using System.Diagnostics;
using Compiler;

var nubFiles = new List<string>();
var libFiles = new List<string>();
var compileLib = false;

for (int i = 0; i < args.Length; i++)
{
    string arg = args[i];

    if (arg.StartsWith("--type="))
    {
        var value = arg.Split("--type=")[1];
        switch (value)
        {
            case "lib":
                compileLib = true;
                break;
            case "exe":
                compileLib = false;
                break;
            default:
                DiagnosticFormatter.Print(Diagnostic.Error("Type must be 'exe' or 'lib'").Build(), Console.Error);
                return 1;
        }
    }
    else if (arg.EndsWith(".nub"))
    {
        nubFiles.Add(arg);
    }
    else if (arg.EndsWith(".nublib"))
    {
        libFiles.Add(arg);
    }
    else if (arg == "--help")
    {
        Console.WriteLine("""
                           Usage: nubc [options] <files>

                           Options:
                             --type=exe        Compile the input files into an executable (default)
                             --type=lib        Compile the input files into a library
                             --help            Show this help message

                           Files:
                             *.nub             Nub source files to compile
                             *.nublib          Precompiled Nub libraries to link

                           Example:
                             nubc --type=exe main.nub utils.nub math.nublib
                           """);
    }
    else
    {
        DiagnosticFormatter.Print(Diagnostic.Error($"Unrecognized option '{arg}'").Build(), Console.Error);
        return 1;
    }
}

var moduleGraphBuilder = ModuleGraph.CreateBuilder();
var asts = new List<Ast>();
var archivePaths = new List<string>();

foreach (var libPath in libFiles)
{
    var lib = NubLib.Unpack(libPath);
    archivePaths.Add(lib.ArchivePath);
    moduleGraphBuilder.AddManifest(lib.Manifest);
}

foreach (var fileName in nubFiles)
{
    var file = File.ReadAllText(fileName);

    var tokens = Tokenizer.Tokenize(fileName, file, out var tokenizerDiagnostics);

    foreach (var diagnostic in tokenizerDiagnostics)
        DiagnosticFormatter.Print(diagnostic, Console.Error);

    if (tokens == null)
        return 1;

    var ast = Parser.Parse(fileName, tokens, out var parserDiagnostics);

    foreach (var diagnostic in parserDiagnostics)
        DiagnosticFormatter.Print(diagnostic, Console.Error);

    if (ast == null)
        return 1;

    moduleGraphBuilder.AddAst(ast);
    asts.Add(ast);
}

var moduleGraph = moduleGraphBuilder.Build(out var moduleGraphDiagnostics);

foreach (var diagnostic in moduleGraphDiagnostics)
    DiagnosticFormatter.Print(diagnostic, Console.Error);

if (moduleGraph == null)
    return 1;

var functions = new List<TypedNodeDefinitionFunc>();

foreach (var ast in asts)
{
    foreach (var func in ast.Definitions.OfType<NodeDefinitionFunc>())
    {
        var typedFunction = TypeChecker.CheckFunction(ast.FileName, ast.ModuleName.Ident, func, moduleGraph, out var typeCheckerDiagnostics);

        foreach (var diagnostic in typeCheckerDiagnostics)
            DiagnosticFormatter.Print(diagnostic, Console.Error);

        if (typedFunction == null)
            return 1;

        functions.Add(typedFunction);
    }
}

var output = Generator.Emit(functions, moduleGraph, compileLib);

if (Directory.Exists(".build"))
{
    CleanDirectory(".build");
}
else
{
    Directory.CreateDirectory(".build");
}

if (compileLib)
{
    File.WriteAllText(".build/out.c", output);
    Process.Start("gcc", ["-Og", "-fvisibility=hidden", "-fno-builtin", "-c", "-o", ".build/out.o", ".build/out.c", .. archivePaths]).WaitForExit();
    Process.Start("ar", ["rcs", ".build/out.a", ".build/out.o"]).WaitForExit();
    NubLib.Pack(".build/out.nublib", ".build/out.a", moduleGraph.CreateManifest());
}
else
{
    File.WriteAllText(".build/out.c", output);
    Process.Start("gcc", ["-Og", "-fvisibility=hidden", "-fno-builtin", "-o", ".build/out", ".build/out.c", .. archivePaths]).WaitForExit();
}

return 0;

static void CleanDirectory(string dirName)
{
    var dir = new DirectoryInfo(dirName);

    foreach (var file in dir.GetFiles())
    {
        file.Delete();
    }

    foreach (var subdir in dir.GetDirectories())
    {
        CleanDirectory(subdir.FullName);
        subdir.Delete();
    }
}