#include <stdio.h>
#include <stdlib.h>
#include <sys/termios.h> 

#include "avr.h"
#include "file.h"
#include "term.h"

// copyright (c)2006 Technologic Systems
// Author: Michael Schmidt

ByteArrayRef AVRreplyGet(FILE *f,ByteArrayRef pReply) {
  ByteArrayRef b;
  byte ck;

  pReply.len = 0;
  b = filePacketGet(f,pReply);
  if (!b.arr) {
    printf("Failed to communicate with AVR\n");
    exit(3);
  }
  return b;
}

// AVR send callback returns:
// 0: to indicate that its satified that the request has succeeded
// 1: to indicate that the request should be re-sent
// 2: to indicate that it wants another reply without a re-send
ByteArrayRef AVRsendRequest(FILE *f,ByteArrayRef req,ByteArrayRef ret,
			    int (*callback)(ByteArrayRef,ByteArrayRef)) {
  ByteArrayRef b;
  int retry,retries=25;
  int replies_till_retry = 2;

  req.arr[req.len-1] = 0;
  req.arr[req.len-1] = 0xFF - ByteArrayRef_Checksum(req);
  serialFramedSend(f,req);
  while (retries--) {
    b = filePacketGet(f,ret);
    if (!b.arr) {
      printf("Failed to communicate with AVR\n");
      exit(3);
    }
    if (b.len == 0) {
      retry = 1;
    } else {
      retry = callback(req,ret);
    }
    if (retry == 0) {
      return b;
    }
    if (--replies_till_retry == 0) {
      serialFramedSend(f,req);
      replies_till_retry = 2;
    }
  }
  printf("Failed to change AVR state\n");
  exit (3);
  //return BYTE_ARRAY_REF(0,0);
}

/*
  Common AVR behavior:
  1. There are only two packets: "request" which is to the AVR and "reply"
     which is from the AVR.
  2. Periodically the AVR sends out its current state in a "reply" packet.
  3. When we send a request, we must "echo" back the AVR state that we don't 
     want to change

  wait for AVR reply packet
  initialize request from reply
  process options to modify request
  if options indicated a more complicated task
    perform that task
  if options indicated a simple request to send
    send request until it is acknowledged
  if (we are displaying the current state)
    read a specific number of packets
    print out the latest state
 */
void _AVRrun(FILE *f,void *data,int argc,char **argv,
	    void (*setup)(FILE *,void *),
	     int (*init)(ByteArrayRef,ByteArrayRef),
	     int (*opt)(FILE *,ByteArrayRef,void *,int *,int,char **),
	     void (*print)(ByteArrayRef,void *),
	     int (*task)(FILE *,int,ByteArrayRef,ByteArrayRef,void*),
	     int (*callback)(ByteArrayRef,ByteArrayRef)
	    ) {
  byte req[256],rep[256];
  ByteArrayRef bReq = BAR(req,256),bRep = BAR(rep,256);
  int todo,loops;

  if (setup) {
    setup(f,data);
  }
  bRep = AVRreplyGet(f,bRep);
  bReq.len = init(bRep,bReq);
  todo = opt(f,bReq,data,&loops,argc,argv);
  if (todo & 0xFFFFFFFE) { // options indicated a simple request to send
    todo |= task(f,todo,bReq,bRep,data);
  }
  if (todo & 1) { // options indicated a simple request to send
    AVRsendRequest(f,bReq,bRep,callback);
  }
  if (loops) {
    while (loops--) {
      bRep = AVRreplyGet(f,bRep);
    }
    print(bRep,data);
  }
}

void AVRrun(char *ser,void *data,int argc,char **argv,
	    void (*setup)(FILE *,void *),
	    int (*init)(ByteArrayRef,ByteArrayRef),
	    int (*opt)(FILE *,ByteArrayRef,void *,int *,int,char **),
	    void (*print)(ByteArrayRef,void *),
	    int (*task)(FILE *,int,ByteArrayRef,ByteArrayRef,void*),
	    int (*callback)(ByteArrayRef,ByteArrayRef)
	    ) {
  FILE *f;
  struct termios saved;

  f = fileOpenOrDie(ser,"r+");
  fileSetBlocking(fileno(f),0);
  termConfigRaw(fileno(f),&saved);

  _AVRrun(f,data,argc,argv,setup,init,opt,print,task,callback);

  tcsetattr(fileno(f),TCSANOW,&saved);
  fclose(f);
}