.
+        // Any local installation should be preferred over the system-wide installation.
+        //
+        var localInstallationRootDirectory = await Pandoc.GetPandocDataFolder(rustService);
+        try
+        {
+            var executableName = PandocExecutableName;
+            var subdirectories = Directory.GetDirectories(localInstallationRootDirectory, "*", SearchOption.AllDirectories);
+            foreach (var subdirectory in subdirectories)
+            {
+                var pandocPath = Path.Combine(subdirectory, executableName);
+                if (File.Exists(pandocPath))
+                    return new(pandocPath, true);
+            }
+        }
+        catch
+        {
+            // ignored
+        }
+        
+        //
+        // When no local installation was found, we assume that the pandoc executable is in the system PATH.
+        //
+        return new(PandocExecutableName, false);
+    }
+    
+    /// <summary>
+    /// Reads the os platform to determine the used executable name.
+    /// </summary>
+    public static string PandocExecutableName => CPU_ARCHITECTURE is RID.WIN_ARM64 or RID.WIN_X64 ? "pandoc.exe" : "pandoc";
+}