// -----------------------------------------------------------------------------
// file="TestRegexGenerate"
// Project: Nitload
// Copyright (c) Nitload.
// SPDX-License-Identifier: MIT
// -----------------------------------------------------------------------------

using Nitload.RegularAnalysis.Abstraction;
using Nitload.RegularAnalysis.Text;
using System;
using System.Collections.Generic;
using System.Runtime.ExceptionServices;
using static Nitload.RegularAnalysis.Text.TextRegexSourceGen;

namespace Nitload
{
    internal static class TestRegexGenerate
    {
        public static int Run(params string[] args)
        {
            if (args.Length > 1) {
                throw new ArgumentException("Expected at most one regex pattern.", nameof(args));
            }
            if (args.Length == 1)
            {
                Print(args[0]);
                return 0;
            }

            while (true)
            {
                Console.Write("regex> ");
                string? pattern = Console.ReadLine();
                if (pattern is null or ":exit") {
                    return 0;
                }
                Print(pattern);
            }
        }

        private static void Print(string pattern)
        {
            TextRegexSource analysis = RegexAnalyzer.Analyze(pattern);
            if (analysis.AnalyseException is not null) {
                ExceptionDispatchInfo.Throw(analysis.AnalyseException);
            }

            SequenceEmitter<string> body = new();
            List<SequenceEmitter<string>> functions = [];
            SourceGenContext context = new();
            ExitLabel exit = context.RequestExitLabel(ExitMode.Goto);
            GenerateMethodSource(analysis.Ast.Root, body, functions, context, exit);

            foreach (string line in body.ToList()) {
                Console.WriteLine(line);
            }
            foreach (SequenceEmitter<string> function in functions)
            {
                foreach (string line in function.ToList()) {
                    Console.WriteLine(line);
                }
            }
        }
    }
}