package stacks

import (
	"encoding/json"
	"strings"
	"testing"
)

// R-489 — the removal reports the volumes it removed, and `[]` when none — never `null`.
//
// COMPANION RED-PROOF (REPORT.md): make removedVolumes return nil for an empty result — the JSON
// reads null and the second assertion fails.
func TestR489_RemovedVolumesIsADifferenceAndNeverNull(t *testing.T) {
	got := removedVolumes([]string{"app_data", "app_db", "app_cache"}, []string{"app_cache"})
	if strings.Join(got, ",") != "app_data,app_db" {
		t.Errorf("before minus after = %v", got)
	}
	b, _ := json.Marshal(RemoveResponse{VolumesRemoved: removedVolumes(nil, nil)})
	if !strings.Contains(string(b), `"volumes_removed":[]`) {
		t.Errorf("no volumes must read as [] — got %s", b)
	}
}

func TestR489_ProjectVolumesReadsTheDockerListing(t *testing.T) {
	m := &Manager{}
	var seen []string
	m.execFn = func(name string, args ...string) (string, error) {
		seen = append([]string{name}, args...)
		return "app_data\napp_db\n\n", nil
	}
	got := m.projectVolumes("app")
	if strings.Join(got, ",") != "app_data,app_db" {
		t.Errorf("volumes = %v", got)
	}
	if !strings.Contains(strings.Join(seen, " "), "label=com.docker.compose.project=app") {
		t.Errorf("must filter by the compose project label; ran %v", seen)
	}
}