using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using DeukBot4.MessageHandlers.Permissions;
using Discord.WebSocket;

namespace DeukBot4.MessageHandlers.CommandHandler.RequestStructure
{
    public class CommandRequest
    {
        private const string CommandNamePattern = "!([a-zA-Z0-9_]*) *(.*)";
        private static readonly Regex CommandNameMatcher = new Regex(CommandNamePattern);

        public Command       Command         { get; }
        //public string        ParameterString { get; }
        public SocketMessage OriginalMessage { get; }
        public RequestParameter[] Parameters { get; private set; }
        public PermissionLevel RequestPermissions { get; }

        private CommandRequest(SocketMessage message, Command command, PermissionLevel requestPermissions, RequestParameter[] parameters)
        {
            OriginalMessage = message;
            Command = command;
            RequestPermissions = requestPermissions;
            Parameters = parameters;
        }

        public enum RequestCode
        {
            OK, Invalid, Forbidden
        }

        public static (CommandRequest, RequestCode) Create(SocketMessage message)
        {
            var originalMessage = message;
            var content = message.Content;
            var res     = CommandNameMatcher.Match(content);
            if (res.Groups.Count <= 2)
                return (null, RequestCode.Invalid);

            var commandName = res.Groups[1].Value;
            var command     = CommandHandler.GetCommand(commandName);
            if (command == null)
            {
                return (null, RequestCode.Invalid);
            }

            var permission = PermissionValidator.GetUserPermissionLevel(message);
            if (permission < command.Permission)
            {
                return (null, RequestCode.Forbidden);
            }
            var parameterString = res.Groups[2].Value;
            var parameters = ParameterMatcher.GetParameterValues(command, parameterString);
            return (new CommandRequest(originalMessage, command, permission, parameters), RequestCode.OK);
        }

    }
}