package state

import (
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"testing"
)

func TestAcquireLockLifecycle(t *testing.T) {
	lockPath := filepath.Join(t.TempDir(), "hecate.lock")
	unlock, err := AcquireLock(lockPath)
	if err != nil {
		t.Fatalf("acquire lock: %v", err)
	}
	if _, err := os.Stat(lockPath); err != nil {
		t.Fatalf("expected lock file to exist: %v", err)
	}
	unlock()
	if _, err := os.Stat(lockPath); !os.IsNotExist(err) {
		t.Fatalf("expected lock file to be removed, got: %v", err)
	}
}

func TestAcquireLockReclaimsStaleLock(t *testing.T) {
	lockPath := filepath.Join(t.TempDir(), "hecate.lock")
	if err := os.WriteFile(lockPath, []byte("pid=999999\n"), 0o600); err != nil {
		t.Fatalf("write stale lock: %v", err)
	}

	unlock, err := AcquireLock(lockPath)
	if err != nil {
		t.Fatalf("acquire lock with stale predecessor: %v", err)
	}
	defer unlock()

	b, err := os.ReadFile(lockPath)
	if err != nil {
		t.Fatalf("read lock: %v", err)
	}
	if !strings.Contains(string(b), "pid=") {
		t.Fatalf("expected lock content to contain pid, got %q", string(b))
	}
}

func TestAcquireLockRejectsActiveLock(t *testing.T) {
	lockPath := filepath.Join(t.TempDir(), "hecate.lock")
	active := "pid=" + strconv.Itoa(os.Getpid()) + "\n"
	if err := os.WriteFile(lockPath, []byte(active), 0o600); err != nil {
		t.Fatalf("write active lock: %v", err)
	}

	if _, err := AcquireLock(lockPath); err == nil {
		t.Fatalf("expected acquire lock to fail when active pid holds lock")
	}
}