using Microsoft.EntityFrameworkCore;
using PnvPanel.Application.Auth;
using PnvPanel.Application.Common.Interfaces;
using PnvPanel.Application.Common.Messaging;
using PnvPanel.Application.Common.Models;
using PnvPanel.Application.Telegram;
using PnvPanel.Domain.Billing;

namespace PnvPanel.Application.Billing.SendRequisitesToTelegram;

public sealed class SendRequisitesToTelegramCommandHandler(
    IAppDbContext dbContext,
    IIdentityService identityService,
    ITelegramNotifier telegramNotifier,
    ICurrentUser currentUser
) : ICommandHandler<SendRequisitesToTelegramCommand, Result>
{
    public async Task<Result> Handle(
        SendRequisitesToTelegramCommand command,
        CancellationToken cancellationToken
    )
    {
        if (currentUser.UserId is not { } userId)
            return Result.Failure(AuthErrors.Unauthorized);

        var request = await dbContext
            .PaymentRequests.AsNoTracking()
            .FirstOrDefaultAsync(r => r.Id == command.RequestId && r.UserId == userId, cancellationToken);
        if (request is null)
            return Result.Failure(BillingErrors.RequestNotFound);

        var linkInfo = await identityService.GetTelegramLinkInfoAsync(userId, cancellationToken);
        if (!linkInfo.IsLinked)
            return Result.Failure(TelegramErrors.NotLinked);

        var settings = await dbContext
            .BillingSettings.AsNoTracking()
            .FirstOrDefaultAsync(cancellationToken);

        var text =
            $"💳 Реквизиты для оплаты ({DescribeRequest(request)}, {request.AmountSnapshot} ₽):\n{settings?.RequisitesText}";

        await telegramNotifier.NotifyUserAsync(userId, text, null, cancellationToken);

        return Result.Success();
    }

    private static string DescribeRequest(PaymentRequest request) =>
        request.Kind == PaymentRequestKind.RoleChangeTopUp ? "доплата за смену роли" : PeriodLabel(request.Period!.Value);

    private static string PeriodLabel(PaymentPeriod period) =>
        period switch
        {
            PaymentPeriod.Quarter => "3 месяца",
            PaymentPeriod.HalfYear => "полгода",
            PaymentPeriod.Year => "год",
            _ => period.ToString(),
        };
}