package sctp

import (
	"bytes"
	"testing"
)

func TestPacketUnmarshal(t *testing.T) {
	pkt := &packet{}

	if err := pkt.unmarshal([]byte{}); err == nil {
		t.Errorf("Unmarshal should fail when a packet is too small to be SCTP")
	}

	headerOnly := []byte{0x13, 0x88, 0x13, 0x88, 0x00, 0x00, 0x00, 0x00, 0x06, 0xa9, 0x00, 0xe1}
	err := pkt.unmarshal(headerOnly)
	switch {
	case err != nil:
		t.Errorf("Unmarshal failed for SCTP packet with no chunks: %v", err)
	case pkt.sourcePort != 5000:
		t.Errorf("Unmarshal passed for SCTP packet, but got incorrect source port exp: %d act: %d", 5000, pkt.sourcePort)
	case pkt.destinationPort != 5000:
		t.Errorf("Unmarshal passed for SCTP packet, but got incorrect destination port exp: %d act: %d", 5000, pkt.destinationPort)
	case pkt.verificationTag != 0:
		t.Errorf("Unmarshal passed for SCTP packet, but got incorrect verification tag exp: %d act: %d", 0, pkt.verificationTag)
	}

	rawChunk := []byte{
		0x13, 0x88, 0x13, 0x88, 0x00, 0x00, 0x00, 0x00, 0x81, 0x46, 0x9d, 0xfc, 0x01, 0x00, 0x00, 0x56, 0x55,
		0xb9, 0x64, 0xa5, 0x00, 0x02, 0x00, 0x00, 0x04, 0x00, 0x08, 0x00, 0xe8, 0x6d, 0x10, 0x30, 0xc0, 0x00, 0x00, 0x04, 0x80,
		0x08, 0x00, 0x09, 0xc0, 0x0f, 0xc1, 0x80, 0x82, 0x00, 0x00, 0x00, 0x80, 0x02, 0x00, 0x24, 0x9f, 0xeb, 0xbb, 0x5c, 0x50,
		0xc9, 0xbf, 0x75, 0x9c, 0xb1, 0x2c, 0x57, 0x4f, 0xa4, 0x5a, 0x51, 0xba, 0x60, 0x17, 0x78, 0x27, 0x94, 0x5c, 0x31, 0xe6,
		0x5d, 0x5b, 0x09, 0x47, 0xe2, 0x22, 0x06, 0x80, 0x04, 0x00, 0x06, 0x00, 0x01, 0x00, 0x00, 0x80, 0x03, 0x00, 0x06, 0x80, 0xc1, 0x00, 0x00,
	}

	if err := pkt.unmarshal(rawChunk); err != nil {
		t.Errorf("Unmarshal failed, has chunk: %v", err)
	}
}

func TestPacketMarshal(t *testing.T) {
	pkt := &packet{}

	headerOnly := []byte{0x13, 0x88, 0x13, 0x88, 0x00, 0x00, 0x00, 0x00, 0x06, 0xa9, 0x00, 0xe1}
	if err := pkt.unmarshal(headerOnly); err != nil {
		t.Errorf("Unmarshal failed for SCTP packet with no chunks: %v", err)
	}

	headerOnlyMarshaled, err := pkt.marshal()
	if err != nil {
		t.Errorf("Marshal failed for SCTP packet with no chunks: %v", err)
	} else if !bytes.Equal(headerOnly, headerOnlyMarshaled) {
		t.Errorf("Unmarshal/Marshaled header only packet did not match \nheaderOnly: % 02x \nheaderOnlyMarshaled % 02x", headerOnly, headerOnlyMarshaled)
	}
}

func BenchmarkPacketGenerateChecksum(b *testing.B) {
	var data [1024]byte

	for i := 0; i < b.N; i++ {
		_ = generatePacketChecksum(data[:])
	}
}
