using System.IO;
using System.Text.RegularExpressions;

if (args.Length != 1)
{
    Console.WriteLine("Usage: <program> [directory of .md.tpl files]");
    return 1;
}
if (!Directory.Exists(args[0]))
{
    Console.WriteLine("Directory does not exist");
    return 1;
}
var files = Directory.GetFiles(args[0], "*.md.tpl");
var macroRegex = new Regex(@"\[(!doclinkclass ){1}([^]]+)\]");
var evaluator = new MatchEvaluator(GenerateFragment);
foreach (var f in files)
{
    var fileTgt = f.Replace(".md.tpl", ".md");

    var sourceText = File.ReadAllText(f);
    var replacedText = macroRegex.Replace(sourceText, evaluator);

    File.WriteAllText(fileTgt, replacedText);
    Console.WriteLine($"Pre-processed: {f} -> {fileTgt}");
}

return 0;

static string GenerateFragment(Match match)
{
    // Groups[2] contains the class name
    var relPrefix = "../"; // Currently assuming that we're processing everything under ../landing/topics
    return $"([.net]({relPrefix}dotnet_api/api/OSGeo.MapGuide.{match.Groups[2].Value}.html), [Java]({relPrefix}java_api/org/osgeo/mapguide/{match.Groups[2].Value}.html), [PHP](TODO.md))";
}