path: root/camel/camel-mime-filter-tohtml.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Authors: Jeffrey Stedfast <fejj@ximian.com>
 *
 *  Copyright 2001 Ximian, Inc. (www.ximian.com)
 *
 *  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; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
 *
 */


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>

#include "camel-url-scanner.h"
#include "camel-mime-filter-tohtml.h"
#include "camel-utf8.h"

/**
 * TODO: convert common text/plain 'markup' to html. eg.:
 *
 * _word_ -> <u>_word_</u>
 * *word* -> <b>*word*</b>
 * /word/ -> <i>/word/</i>
 **/

#define d(x)

#define CONVERT_WEB_URLS  CAMEL_MIME_FILTER_TOHTML_CONVERT_URLS
#define CONVERT_ADDRSPEC  CAMEL_MIME_FILTER_TOHTML_CONVERT_ADDRESSES

static struct {
    unsigned int mask;
    urlpattern_t pattern;
} patterns[] = {
    { CONVERT_WEB_URLS, { "file://",   "",        camel_url_file_start,     camel_url_file_end     } },
    { CONVERT_WEB_URLS, { "ftp://",    "",        camel_url_web_start,      camel_url_web_end      } },
    { CONVERT_WEB_URLS, { "http://",   "",        camel_url_web_start,      camel_url_web_end      } },
    { CONVERT_WEB_URLS, { "https://",  "",        camel_url_web_start,      camel_url_web_end      } },
    { CONVERT_WEB_URLS, { "news://",   "",        camel_url_web_start,      camel_url_web_end      } },
    { CONVERT_WEB_URLS, { "nntp://",   "",        camel_url_web_start,      camel_url_web_end      } },
    { CONVERT_WEB_URLS, { "telnet://", "",        camel_url_web_start,      camel_url_web_end      } },
    { CONVERT_WEB_URLS, { "www.",      "http://", camel_url_web_start,      camel_url_web_end      } },
    { CONVERT_WEB_URLS, { "ftp.",      "ftp://",  camel_url_web_start,      camel_url_web_end      } },
    { CONVERT_ADDRSPEC, { "@",         "mailto:", camel_url_addrspec_start, camel_url_addrspec_end } },
};

#define NUM_URL_PATTERNS (sizeof (patterns) / sizeof (patterns[0]))

static void camel_mime_filter_tohtml_class_init (CamelMimeFilterToHTMLClass *klass);
static void camel_mime_filter_tohtml_init       (CamelMimeFilterToHTML *filter);
static void camel_mime_filter_tohtml_finalize   (CamelObject *obj);

static CamelMimeFilterClass *camel_mime_filter_tohtml_parent;


CamelType
camel_mime_filter_tohtml_get_type (void)
{
    static CamelType type = CAMEL_INVALID_TYPE;
    
    if (type == CAMEL_INVALID_TYPE) {
        type = camel_type_register (camel_mime_filter_get_type (),
                        "CamelMimeFilterToHTML",
                        sizeof (CamelMimeFilterToHTML),
                        sizeof (CamelMimeFilterToHTMLClass),
                        (CamelObjectClassInitFunc) camel_mime_filter_tohtml_class_init,
                        NULL,
                        (CamelObjectInitFunc) camel_mime_filter_tohtml_init,
                        (CamelObjectFinalizeFunc) camel_mime_filter_tohtml_finalize);
    }
    
    return type;
}

static void
camel_mime_filter_tohtml_finalize (CamelObject *obj)
{
    CamelMimeFilterToHTML *filter = (CamelMimeFilterToHTML *) obj;
    
    camel_url_scanner_free (filter->scanner);
}

static void
camel_mime_filter_tohtml_init (CamelMimeFilterToHTML *filter)
{
    filter->scanner = camel_url_scanner_new ();
    
    filter->flags = 0;
    filter->colour = 0;
    filter->column = 0;
    filter->pre_open = FALSE;
}


static char *
check_size (CamelMimeFilter *filter, char *outptr, char **outend, size_t len)
{
    size_t offset;
    
    if (*outend - outptr >= len)
        return outptr;
    
    offset = outptr - filter->outbuf;
    
    camel_mime_filter_set_size (filter, filter->outsize + len, TRUE);
    
    *outend = filter->outbuf + filter->outsize;
    
    return filter->outbuf + offset;
}

static int
citation_depth (const char *in)
{
    register const char *inptr = in;
    int depth = 1;
    
    if (*inptr++ != '>')
        return 0;
    
    /* check that it isn't an escaped From line */
    if (!strncmp (inptr, "From", 4))
        return 0;
    
    while (*inptr != '\n') {
        if (*inptr == ' ')
            inptr++;
        
        if (*inptr++ != '>')
            break;
        
        depth++;
    }
    
    return depth;
}

static char *
writeln (CamelMimeFilter *filter, const char *in, const char *inend, char *outptr, char **outend)
{
    CamelMimeFilterToHTML *html = (CamelMimeFilterToHTML *) filter;
    const char *inptr = in;

    while (inptr < inend) {
        guint32 u;

        outptr = check_size (filter, outptr, outend, 16);

        u = camel_utf8_getc_limit ((const unsigned char **) &inptr, inend);
        switch (u) {
        case 0xffff:
            g_warning("Truncated utf8 buffer");
            return outptr;
        case '<':
            outptr = g_stpcpy (outptr, "&lt;");
            html->column++;
            break;
        case '>':
            outptr = g_stpcpy (outptr, "&gt;");
            html->column++;
            break;
        case '&':
            outptr = g_stpcpy (outptr, "&amp;");
            html->column++;
            break;
        case '"':
            outptr = g_stpcpy (outptr, "&quot;");
            html->column++;
            break;
        case '\t':
            if (html->flags & (CAMEL_MIME_FILTER_TOHTML_CONVERT_SPACES)) {
                do {
                    outptr = check_size (filter, outptr, outend, 7);
                    outptr = g_stpcpy (outptr, "&nbsp;");
                    html->column++;
                } while (html->column % 8);
                break;
            }
            /* otherwise, FALL THROUGH */
        case ' ':
            if (html->flags & CAMEL_MIME_FILTER_TOHTML_CONVERT_SPACES
                && ((inptr == (in + 1) || *inptr == ' ' || *inptr == '\t'))) {
                outptr = g_stpcpy (outptr, "&nbsp;");
                html->column++;
                break;
            }
            /* otherwise, FALL THROUGH */
        default:
            if (u >= 20 && u <0x80)
                *outptr++ = u;
            else {
                if (html->flags & CAMEL_MIME_FILTER_TOHTML_ESCAPE_8BIT)
                    *outptr++ = '?';
                else
                    outptr += sprintf(outptr, "&#%u;", u);
            }
            html->column++;
            break;
        }
    }
    
    return outptr;
}

static void
html_convert (CamelMimeFilter *filter, char *in, size_t inlen, size_t prespace,
          char **out, size_t *outlen, size_t *outprespace, gboolean flush)
{
    CamelMimeFilterToHTML *html = (CamelMimeFilterToHTML *) filter;
    register char *inptr, *outptr;
    char *start, *outend;
    const char *inend;
    int depth;

    if (inlen == 0) {
        *out = in;
        *outlen = 0;
        *outprespace = 0;

        return;
    }
    
    camel_mime_filter_set_size (filter, inlen * 2 + 6, FALSE);
    
    inptr = in;
    inend = in + inlen;
    outptr = filter->outbuf;
    outend = filter->outbuf + filter->outsize;
    
    if (html->flags & CAMEL_MIME_FILTER_TOHTML_PRE && !html->pre_open) {
        outptr = g_stpcpy (outptr, "<pre>");
        html->pre_open = TRUE;
    }

    start = inptr;
    do {
        while (inptr < inend && *inptr != '\n')
            inptr++;

        if (inptr >= inend && !flush)
            break;

        html->column = 0;
        depth = 0;
        
        if (html->flags & CAMEL_MIME_FILTER_TOHTML_MARK_CITATION) {
            if ((depth = citation_depth (start)) > 0) {
                /* FIXME: we could easily support multiple colour depths here */
                
                outptr = check_size (filter, outptr, &outend, 25);
                outptr += sprintf(outptr, "<font color=\"#%06x\">", (html->colour & 0xffffff));
            } else if (*start == '>') {
                /* >From line */
                start++;
            }
        } else if (html->flags & CAMEL_MIME_FILTER_TOHTML_CITE) {
            outptr = check_size (filter, outptr, &outend, 6);
            outptr = g_stpcpy (outptr, "&gt; ");
            html->column += 2;
        }
        
#define CONVERT_URLS (CAMEL_MIME_FILTER_TOHTML_CONVERT_URLS | CAMEL_MIME_FILTER_TOHTML_CONVERT_ADDRESSES)
        if (html->flags & CONVERT_URLS) {
            size_t matchlen, buflen, len;
            urlmatch_t match;
            
            len = inptr - start;
            
            do {
                if (camel_url_scanner_scan (html->scanner, start, len, &match)) {
                    /* write out anything before the first regex match */
                    outptr = writeln (filter, start, start + match.um_so,
                              outptr, &outend);
                    
                    start += match.um_so;
                    len -= match.um_so;
                    
                    matchlen = match.um_eo - match.um_so;
                    
                    buflen = 20 + strlen (match.prefix) + matchlen + matchlen;
                    outptr = check_size (filter, outptr, &outend, buflen);
                    
                    /* write out the href tag */
                    outptr = g_stpcpy (outptr, "<a href=\"");
                    outptr = g_stpcpy (outptr, match.prefix);
                    memcpy (outptr, start, matchlen);
                    outptr += matchlen;
                    outptr = g_stpcpy (outptr, "\">");
                    
                    /* now write the matched string */
                    memcpy (outptr, start, matchlen);
                    html->column += matchlen;
                    outptr += matchlen;
                    start += matchlen;
                    len -= matchlen;
                    
                    /* close the href tag */
                    outptr = g_stpcpy (outptr, "</a>");
                } else {
                    /* nothing matched so write out the remainder of this line buffer */
                    outptr = writeln (filter, start, start + len, outptr, &outend);
                    break;
                }
            } while (len > 0);
        } else {
            outptr = writeln (filter, start, inptr, outptr, &outend);
        }
        
        if ((html->flags & CAMEL_MIME_FILTER_TOHTML_MARK_CITATION) && depth > 0) {
            outptr = check_size (filter, outptr, &outend, 8);
            outptr = g_stpcpy (outptr, "</font>");
        }
        
        if (inptr < inend) {
            if (html->flags & CAMEL_MIME_FILTER_TOHTML_CONVERT_NL) {
                outptr = check_size (filter, outptr, &outend, 5);
                outptr = g_stpcpy (outptr, "<br>");
            }
            
            *outptr++ = '\n';
        }
        
        start = ++inptr;
    } while (inptr < inend);
    
    if (flush) {
        /* flush the rest of our input buffer */
        if (start < inend)
            outptr = writeln (filter, start, inend, outptr, &outend);
        
        if (html->pre_open) {
            /* close the pre-tag */
            outptr = check_size (filter, outptr, &outend, 10);
            outptr = g_stpcpy (outptr, "</pre>");
        }
    } else if (start < inend) {
        /* backup */
        camel_mime_filter_backup (filter, start, (unsigned) (inend - start));
    }
    
    *out = filter->outbuf;
    *outlen = outptr - filter->outbuf;
    *outprespace = filter->outpre;
}

static void
filter_filter (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
           char **out, size_t *outlen, size_t *outprespace)
{
    html_convert (filter, in, len, prespace, out, outlen, outprespace, FALSE);
}

static void 
filter_complete (CamelMimeFilter *filter, char *in, size_t len, size_t prespace,
         char **out, size_t *outlen, size_t *outprespace)
{
    html_convert (filter, in, len, prespace, out, outlen, outprespace, TRUE);
}

static void
filter_reset (CamelMimeFilter *filter)
{
    CamelMimeFilterToHTML *html = (CamelMimeFilterToHTML *) filter;
    
    html->column = 0;
    html->pre_open = FALSE;
}

static void
camel_mime_filter_tohtml_class_init (CamelMimeFilterToHTMLClass *klass)
{
    CamelMimeFilterClass *filter_class = (CamelMimeFilterClass *) klass;
    
    camel_mime_filter_tohtml_parent = CAMEL_MIME_FILTER_CLASS (camel_type_get_global_classfuncs (camel_mime_filter_get_type ()));
    
    filter_class->reset = filter_reset;
    filter_class->filter = filter_filter;
    filter_class->complete = filter_complete;
}


/**
 * camel_mime_filter_tohtml_new:
 * @flags:
 * @colour:
 *
 * Creates a new CamelMimeFilterToHTML object.
 *
 * Returns a new CamelMimeFilter object.
 **/
CamelMimeFilter *
camel_mime_filter_tohtml_new (guint32 flags, guint32 colour)
{
    CamelMimeFilterToHTML *new;
    int i;
    
    new = CAMEL_MIME_FILTER_TOHTML (camel_object_new (camel_mime_filter_tohtml_get_type ()));
    
    new->flags = flags;
    new->colour = colour;
    
    for (i = 0; i < NUM_URL_PATTERNS; i++) {
        if (patterns[i].mask & flags)
            camel_url_scanner_add (new->scanner, &patterns[i].pattern);
    }
    
    return CAMEL_MIME_FILTER (new);
}


char *
camel_text_to_html (const char *in, guint32 flags, guint32 colour)
{
    CamelMimeFilter *filter;
    size_t outlen, outpre;
    char *outbuf;
    
    g_return_val_if_fail (in != NULL, NULL);
    
    filter = camel_mime_filter_tohtml_new (flags, colour);
    
    camel_mime_filter_complete (filter, (char *) in, strlen (in), 0,
                    &outbuf, &outlen, &outpre);
    
    outbuf = g_strndup (outbuf, outlen);
    
    camel_object_unref (filter);
    
    return outbuf;
}