using EntKube.Provisioning.Domain;
using EntKube.Provisioning.Features.MongoClusters;
using EntKube.Provisioning.Features.MongoClusters.AdoptMongoCluster;
using EntKube.Provisioning.Features.MongoClusters.CreateMongoCluster;
using EntKube.Provisioning.Features.MongoClusters.AddDatabase;
using EntKube.Provisioning.Features.MongoClusters.UpgradeMongoCluster;
using EntKube.Provisioning.Features.MongoClusters.ConfigureMongoCluster;
using EntKube.Provisioning.Features.MongoClusters.RestoreBackup;
using EntKube.Provisioning.Infrastructure;
using EntKube.SharedKernel.Domain;
using FluentAssertions;
using Moq;

namespace EntKube.Provisioning.Tests.Features;

/// <summary>
/// Tests for all MongoDB cluster management features. Each test verifies that
/// the handler correctly orchestrates domain logic + K8s client interactions.
/// </summary>
public class MongoClusterFeatureTests
{
    private readonly InMemoryMongoClusterRepository repository;
    private readonly InMemoryMinioInstanceRepository minioRepository;
    private readonly Mock<IMongoClusterClient> mongoClient;

    public MongoClusterFeatureTests()
    {
        repository = new InMemoryMongoClusterRepository();
        minioRepository = new InMemoryMinioInstanceRepository();
        mongoClient = new Mock<IMongoClusterClient>();
    }

    // ─── Create Cluster ───────────────────────────────────────────────────────

    [Fact]
    public async Task CreateCluster_WithValidRequest_CreatesAndCallsK8sClient()
    {
        // Arrange — A platform admin wants a new 3-member MongoDB replica set
        // with mongodump backups to MinIO.

        CreateMongoClusterHandler handler = new(repository, mongoClient.Object, minioRepository);

        CreateMongoClusterRequest request = new(
            EnvironmentId: Guid.NewGuid(),
            ClusterId: Guid.NewGuid(),
            Name: "platform-mongo",
            Namespace: "mongodb-system",
            MongoVersion: "7.0.12",
            Members: 3,
            StorageSize: "50Gi",
            KubeConfig: "apiVersion: v1\nkind: Config",
            ContextName: "prod-ctx",
            MinioEndpoint: "minio.minio-system.svc:9000",
            MinioBucket: "mongo-backups",
            MinioCredentialsSecret: "minio-mongo-creds");

        // Act

        Result<Guid> result = await handler.HandleAsync(request);

        // Assert — Cluster created in repository and K8s client called.

        result.IsSuccess.Should().BeTrue();
        result.Value.Should().NotBe(Guid.Empty);

        IReadOnlyList<MongoCluster> clusters = await repository.GetAllAsync();
        clusters.Should().HaveCount(1);
        clusters[0].Name.Should().Be("platform-mongo");
        clusters[0].Status.Should().Be(MongoClusterStatus.Provisioning);

        mongoClient.Verify(c => c.CreateClusterAsync(
            "apiVersion: v1\nkind: Config",
            "prod-ctx",
            It.Is<MongoClusterSpec>(s =>
                s.Name == "platform-mongo" &&
                s.MongoVersion == "7.0.12" &&
                s.Members == 3 &&
                s.MinioEndpoint == "minio.minio-system.svc:9000"),
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task CreateCluster_WithMissingName_ReturnsFailure()
    {
        // Arrange

        CreateMongoClusterHandler handler = new(repository, mongoClient.Object, minioRepository);

        CreateMongoClusterRequest request = new(
            EnvironmentId: Guid.NewGuid(),
            ClusterId: Guid.NewGuid(),
            Name: "",
            Namespace: "ns",
            MongoVersion: "7.0.12",
            Members: 3,
            StorageSize: "50Gi",
            KubeConfig: "config",
            ContextName: "ctx",
            MinioEndpoint: "minio:9000",
            MinioBucket: "bucket",
            MinioCredentialsSecret: "secret");

        // Act

        Result<Guid> result = await handler.HandleAsync(request);

        // Assert

        result.IsFailure.Should().BeTrue();
        result.Error.Should().Contain("name");
    }

    // ─── Adopt Cluster ────────────────────────────────────────────────────────

    [Fact]
    public async Task AdoptCluster_WithDiscoveredClusters_ImportsAll()
    {
        // Arrange — The K8s cluster has 2 existing MongoDBCommunity clusters.

        mongoClient.Setup(c => c.DiscoverClustersAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<DiscoveredMongoCluster>
            {
                new("prod-mongo", "mongodb-system", "7.0.12", 3, "100Gi",
                    new List<string> { "app_db", "analytics_db" },
                    "minio.minio-system.svc:9000", "mongo-backups", "minio-creds"),
                new("staging-mongo", "mongodb-staging", "6.0.16", 1, "20Gi",
                    new List<string> { "staging_db" },
                    "minio.minio-system.svc:9000", "mongo-backups-staging", "minio-creds")
            });

        AdoptMongoClustersHandler handler = new(repository, mongoClient.Object);

        AdoptMongoClustersRequest request = new(
            EnvironmentId: Guid.NewGuid(),
            ClusterId: Guid.NewGuid(),
            KubeConfig: "config",
            ContextName: "ctx");

        // Act

        Result<List<Guid>> result = await handler.HandleAsync(request);

        // Assert — Both clusters adopted and stored in Running state.

        result.IsSuccess.Should().BeTrue();
        result.Value.Should().HaveCount(2);

        IReadOnlyList<MongoCluster> all = await repository.GetAllAsync();
        all.Should().HaveCount(2);
        all[0].Status.Should().Be(MongoClusterStatus.Running);
        all[0].Databases.Should().Contain("app_db");
        all[1].Databases.Should().Contain("staging_db");
    }

    [Fact]
    public async Task AdoptCluster_WithNoClusters_ReturnsEmptyList()
    {
        // Arrange — No MongoDBCommunity clusters found on K8s.

        mongoClient.Setup(c => c.DiscoverClustersAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<DiscoveredMongoCluster>());

        AdoptMongoClustersHandler handler = new(repository, mongoClient.Object);

        AdoptMongoClustersRequest request = new(Guid.NewGuid(), Guid.NewGuid(), "config", "ctx");

        // Act

        Result<List<Guid>> result = await handler.HandleAsync(request);

        // Assert

        result.IsSuccess.Should().BeTrue();
        result.Value.Should().BeEmpty();
    }

    // ─── Add Database ─────────────────────────────────────────────────────────

    [Fact]
    public async Task AddDatabase_ToRunningCluster_CreatesDatabaseOnK8s()
    {
        // Arrange — A running MongoDB cluster exists.

        MongoCluster mongoCluster = MongoCluster.Create(
            Guid.NewGuid(), Guid.NewGuid(), "prod-mongo", "mongodb-system", "7.0.12", 3, "50Gi",
            "minio:9000", "bucket", "secret");
        mongoCluster.MarkRunning();
        await repository.AddAsync(mongoCluster);

        AddMongoDatabaseHandler handler = new(repository, mongoClient.Object);

        AddMongoDatabaseRequest request = new(
            MongoClusterId: mongoCluster.Id,
            DatabaseName: "new_app_db",
            OwnerRole: "app_user",
            KubeConfig: "config",
            ContextName: "ctx");

        // Act

        Result<string> result = await handler.HandleAsync(request);

        // Assert

        result.IsSuccess.Should().BeTrue();

        MongoCluster? updated = await repository.GetByIdAsync(mongoCluster.Id);
        updated!.Databases.Should().Contain("new_app_db");

        mongoClient.Verify(c => c.CreateDatabaseAsync(
            "config", "ctx", "prod-mongo", "mongodb-system", "new_app_db", "app_user",
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task AddDatabase_ToNonExistentCluster_ReturnsFailure()
    {
        // Arrange

        AddMongoDatabaseHandler handler = new(repository, mongoClient.Object);

        AddMongoDatabaseRequest request = new(Guid.NewGuid(), "db", "user", "config", "ctx");

        // Act

        Result<string> result = await handler.HandleAsync(request);

        // Assert

        result.IsFailure.Should().BeTrue();
        result.Error.Should().Contain("not found");
    }

    // ─── Upgrade Cluster ──────────────────────────────────────────────────────

    [Fact]
    public async Task UpgradeCluster_WithValidVersion_InitiatesUpgradeOnK8s()
    {
        // Arrange — A running cluster at version 6.0.16.

        MongoCluster mongoCluster = MongoCluster.Create(
            Guid.NewGuid(), Guid.NewGuid(), "prod-mongo", "mongodb-system", "6.0.16", 3, "50Gi",
            "minio:9000", "bucket", "secret");
        mongoCluster.MarkRunning();
        await repository.AddAsync(mongoCluster);

        mongoClient.Setup(c => c.GetAvailableVersionsAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<string> { "6.0.16", "6.0.17", "7.0.12", "7.0.14" });

        UpgradeMongoClusterHandler handler = new(repository, mongoClient.Object);

        UpgradeMongoClusterRequest request = new(
            MongoClusterId: mongoCluster.Id,
            TargetVersion: "7.0.12",
            KubeConfig: "config",
            ContextName: "ctx");

        // Act

        Result<string> result = await handler.HandleAsync(request);

        // Assert — Domain transitions to Upgrading, K8s client called.

        result.IsSuccess.Should().BeTrue();

        MongoCluster? updated = await repository.GetByIdAsync(mongoCluster.Id);
        updated!.Status.Should().Be(MongoClusterStatus.Upgrading);
        updated.TargetVersion.Should().Be("7.0.12");

        mongoClient.Verify(c => c.UpgradeClusterAsync(
            "config", "ctx", "prod-mongo", "mongodb-system", "7.0.12",
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task UpgradeCluster_ToUnavailableVersion_ReturnsFailure()
    {
        // Arrange — Version 99.0 doesn't exist.

        MongoCluster mongoCluster = MongoCluster.Create(
            Guid.NewGuid(), Guid.NewGuid(), "prod-mongo", "mongodb-system", "7.0.12", 3, "50Gi",
            "minio:9000", "bucket", "secret");
        mongoCluster.MarkRunning();
        await repository.AddAsync(mongoCluster);

        mongoClient.Setup(c => c.GetAvailableVersionsAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<string> { "7.0.12", "7.0.14" });

        UpgradeMongoClusterHandler handler = new(repository, mongoClient.Object);

        UpgradeMongoClusterRequest request = new(mongoCluster.Id, "99.0", "config", "ctx");

        // Act

        Result<string> result = await handler.HandleAsync(request);

        // Assert

        result.IsFailure.Should().BeTrue();
        result.Error.Should().Contain("not available");
    }

    // ─── Configure Cluster ────────────────────────────────────────────────────

    [Fact]
    public async Task ConfigureCluster_ScaleMembers_UpdatesK8sAndDomain()
    {
        // Arrange — Scale a running cluster from 3 to 5 members.

        MongoCluster mongoCluster = MongoCluster.Create(
            Guid.NewGuid(), Guid.NewGuid(), "prod-mongo", "mongodb-system", "7.0.12", 3, "50Gi",
            "minio:9000", "bucket", "secret");
        mongoCluster.MarkRunning();
        await repository.AddAsync(mongoCluster);

        ConfigureMongoClusterHandler handler = new(repository, mongoClient.Object);

        ConfigureMongoClusterRequest request = new(
            MongoClusterId: mongoCluster.Id,
            Members: 5,
            StorageSize: null,
            BackupSchedule: null,
            BackupRetentionDays: null,
            KubeConfig: "config",
            ContextName: "ctx");

        // Act

        Result<string> result = await handler.HandleAsync(request);

        // Assert

        result.IsSuccess.Should().BeTrue();

        MongoCluster? updated = await repository.GetByIdAsync(mongoCluster.Id);
        updated!.Members.Should().Be(5);

        mongoClient.Verify(c => c.UpdateClusterAsync(
            "config", "ctx",
            It.Is<MongoClusterSpec>(s => s.Members == 5),
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task ConfigureCluster_UpdateBackupSchedule_UpdatesBackupCronJob()
    {
        // Arrange — Change backup schedule to every 6 hours with 30-day retention.

        MongoCluster mongoCluster = MongoCluster.Create(
            Guid.NewGuid(), Guid.NewGuid(), "prod-mongo", "mongodb-system", "7.0.12", 3, "50Gi",
            "minio:9000", "bucket", "secret");
        mongoCluster.MarkRunning();
        await repository.AddAsync(mongoCluster);

        ConfigureMongoClusterHandler handler = new(repository, mongoClient.Object);

        ConfigureMongoClusterRequest request = new(
            MongoClusterId: mongoCluster.Id,
            Members: null,
            StorageSize: null,
            BackupSchedule: "0 */6 * * *",
            BackupRetentionDays: 30,
            KubeConfig: "config",
            ContextName: "ctx");

        // Act

        Result<string> result = await handler.HandleAsync(request);

        // Assert

        result.IsSuccess.Should().BeTrue();

        MongoCluster? updated = await repository.GetByIdAsync(mongoCluster.Id);
        updated!.BackupConfig!.Schedule.Should().Be("0 */6 * * *");
        updated.BackupConfig.RetentionDays.Should().Be(30);

        mongoClient.Verify(c => c.ConfigureScheduledBackupAsync(
            "config", "ctx", "prod-mongo", "mongodb-system", "0 */6 * * *", 30,
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task ConfigureCluster_NonExistent_ReturnsFailure()
    {
        // Arrange

        ConfigureMongoClusterHandler handler = new(repository, mongoClient.Object);

        ConfigureMongoClusterRequest request = new(
            Guid.NewGuid(), Members: 5, StorageSize: null,
            BackupSchedule: null, BackupRetentionDays: null,
            KubeConfig: "config", ContextName: "ctx");

        // Act

        Result<string> result = await handler.HandleAsync(request);

        // Assert

        result.IsFailure.Should().BeTrue();
        result.Error.Should().Contain("not found");
    }

    // ─── Adopt De-duplication ─────────────────────────────────────────────────

    [Fact]
    public async Task AdoptCluster_WhenClusterAlreadyAdopted_SkipsDuplicate()
    {
        // Arrange — The platform already has a cluster adopted. Re-running
        // discovery should not create a duplicate but update databases.

        Guid clusterId = Guid.NewGuid();

        MongoCluster existing = MongoCluster.Adopt(
            Guid.NewGuid(), clusterId, "prod-mongo", "mongodb-system", "7.0.12", 3, "100Gi",
            "minio:9000", "mongo-backups", "minio-creds",
            databases: new List<string> { "app_db" });

        await repository.AddAsync(existing);

        mongoClient.Setup(c => c.DiscoverClustersAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<DiscoveredMongoCluster>
            {
                new("prod-mongo", "mongodb-system", "7.0.12", 3, "100Gi",
                    new List<string> { "app_db", "analytics_db" },
                    "minio:9000", "mongo-backups", "minio-creds"),
                new("new-mongo", "mongodb-staging", "6.0.17", 1, "20Gi",
                    new List<string> { "staging_db" },
                    "minio:9000", "mongo-backups-staging", "minio-creds")
            });

        AdoptMongoClustersHandler handler = new(repository, mongoClient.Object);

        AdoptMongoClustersRequest request = new(Guid.NewGuid(), clusterId, "config", "ctx");

        // Act

        Result<List<Guid>> result = await handler.HandleAsync(request);

        // Assert — Only the new cluster is adopted, the existing one is updated.

        result.IsSuccess.Should().BeTrue();

        IReadOnlyList<MongoCluster> all = await repository.GetByClusterIdAsync(clusterId);
        all.Should().HaveCount(2);
        all.Should().ContainSingle(c => c.Name == "prod-mongo");
        all.Should().ContainSingle(c => c.Name == "new-mongo");

        // The existing cluster's databases should be updated.

        MongoCluster? updated = all.First(c => c.Name == "prod-mongo");
        updated.Databases.Should().Contain("analytics_db");
    }

    [Fact]
    public async Task AdoptCluster_WithClusterWithoutBackup_AdoptsWithDefaults()
    {
        // Arrange — A MongoDBCommunity cluster with no MinIO backup configured.

        mongoClient.Setup(c => c.DiscoverClustersAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<DiscoveredMongoCluster>
            {
                new("dev-mongo", "default", "7.0.12", 1, "10Gi",
                    new List<string> { "myapp" },
                    null, null, null)
            });

        AdoptMongoClustersHandler handler = new(repository, mongoClient.Object);

        AdoptMongoClustersRequest request = new(Guid.NewGuid(), Guid.NewGuid(), "config", "ctx");

        // Act

        Result<List<Guid>> result = await handler.HandleAsync(request);

        // Assert — Cluster adopted with default MinIO settings.

        result.IsSuccess.Should().BeTrue();
        result.Value.Should().HaveCount(1);

        IReadOnlyList<MongoCluster> all = await repository.GetAllAsync();
        all[0].Name.Should().Be("dev-mongo");
        all[0].Status.Should().Be(MongoClusterStatus.Running);
    }

    // ─── Restore Backup ───────────────────────────────────────────────────────

    [Fact]
    public async Task RestoreBackup_WithValidCluster_CallsMongoClient()
    {
        // Arrange — A running cluster with a backup we want to restore from.

        MongoCluster mongoCluster = MongoCluster.Adopt(
            Guid.NewGuid(), Guid.NewGuid(), "prod-mongo", "mongodb-system", "7.0.12", 3, "50Gi",
            "minio:9000", "bucket", "secret",
            databases: new List<string> { "app_db" });

        await repository.AddAsync(mongoCluster);

        RestoreMongoBackupHandler handler = new(repository, mongoClient.Object);

        RestoreMongoBackupRequest request = new(
            MongoClusterId: mongoCluster.Id,
            BackupName: "prod-mongo-dump-20250510120000",
            RestoredClusterName: "prod-mongo-restored",
            KubeConfig: "config",
            ContextName: "ctx",
            TargetTime: null);

        // Act

        Result<Guid> result = await handler.HandleAsync(request);

        // Assert — A new cluster should be created from the backup.

        result.IsSuccess.Should().BeTrue();

        mongoClient.Verify(c => c.RestoreBackupAsync(
            "config", "ctx",
            It.Is<RestoreFromMongoBackupSpec>(s =>
                s.SourceClusterName == "prod-mongo" &&
                s.RestoredClusterName == "prod-mongo-restored" &&
                s.BackupName == "prod-mongo-dump-20250510120000" &&
                s.Namespace == "mongodb-system"),
            It.IsAny<CancellationToken>()), Times.Once);

        // The restored cluster should be persisted as a new aggregate.

        IReadOnlyList<MongoCluster> all = await repository.GetAllAsync();
        all.Should().HaveCount(2);
        all.Should().ContainSingle(c => c.Name == "prod-mongo-restored");
    }

    [Fact]
    public async Task RestoreBackup_WithPointInTimeRecovery_PassesTargetTime()
    {
        // Arrange — Restore to a specific point in time using oplog replay.

        MongoCluster mongoCluster = MongoCluster.Adopt(
            Guid.NewGuid(), Guid.NewGuid(), "prod-mongo", "mongodb-system", "7.0.12", 3, "50Gi",
            "minio:9000", "bucket", "secret");

        await repository.AddAsync(mongoCluster);

        RestoreMongoBackupHandler handler = new(repository, mongoClient.Object);

        DateTimeOffset targetTime = new(2025, 5, 10, 10, 30, 0, TimeSpan.Zero);

        RestoreMongoBackupRequest request = new(
            MongoClusterId: mongoCluster.Id,
            BackupName: null,
            RestoredClusterName: "prod-mongo-pitr",
            KubeConfig: "config",
            ContextName: "ctx",
            TargetTime: targetTime);

        // Act

        Result<Guid> result = await handler.HandleAsync(request);

        // Assert

        result.IsSuccess.Should().BeTrue();

        mongoClient.Verify(c => c.RestoreBackupAsync(
            "config", "ctx",
            It.Is<RestoreFromMongoBackupSpec>(s =>
                s.TargetTime == targetTime &&
                s.RestoredClusterName == "prod-mongo-pitr"),
            It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task RestoreBackup_SourceClusterNotFound_ReturnsFailure()
    {
        // Arrange

        RestoreMongoBackupHandler handler = new(repository, mongoClient.Object);

        RestoreMongoBackupRequest request = new(
            Guid.NewGuid(), "backup-name", "restored-cluster", "config", "ctx", null);

        // Act

        Result<Guid> result = await handler.HandleAsync(request);

        // Assert

        result.IsFailure.Should().BeTrue();
        result.Error.Should().Contain("not found");
    }

    // ─── List Live Databases ──────────────────────────────────────────────────

    [Fact]
    public async Task AdoptCluster_WithLiveDatabases_IncludesAllDatabases()
    {
        // Arrange — Discovery from the CRD spec only finds configured databases,
        // but the live MongoDB has additional databases created via shell.

        mongoClient.Setup(c => c.DiscoverClustersAsync(
            It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<DiscoveredMongoCluster>
            {
                new("prod-mongo", "mongodb-system", "7.0.12", 3, "100Gi",
                    new List<string> { "app_db" },
                    "minio:9000", "mongo-backups", "minio-creds")
            });

        // The live database listing discovers additional databases.

        mongoClient.Setup(c => c.ListLiveDatabasesAsync(
            It.IsAny<string>(), It.IsAny<string>(),
            "prod-mongo", "mongodb-system", It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<string> { "app_db", "analytics_db", "reporting_db" });

        AdoptMongoClustersHandler handler = new(repository, mongoClient.Object);

        AdoptMongoClustersRequest request = new(Guid.NewGuid(), Guid.NewGuid(), "config", "ctx");

        // Act

        Result<List<Guid>> result = await handler.HandleAsync(request);

        // Assert — All three databases should be imported.

        result.IsSuccess.Should().BeTrue();

        IReadOnlyList<MongoCluster> all = await repository.GetAllAsync();
        all[0].Databases.Should().HaveCount(3);
        all[0].Databases.Should().Contain("app_db");
        all[0].Databases.Should().Contain("analytics_db");
        all[0].Databases.Should().Contain("reporting_db");
    }
}