package kubernetes

import (
	"context"
	"errors"
	"net/url"
	"syscall"
	"testing"

	corev1 "k8s.io/api/core/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/client/fake"
	"sigs.k8s.io/controller-runtime/pkg/client/interceptor"

	"gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/internal/provider"
)

type listFunc func(ctx context.Context, c client.WithWatch, list client.ObjectList, opts ...client.ListOption) error

func newCheckProvider(list listFunc) *Provider {
	scheme := runtime.NewScheme()
	if err := corev1.AddToScheme(scheme); err != nil {
		panic(err)
	}
	c := fake.NewClientBuilder().WithScheme(scheme).WithInterceptorFuncs(interceptor.Funcs{List: list}).Build()
	p := newWithClient(c, provider.ProviderConfig{Name: "kubernetes"})
	p.apiHost = "https://10.96.0.1:443"
	return p
}

func TestCheck_reachable(t *testing.T) {
	t.Parallel()
	p := newTestProvider(testPod("ns", "a", "uid-a", corev1.PodRunning, "10.0.0.1"))
	p.apiHost = "https://10.96.0.1:443"

	got := p.Check(context.Background())

	if len(got) != 1 {
		t.Fatalf("Check() returned %d targets, want 1", len(got))
	}
	ts := got[0]
	if !ts.Ready || ts.Reason != provider.ReasonReachable || ts.Message != "" {
		t.Errorf("Check() = %+v, want ready and Reachable", ts)
	}
	if ts.Name != "apiserver" || ts.Address != "https://10.96.0.1:443" {
		t.Errorf("target = %q at %q, want apiserver at https://10.96.0.1:443", ts.Name, ts.Address)
	}
}

func TestCheck_listOptions(t *testing.T) {
	t.Parallel()
	var got client.ListOptions
	p := newCheckProvider(func(ctx context.Context, c client.WithWatch, list client.ObjectList, opts ...client.ListOption) error {
		got.ApplyOptions(opts)
		return c.List(ctx, list, opts...)
	})

	p.Check(context.Background())

	if got.Limit != 1 {
		t.Errorf("Limit = %d, want 1", got.Limit)
	}
	if got.Namespace != "" {
		t.Errorf("Namespace = %q, want cluster-wide", got.Namespace)
	}
	want := provider.LabelManaged + "=" + provider.LabelManagedYes
	if got.LabelSelector == nil || got.LabelSelector.String() != want {
		t.Errorf("LabelSelector = %v, want %s", got.LabelSelector, want)
	}
}

func TestCheck_failureReasons(t *testing.T) {
	t.Parallel()
	pods := schema.GroupResource{Resource: "pods"}
	ended, cancel := context.WithCancel(context.Background())
	cancel()

	tests := []struct {
		name string
		ctx  context.Context
		err  error
		want string
	}{
		{"forbidden", context.Background(), apierrors.NewForbidden(pods, "", errors.New("rbac denied")), provider.ReasonForbidden},
		{"unauthorized", context.Background(), apierrors.NewUnauthorized("token expired"), provider.ReasonUnauthorized},
		{"api timeout", context.Background(), apierrors.NewTimeoutError("slow etcd", 1), provider.ReasonTimeout},
		{"server timeout", context.Background(), apierrors.NewServerTimeout(pods, "list", 1), provider.ReasonTimeout},
		{"context ended", ended, context.Canceled, provider.ReasonTimeout},
		{"internal error", context.Background(), apierrors.NewInternalError(errors.New("etcd down")), provider.ReasonAPIError},
		{"connection refused", context.Background(), &url.Error{
			Op: "Get", URL: "https://10.96.0.1:443/api/v1/pods", Err: syscall.ECONNREFUSED,
		}, provider.ReasonUnreachable},
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			p := newCheckProvider(func(context.Context, client.WithWatch, client.ObjectList, ...client.ListOption) error {
				return tc.err
			})

			got := p.Check(tc.ctx)

			if len(got) != 1 {
				t.Fatalf("Check() returned %d targets, want 1", len(got))
			}
			if got[0].Ready || got[0].Reason != tc.want || got[0].Message != tc.err.Error() {
				t.Errorf("Check() = %+v, want not ready, reason %s, message %q", got[0], tc.want, tc.err.Error())
			}
		})
	}
}