package config

import "testing"

func TestStoreOverlayKeepsBaseSeparate(t *testing.T) {
	base := Default()
	s := NewStore(base, "")
	if s.Base() != base || s.Get() != base {
		t.Fatal("without an overlay base and current are the same config")
	}

	extra := Group{Name: "from-cluster", Policy: "deny"}
	s.SetOverlay(func(b *Config) *Config {
		next := *b
		next.ACL.Groups = append(append([]Group(nil), b.ACL.Groups...), extra)
		return &next
	})
	var seen *Config
	s.OnSwap(func(c *Config) { seen = c })
	gen := s.Generation()
	s.Reapply()

	if got := s.Get().ACL.Groups; len(got) != 1 || got[0].Name != "from-cluster" {
		t.Fatalf("effective groups = %+v", got)
	}
	if len(s.Base().ACL.Groups) != 0 {
		t.Fatal("the overlay leaked into the base")
	}
	if seen != s.Get() || s.Generation() != gen+1 {
		t.Fatal("Reapply must run the swap hooks and bump the generation")
	}

	// A write (the API persisting a change) replaces the base; the overlay
	// is applied on top of it again.
	written := Default()
	written.ACL.Groups = []Group{{Name: "yaml", Policy: "allow"}}
	if err := s.Swap(written); err != nil {
		t.Fatal(err)
	}
	if got := s.Get().ACL.Groups; len(got) != 2 || got[0].Name != "yaml" || got[1].Name != "from-cluster" {
		t.Fatalf("after Swap = %+v", got)
	}
	if got := s.Base().ACL.Groups; len(got) != 1 {
		t.Fatalf("base after Swap = %+v", got)
	}
}