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

namespace GmRelay.Bot.Features.Sessions.CreateSession;

public sealed class CreateSessionHandler(
    NpgsqlDataSource dataSource,
    ITelegramBotClient botClient,
    ILogger<CreateSessionHandler> logger)
{
    public async Task HandleAsync(Message message, CancellationToken cancellationToken)
    {
        var parseResult = NewSessionCommandParser.Parse(message.Text, DateTimeOffset.UtcNow);

        foreach (var timeInput in parseResult.PastTimeInputs)
        {
            await botClient.SendMessage(
                message.Chat.Id,
                $"⚠️ Предупреждение: дата {timeInput} находится в прошлом и будет пропущена.",
                cancellationToken: cancellationToken);
        }

        foreach (var timeInput in parseResult.InvalidTimeInputs)
        {
            await botClient.SendMessage(
                message.Chat.Id,
                $"⚠️ Предупреждение: некорректный формат времени '{timeInput}'. Пропущено.",
                cancellationToken: cancellationToken);
        }

        foreach (var seatLimitInput in parseResult.InvalidSeatLimitInputs)
        {
            await botClient.SendMessage(
                message.Chat.Id,
                $"⚠️ Предупреждение: некорректный лимит мест '{seatLimitInput}'. Укажите целое число больше 0.",
                cancellationToken: cancellationToken);
        }

        if (!parseResult.IsValid)
        {
            await botClient.SendMessage(
                chatId: message.Chat.Id,
                text: "❌ Не удалось распознать формат. Пожалуйста, используйте шаблон:\n\n/newsession\nНазвание: My Game\nВремя: 15.05.2026 19:30\nВремя: 22.05.2026 19:30\nМест: 4\nСсылка: https://link",
                cancellationToken: cancellationToken);
            return;
        }

        var title = parseResult.Title!;
        var link = parseResult.Link!;
        var gmId = message.From!.Id;
        var gmName = message.From.FirstName + (string.IsNullOrEmpty(message.From.LastName) ? string.Empty : $" {message.From.LastName}");
        var gmUsername = message.From.Username;

        var chatId = message.Chat.Id;
        var chatTitle = message.Chat.Title ?? "Private Chat";

        await using var connection = await dataSource.OpenConnectionAsync(cancellationToken);
        await using var transaction = await connection.BeginTransactionAsync(cancellationToken);

        try
        {
            await connection.ExecuteAsync(
                """
                INSERT INTO players (telegram_id, display_name, telegram_username)
                VALUES (@TgId, @Name, @Username)
                ON CONFLICT (telegram_id) DO UPDATE
                SET display_name = EXCLUDED.display_name,
                    telegram_username = EXCLUDED.telegram_username;
                """,
                new { TgId = gmId, Name = gmName, Username = gmUsername },
                transaction);

            var groupId = await connection.ExecuteScalarAsync<Guid>(
                """
                INSERT INTO game_groups (telegram_chat_id, name, gm_telegram_id)
                VALUES (@ChatId, @ChatName, @GmId)
                ON CONFLICT (telegram_chat_id) DO UPDATE SET name = EXCLUDED.name
                RETURNING id;
                """,
                new { ChatId = chatId, ChatName = chatTitle, GmId = gmId },
                transaction);

            int? messageThreadId = null;
            if (message.Chat.IsForum)
            {
                var topic = await botClient.CreateForumTopic(
                    chatId: chatId,
                    name: $"🎲 Игры: {title}",
                    cancellationToken: cancellationToken);
                messageThreadId = topic.MessageThreadId;
            }

            var batchId = Guid.NewGuid();
            var sessions = new List<SessionBatchDto>();

            foreach (var scheduledAt in parseResult.ScheduledTimes.OrderBy(value => value))
            {
                var sessionId = await connection.ExecuteScalarAsync<Guid>(
                    """
                    INSERT INTO sessions (batch_id, group_id, title, join_link, scheduled_at, status, thread_id, max_players)
                    VALUES (@BatchId, @GroupId, @Title, @Link, @ScheduledAt, @Status, @ThreadId, @MaxPlayers)
                    RETURNING id;
                    """,
                    new
                    {
                        BatchId = batchId,
                        GroupId = groupId,
                        Title = title,
                        Link = link,
                        ScheduledAt = scheduledAt,
                        ThreadId = messageThreadId,
                        MaxPlayers = parseResult.MaxPlayers,
                        Status = SessionStatus.Planned
                    },
                    transaction);

                sessions.Add(new SessionBatchDto(sessionId, scheduledAt.UtcDateTime, SessionStatus.Planned, parseResult.MaxPlayers));
            }

            await transaction.CommitAsync(cancellationToken);
            logger.LogInformation("Создан батч {BatchId} с {Count} сессиями в группе {GroupId}", batchId, sessions.Count, groupId);

            var renderResult = SessionBatchRenderer.Render(title, sessions, Array.Empty<ParticipantBatchDto>());

            var batchMessage = await botClient.SendMessage(
                chatId: chatId,
                messageThreadId: messageThreadId,
                text: renderResult.Text,
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Html,
                replyMarkup: renderResult.Markup,
                cancellationToken: cancellationToken);

            await connection.ExecuteAsync(
                "UPDATE sessions SET batch_message_id = @MsgId WHERE batch_id = @BatchId",
                new { MsgId = batchMessage.MessageId, BatchId = batchId });

            try
            {
                await botClient.DeleteMessage(
                    chatId: chatId,
                    messageId: message.MessageId,
                    cancellationToken: cancellationToken);
            }
            catch (Exception ex)
            {
                logger.LogWarning(ex, "Не удалось удалить исходное сообщение {MessageId} в чате {ChatId}", message.MessageId, chatId);
            }
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "Ошибка при создании сессии");
            await transaction.RollbackAsync(cancellationToken);
            await botClient.SendMessage(chatId, "💥 Произошла ошибка базы данных при создании сессии.", cancellationToken: cancellationToken);
        }
    }
}