package utils

import (
	"testing"

	"github.com/stretchr/testify/assert"
)

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())
	})
}