package pi

import (
	"errors"
	"os"
	"os/exec"
	"path/filepath"
	"testing"
)

func TestAdvisoryLockRejectsAConcurrentOwner(t *testing.T) {
	statePath := filepath.Join(t.TempDir(), "update-state.json")
	first, err := acquireLock(statePath)
	if err != nil {
		t.Fatal(err)
	}
	defer first.Release()
	second, err := acquireLock(statePath)
	if second != nil {
		second.Release()
	}
	if !errors.Is(err, ErrLockHeld) {
		t.Fatalf("second acquireLock() error = %v, want ErrLockHeld", err)
	}
}

func TestAdvisoryLockCrashReleasesAndReacquires(t *testing.T) {
	statePath := filepath.Join(t.TempDir(), "update-state.json")
	if os.Getenv("THOTHCTL_LOCK_CRASH_HELPER") == "1" {
		lock, err := acquireLock(os.Getenv("THOTHCTL_LOCK_STATE"))
		if err != nil || lock == nil {
			os.Exit(23)
		}
		os.Exit(0) // Deliberately bypass Release: the OS must release ownership.
	}
	command := exec.Command(os.Args[0], "-test.run=^TestAdvisoryLockCrashReleasesAndReacquires$")
	command.Env = append(os.Environ(), "THOTHCTL_LOCK_CRASH_HELPER=1", "THOTHCTL_LOCK_STATE="+statePath)
	if output, err := command.CombinedOutput(); err != nil {
		t.Fatalf("crash helper failed: %v: %s", err, output)
	}
	lock, err := acquireLock(statePath)
	if err != nil {
		t.Fatalf("acquireLock() after owner crash = %v", err)
	}
	lock.Release()
}

func TestAdvisoryLockIgnoresPartialDiagnosticMetadata(t *testing.T) {
	statePath := filepath.Join(t.TempDir(), "update-state.json")
	if err := os.WriteFile(statePath+".lock", nil, 0o600); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(statePath+".lock.owner.json", []byte("{partial"), 0o600); err != nil {
		t.Fatal(err)
	}
	lock, err := acquireLock(statePath)
	if err != nil {
		t.Fatalf("acquireLock() with partial diagnostics = %v", err)
	}
	lock.Release()
}