package parser

type h264Parser struct {
  inputBuffer []byte
  isParsing bool
  parserOutputChanRef chan []byte
  userOutputChanRef chan []byte
  inputChan chan byte
}

func NewH264Parser() (p *h264Parser) {
  p = new(h264Parser)
  p.isParsing = true
  p.inputChan = make(chan byte, 10000)
  return
}

func (p* h264Parser)Stop(){
  p.isParsing = false
}

func (p *h264Parser)Start(){
  go p.parse()
}

func (p *h264Parser)GetInputChan() chan byte {
  return p.inputChan
}

func (p *h264Parser)GetOutputChan() chan []byte {
  return p.userOutputChanRef
}

func (p *h264Parser)SetOutputChan(aChan chan []byte){
  p.parserOutputChanRef = aChan
  p.userOutputChanRef = aChan
}

func (p *h264Parser)parse() {
	outputBuffer := make([]byte, 0, 10000)
	searchingForEnd := false
	for p.isParsing {
    aByte := <-p.inputChan
		outputBuffer = append(outputBuffer, aByte)
		for i:=1; aByte == 0x00 && i != 4; i++ {
			aByte = <-p.inputChan
			outputBuffer = append(outputBuffer, aByte)
			if ( aByte == 0x01 && i == 2 ) || ( aByte == 0x01 && i == 3 ) {
				if searchingForEnd {
          output := append(append(itut.StartCode1(),itut.AUD()...),outputBuffer[:len(outputBuffer)-(i+1)]...)
					p.parserOutputChanRef<-output
					outputBuffer = outputBuffer[len(outputBuffer)-1-i:]
					searchingForEnd = false
				}
				aByte = <-p.inputChan
				outputBuffer = append(outputBuffer, aByte)
				if nalType := aByte & 0x1F; nalType == 1 || nalType == 5 {
					searchingForEnd = true
				}
			}
		}
	}
}