using Dapper;
using GmRelay.Shared.Domain;
using Npgsql;
using Telegram.Bot;
using Telegram.Bot.Types;
using Telegram.Bot.Types.ReplyMarkups;

namespace GmRelay.Bot.Features.Sessions.ListSessions;

internal sealed record SessionListItemDto(Guid Id, string Title, DateTime ScheduledAt, string Status, int? MaxPlayers, int PlayerCount, int WaitlistCount, bool CanManage);

internal static class SessionListMessageRenderer
{
    public static (string Text, InlineKeyboardMarkup? Markup) Render(IReadOnlyList<SessionListItemDto> sessions)
    {
        var text = "📅 <b>Ближайшие игры:</b>\n\n";
        foreach (var session in sessions)
        {
            var seats = session.MaxPlayers.HasValue
                ? $"{session.PlayerCount}/{session.MaxPlayers.Value}"
                : session.PlayerCount.ToString(System.Globalization.CultureInfo.InvariantCulture);
            var waitlist = session.WaitlistCount > 0 ? $", ожидание: {session.WaitlistCount}" : string.Empty;
            text += $"🔹 <b>{session.ScheduledAt.FormatMoscow()}</b> — {System.Net.WebUtility.HtmlEncode(session.Title)} (Места: {seats}{waitlist})\n";
        }

        var canManage = sessions.Count > 0 && sessions.First().CanManage;
        if (!canManage)
        {
            return (text, null);
        }

        var buttons = new List<InlineKeyboardButton[]>();
        foreach (var session in sessions)
        {
            var dateTitle = session.ScheduledAt.FormatMoscowShort();
            buttons.Add(
            [
                InlineKeyboardButton.WithCallbackData($"❌ {dateTitle}", $"cancel_session:{session.Id}"),
                InlineKeyboardButton.WithCallbackData($"⏰ {dateTitle}", $"reschedule_session:{session.Id}")
            ]);

            if (SessionCapacityRules.CanPromoteWaitlistedPlayer(session.MaxPlayers, session.PlayerCount, session.WaitlistCount))
            {
                buttons.Add(
                [
                    InlineKeyboardButton.WithCallbackData($"⬆️ Из ожидания {dateTitle}", $"promote_waitlist:{session.Id}")
                ]);
            }

            buttons.Add(
            [
                InlineKeyboardButton.WithCallbackData($"🗑 Удалить {dateTitle}", $"delete_session:{session.Id}")
            ]);
        }

        return (text, new InlineKeyboardMarkup(buttons));
    }
}

public sealed class ListSessionsHandler(
    NpgsqlDataSource dataSource,
    ITelegramBotClient botClient)
{
    public async Task HandleAsync(Message message, CancellationToken cancellationToken)
    {
        await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);

        var sessions = await connection.QueryAsync<SessionListItemDto>(
            @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt, s.status as Status, s.max_players as MaxPlayers,
                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Active) as PlayerCount,
                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Waitlisted) as WaitlistCount,
                     EXISTS (
                         SELECT 1
                         FROM group_managers gm
                         JOIN players manager_player ON manager_player.id = gm.player_id
                         WHERE gm.group_id = s.group_id
                           AND manager_player.telegram_id = @TelegramUserId
                     ) AS CanManage
              FROM sessions s
              JOIN game_groups g ON s.group_id = g.id
              LEFT JOIN session_participants sp ON s.id = sp.session_id
              WHERE g.telegram_chat_id = @ChatId AND s.status != @Cancelled AND s.scheduled_at > NOW()
              GROUP BY s.id, s.title, s.scheduled_at, s.status, s.max_players, s.group_id
              ORDER BY s.scheduled_at ASC",
            new
            {
                ChatId = message.Chat.Id,
                TelegramUserId = message.From?.Id,
                Cancelled = SessionStatus.Cancelled,
                Active = ParticipantRegistrationStatus.Active,
                Waitlisted = ParticipantRegistrationStatus.Waitlisted
            });

        var sessionsList = sessions.ToList();

        if (sessionsList.Count == 0)
        {
            await botClient.SendMessage(
                chatId: message.Chat.Id,
                text: "📭 В этой группе нет предстоящих игр.",
                cancellationToken: cancellationToken);
            return;
        }

        var renderResult = SessionListMessageRenderer.Render(sessionsList);

        await botClient.SendMessage(
            chatId: message.Chat.Id,
            text: renderResult.Text,
            parseMode: Telegram.Bot.Types.Enums.ParseMode.Html,
            replyMarkup: renderResult.Markup,
            cancellationToken: cancellationToken);
    }
}