package apply

import (
	"testing"

	"github.com/novox/mesh-host/internal/declaration"
)

// **A container's mesh names are part of what it is** (novox/hq 04-ISSUES/135).
//
// A container resolves every machine and every public name through the entries it was given when it
// was created, and nothing re-reads them. So a container the host leaves alone because nothing else
// about it changed is a container that cannot reach anything by name — for ever, while every check
// reports it running. That is what happened when this mesh's overlay range moved: one container kept
// an address five days out of date and restarted 2286 times against a database it could no longer
// find, and the host compared everything about it except that.
func TestAContainersMeshNamesAreComparedLikeTheRestOfIt(t *testing.T) {
	was := &declaration.Container{
		Name: "umami", Image: "ghcr.io/example/umami@sha256:" + zeros(64),
		Hosts: []string{"novox.internal:10.42.0.1", "umami.novox.be:10.42.0.1"},
	}
	moved := &declaration.Container{
		Name: was.Name, Image: was.Image,
		Hosts: []string{"novox.internal:10.10.0.1", "umami.novox.be:10.10.0.1"},
	}
	if containerSpecReading(was, nil, nil) == containerSpecReading(moved, nil, nil) {
		t.Fatal("a container whose mesh names moved compares equal, so it is never recreated")
	}

	// And the order they arrive in is not a change: the digest must not move for a reordering
	// nobody made.
	reordered := &declaration.Container{
		Name: moved.Name, Image: moved.Image,
		Hosts: []string{moved.Hosts[1], moved.Hosts[0]},
	}
	if containerSpecReading(moved, nil, nil) != containerSpecReading(reordered, nil, nil) {
		t.Fatal("the same names in another order read as a different container")
	}

	// A container the mesh gives no names is unaffected, so nothing is recreated for a field it
	// does not set.
	plain := &declaration.Container{Name: "plex", Image: was.Image}
	if containerSpecReading(plain, nil, nil) == containerSpecReading(was, nil, nil) {
		return // different for other reasons, which is fine
	}
}

func zeros(n int) string {
	out := make([]byte, n)
	for i := range out {
		out[i] = '0'
	}
	return string(out)
}