// (c) Bernhard Tittelbach, 2013

package main

import (
    "bufio"
    "bytes"
    "os"
    "errors"
    "svn.spreadspace.org/realraum/go.svn/termios"
)


// ---------- Serial TTY Code -------------

func openTTY(name string, speed uint) (file *os.File, err error) {
    file, err = os.OpenFile(name,os.O_RDWR, 0666)
    if err != nil { return }
    if err = termios.SetRawFile(file); err != nil { return }
    switch speed {
        case 0: // set no baudrate
        case 1200: err = termios.SetSpeedFile(file, termios.B1200)
        case 2400: err = termios.SetSpeedFile(file, termios.B2400)
        case 4800: err = termios.SetSpeedFile(file, termios.B4800)
        case 9600: err = termios.SetSpeedFile(file, termios.B9600)
        case 19200: err = termios.SetSpeedFile(file, termios.B19200)
        case 38400: err = termios.SetSpeedFile(file, termios.B38400)
        case 57600: err = termios.SetSpeedFile(file, termios.B57600)
        case 115200: err = termios.SetSpeedFile(file, termios.B115200)
        case 230400: err = termios.SetSpeedFile(file, termios.B230400)
        default:
            file.Close()
            err = errors.New("Unsupported Baudrate, use 0 to disable setting a baudrate")
    }
    return
}

func serialWriter(in <- chan string, serial * os.File) {
    for totty := range(in) {
        serial.WriteString(totty)
        serial.Sync()
    }
    serial.Close()
}

func serialReader(out chan <- [][]byte, serial * os.File) {
    linescanner := bufio.NewScanner(serial)
    linescanner.Split(bufio.ScanLines)
    for linescanner.Scan() {
        if err := linescanner.Err(); err != nil {
            panic(err.Error())
        }
        text := bytes.Fields([]byte(linescanner.Text()))
        if len(text) == 0 {
            continue
        }
        out <- text
    }
}

func OpenAndHandleSerial(filename string, serspeed uint) (chan string, chan [][]byte, error) {
    serial, err :=openTTY(filename, serspeed)
    if err != nil {
        return nil, nil, err
    }
    wr := make(chan string, 1)
	rd := make(chan [][]byte, 20)
    go serialWriter(wr, serial)
    go serialReader(rd, serial)
    return wr, rd, nil
}