/* XLink85  -  TI85<->PC  link  program,  Copyright (c) 1996 Jani Halme	*/
/*									*/
/* This program is free software; you can redistribute it and/or modify */
/* it under the terms of the GNU General Public License as published by */
/* the Free Software Foundation; either version 2 of the License or (at */
/* your option) any later version.					*/
/*									*/
/* This program is distributed  in the hope that it will be useful, but */
/* WITHOUT  ANY   WARRANTY;  without  even   the  implied  warranty  of */
/* MERCHANTABILITY  or FITNESS  FOR A  PARTICULAR  PURPOSE. See the GNU */
/* General Public License for more details.				*/
/*									*/
/* You  should  have  received a copy of the GNU General Public License */
/* along  with  this  program;  it  now,  write  to  the  Free Software	*/
/* Foundation, Inc., Mass Ave, Cambridge, MA02139.			*/
/*									*/  
/* The   author   can   be   contacted  by   email   at:  jaadha@utu.fi */
									
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "ti85comm.h"
#include "version.h"

int sendgroup(char filename[255])
{
	FILE *var_file=NULL;
	unsigned short checkbytes, checksum, checksum2, var_length, i, varcnt, hdr_len;
	unsigned char var_type;
	unsigned char var_namelength;
	char var_name[9];
	unsigned long var_offset;

	varcnt=0;
	var_file=fopen(filename, "rb");
	fread(buffer, sizeof(char), 8, var_file);
	if (memcmp(buffer, &identifier, 3)==0)
	{
		fseek(var_file, 0x35, 0);
		fread(&checkbytes, sizeof(short), 1, var_file);	
		fread(buffer, sizeof(char), checkbytes, var_file);
		checksum=0;
		for(i=0;i<checkbytes;i++) checksum+=buffer[i];
		checksum=checksum & 65535;
		fread(&checksum2, sizeof(short), 1, var_file);
		
		/* var_offset points to start of first group entry */
		var_offset=0x37; 
		if (checksum==checksum2)
		{
			/* backup or variable? */
			fseek(var_file, 0x3b, SEEK_SET);
			fread(&var_type, sizeof(char), 1, var_file);
			if (var_type==0x1d)
			{
				/* send backup image to calculator */
				printf("send85: Sending system backup from '%s'\n", filename);
				fseek(var_file, 0x37, SEEK_SET);
				fread(&hdr_len, sizeof(short), 1, var_file);
				fread(buffer, sizeof(char), hdr_len, var_file);
				put_packet(PAK_VARHEADER, hdr_len);
				if (get_packet()!=PAK_REQDATA)
				{
					printf("send85: Calculator refused to receive system backup!\n");
					exit(-1);
				}
				put_packet(PAK_ACKNOWLEDGE, 0);
				
				/* send backup data packets */
				for(i=0;i<3;i++)
				{
					fread(&hdr_len, sizeof(short), 1, var_file);
					fread(buffer, sizeof(char), hdr_len, var_file);
					put_packet(PAK_DATAPART, hdr_len);
				}
				printf("send85: Backup transfer OK!\n");
				fclose(var_file);
				exit(0);
				/* exit here, so no PAK_LASTVAR will be sent */
			}
			else do
			{
				fseek(var_file, var_offset+4, SEEK_SET); 
	 			fread(&var_type, sizeof(char), 1, var_file); 
				fread(&var_namelength, sizeof(char), 1, var_file);
				fread(&var_name, sizeof(char), var_namelength, var_file); 
				var_name[var_namelength]=0;
				fread(&var_length, sizeof(short), 1, var_file);
				
				/* send variable header */
				printf("send85: Sending %8s, type %5s, from %12s\n", 
					var_name, var_types[var_type], filename);
				buffer[1]=(var_length >> 8); 
				buffer[0]=(var_length & 255);
				buffer[2]=var_type; 
				buffer[3]=var_namelength;
				memcpy(buffer+4, &var_name, var_namelength);
				put_packet(PAK_VARHEADER, var_namelength+4);
				
				i=get_packet();
				switch (i)
				{
					case PAK_REQDATA:
					{
						put_packet(PAK_ACKNOWLEDGE, 0);
						/* send variable data */
						fread(buffer, sizeof(char), var_length, var_file);
						put_packet(PAK_DATAPART, var_length);
						printf("send85: OK!\n");
						varcnt++;
						break;
					}
					case PAK_SKIPVAR:
					{
						fseek(var_file, var_length, SEEK_CUR);
						switch (buffer[0])
						{
							case 2: printf("send85: Variable skipped!\n"); break;
							case 1: printf("send85: Transfer aborted by calculator!\n"); exit(-1);
							case 3: printf("send85: Calculator out of memory!\n"); exit(-1);
							default: printf("send85: Transfer failed!\n"); exit(-1);
						}
						break;
					}
					default:
					{
						printf("Invalid ACK packet!\n");
						exit(-1);
					}
				}
				var_offset=ftell(var_file);
			} while (var_offset<(0x37+checkbytes));
			fclose(var_file);
		}
		else
		{
			printf("send85: Grouped file has incorrect checksum!\n");
			exit(-1);
		}
	}
	return varcnt;
}


void main(argc, argv) int argc;	char **argv;
{
	int i, ii;
	struct stat statbuf;

	printf(VERSION_HDR);
 	
	init_link();
	if (argc>1)
	{
		ii=0;
		for (i=1;i<argc;i++)
		{
			if (stat(argv[i], &statbuf)==0)		
				ii+=sendgroup(argv[i]);
			else 
				printf("send85: File '%s' does not exist!\n", argv[i]);
		}
		/* no more variables... */
		if (ii>0)
		{
			put_packet(PAK_LASTVAR, 0);
			i=get_packet();		
		}
		printf("send85: %d variables sent\n", ii);
	} else printf("send85: No files specified - aborting!\n");
}