package daemonsetdnstest

import (
	"bytes"
	"embed"
	"fmt"
	"io/fs"
	"strings"

	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/kustomize/kyaml/kio"

	"edge-infra.dev/pkg/k8s/decoder"
	"edge-infra.dev/pkg/k8s/runtime/sap"
	"edge-infra.dev/pkg/k8s/unstructured"
	"edge-infra.dev/test/f2"
	"edge-infra.dev/test/f2/x/ktest"
)

// testdata/base_manifests.yaml  -- the contents of this file are generated by a genrule
//
//go:embed testdata
var manifestsData embed.FS

var (
	// Loaded by LoadManifest and then applied in Install
	// TODO(aw185187): This isn't safe for concurrent tests on the same cluster
	// using the DNS component.
	manifests []*unstructured.Unstructured
)

// LoadManifests is a [edge-infra.dev/test/f2.SetupFn] to be used to load
// DaemonSet DNS component manifests as part of framework initialization.
//
// Example Framework setup:
//
//		var f f2.Framework
//		func TestMain(m *testing.M) {
//			f = f2.New(
//	      context.Background(),
//				f2.WithExtensions(
//					ktest.New(),
//				),
//			).
//			Setup(func(ctx f2.Context) (f2.Context, error) {
//				if !integration.IsL2() {
//					return ctx, fmt.Errorf("%w: requires L2 integration test level", f2.ErrSkip)
//				}
//				return ctx, nil
//			}).
//			Setup(daemonsetdnstest.LoadManifests, daemonsetdnstest.Install)
//
// For each Feature that depends on the DNS component, add [Install] to the
// feature's Setup functions.
func LoadManifests(ctx f2.Context) (f2.Context, error) {
	manifestsBytes, err := fs.ReadFile(manifestsData, "testdata/local_manifests.yaml")
	if err != nil {
		return ctx, fmt.Errorf("failed to read manifests: %w", err)
	}

	manifests, err = processManifests(string(manifestsBytes))
	if err != nil {
		return ctx, err
	}

	return ctx, nil
}

// Install is a [edge-infra.dev/test/f2.SetupFn] to be used to apply the DNS
// component and wait for it to be ready.
//
// If the DaemonSet DNS component already exists in the cluster this function
// will make no changes to the current version, otherwise it will install the
// DaemonSet DNS component.
//
// TODO: allow forcing overwriting existing components via cli flag
func Install(ctx f2.Context) (f2.Context, error) {
	// TODO: a lot of this is duplicated from novnc_test. Move into kssert?
	k, err := ktest.FromContext(ctx)
	if err != nil {
		return ctx, err
	}

	mgr, err := sap.NewResourceManagerFromConfig(k.Env.Config, client.Options{}, ktest.FieldManagerOwner())
	if err != nil {
		return ctx, err
	}

	cs, err := mgr.ApplyAllStaged(ctx, manifests, sap.ApplyOptions{
		Force:       true,
		WaitTimeout: k.Timeout,
	})
	if err != nil {
		return ctx, err
	}

	return ctx, mgr.WaitForSet(ctx, cs.ToObjMetadataSet(), sap.WaitOptions{
		Timeout: k.Timeout,
	})
}

func processManifests(manifests string) ([]*unstructured.Unstructured, error) {
	reader := kio.ByteReader{
		Reader: strings.NewReader(manifests),
	}

	out, err := reader.Read()
	if err != nil {
		return nil, err
	}

	buf := bytes.Buffer{}
	writer := kio.ByteWriter{
		Writer: &buf,
	}

	err = writer.Write(out)
	if err != nil {
		return nil, err
	}

	return decoder.DecodeYAML(buf.Bytes())
}