using MultiversalDiplomacy.Model;

namespace MultiversalDiplomacy.Script;

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

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

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

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

            case "map" when args.Length == 1:
                WriteLine("Usage:");
                WriteLine("  map <variant>");
                WriteLine("Available variants:");
                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)) {
                    WriteLine($"Unknown variant \"{mapType}\"");
                    WriteLine("Available variants:");
                    WriteLine($"  {string.Join(", ", Enum.GetNames<MapType>().Select(s => s.ToLowerInvariant()))}");
                    break;
                }
                World world = World.WithMap(Map.FromType(map));
                WriteLine($"Created a new {map} game");
                return new SetupScriptHandler(WriteLine, world);

            default:
                WriteLine($"Unrecognized command: \"{command}\"");
                break;
        }

        return this;
    }
}