%{

#include <string.h>
#include "q.h"
#include "parser.h"

//RVALUE	 {NUMBER}|{PERCENT}|{NAME}|\"{STRING}\"|{DIM}
//<a>.                {printf("<a>%s\n", yytext);}
// %x: exclusive, %s: inclusive
char*type_names[] = {"twip","number","command","string","assignment","identifier","label","end"};
static int line=1;
static int column=1;

mem_t strings;
mem_t tokens;

static void count(char*text, int len, int condition)
{
    int t;
    for(t=0;t<len;t++) {
	if(text[t]=='\n') {
	    line++;
	    column=1;
	} else {
	    column++;
	}
    }
}

static char*prefix = 0;

static void store(enum type_t type, int line, int column, char*text, int length)
{
    struct token_t token;
    string_t tmp;
    token.type = type;
    token.line = line;
    token.column = column;
    //printf("->%d(%s) %s\n", type, type_names[type], text);fflush(stdout);

    token.text = 0;
    switch(type) {
	case END:
	    string_set2(&tmp, "", 0);
	    token.text = (char*)mem_putstring(&strings, tmp);
	break;
	case STRING:
	    string_set2(&tmp, text+1, length-2);
	    token.text = (char*)mem_putstring(&strings, tmp);
	break;
	case TWIP: 
	case NUMBER: 
	case IDENTIFIER:
	    string_set2(&tmp, text, length);
	    if(prefix) {
		//strcat
		token.text = (char*)mem_put(&strings, prefix, strlen(prefix));
		mem_putstring(&strings, tmp);
	    } else {
		token.text = (char*)mem_putstring(&strings, tmp);
	    }
	    prefix = 0;
	break;
	case LABEL:
	    string_set2(&tmp, text, length-1);
	    token.text = (char*)mem_putstring(&strings, tmp);
	break;
	case COMMAND:
	    string_set2(&tmp, text+1, length-1);
	    token.text = (char*)mem_putstring(&strings, tmp);
	break;
	case ASSIGNMENT: {
	    char*x = &text[length-1];
	    if(x[-1] == '-' || x[-1] == '+')
		x--;
	    do{x--;} while(*x==32 || *x==10 || *x==13 || *x=='\t');
	    x++; //first space
	    string_set2(&tmp, text, x-text);
	    token.text = (char*)mem_putstring(&strings, tmp);
	    /*char*y,*x = strchr(text, '=');
	    if(!x) exit(1);
	    y=x;
	    do{y--;} while(*y==32 || *y==10 || *y==13 || *y=='\t');
	    do{x++;} while(*x==32 || *x==10 || *x==13 || *x=='\t');
	    token.text1 = (char*)put(&strings, text, y-text + 1, 1);
	    token.text2 = (char*)put(&strings, x, length-(x-text), 1);*/
	} break;
    }

    mem_put(&tokens, &token, sizeof(struct token_t));
    prefix = 0;
}

#define c() {count(yytext, yyleng, YY_START);}
#define s(type) {store(type, line, column, yytext, yyleng);}
%}

%s R
%x BINARY

NAME	 [a-zA-Z_./](-*[a-zA-Z0-9_./])*
TWIP	 ([0-9]+(\.([0-9]([05])?)?)?)
NUMBER	 [0-9]+(\.[0-9]*)?
PERCENT	 {NUMBER}%
STRING   (\\.|[^\\"\n])*
S	 [ \n\r\t]
RVALUE	 \"{STRING}\"|([^ \n\r\t]+)

%%

<BINARY>\] {c();BEGIN(0);}
<BINARY>.  {c();}
<BINARY>\n {c();}
{TWIP}/[ \n\r\t]            {s(TWIP);c();BEGIN(0);}
{NUMBER}/[ \n\r\t]	    {s(NUMBER);c();BEGIN(0);}
^#[^\n]*\n                  {c();}
[ \t\r]#[^\n]*\n            {c();}
\"{STRING}\"	            {s(STRING);c();BEGIN(0);}
\"{STRING}$	            {c();printf("unterminated string in line %d: %s\n", line, yytext);exit(1);yyterminate();}
{NAME}{S}*\+=		    {s(ASSIGNMENT);prefix="<plus>";c();BEGIN(R);}
{NAME}{S}*-=		    {s(ASSIGNMENT);prefix="<minus>";c();BEGIN(R);}
{NAME}{S}*=		    {s(ASSIGNMENT);c();BEGIN(R);}
<R>{ /* values which appear only on the right-hand side of assignments, like: x=50% */
    [^ \n\t\r]*		    {s(IDENTIFIER);c();BEGIN(0);}
}
\.{NAME}	            {s(COMMAND);c();}
{NAME}{S}*:                 {s(LABEL);c();}
{NAME}                      {s(IDENTIFIER);c();}
"["		            {c();BEGIN(BINARY);}
{S} 		            {c();}
.		            {char c,c1=0;
		             printf("Syntax error in line %d, %d: %s", line, column, yytext);
		             while(1) {
		                 c=input();
				 if(!c1) c1=c;
		                 if(c=='\n' || c==EOF) 
		                     break;
		                printf("%c", c);
		             }
			     if(c1>='0' && c1<='9')
				 printf(" (identifiers must not start with a digit)");
		             printf("\n");
			     exit(1);
		             yyterminate();
		            }
<<EOF>>		            {c();s(END);yyterminate();}
%%

int yywrap()
{
    return 1;
}

void freeTokens(struct token_t*file)
{
    mem_clear(&strings);
    mem_clear(&tokens);
}

struct token_t* generateTokens(char*filename)
{
    FILE*fi = fopen(filename, "rb");
    int t;
    struct token_t*result;
    int num;
    if(!fi) {
	printf("Couldn't find file %s\n", filename);
	return 0;
    }
    yyin = fi;

    mem_init(&strings);
    mem_init(&tokens);
    mem_put(&strings, &t, 1); //hack- make all valid strings start at position >0

    line=1;
    column=1;

    yylex();
    yy_delete_buffer(yy_current_buffer);

    result = (struct token_t*)tokens.buffer;
    num = tokens.pos/sizeof(struct token_t);

    for(t=0;t<tokens.pos/sizeof(struct token_t);t++) {
	if(result[t].text)
	    result[t].text += (int)strings.buffer;
    }

    fclose(fi);
    return result;
}