#include <stdio.h>
#include <string.h> /* strlen() */
#include <stdlib.h> /* exit() */

#include "version.h"

/* TODO */
/* match lowecase tokens as well as upper case ones */



/* Info from http://docs.info.apple.com/article.html?coll=ap&artnum=57 */

/* In memory, applesoft file starts at address $801        */
/* format is <LINE><LINE><LINE>$00$00                      */
/* Where <LINE> is:                                        */
/*    2 bytes (little endian) of LINK indicating addy of next line */ 
/*    2 bytes (little endian) giving the line number       */
/*    a series of bytes either ASCII or tokens (see below) */
/*    a $0 char indicating end of line                     */


   /* Starting at 0x80 */
char applesoft_tokens[][8]={
   
/* 80 */ "END","FOR","NEXT","DATA","INPUT","DEL","DIM","READ",
/* 88 */ "GR","TEXT","PR #","IN #","CALL","PLOT","HLIN","VLIN",
/* 90 */ "HGR2","HGR","HCOLOR=","HPLOT","DRAW","XDRAW","HTAB","HOME",
/* 98 */ "ROT=","SCALE=","SHLOAD","TRACE","NOTRACE","NORMAL","INVERSE","FLASH",
/* A0 */ "COLOR=","POP","VTAB ","HIMEM:","LOMEM:","ONERR","RESUME","RECALL",
/* A8 */ "STORE","SPEED=","LET","GOTO","RUN","IF","RESTORE","&",
/* B0 */ "GOSUB","RETURN","REM","STOP","ON","WAIT","LOAD","SAVE",
/* B8 */ "DEF FN","POKE","PRINT","CONT","LIST","CLEAR","GET","NEW",
/* C0 */ "TAB","TO","FN","SPC(","THEN","AT","NOT","STEP",
/* C8 */ "+","-","*","/","^","AND","OR",">",
/* D0 */ "=","<","SGN","INT","ABS","USR","FRE","SCRN (",
/* D8 */ "PDL","POS","SQR","RND","LOG","EXP","COS","SIN",
/* E0 */ "TAN","ATN","PEEK","LEN","STR$","VAL","ASC","CHR$",
/* E8 */ "LEFT$","RIGHT$","MID$","","","","","",
/* F0 */ "","","","","","","","",
/* F8 */ "","","","","","(","(","("
};

#define LOW(_x)  ((_x)&0xff) 
#define HIGH(_x) (((_x)>>8)&0xff)
#define MAXSIZE 65535

/* File cannot be longer than 64k */
unsigned char output[MAXSIZE+1];

char *line_ptr;
int line=0;
char input_line[BUFSIZ];

static void show_problem(char *line_ptr) {
   int offset,i;
   
   offset=(int)(line_ptr-input_line);
   fprintf(stderr,"%s",input_line);
   for(i=0;i<offset;i++) fputc(' ',stderr);
   fprintf(stderr,"^\n");
}

   

static int getnum(void) {
   int num=0;
   
   /* skip any whitespace */
   while((*line_ptr<=' ') && (*line_ptr!=0)) line_ptr++;
   
   while (*line_ptr>' ') {
      if ((*line_ptr<'0')||(*line_ptr>'9')) {
	 fprintf(stderr,"Invalid line number line %d\n",line);
	 show_problem(line_ptr);
	 exit(-1);
      }
      num*=10;
      num+=(*line_ptr)-'0';
      line_ptr++;
   }

   if (!line_ptr) {
      fprintf(stderr,"Missing line number line %d\n",line);
      exit(-1);
   }
      
   return num;	
}

static int in_quotes;

static int find_token() {
   
   int ch,i;
   
   ch=*line_ptr;
   /* don't skip whitespace in quotes */
   if (!in_quotes) {	
      while(ch<=' ') {	
         if ((ch=='\n') || (ch=='\r') || (ch=='\0')) {
            return 0;
         }
         line_ptr++;
         ch=*line_ptr;
      }
   }
   
   
      /* toggle quotes mode */
   if (ch=='\"') in_quotes=!in_quotes;
	
      /* don't tokenize if in quotes */
   if (!in_quotes) {
	
  // fprintf(stderr,"%s",line_ptr);
   for(i=0;i<107;i++) {
      if (!strncmp(line_ptr,applesoft_tokens[i],strlen(applesoft_tokens[i]))) {
//	 fprintf(stderr,"Found token %x (%s) %d\n",0x80+i,applesoft_tokens[i],i);
	 line_ptr+=strlen(applesoft_tokens[i]);
	 return 0x80+i;
      }
//      fprintf(stderr,"%s ",applesoft_tokens[i]);
   }
   }
   
//   fprintf(stderr,"\n");
      /* not a token, just ascii */
   line_ptr++;
   return ch;
}

static void check_oflo(int size) {
   if (size>MAXSIZE) {
      fprintf(stderr,"Output file too big!\n");
      exit(-1);
   }   
}

	
   

int main(int argc, char **argv) {
   
   int offset=2,i;

   int linenum,link_offset;
   int link_value=0x801; /* start of applesoft program */
   int token;

   while(1) {
         /* get line from input file */
      line_ptr=fgets(input_line,BUFSIZ,stdin);
      line++;
      if (line_ptr==NULL) break;
      linenum=getnum();
      if (linenum>65535) {
	 printf("Invalid line number %d\n",linenum);
	 exit(-1);
      }
      link_offset=offset;
      check_oflo(offset+4);
      output[offset+2]=LOW(linenum);
      output[offset+3]=HIGH(linenum);
      offset+=4;
      
      
      while(1) {
	 token=find_token();
	 output[offset]=token;
	 offset++;
	 check_oflo(offset);
	 if (!token) break;
      }
      
	 
      /* 2 bytes is to ignore size from beginning of file */
      link_value=0x801+(offset-2);
      
      /* point link value to next line */
      check_oflo(offset+2);
      output[link_offset]=LOW(link_value);
      output[link_offset+1]=HIGH(link_value);
   }
   /* set last link field to $00 $00 which indicates EOF */
   check_oflo(offset+2);
   output[offset]='\0';
   output[offset+1]='\0';
   offset+=2;
   
     /* Set filesize */
     /* -1 to match observed values */
   output[0]=LOW(offset-1);
   output[1]=HIGH(offset-1);
   /* output our file */
   for(i=0;i<offset;i++) putchar(output[i]);
   
   return 0;
}