package main

import (
	"context"
	app "k8s.io/api/apps/v1"
	core "k8s.io/api/core/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	meta "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"os"
	"path/filepath"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/envtest"
	"testing"
)

func TestAPIServerConvergence(t *testing.T) {
	if os.Getenv("KUBEBUILDER_ASSETS") == "" {
		t.Skip("set KUBEBUILDER_ASSETS to run envtest")
	}
	env := envtest.Environment{CRDDirectoryPaths: []string{filepath.Join("..", "..", "k8s", "envtest")}, ErrorIfCRDPathMissing: true}
	cfg, err := env.Start()
	if err != nil {
		t.Fatal(err)
	}
	defer env.Stop()
	c, err := client.New(cfg, client.Options{})
	if err != nil {
		t.Fatal(err)
	}
	ctx := context.Background()
	ns := "modeldock-lab"
	if err = c.Create(ctx, &core.Namespace{ObjectMeta: meta.ObjectMeta{Name: ns}}); err != nil {
		t.Fatal(err)
	}
	u := resource()
	u.SetName("case")
	u.SetNamespace(ns)
	u.Object["spec"] = map[string]any{"image": "nginx:stable-alpine", "replicas": int64(1)}
	if err = c.Create(ctx, u); err != nil {
		t.Fatal(err)
	}
	req := ctrl.Request{NamespacedName: client.ObjectKeyFromObject(u)}
	r := Controller{c}
	tick := func() {
		t.Helper()
		if _, err := r.Reconcile(ctx, req); err != nil {
			t.Fatal(err)
		}
	}
	tick()
	tick()
	d := &app.Deployment{}
	if err = c.Get(ctx, req.NamespacedName, d); err != nil {
		t.Fatal(err)
	}
	rv := d.ResourceVersion
	tick()
	if err := c.Get(ctx, req.NamespacedName, d); err != nil {
		t.Fatal(err)
	}
	if rv != d.ResourceVersion {
		t.Fatal("unchanged child rewritten")
	}
	if !meta.IsControlledBy(d, u) {
		t.Fatal("missing owner")
	}
	if err := c.Get(ctx, req.NamespacedName, u); err != nil {
		t.Fatal(err)
	}
	phase, _, _ := unstructured.NestedString(u.Object, "status", "phase")
	if phase != "Progressing" {
		t.Fatal(phase)
	}

	// Simulate a second writer changing the declaration after our read.
	stale := u.DeepCopy()
	if err := unstructured.SetNestedField(u.Object, int64(2), "spec", "replicas"); err != nil {
		t.Fatal(err)
	}
	if err := c.Update(ctx, u); err != nil {
		t.Fatal(err)
	}
	stale.SetAnnotations(map[string]string{"study": "stale"})
	if err := c.Update(ctx, stale); !apierrors.IsConflict(err) {
		t.Fatalf("expected conflict, got %v", err)
	}
	// A fresh reconciler gets only a key, not the event that changed replicas.
	r = Controller{c}
	tick()
	if err := c.Get(ctx, req.NamespacedName, d); err != nil {
		t.Fatal(err)
	}
	if *d.Spec.Replicas != 2 {
		t.Fatalf("stale desired replicas: %d", *d.Spec.Replicas)
	}
}