using EntKube.Provisioning.Domain;
using FluentAssertions;

namespace EntKube.Provisioning.Tests.Domain;

public class GrafanaInstanceTests
{
    private readonly Guid environmentId = Guid.NewGuid();
    private readonly Guid clusterId = Guid.NewGuid();

    // ─── Creation ───────────────────────────────────────────────────────

    [Fact]
    public void Create_WithValidInputs_CreatesInstanceInPendingState()
    {
        // Arrange & Act — An operator provisions a Grafana instance for an environment.
        // Grafana is per-environment: one centralized visualization for all clusters
        // in that environment, deployed to a specific cluster.

        GrafanaInstance instance = GrafanaInstance.Create(
            environmentId, clusterId, "prod-grafana", "monitoring");

        // Assert — The instance should be in Pending state with sensible defaults.

        instance.Id.Should().NotBe(Guid.Empty);
        instance.EnvironmentId.Should().Be(environmentId);
        instance.ClusterId.Should().Be(clusterId);
        instance.Name.Should().Be("prod-grafana");
        instance.Namespace.Should().Be("monitoring");
        instance.Status.Should().Be(GrafanaInstanceStatus.Pending);
        instance.CreatedAt.Should().BeCloseTo(DateTimeOffset.UtcNow, TimeSpan.FromSeconds(5));

        // Grafana defaults

        instance.Persistence.Should().BeFalse();
        instance.PersistenceSize.Should().Be("10Gi");
        instance.Oidc.Should().BeNull();
        instance.Ingress.Should().BeNull();
    }

    [Fact]
    public void Create_WithEmptyEnvironmentId_ThrowsArgumentException()
    {
        // Arrange & Act — Grafana must belong to an environment.

        Action act = () => GrafanaInstance.Create(Guid.Empty, clusterId, "prod-grafana", "monitoring");

        // Assert

        act.Should().Throw<ArgumentException>()
            .WithParameterName("environmentId");
    }

    [Fact]
    public void Create_WithEmptyClusterId_ThrowsArgumentException()
    {
        // Arrange & Act — Grafana must be deployed to a specific cluster.

        Action act = () => GrafanaInstance.Create(environmentId, Guid.Empty, "prod-grafana", "monitoring");

        // Assert

        act.Should().Throw<ArgumentException>()
            .WithParameterName("clusterId");
    }

    [Fact]
    public void Create_WithEmptyName_ThrowsArgumentException()
    {
        // Arrange & Act

        Action act = () => GrafanaInstance.Create(environmentId, clusterId, "", "monitoring");

        // Assert

        act.Should().Throw<ArgumentException>()
            .WithParameterName("name");
    }

    [Fact]
    public void Create_WithEmptyNamespace_ThrowsArgumentException()
    {
        // Arrange & Act

        Action act = () => GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "");

        // Assert

        act.Should().Throw<ArgumentException>()
            .WithParameterName("ns");
    }

    // ─── Persistence Configuration ──────────────────────────────────

    [Fact]
    public void ConfigurePersistence_UpdatesSettings()
    {
        // Arrange — An operator wants Grafana to keep dashboards across restarts.

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        // Act

        instance.ConfigurePersistence(enabled: true, size: "20Gi");

        // Assert

        instance.Persistence.Should().BeTrue();
        instance.PersistenceSize.Should().Be("20Gi");
    }

    // ─── OIDC Configuration ─────────────────────────────────────────

    [Fact]
    public void ConfigureOidc_SetsOidcProvider()
    {
        // Arrange — Integrate Grafana with an OIDC provider (e.g., Entra ID)
        // so users authenticate with corporate credentials.

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        // Act

        OidcConfiguration oidc = new(
            Provider: "generic_oauth",
            ClientId: "grafana-client-id",
            ClientSecretRef: "vault://monitoring/grafana-oidc-client-secret",
            AuthUrl: "https://login.microsoftonline.com/tenant-id/oauth2/v2.0/authorize",
            TokenUrl: "https://login.microsoftonline.com/tenant-id/oauth2/v2.0/token",
            ApiUrl: "https://graph.microsoft.com/oidc/userinfo",
            Scopes: "openid profile email",
            RoleAttributePath: "contains(groups[*], 'admin-group-id') && 'Admin' || 'Viewer'",
            AutoLogin: true);

        instance.ConfigureOidc(oidc);

        // Assert

        instance.Oidc.Should().NotBeNull();
        instance.Oidc!.Provider.Should().Be("generic_oauth");
        instance.Oidc.ClientId.Should().Be("grafana-client-id");
        instance.Oidc.ClientSecretRef.Should().Be("vault://monitoring/grafana-oidc-client-secret");
        instance.Oidc.AutoLogin.Should().BeTrue();
    }

    [Fact]
    public void ConfigureOidc_WithEmptyClientId_ThrowsArgumentException()
    {
        // Arrange

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        // Act & Assert

        OidcConfiguration oidc = new(
            Provider: "generic_oauth",
            ClientId: "",
            ClientSecretRef: "vault://secret",
            AuthUrl: "https://example.com/auth",
            TokenUrl: "https://example.com/token",
            ApiUrl: "https://example.com/userinfo",
            Scopes: "openid",
            RoleAttributePath: null,
            AutoLogin: false);

        Action act = () => instance.ConfigureOidc(oidc);

        act.Should().Throw<ArgumentException>();
    }

    [Fact]
    public void RemoveOidc_ClearsOidcConfiguration()
    {
        // Arrange — A Grafana instance with OIDC configured.

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        OidcConfiguration oidc = new(
            Provider: "generic_oauth",
            ClientId: "client-id",
            ClientSecretRef: "vault://secret",
            AuthUrl: "https://example.com/auth",
            TokenUrl: "https://example.com/token",
            ApiUrl: "https://example.com/userinfo",
            Scopes: "openid",
            RoleAttributePath: null,
            AutoLogin: false);

        instance.ConfigureOidc(oidc);

        // Act — Remove OIDC, fall back to local auth.

        instance.RemoveOidc();

        // Assert

        instance.Oidc.Should().BeNull();
    }

    // ─── Ingress ────────────────────────────────────────────────────

    [Fact]
    public void ConfigureIngress_SetsGrafanaRouting()
    {
        // Arrange — Publish Grafana externally with its own hostname.

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        // Act

        GrafanaIngressConfiguration ingress = new(
            Enabled: true,
            Provider: IngressProvider.GatewayApi,
            Hostname: "grafana.prod01.example.com",
            TlsEnabled: true,
            TlsCertificateMode: TlsCertificateMode.CertManager,
            TlsSecretName: null,
            ClusterIssuer: "letsencrypt-prod");

        instance.ConfigureIngress(ingress);

        // Assert

        instance.Ingress.Should().NotBeNull();
        instance.Ingress!.Enabled.Should().BeTrue();
        instance.Ingress.Provider.Should().Be(IngressProvider.GatewayApi);
        instance.Ingress.Hostname.Should().Be("grafana.prod01.example.com");
        instance.Ingress.TlsCertificateMode.Should().Be(TlsCertificateMode.CertManager);
        instance.Ingress.ClusterIssuer.Should().Be("letsencrypt-prod");
    }

    [Fact]
    public void DisableIngress_ClearsIngressConfig()
    {
        // Arrange

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        GrafanaIngressConfiguration ingress = new(
            Enabled: true,
            Provider: IngressProvider.GatewayApi,
            Hostname: "grafana.example.com",
            TlsEnabled: true,
            TlsCertificateMode: TlsCertificateMode.Manual,
            TlsSecretName: "grafana-tls");

        instance.ConfigureIngress(ingress);

        // Act

        instance.DisableIngress();

        // Assert

        instance.Ingress.Should().BeNull();
    }

    // ─── Dashboards ─────────────────────────────────────────────────

    [Fact]
    public void AddDashboard_StoresDashboardDefinition()
    {
        // Arrange — Dashboards are JSON definitions deployed as ConfigMaps
        // with the grafana_dashboard=1 label so the sidecar picks them up.

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        // Act — Add a Kubernetes cluster dashboard.

        GrafanaDashboard dashboard = new(
            Name: "k8s-cluster",
            DisplayName: "Kubernetes Cluster",
            Category: DashboardCategory.Kubernetes,
            JsonContent: """{"dashboard": {"title": "K8s Cluster"}}""");

        instance.AddDashboard(dashboard);

        // Assert

        instance.Dashboards.Should().HaveCount(1);
        instance.Dashboards[0].Name.Should().Be("k8s-cluster");
        instance.Dashboards[0].Category.Should().Be(DashboardCategory.Kubernetes);
    }

    [Fact]
    public void AddDashboard_WithDuplicateName_ThrowsInvalidOperationException()
    {
        // Arrange

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        GrafanaDashboard dashboard = new(
            Name: "k8s-cluster",
            DisplayName: "Kubernetes Cluster",
            Category: DashboardCategory.Kubernetes,
            JsonContent: """{"dashboard": {}}""");

        instance.AddDashboard(dashboard);

        // Act & Assert — Can't add two dashboards with the same name.

        Action act = () => instance.AddDashboard(dashboard);

        act.Should().Throw<InvalidOperationException>();
    }

    [Fact]
    public void RemoveDashboard_DeletesByName()
    {
        // Arrange

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        instance.AddDashboard(new GrafanaDashboard("k8s-cluster", "Kubernetes Cluster", DashboardCategory.Kubernetes, "{}"));
        instance.AddDashboard(new GrafanaDashboard("istio-mesh", "Istio Mesh", DashboardCategory.Istio, "{}"));

        // Act

        instance.RemoveDashboard("k8s-cluster");

        // Assert

        instance.Dashboards.Should().HaveCount(1);
        instance.Dashboards[0].Name.Should().Be("istio-mesh");
    }

    // ─── Lifecycle ──────────────────────────────────────────────────

    [Fact]
    public void MarkRunning_SetsStatusToRunning()
    {
        // Arrange

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        // Act

        instance.MarkRunning();

        // Assert

        instance.Status.Should().Be(GrafanaInstanceStatus.Running);
    }

    [Fact]
    public void MarkDegraded_SetsStatusToDegraded()
    {
        // Arrange

        GrafanaInstance instance = GrafanaInstance.Create(environmentId, clusterId, "prod-grafana", "monitoring");

        // Act

        instance.MarkDegraded();

        // Assert

        instance.Status.Should().Be(GrafanaInstanceStatus.Degraded);
    }
}