using Discord;
using Discord.Commands;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
using System.Linq;
using EventBot.Attributes;
using EventBot.Services;
using Discord.Addons.Interactive;
using EventBot.Misc;

namespace EventBot.Modules
{
    public class BasicModule : ModuleBase<SocketCommandContext>
    {
        private readonly DatabaseService _database;
        public BasicModule(DatabaseService database)
        {
            _database = database;
        }

        [RequireUserPermission(GuildPermission.Administrator, Group = "Permission")]
        [RequireOwner(Group = "Permission")]
        [RequireContext(ContextType.Guild)]
        [Command("prefix")]
        [Name("Configure prefix")]
        [Summary("Gets prefix.")]
        public async Task PrefixCommand()
        {
            var guildConfig = _database.GuildConfigs.FirstOrDefault(g => g.GuildId == Context.Guild.Id);
            if (guildConfig == null)
                throw new Exception("No guild config was foumd.");
            if(guildConfig.Prefix != null)
                await ReplyAsync($"Current prefix is `{guildConfig.Prefix}`");
            else
                await ReplyAsync($"There is no prefix set for this guild.");
        }

        [RequireUserPermission(GuildPermission.Administrator, Group = "Permission")]
        [RequireOwner(Group = "Permission")]
        [RequireContext(ContextType.Guild)]
        [Command("prefix")]
        [Name("Configure prefix")]
        [Summary("Sets prefix.")]
        public async Task PrefixCommand(
            [Summary("New prefix to set")] string newPrefix)
        {
            var guildConfig = _database.GuildConfigs.FirstOrDefault(g => g.GuildId == Context.Guild.Id);
            if (guildConfig == null)
                throw new Exception("No guild config was foumd.");
            guildConfig.Prefix = newPrefix;
            await _database.SaveChangesAsync();
            await ReplyAsync($"Prefix has been set to `{guildConfig.Prefix}`");
        }


        [Group("help")]
        public class HelpModule : InteractiveBase<SocketCommandContext>
        {

            private readonly CommandService _commands;
            public HelpModule(CommandService commands)
            {
                _commands = commands;
            }

            [Command]
            [Name("Help")]
            [Summary("Lists all commands with there descriptions.")]
            public async Task DefaultHelpAsync()
            {
                var pagedCommands = _commands.Commands
                    .OrderBy(c => c.Aliases[0])
                    .Where(c => c.Attributes
                        .Select(a => {
                            switch (a)
                            {
                                case NoHelpAttribute _:
                                    return false;
                                case RequireContextAttribute rc:
                                    return Context.IsContextType(rc.Contexts);
                                default:
                                    return true;
                            }
                        })
                        .Aggregate(true, (a, r) => a && r))
                    .SelectMany(c => c.Aliases.Select(a => new { CI = c, MA = (c.Aliases[0] == a), A = a}).Reverse())
                    .Select((e, i) => new { Command = e, Index = i })
                    .GroupBy(o => o.Index / 20)
                    .Select(g => g.Select(o => o.Command));

                var pager = new PaginatedMessage()
                {
                    Title = "Command list",
                    Color = Color.DarkBlue,
                    Pages = pagedCommands.Select(p => string.Join("\r\n", p.Select(c => {
                        if (c.MA)
                            return $"`{c.CI.FormatCallHelpString()}` - **{c.CI.Name}**";
                        else
                            return $"`{c.A}` `↪`";
                    }))),
                    Options = new PaginatedAppearanceOptions()
                    {
                        Info = null,
                        JumpDisplayOptions = JumpDisplayOptions.Never
                    }
                };
                await PagedReplyAsync(pager);
            }
        }
    }
}