using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using DeukBot4.MessageHandlers.CommandHandler.RequestStructure;
using DeukBot4.MessageHandlers.Permissions;
using DeukBot4.Utilities;
using Discord.WebSocket;

namespace DeukBot4.MessageHandlers.CommandHandler
{
    public static class CommandHandler
    {
        public static Dictionary<string, Command> Commands { get; private set; } = new Dictionary<string, Command>();
        public const char CommandTrigger = '!';

        public static void Build()
        {
            var commandContainers = typeof(CommandHandler).Assembly.GetTypes()
                .Where(x => typeof(CommandContainerBase).IsAssignableFrom(x) && !x.IsAbstract);

            foreach (var commandContainer in commandContainers)
            {
                if (!(Activator.CreateInstance(commandContainer) is CommandContainerBase obj))
                    continue;
                var commands = obj.GetCommands();
                foreach (var command in commands)
                {
                    Commands.Add(command.Name.ToLowerInvariant(), command);
                }

                Logger.Log($"Loaded following commands for container {obj.Name}: {commands.Select(x => x.Name).Join(", ")}");

            }

        }

        public static async Task HandleMessage(SocketMessage message)
        {
            if (message.Content[0] != CommandTrigger) return;
            var req = CommandRequest.Create(message);
            var resultCode = req.Item2;
            if (resultCode == CommandRequest.RequestCode.Invalid)
            {
                await Logger.LogError("Invalid content: " + message.Content);
                return;
            }
            else if (resultCode == CommandRequest.RequestCode.Forbidden)
            {
                await Logger.Log(
                    $"Unauthorized user tried to run command: {message.Author.Username} -> {message.Content}");

            }
            else if (resultCode == CommandRequest.RequestCode.OK)
            {
                await req.Item1.Command.Invoke(req.Item1);

            }
        }

        public static Command GetCommand(string name)
        {
            return Commands.TryGetValue(name.ToLowerInvariant(), out var com) ? com : null;
        }
    }
}