using Microsoft.Extensions.Logging;
using PnvPanel.Application.Admin.Users;
using PnvPanel.Application.Auth;
using PnvPanel.Application.Billing;
using PnvPanel.Application.Common.Interfaces;
using PnvPanel.Application.Common.Messaging;
using PnvPanel.Application.Common.Models;
using PnvPanel.Domain.Audit;

namespace PnvPanel.Application.Admin.Billing;

public sealed class GrantBillingGiftCommandHandler(
    IAppDbContext dbContext,
    IIdentityService identityService,
    IXuiPanelGateway gateway,
    IRealtimeNotifier notifier,
    ITelegramNotifier telegramNotifier,
    ICurrentUser currentUser,
    ILogger<GrantBillingGiftCommandHandler> logger
) : ICommandHandler<GrantBillingGiftCommand, Result>
{
    public async Task<Result> Handle(GrantBillingGiftCommand command, CancellationToken cancellationToken)
    {
        if (currentUser.UserId is not { } adminId)
            return Result.Failure(AuthErrors.Unauthorized);

        var profile = await identityService.GetProfileAsync(command.UserId, cancellationToken);
        if (profile is null)
            return Result.Failure(UserErrors.NotFound);

        if (!profile.BillingEnabled)
            return Result.Failure(BillingErrors.NotEnabled);

        var now = DateTimeOffset.UtcNow;
        var baseline = profile.BillingPaidUntil is { } paidUntil && paidUntil > now ? paidUntil : now;
        var newPaidUntil = baseline.AddDays(command.Days);

        var extendResult = await identityService.ExtendBillingPaidUntilAsync(
            command.UserId,
            newPaidUntil,
            cancellationToken
        );
        if (!extendResult.IsSuccess)
            return extendResult;

        await BillingConfigResumer.ResumeConfigsAsync(
            dbContext,
            gateway,
            notifier,
            logger,
            command.UserId,
            newPaidUntil,
            cancellationToken
        );

        dbContext.AuditLogs.Add(
            AuditLog.Create(
                adminId,
                "BillingGiftGranted",
                "User",
                command.UserId.ToString(),
                metadata: $"{{\"days\":{command.Days}}}",
                AuditSource.Web
            )
        );

        await telegramNotifier.NotifyUserAsync(
            command.UserId,
            $"🎁 Вам подарено {command.Days} дн. подписки! Доступ продлён до {newPaidUntil:dd.MM.yyyy}.",
            "/billing",
            cancellationToken
        );

        return Result.Success();
    }
}