mkdio.c

/*
 * mkdio -- markdown front end input functions
 *
 * Copyright (C) 2007 David L Parsons.
 * The redistribution terms are provided in the COPYRIGHT file that must
 * be distributed with this source code.
 */
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

#include "cstring.h"
#include "markdown.h"
#include "amalloc.h"

typedef ANCHOR(Line) LineAnchor;

/* create a new blank Document
 */
Document*
__mkd_new_Document()
{
	Document *ret = calloc(sizeof(Document), 1);

	if ( ret ) {
		if ( ret->ctx = calloc(sizeof(MMIOT), 1) ) {
			ret->magic = VALID_DOCUMENT;
			return ret;
		}
		free(ret);
	}
	return 0;
}


/* add a line to the markdown input chain, expanding tabs and
 * noting the presence of special characters as we go.
 */
void
__mkd_enqueue(Document* a, Cstring *line)
{
	Line *p = calloc(sizeof *p, 1);
	unsigned char c;
	int xp = 0;
	int			  size = S(*line);
	unsigned char *str = (unsigned char*)T(*line);

	CREATE(p->text);
	ATTACH(a->content, p);

	while ( size-- ) {
		if ( (c = *str++) == '\t' ) {
			/* expand tabs into ->tabstop spaces.  We use ->tabstop
			 * because the ENTIRE FREAKING COMPUTER WORLD uses editors
			 * that don't do ^T/^D, but instead use tabs for indentation,
			 * and, of course, set their tabs down to 4 spaces 
			 */
			do {
				EXPAND(p->text) = ' ';
			} while ( ++xp % a->tabstop );
		}
		else if ( c >= ' ' ) {
			if ( c == '|' )
				p->flags |= PIPECHAR;
			EXPAND(p->text) = c;
			++xp;
		}
	}
	EXPAND(p->text) = 0;
	S(p->text)--;
	p->dle = mkd_firstnonblank(p);
}


/* trim leading blanks from a header line
 */
void
__mkd_header_dle(Line *p)
{
	CLIP(p->text, 0, 1);
	p->dle = mkd_firstnonblank(p);
}


/* build a Document from any old input.
 */
typedef int (*getc_func)(void*);

Document *
populate(getc_func getc, void* ctx, int flags)
{
	Cstring line;
	Document *a = __mkd_new_Document();
	int c;
	int pandoc = 0;

	if ( !a ) return 0;

	a->tabstop = (flags & MKD_TABSTOP) ? 4 : TABSTOP;

	CREATE(line);

	while ( (c = (*getc)(ctx)) != EOF ) {
		if ( c == '\n' ) {
			if ( pandoc != EOF && pandoc < 3 ) {
				if ( S(line) && (T(line)[0] == '%') )
					pandoc++;
				else
					pandoc = EOF;
			}
			__mkd_enqueue(a, &line);
			S(line) = 0;
		}
		else if ( isprint(c) || isspace(c) || (c & 0x80) )
			EXPAND(line) = c;
	}

	if ( S(line) )
		__mkd_enqueue(a, &line);

	DELETE(line);

	if ( (pandoc == 3) && !(flags & (MKD_NOHEADER|MKD_STRICT)) ) {
		/* the first three lines started with %, so we have a header.
		 * clip the first three lines out of content and hang them
		 * off header.
		 */
		Line *headers = T(a->content);

		a->title = headers;				__mkd_header_dle(a->title);
		a->author= headers->next;		__mkd_header_dle(a->author);
		a->date	 = headers->next->next; __mkd_header_dle(a->date);

		T(a->content) = headers->next->next->next;
	}

	return a;
}


/* convert a file into a linked list
 */
Document *
mkd_in(FILE *f, DWORD flags)
{
	return populate((getc_func)fgetc, f, flags & INPUT_MASK);
}


/* return a single character out of a buffer
 */
int
__mkd_io_strget(struct string_stream *in)
{
	if ( !in->size ) return EOF;

	--(in->size);

	return *(in->data)++;
}


/* convert a block of text into a linked list
 */
Document *
mkd_string(const char *buf, int len, DWORD flags)
{
	struct string_stream about;

	about.data = buf;
	about.size = len;

	return populate((getc_func)__mkd_io_strget, &about, flags & INPUT_MASK);
}


/* write the html to a file (xmlified if necessary)
 */
int
mkd_generatehtml(Document *p, FILE *output)
{
	char *doc;
	int szdoc;

	if ( (szdoc = mkd_document(p, &doc)) != EOF ) {
		if ( p->ctx->flags & MKD_CDATA )
			mkd_generatexml(doc, szdoc, output);
		else
			fwrite(doc, szdoc, 1, output);
		putc('\n', output);
		return 0;
	}
	return -1;
}


/* convert some markdown text to html
 */
int
markdown(Document *document, FILE *out, int flags)
{
	if ( mkd_compile(document, flags) ) {
		mkd_generatehtml(document, out);
		mkd_cleanup(document);
		return 0;
	}
	return -1;
}


/* write out a Cstring, mangled into a form suitable for `<a href=` or `<a id=`
 */
void
mkd_string_to_anchor(char *s, int len, mkd_sta_function_t outchar,
									   void *out, int labelformat)
{
	unsigned char c;

	int i, size;
	char *line;

	size = mkd_line(s, len, &line, IS_LABEL);
	
	if ( labelformat && (size>0) && !isalpha(line[0]) )
		(*outchar)('L',out);
	for ( i=0; i < size ; i++ ) {
		c = line[i];
		if ( labelformat ) {
			if ( isalnum(c) || (c == '_') || (c == ':') || (c == '-') || (c == '.' ) )
				(*outchar)(c, out);
			else
				(*outchar)('.', out);
		}
		else
			(*outchar)(c,out);
	}
		
	if (line)
		free(line);
}


/*	___mkd_reparse() a line
 */
static void
mkd_parse_line(char *bfr, int size, MMIOT *f, int flags)
{
	___mkd_initmmiot(f, 0);
	f->flags = flags & USER_FLAGS;
	___mkd_reparse(bfr, size, 0, f, 0);
	___mkd_emblock(f);
}


/* ___mkd_reparse() a line, returning it in malloc()ed memory
 */
int
mkd_line(char *bfr, int size, char **res, DWORD flags)
{
	MMIOT f;
	int len;
	
	mkd_parse_line(bfr, size, &f, flags);

	if ( len = S(f.out) ) {
		/* kludge alert;  we know that T(f.out) is malloced memory,
		 * so we can just steal it away.   This is awful -- there
		 * should be an opaque method that transparently moves 
		 * the pointer out of the embedded Cstring.
		 */
		EXPAND(f.out) = 0;
		*res = T(f.out);
		T(f.out) = 0;
		S(f.out) = ALLOCATED(f.out) = 0;
	}
	else {
		 *res = 0;
		 len = EOF;
	 }
	___mkd_freemmiot(&f, 0);
	return len;
}


/* ___mkd_reparse() a line, writing it to a FILE
 */
int
mkd_generateline(char *bfr, int size, FILE *output, DWORD flags)
{
	MMIOT f;

	mkd_parse_line(bfr, size, &f, flags);
	if ( flags & MKD_CDATA )
		mkd_generatexml(T(f.out), S(f.out), output);
	else
		fwrite(T(f.out), S(f.out), 1, output);

	___mkd_freemmiot(&f, 0);
	return 0;
}


/* set the url display callback
 */
void
mkd_e_url(Document *f, mkd_callback_t edit)
{
	if ( f )
		f->cb.e_url = edit;
}


/* set the url options callback
 */
void
mkd_e_flags(Document *f, mkd_callback_t edit)
{
	if ( f )
		f->cb.e_flags = edit;
}


/* set the url display/options deallocator
 */
void
mkd_e_free(Document *f, mkd_free_t dealloc)
{
	if ( f )
		f->cb.e_free = dealloc;
}


/* set the url display/options context data field
 */
void
mkd_e_data(Document *f, void *data)
{
	if ( f )
		f->cb.e_data = data;
}


/* set the href prefix for markdown extra style footnotes
 */
void
mkd_ref_prefix(Document *f, char *data)
{
	if ( f )
		f->ref_prefix = data;
}