package ackhandler

import (
	"github.com/lucas-clemente/quic-go/protocol"
	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
)

var _ = Describe("AckHandler", func() {
	var handler *outgoingPacketAckHandler
	BeforeEach(func() {
		handler = NewOutgoingPacketAckHandler().(*outgoingPacketAckHandler)
	})

	Context("SentPacket", func() {
		It("accepts three consecutive packets", func() {
			entropy := EntropyAccumulator(0)
			packet1 := Packet{PacketNumber: 1, Plaintext: []byte{0x13, 0x37}, EntropyBit: true}
			packet2 := Packet{PacketNumber: 2, Plaintext: []byte{0xBE, 0xEF}, EntropyBit: true}
			err := handler.SentPacket(&packet1)
			Expect(err).ToNot(HaveOccurred())
			err = handler.SentPacket(&packet2)
			Expect(err).ToNot(HaveOccurred())
			Expect(handler.lastSentPacketNumber).To(Equal(protocol.PacketNumber(2)))
			Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(1)))
			Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(2)))
			entropy.Add(packet1.PacketNumber, packet1.EntropyBit)
			Expect(handler.packetHistory[1].PacketNumber).To(Equal(protocol.PacketNumber(1)))
			Expect(handler.packetHistory[1].Entropy).To(Equal(entropy))
			entropy.Add(packet2.PacketNumber, packet2.EntropyBit)
			Expect(handler.packetHistory[2].PacketNumber).To(Equal(protocol.PacketNumber(2)))
			Expect(handler.packetHistory[2].Entropy).To(Equal(entropy))
		})

		It("rejects packets with the same packet number", func() {
			packet1 := Packet{PacketNumber: 1, Plaintext: []byte{0x13, 0x37}, EntropyBit: true}
			packet2 := Packet{PacketNumber: 1, Plaintext: []byte{0xBE, 0xEF}, EntropyBit: false}
			err := handler.SentPacket(&packet1)
			Expect(err).ToNot(HaveOccurred())
			err = handler.SentPacket(&packet2)
			Expect(err).To(HaveOccurred())
			Expect(handler.lastSentPacketNumber).To(Equal(protocol.PacketNumber(1)))
			Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(1)))
		})

		It("rejects non-consecutive packets", func() {
			packet1 := Packet{PacketNumber: 1, Plaintext: []byte{0x13, 0x37}, EntropyBit: true}
			packet2 := Packet{PacketNumber: 3, Plaintext: []byte{0xBE, 0xEF}, EntropyBit: false}
			err := handler.SentPacket(&packet1)
			Expect(err).ToNot(HaveOccurred())
			err = handler.SentPacket(&packet2)
			Expect(err).To(HaveOccurred())
			Expect(handler.lastSentPacketNumber).To(Equal(protocol.PacketNumber(1)))
			Expect(handler.packetHistory).To(HaveKey(protocol.PacketNumber(1)))
			Expect(handler.packetHistory).ToNot(HaveKey(protocol.PacketNumber(2)))
			Expect(handler.packetHistory).ToNot(HaveKey(protocol.PacketNumber(2)))
		})
	})
})