using MultiversalDiplomacy.Model;

namespace MultiversalDiplomacy.Script;

/// <summary>
/// A script handler for the interactive repl.
/// </summary>
public class ReplScriptHandler : IScriptHandler
{
    public string Prompt => "5dp> ";

    public IScriptHandler? HandleInput(string input)
    {
        var args = input.Split(' ', StringSplitOptions.RemoveEmptyEntries);
        if (args.Length == 0)
        {
            return this;
        }

        var command = args[0];
        switch (command)
        {
            case "help":
            case "?":
                Console.WriteLine("Commands:");
                Console.WriteLine("  help, ?: print this message");
                Console.WriteLine("  map <variant>: start a new game of the given variant");
                Console.WriteLine("  stab: stab");
                break;

            case "stab":
                Console.WriteLine("stab");
                break;

            case "map" when args.Length == 1:
                Console.WriteLine("Usage:");
                Console.WriteLine("  map <variant>");
                Console.WriteLine("Available variants:");
                Console.WriteLine($"  {string.Join(", ", Enum.GetNames<MapType>().Select(s => s.ToLowerInvariant()))}");
                break;

            case "map" when args.Length > 1:
                string mapType = args[1].Trim();
                if (!Enum.TryParse(mapType, ignoreCase: true, out MapType map)) {
                    Console.WriteLine($"Unknown variant {mapType}");
                    Console.WriteLine("Available variants:");
                    Console.WriteLine($"  {string.Join(", ", Enum.GetNames<MapType>().Select(s => s.ToLowerInvariant()))}");
                    break;
                }
                World world = World.WithMap(Map.FromType(map));
                Console.WriteLine($"Created a new {map} game");
                return new SetupScriptHandler(world);

            default:
                // noop on comments that begin with #
                if (!command.StartsWith('#')) {
                    Console.WriteLine($"Unrecognized command: {command}");
                }
                break;
        }

        return this;
    }
}