using Nub.Lang.Backend;
using Nub.Lang.Frontend.Diagnostics;
using Nub.Lang.Frontend.Lexing;
using Nub.Lang.Frontend.Parsing;
using Nub.Lang.Frontend.Typing;

namespace Nub.Lang;

internal static class Program
{
    public static int Main(string[] args)
    {
        if (args.Length != 2)
        {
            Console.Error.WriteLine("Usage:       nub <input-dir>");
            Console.Error.WriteLine("Example:     nub src");
            return 1;
        }

        var srcDir = Path.GetFullPath(args[0]);

        if (!Directory.Exists(srcDir))
        {
            Console.Error.WriteLine($"Error: Input directory '{srcDir}' does not exist.");
            return 1;
        }

        return Compile(srcDir);
    }

    private static int Compile(string srcDir)
    {
        var error = false;
        var lexer = new Lexer();
        var parser = new Parser();
        var typeChecker = new TypeChecker();

        List<SourceFile> files = [];
        foreach (var file in Directory.EnumerateFiles(srcDir, "*.nub", SearchOption.AllDirectories))
        {
            var content = File.ReadAllText(file);

            var tokenizeResult = lexer.Tokenize(new SourceText(file, content));
            tokenizeResult.PrintAllDiagnostics();
            error = error || tokenizeResult.HasErrors;

            var parseResult = parser.ParseModule(tokenizeResult.Value);
            parseResult.PrintAllDiagnostics();
            error = error || parseResult.HasErrors;

            if (parseResult.Value != null)
            {
                files.Add(parseResult.Value);
            }
        }

        var typeCheckResult = typeChecker.TypeCheck(files);
        typeCheckResult.PrintAllDiagnostics();
        error = error || typeCheckResult.HasErrors;

        var generator = new Generator(typeCheckResult.Value);
        var result = generator.Generate();
        
        Console.Out.Write(result);

        return error ? 1 : 0;
    }
}