using System.Reflection;
using NubLang.CLI;
using NubLang.Code;
using NubLang.Diagnostics;
using NubLang.Generation.QBE;
using NubLang.Parsing;
using NubLang.Parsing.Syntax;
using NubLang.Tokenization;
using NubLang.TypeChecking;
using Module = NubLang.TypeChecking.Module;

var options = new Options();

for (var i = 0; i < args.Length; i++)
{
    var arg = args[i];
    switch (arg)
    {
        case "-o":
        {
            ++i;
            if (i >= args.Length)
            {
                return 1;
            }

            options.OutputPath = args[i];
            break;
        }
        default:
        {
            options.Files.Add(new SourceFile(arg));
            break;
        }
    }
}

foreach (var file in options.Files)
{
    if (!File.Exists(file.Path))
    {
        Console.Error.WriteLine($"File '{file}' does not exist");
        return 1;
    }
}

var diagnostics = new List<Diagnostic>();

var syntaxTrees = new List<SyntaxTree>();
foreach (var file in options.Files)
{
    var tokenizer = new Tokenizer(file);
    var tokens = tokenizer.Tokenize().ToList();
    diagnostics.AddRange(tokenizer.GetDiagnostics());

    var parser = new Parser();
    var syntaxTree = parser.Parse(tokens);

    diagnostics.AddRange(parser.GetDiagnostics());

    syntaxTrees.Add(syntaxTree);
}

var moduleSignatures = ModuleSignature.CollectFromSyntaxTrees(syntaxTrees);
var modules = Module.CollectFromSyntaxTrees(syntaxTrees);

var typedModules = new List<TypedModule>();

foreach (var module in modules)
{
    var typeChecker = new TypeChecker(module, moduleSignatures);
    var typedModule = typeChecker.CheckModule();
    diagnostics.AddRange(typeChecker.GetDiagnostics());
    typedModules.Add(typedModule);
}

foreach (var diagnostic in diagnostics)
{
    Console.Error.WriteLine(diagnostic.FormatANSI());
}

if (diagnostics.Any(diagnostic => diagnostic.Severity == DiagnosticSeverity.Error))
{
    return 1;
}

var objectFiles = new List<string>();

for (var i = 0; i < typedModules.Count; i++)
{
    var typedModule = typedModules[i];
    var outFileName = Path.Combine(".build", Path.ChangeExtension(options.Files[i].Path, null));

    var outFileDir = Path.GetDirectoryName(outFileName);
    if (!string.IsNullOrEmpty(outFileDir))
    {
        Directory.CreateDirectory(outFileDir);
    }

    var generator = new QBEGenerator(typedModule, moduleSignatures);
    var ssa = generator.Emit();

    var ssaFilePath = Path.ChangeExtension(outFileName, "ssa");
    File.WriteAllText(ssaFilePath, ssa);

    var asmFilePath = Path.ChangeExtension(outFileName, "s");
    var qbeSuccess = await QBE.Invoke(ssaFilePath, asmFilePath);

    if (!qbeSuccess)
    {
        return 1;
    }

    var objFilePath = Path.ChangeExtension(outFileName, "o");
    var asmSuccess = await GCC.Assemble(asmFilePath, objFilePath);

    if (!asmSuccess)
    {
        return 1;
    }

    objectFiles.Add(objFilePath);
}

var outPath = options.OutputPath ?? Path.Combine("out.a");
var outDir = Path.GetDirectoryName(outPath);
if (!string.IsNullOrEmpty(outDir))
{
    Directory.CreateDirectory(outDir);
}

var archiveResult = await Archive.Invoke(outPath, objectFiles);
if (!archiveResult)
{
    return 1;
}

return 0;