package utils

import (
	"github.com/stretchr/testify/assert"
	"testing"
)

func Test_DefaultSequenceNumberGenerator(t *testing.T) {

	t.Run("next", func(t *testing.T) {
		var sequenceGenerator = NewDefaultSequenceNumberGenerator()
		assert.Equal(t, uint64(0), (*sequenceGenerator).Next())
	})

	t.Run("revert", func(t *testing.T) {
		var sequenceGenerator = NewDefaultSequenceNumberGenerator()
		assert.Equal(t, uint64(0), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(1), (*sequenceGenerator).Next())
		(*sequenceGenerator).Revert(uint64(1))
		assert.Equal(t, uint64(1), (*sequenceGenerator).Next())
	})

	t.Run("revert first", func(t *testing.T) {
		var sequenceGenerator = NewDefaultSequenceNumberGenerator()
		assert.Equal(t, uint64(0), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(1), (*sequenceGenerator).Next())
		(*sequenceGenerator).Revert(uint64(0))
		assert.Equal(t, uint64(0), (*sequenceGenerator).Next())
	})

	t.Run("revert same value multiple times", func(t *testing.T) {
		var sequenceGenerator = NewDefaultSequenceNumberGenerator()
		assert.Equal(t, uint64(0), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(1), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(2), (*sequenceGenerator).Next())
		(*sequenceGenerator).Revert(uint64(1))
		(*sequenceGenerator).Revert(uint64(1))
		assert.Equal(t, uint64(1), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(3), (*sequenceGenerator).Next())
	})

	t.Run("get and revert multiple", func(t *testing.T) {
		var sequenceGenerator = NewDefaultSequenceNumberGenerator()
		assert.Equal(t, uint64(0), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(1), (*sequenceGenerator).Next())
		(*sequenceGenerator).Revert(uint64(1))
		assert.Equal(t, uint64(1), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(2), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(3), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(4), (*sequenceGenerator).Next())
		(*sequenceGenerator).Revert(uint64(2))
		(*sequenceGenerator).Revert(uint64(3))
		assert.Equal(t, uint64(2), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(3), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(5), (*sequenceGenerator).Next())
		assert.Equal(t, uint64(6), (*sequenceGenerator).Next())
	})
}