package lockfile_test

import (
	"io/ioutil"
	"os"
	"testing"

	"after-lock/lockfile"
)


func tmpFile() string {
	tf, err := ioutil.TempFile("", "lockfile_test*")
	if err != nil {
		panic(err)
	}
	return tf.Name()
}

func TestNotLockedUnlockPanics(t *testing.T) {
	defer func() {
        if r := recover(); r == nil {
            t.Errorf("Unlock() did not panic")
        }
    }()

	tf := tmpFile()
	defer os.Remove(tf)


	err := lockfile.New(tf).Unlock()
	if err != nil {
		panic(err)
	}
}

func TestSecondLockFails(t *testing.T) {
	tf := tmpFile()
	defer os.Remove(tf)

	fl1 := lockfile.New(tf)
	err := fl1.Lock()
	if err != nil {
		panic(err)
	}
	defer fl1.Unlock()

	fl2 := lockfile.New(tf)
	err = fl2.Lock()
	if err == nil {
		t.Errorf("Second Lock() did not fail")
	}
}

func TestLockUnlock(t *testing.T) {
	tf := tmpFile()
	defer os.Remove(tf)

	fl := lockfile.New(tf)
	err := fl.Lock()
	if err != nil {
		panic(err)
	}
	err = fl.Unlock()
	if err != nil {
		panic(err)
	}
	if _, err := os.Stat(tf); !os.IsNotExist(err) {
		t.Errorf("Lockfile %s still exists", tf)
	}
}