using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using NSubstitute;
using PnvPanel.Application.Auth;
using PnvPanel.Application.Common.Interfaces;
using PnvPanel.Application.Common.Models;
using PnvPanel.Application.Configs;
using PnvPanel.Application.Configs.Rotate;
using PnvPanel.Application.Tests.TestSupport;
using PnvPanel.Domain.Activation;
using PnvPanel.Domain.Apps;
using PnvPanel.Domain.Audit;
using PnvPanel.Domain.Billing;
using PnvPanel.Domain.Configs;
using PnvPanel.Domain.Inbounds;
using PnvPanel.Domain.Instructions;
using PnvPanel.Domain.News;
using PnvPanel.Domain.Nodes;
using PnvPanel.Domain.Plans;
using PnvPanel.Domain.Media;
using PnvPanel.Domain.Pricing;
using PnvPanel.Domain.Support;
using PnvPanel.Domain.Telegram;
using PnvPanel.Infrastructure.Persistence;
using Xunit;

namespace PnvPanel.Application.Tests.Configs.Rotate;

/// <summary>Оборачивает реальный AppDbContext, но всегда фейлит SaveChangesAsync — симулирует сбой БД
/// после успешного создания клиента в панели (DbUpdateException — единственный тип, который ловит
/// RotateVpnConfigCommandHandler для компенсирующего отката).</summary>
public sealed class ThrowingSaveDbContext(AppDbContext inner) : IAppDbContext
{
    public DbSet<ActivationRequest> ActivationRequests => inner.ActivationRequests;
    public DbSet<AuditLog> AuditLogs => inner.AuditLogs;
    public DbSet<TelegramLinkToken> TelegramLinkTokens => inner.TelegramLinkTokens;
    public DbSet<TelegramLoginRequest> TelegramLoginRequests => inner.TelegramLoginRequests;
    public DbSet<Node> Nodes => inner.Nodes;
    public DbSet<Inbound> Inbounds => inner.Inbounds;
    public DbSet<VpnConfig> VpnConfigs => inner.VpnConfigs;
    public DbSet<TrafficSample> TrafficSamples => inner.TrafficSamples;
    public DbSet<ClientApp> ClientApps => inner.ClientApps;
    public DbSet<NewsPost> NewsPosts => inner.NewsPosts;
    public DbSet<SupportTicket> SupportTickets => inner.SupportTickets;
    public DbSet<TicketComment> TicketComments => inner.TicketComments;
    public DbSet<TicketAttachment> TicketAttachments => inner.TicketAttachments;
    public DbSet<InstructionIntro> InstructionIntros => inner.InstructionIntros;
    public DbSet<InstructionTab> InstructionTabs => inner.InstructionTabs;
    public DbSet<MediaImage> MediaImages => inner.MediaImages;
    public DbSet<PricingSettings> PricingSettings => inner.PricingSettings;
    public DbSet<PricingDiscountTier> PricingDiscountTiers => inner.PricingDiscountTiers;
    public DbSet<BillingSettings> BillingSettings => inner.BillingSettings;
    public DbSet<PaymentRequest> PaymentRequests => inner.PaymentRequests;
    public DbSet<Plan> Plans => inner.Plans;
    public DatabaseFacade Database => inner.Database;

    public Task<int> SaveChangesAsync(CancellationToken cancellationToken) =>
        throw new DbUpdateException("simulated failure");
}

public class RotateVpnConfigCommandHandlerTests
{
    private readonly IXuiPanelGateway _gateway = Substitute.For<IXuiPanelGateway>();
    private readonly IIdentityService _identityService = Substitute.For<IIdentityService>();

    private static CurrentUserProfile MakeProfile(Guid userId) =>
        new(
            userId,
            "alice",
            Guid.NewGuid(),
            "user",
            true,
            false,
            3,
            null,
            RoleQuota.Unlimited,
            "sub-token",
            false,
            null,
            false
        );

    [Fact]
    public async Task Handle_WhenActiveConfigOwnedByUser_RotatesAndAddsNewClient()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(MakeProfile(userId));

        var node = Node.Register(
            "node-1",
            new Uri("https://node1.example.com"),
            new NodeCredentials("admin", "protected"),
            null
        );
        var inbound = Inbound.FromRemote(node.Id, "1", VpnProtocol.Vless, "remark", 443);
        var config = VpnConfig.Create(userId, inbound.Id, VpnProtocol.Vless, "my-config");
        config.AssignRemoteClient("old-external-id");

        dbContext.Nodes.Add(node);
        dbContext.Inbounds.Add(inbound);
        dbContext.VpnConfigs.Add(config);
        await dbContext.SaveChangesAsync(CancellationToken.None);

        _gateway
            .AddClientAsync(
                Arg.Any<Node>(),
                inbound.RemoteInboundId,
                config.Protocol,
                Arg.Any<string>(),
                Arg.Any<string>(),
                Arg.Any<int>(),
                Arg.Any<DateTimeOffset?>(),
                Arg.Any<CancellationToken>()
            )
            .Returns(Result.Success("new-external-id"));

        var handler = new RotateVpnConfigCommandHandler(
            dbContext,
            _gateway,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new RotateVpnConfigCommand(config.Id),
            CancellationToken.None
        );

        Assert.True(result.IsSuccess);
        Assert.Equal("new-external-id", config.ClientExternalId);
        await _gateway
            .Received(1)
            .RemoveClientAsync(
                Arg.Any<Node>(),
                inbound.RemoteInboundId,
                "old-external-id",
                config.Protocol,
                Arg.Any<CancellationToken>()
            );
    }

    [Fact]
    public async Task Handle_WhenConfigNotFound_ReturnsNotFound()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();

        var handler = new RotateVpnConfigCommandHandler(
            dbContext,
            _gateway,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new RotateVpnConfigCommand(Guid.NewGuid()),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(ConfigErrors.NotFound, result.Error);
    }

    [Fact]
    public async Task Handle_WhenConfigBelongsToAnotherUser_ReturnsNotFound()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var ownerId = Guid.NewGuid();
        var otherUserId = Guid.NewGuid();

        var inbound = Inbound.FromRemote(Guid.NewGuid(), "1", VpnProtocol.Vless, "remark", 443);
        var config = VpnConfig.Create(ownerId, inbound.Id, VpnProtocol.Vless, null);

        dbContext.Inbounds.Add(inbound);
        dbContext.VpnConfigs.Add(config);
        await dbContext.SaveChangesAsync(CancellationToken.None);

        var handler = new RotateVpnConfigCommandHandler(
            dbContext,
            _gateway,
            _identityService,
            FakeCurrentUser.Authenticated(otherUserId)
        );

        var result = await handler.Handle(
            new RotateVpnConfigCommand(config.Id),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(ConfigErrors.NotFound, result.Error);
    }

    [Fact]
    public async Task Handle_WhenConfigAlreadyRevoked_ReturnsNotFound()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();

        var inbound = Inbound.FromRemote(Guid.NewGuid(), "1", VpnProtocol.Vless, "remark", 443);
        var config = VpnConfig.Create(userId, inbound.Id, VpnProtocol.Vless, null);
        config.Revoke();

        dbContext.Inbounds.Add(inbound);
        dbContext.VpnConfigs.Add(config);
        await dbContext.SaveChangesAsync(CancellationToken.None);

        var handler = new RotateVpnConfigCommandHandler(
            dbContext,
            _gateway,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new RotateVpnConfigCommand(config.Id),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(ConfigErrors.NotFound, result.Error);
    }

    [Fact]
    public async Task Handle_WhenGatewayAddClientFails_ReturnsFailureWithoutMutatingConfig()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(MakeProfile(userId));

        var node = Node.Register(
            "node-1",
            new Uri("https://node1.example.com"),
            new NodeCredentials("admin", "protected"),
            null
        );
        var inbound = Inbound.FromRemote(node.Id, "1", VpnProtocol.Vless, "remark", 443);
        var config = VpnConfig.Create(userId, inbound.Id, VpnProtocol.Vless, null);
        config.AssignRemoteClient("old-external-id");

        dbContext.Nodes.Add(node);
        dbContext.Inbounds.Add(inbound);
        dbContext.VpnConfigs.Add(config);
        await dbContext.SaveChangesAsync(CancellationToken.None);

        var gatewayError = Error.Failure("Xui.Unreachable", "Панель недоступна.");
        _gateway
            .AddClientAsync(
                Arg.Any<Node>(),
                inbound.RemoteInboundId,
                config.Protocol,
                Arg.Any<string>(),
                Arg.Any<string>(),
                Arg.Any<int>(),
                Arg.Any<DateTimeOffset?>(),
                Arg.Any<CancellationToken>()
            )
            .Returns(Result.Failure<string>(gatewayError));

        var handler = new RotateVpnConfigCommandHandler(
            dbContext,
            _gateway,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new RotateVpnConfigCommand(config.Id),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(gatewayError, result.Error);
        Assert.Equal("old-external-id", config.ClientExternalId);
    }

    [Fact]
    public async Task Handle_WhenSaveChangesFailsAfterAddClient_RemovesOrphanedClientAndReturnsRotateFailed()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(MakeProfile(userId));

        var node = Node.Register(
            "node-1",
            new Uri("https://node1.example.com"),
            new NodeCredentials("admin", "protected"),
            null
        );
        var inbound = Inbound.FromRemote(node.Id, "1", VpnProtocol.Vless, "remark", 443);
        var config = VpnConfig.Create(userId, inbound.Id, VpnProtocol.Vless, null);
        config.AssignRemoteClient("old-external-id");

        dbContext.Nodes.Add(node);
        dbContext.Inbounds.Add(inbound);
        dbContext.VpnConfigs.Add(config);
        await dbContext.SaveChangesAsync(CancellationToken.None);

        _gateway
            .AddClientAsync(
                Arg.Any<Node>(),
                inbound.RemoteInboundId,
                config.Protocol,
                Arg.Any<string>(),
                Arg.Any<string>(),
                Arg.Any<int>(),
                Arg.Any<DateTimeOffset?>(),
                Arg.Any<CancellationToken>()
            )
            .Returns(Result.Success("new-external-id"));

        var handler = new RotateVpnConfigCommandHandler(
            new ThrowingSaveDbContext(dbContext),
            _gateway,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new RotateVpnConfigCommand(config.Id),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(ConfigErrors.RotateFailed, result.Error);
        // Осиротевший клиент, успевший создаться в панели до сбоя SaveChanges, откатывается.
        await _gateway
            .Received(1)
            .RemoveClientAsync(
                Arg.Any<Node>(),
                inbound.RemoteInboundId,
                "new-external-id",
                config.Protocol,
                Arg.Any<CancellationToken>()
            );
        await _gateway
            .DidNotReceive()
            .RemoveClientAsync(
                Arg.Any<Node>(),
                inbound.RemoteInboundId,
                "old-external-id",
                config.Protocol,
                Arg.Any<CancellationToken>()
            );
    }
}