using System.Linq;
using Texty.Scripts.Game;

namespace Texty.Scripts.Commands
{
    public enum LookModifier
    {
        At,
        Around
    }

    public class LookCommand : Command
    {
        public LookCommand()
        {
        }

        public LookCommand(string[] arguments) : base(CommandType.Look, arguments)
        {
            (Modifier, arguments) = TryParseModifier(arguments);
            Target = string.Join(" ", arguments);
        }

        public string Target { get; }
        public LookModifier? Modifier { get; }

        /// <summary>
        ///     Access this <c>LookCommand</c>'s modifier as a string.
        /// </summary>
        /// <remarks>
        ///     This function is provided as a means for testing the modifier parsing from GDScript.
        /// </remarks>
        private string ModifierAsString => Modifier?.ToString();

        public override string ToString()
        {
            return $"look {ModifierAsString?.ToLower()} {string.Join(" ", Target)}";
        }

        /// <summary>
        ///     Try to parse this <c>LookCommand</c>'s modifier from the given arguments.
        /// </summary>
        /// <param name="arguments">The arguments given to this look commands</param>
        /// <returns>A pair consisting of the parse modifier and the remaining arguments</returns>
        private static (LookModifier?, string[]) TryParseModifier(string[] arguments)
        {
            if (arguments.Length == 0)
                return (null, arguments);

            return arguments[0].ToLower() switch
            {
                "at" => (LookModifier.At, arguments.Skip(1).ToArray()),
                "around" => (LookModifier.Around, new string[] { }),
                _ => (null, arguments)
            };
        }
    }
}