using System.Collections.Generic;
using System.Linq;

namespace DeukBot4.MessageHandlers.CommandHandler
{
    public abstract class CommandContainerBase
    {
        public abstract string Name { get; }

        public Command[] GetCommands()
        {
            var funcs = GetType().GetMethods()
                .Where(x => x.GetCustomAttributes(typeof(CommandAttribute), true).Length > 0);
            var commands = new List<Command>();

            foreach (var methodInfo in funcs)
            {
                // grab all command attributes, cast them properly
                var commandAttributes = methodInfo.GetCustomAttributes(typeof(CommandAttribute), true)
                    .Select(x => x as CommandAttribute).ToArray();

                // get the help attribute if it exists
                CommandHelpAttribute helpAttribute = null;
                var helpAttributes = methodInfo.GetCustomAttributes(typeof(CommandHelpAttribute), true)
                    .Select(x => x as CommandHelpAttribute).ToArray();
                if (helpAttributes.Any())
                    helpAttribute = helpAttributes[0];


                // grab all of the potential parameter type arrays
                var parameters = methodInfo.GetCustomAttributes(typeof(CommandParametersAttribute), true)
                    .Select(x => (CommandParametersAttribute) x)
                    .Select(x => x.Types.ToArray())
                    .ToArray();

                // check if the function has the attribute for blocking usage in PMs
                var forbidPm = methodInfo.GetCustomAttributes(typeof(BlockUsageInPmAttribute), true).Any();

                var matchParametersExactly =
                    methodInfo.GetCustomAttributes(typeof(RequireParameterMatchAttribute), true).Any();
                var firstCommand = commandAttributes.First();
                Command command;
                if (helpAttribute == null)
                {
                    command = (new Command(firstCommand.Command, firstCommand.Permission, parameters,
                        forbidPm, matchParametersExactly, methodInfo, this));
                }
                else
                {
                    command = (new Command(firstCommand.Command, firstCommand.Permission,
                        helpAttribute.ShortHelp, helpAttribute.LongHelp, parameters, forbidPm,
                        matchParametersExactly, methodInfo, this));

                }
                for (var i = 1; i < commandAttributes.Length; i++)
                {
                    var cmd = commandAttributes[i];
                    if (cmd == null)
                        continue;
                    command.Alternatives.Add(cmd.Command);
                }
                commands.Add(command);
            }
            return commands.ToArray();
        }
    }
}