package qlog

import (
	"bytes"
	"encoding/json"

	"github.com/francoispqt/gojay"

	"github.com/refraction-networking/uquic/internal/protocol"
	"github.com/refraction-networking/uquic/internal/wire"
	"github.com/refraction-networking/uquic/logging"

	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
)

var _ = Describe("Packet Header", func() {
	It("determines the packet type from the encryption level", func() {
		Expect(getPacketTypeFromEncryptionLevel(protocol.EncryptionInitial)).To(BeEquivalentTo(logging.PacketTypeInitial))
		Expect(getPacketTypeFromEncryptionLevel(protocol.EncryptionHandshake)).To(BeEquivalentTo(logging.PacketTypeHandshake))
		Expect(getPacketTypeFromEncryptionLevel(protocol.Encryption0RTT)).To(BeEquivalentTo(logging.PacketType0RTT))
		Expect(getPacketTypeFromEncryptionLevel(protocol.Encryption1RTT)).To(BeEquivalentTo(logging.PacketType1RTT))
	})

	Context("marshalling", func() {
		check := func(hdr *wire.ExtendedHeader, expected map[string]interface{}) {
			buf := &bytes.Buffer{}
			enc := gojay.NewEncoder(buf)
			ExpectWithOffset(1, enc.Encode(transformLongHeader(hdr))).To(Succeed())
			data := buf.Bytes()
			ExpectWithOffset(1, json.Valid(data)).To(BeTrue())
			checkEncoding(data, expected)
		}

		It("marshals a header with a payload length", func() {
			check(
				&wire.ExtendedHeader{
					PacketNumber: 42,
					Header: wire.Header{
						Type:    protocol.PacketTypeInitial,
						Length:  123,
						Version: protocol.Version(0xdecafbad),
					},
				},
				map[string]interface{}{
					"packet_type":   "initial",
					"packet_number": 42,
					"dcil":          0,
					"scil":          0,
					"version":       "decafbad",
				},
			)
		})

		It("marshals an Initial with a token", func() {
			check(
				&wire.ExtendedHeader{
					PacketNumber: 4242,
					Header: wire.Header{
						Type:    protocol.PacketTypeInitial,
						Length:  123,
						Version: protocol.Version(0xdecafbad),
						Token:   []byte{0xde, 0xad, 0xbe, 0xef},
					},
				},
				map[string]interface{}{
					"packet_type":   "initial",
					"packet_number": 4242,
					"dcil":          0,
					"scil":          0,
					"version":       "decafbad",
					"token":         map[string]interface{}{"data": "deadbeef"},
				},
			)
		})

		It("marshals a Retry packet", func() {
			check(
				&wire.ExtendedHeader{
					Header: wire.Header{
						Type:            protocol.PacketTypeRetry,
						SrcConnectionID: protocol.ParseConnectionID([]byte{0x11, 0x22, 0x33, 0x44}),
						Version:         protocol.Version(0xdecafbad),
						Token:           []byte{0xde, 0xad, 0xbe, 0xef},
					},
				},
				map[string]interface{}{
					"packet_type": "retry",
					"dcil":        0,
					"scil":        4,
					"scid":        "11223344",
					"token":       map[string]interface{}{"data": "deadbeef"},
					"version":     "decafbad",
				},
			)
		})

		It("marshals a packet with packet number 0", func() {
			check(
				&wire.ExtendedHeader{
					PacketNumber: 0,
					Header: wire.Header{
						Type:    protocol.PacketTypeHandshake,
						Version: protocol.Version(0xdecafbad),
					},
				},
				map[string]interface{}{
					"packet_type":   "handshake",
					"packet_number": 0,
					"dcil":          0,
					"scil":          0,
					"version":       "decafbad",
				},
			)
		})

		It("marshals a header with a source connection ID", func() {
			check(
				&wire.ExtendedHeader{
					PacketNumber: 42,
					Header: wire.Header{
						Type:            protocol.PacketTypeHandshake,
						SrcConnectionID: protocol.ParseConnectionID([]byte{0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff}),
						Version:         protocol.Version(0xdecafbad),
					},
				},
				map[string]interface{}{
					"packet_type":   "handshake",
					"packet_number": 42,
					"dcil":          0,
					"scil":          16,
					"scid":          "00112233445566778899aabbccddeeff",
					"version":       "decafbad",
				},
			)
		})
	})
})