package system

import (
	"context"
	"testing"
)

// A one-shot unit that did its work and exited is satisfied, not stopped.
//
// **This made the firewall permanently unsatisfiable.** Its unit loads a rule set and exits, so it
// is inactive the instant it succeeds — the host started it, it worked, the host read back
// "stopped" and reported the machine as not doing what it was told. On every apply, for ever, with
// the rules correctly in place the whole time.
func TestAOneShotThatFinishedIsRunning(t *testing.T) {
	run := func(_ context.Context, _ string, _ ...string) (string, error) {
		return "LoadState=loaded\nActiveState=inactive\nType=oneshot\nRemainAfterExit=no\nExecMainStatus=0\n", nil
	}
	state, err := arch{}.ServiceState(context.Background(), run, "nftables.service")
	if err != nil {
		t.Fatalf("a one-shot that succeeded was an error: %v", err)
	}
	if state != "running" {
		t.Fatalf("a one-shot that did its work reads as %q, so it can never be satisfied", state)
	}
}

// And one that failed is still stopped, or the host would report success for work that did not
// happen — which is the opposite mistake and the worse one.
func TestAOneShotThatFailedIsStopped(t *testing.T) {
	run := func(_ context.Context, _ string, _ ...string) (string, error) {
		return "LoadState=loaded\nActiveState=inactive\nType=oneshot\nRemainAfterExit=no\nExecMainStatus=1\n", nil
	}
	state, err := arch{}.ServiceState(context.Background(), run, "nftables.service")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if state != "stopped" {
		t.Fatalf("a one-shot that failed reads as %q, so a broken firewall reports success", state)
	}
}

// A unit that lingers deliberately is unaffected: it says so, and its active state is the answer.
func TestAOneShotThatRemainsIsJudgedByItsActiveState(t *testing.T) {
	run := func(_ context.Context, _ string, _ ...string) (string, error) {
		return "LoadState=loaded\nActiveState=active\nType=oneshot\nRemainAfterExit=yes\nExecMainStatus=0\n", nil
	}
	state, _ := arch{}.ServiceState(context.Background(), run, "thing.service")
	if state != "running" {
		t.Fatalf("a lingering one-shot reads as %q", state)
	}
}