using Dapper;
using Npgsql;
using Telegram.Bot;

namespace GmRelay.Bot.Features.Sessions.RescheduleSession;

// ── Command ──────────────────────────────────────────────────────────

public sealed record InitiateRescheduleCommand(
    Guid SessionId,
    long TelegramUserId,
    string CallbackQueryId,
    long ChatId,
    int MessageId);

// ── DTOs ─────────────────────────────────────────────────────────────

internal sealed record RescheduleSessionInfoDto(string Title, long GmId);

// ── Handler ──────────────────────────────────────────────────────────

/// <summary>
/// Handles the "⏰ Перенести" button press from the batch message.
/// Creates a reschedule proposal in AwaitingTime status and prompts
/// the GM to enter the new time via a regular text message.
/// </summary>
public sealed class InitiateRescheduleHandler(
    NpgsqlDataSource dataSource,
    ITelegramBotClient bot,
    ILogger<InitiateRescheduleHandler> logger)
{
    public async Task HandleAsync(InitiateRescheduleCommand command, CancellationToken ct)
    {
        await using var connection = await dataSource.OpenConnectionAsync(ct);

        // 1. Verify GM ownership
        var session = await connection.QuerySingleOrDefaultAsync<RescheduleSessionInfoDto>(
            """
            SELECT s.title AS Title, g.gm_telegram_id AS GmId
            FROM sessions s
            JOIN game_groups g ON s.group_id = g.id
            WHERE s.id = @SessionId AND s.status != 'Cancelled'
            """,
            new { command.SessionId });

        if (session is null)
        {
            await bot.AnswerCallbackQuery(command.CallbackQueryId, "Сессия не найдена.", cancellationToken: ct);
            return;
        }

        if (session.GmId != command.TelegramUserId)
        {
            await bot.AnswerCallbackQuery(command.CallbackQueryId,
                "Только Мастер Игры (GM) может переносить сессию.", showAlert: true, cancellationToken: ct);
            return;
        }

        // 2. Check no active proposal exists
        var hasActive = await connection.ExecuteScalarAsync<bool>(
            """
            SELECT EXISTS (
                SELECT 1 FROM reschedule_proposals
                WHERE session_id = @SessionId AND status IN ('AwaitingTime', 'Voting')
            )
            """,
            new { command.SessionId });

        if (hasActive)
        {
            await bot.AnswerCallbackQuery(command.CallbackQueryId,
                "Уже есть активный запрос на перенос этой сессии.", showAlert: true, cancellationToken: ct);
            return;
        }

        // 3. Create proposal in AwaitingTime status
        await connection.ExecuteAsync(
            """
            INSERT INTO reschedule_proposals (session_id, proposed_by, status)
            VALUES (@SessionId, @GmId, 'AwaitingTime')
            """,
            new { command.SessionId, GmId = command.TelegramUserId });

        logger.LogInformation("Reschedule initiated for session {SessionId} by GM {GmId}", command.SessionId, command.TelegramUserId);

        // 4. Prompt GM in chat
        await bot.AnswerCallbackQuery(command.CallbackQueryId,
            "Введите новое время в чат (формат: ДД.ММ.ГГГГ ЧЧ:ММ)", cancellationToken: ct);

        await bot.SendMessage(
            chatId: command.ChatId,
            text: $"⏰ Укажите новое время для сессии «{session.Title}» в формате:\n<code>ДД.ММ.ГГГГ ЧЧ:ММ</code>\n\nНапример: <code>25.04.2026 19:30</code>",
            parseMode: Telegram.Bot.Types.Enums.ParseMode.Html,
            cancellationToken: ct);
    }
}