using System.Text.RegularExpressions;

using MultiversalDiplomacy.Model;

namespace MultiversalDiplomacy.Script;

public class AdjudicationQueryScriptHandler(
    Action<string> WriteLine,
    World world,
    bool strict = false)
    : IScriptHandler
{
    public string Prompt => "valid> ";

    public World World { get; private set; } = world;

    /// <summary>
    /// Whether unsuccessful commands should terminate the script.
    /// </summary>
    public bool Strict { get; } = strict;

    public IScriptHandler? HandleInput(string input)
    {
        var args = input.Split(' ', 2, StringSplitOptions.RemoveEmptyEntries);
        if (args.Length == 0 || input.StartsWith('#'))
        {
            return this;
        }

        var command = args[0];
        switch (command)
        {
            case "---":
                WriteLine("Ready for orders");
                return new GameScriptHandler(WriteLine, World, Strict);

            case "assert" when args.Length == 1:
                WriteLine("Usage:");
                break;

            case "assert":
                if (!EvaluateAssertion(args[1])) return Strict ? null : this;
                break;

            case "status":
                throw new NotImplementedException();

            default:
                WriteLine($"Unrecognized command: \"{command}\"");
                if (Strict) return null;
                break;
        }

        return this;
    }

    private bool EvaluateAssertion(string assertion)
    {
        var args = assertion.Split(' ', 2, StringSplitOptions.RemoveEmptyEntries);

        switch (args[0])
        {
            case "true":
                return true;

            case "false":
                return false;

            case "order-valid":
                // Assert order was valid

            case "order-invalid":
                // Assert order was invalid

            case "has-past":
                // Assert a timeline's past

            case "holds":
                // Assert a unit successfully held

            case "dislodged":
                // Assert a unit was dislodged

            case "moves":
                // Assert a unit successfully moved

            case "no-move":
                // Assert a unit did not move

            case "supports":
                // Assert a unit's support was given

            case "cut":
                // Assert a unit's support was cut

            default:
                WriteLine($"Unknown assertion \"{args[0]}\"");
                return !Strict;
        }
    }
}