package rtcp

import (
	"encoding/binary"
	"io"
	"io/ioutil"
)

const (
	reportBlockSize = 6
)

type Header struct {
	Version     uint8  // RTCP version.
	Padding     bool   // Padding indicator.
	ReportCount uint8  // Number of reports contained.
	Type        uint8  // Type of RTCP packet.
	SSRC        uint32 // Source identifier.
}

type ReportBlock struct {
	SSRC            uint32 // Source identifier.
	FractionLost    uint8  // Fraction of packets lost.
	PacketsLost     uint32 // Cumulative number of packets lost.
	HighestSequence uint32 // Extended highest sequence number received.
	Jitter          uint32 // Interarrival jitter.
	LSR             uint32 // Last sender report timestamp.
	DLSR            uint32 // Delay since last sender report.
}

type ReceiverReport struct {
	Header

	Blocks     []ReportBlock
	Extensions [][4]byte
}

func (r *ReceiverReport) Bytes() []byte {
	l := 8 + 4*reportBlockSize*len(r.Blocks) + 4*len(r.Extensions)
	buf := make([]byte, l)

	buf[0] = r.Version<<6 | asByte(r.Padding)<<5 | 0x1f&r.ReportCount
	buf[1] = r.Type

	l = 1 + reportBlockSize*len(r.Blocks) + len(r.Extensions)
	binary.BigEndian.PutUint16(buf[2:], uint16(l))

	buf[4] = byte(r.SSRC)

	idx := 8
	for _, b := range r.Blocks {
		binary.BigEndian.PutUint32(buf[idx:], b.SSRC)
		idx += 4
		binary.BigEndian.PutUint32(buf[idx:], b.PacketsLost)
		buf[idx] = b.FractionLost
		idx += 4
		binary.BigEndian.PutUint32(buf[idx:], b.HighestSequence)
		idx += 4
		binary.BigEndian.PutUint32(buf[idx:], b.Jitter)
		idx += 4
		binary.BigEndian.PutUint32(buf[idx:], b.LSR)
		idx += 4
		binary.BigEndian.PutUint32(buf[idx:], b.DLSR)
		idx += 4
	}

	for _, e := range r.Extensions {
		binary.BigEndian.PutUint32(buf[idx:], binary.BigEndian.Uint32(e[:]))
		idx += 4
	}

	return buf
}

type Chunk struct {
	Type uint8
	Test []byte
}

type SourceDescription struct {
	Header

	Chunks []Chunk
}

func (d *SourceDescription) Bytes() []byte {

}

func asByte(b bool) byte {
	if b {
		return 0x01
	}
	return 0x00
}
func Handle(r io.Reader) error {
	io.Copy(ioutil.Discard, r)
	return nil
}